阅读说明：本技术 阀板和顶盖组件 (Valve plate and head assembly ) 是由 安东尼·弗兰西斯·戈立布什 罗伯特·约瑟夫·萨皮格 于 2018-04-05 设计创作，主要内容包括：一种用于具有第一缸和第二缸的多缸压缩机或泵的头部组件包括阀板,阀板具有第一缸部分、第二缸部分以及定位于其间的第三部分。阀板还包括阀板面,阀板面具有延伸穿过第一缸部分的第一孔和延伸穿过第二缸部分的第二孔。头部组件还包括具有顶盖面的顶盖、以及从阀板面和顶盖面中的一个延伸以形成通道的至少一个壁。顶盖可联接至阀板,使得通道与阀板面和顶盖面中的另一个协作,以形成在阀板的第一孔与第二孔之间延伸并封闭阀板的第一孔和第二孔的腔室。(A head assembly for a multi-cylinder compressor or pump having first and second cylinders includes a valve plate having a first cylinder portion, a second cylinder portion, and a third portion positioned therebetween. The valve plate also includes a valve plate face having a first bore extending through the first cylinder portion and a second bore extending through the second cylinder portion. The head assembly also includes a cap having a cap face, and at least one wall extending from one of the valve plate face and the cap face to form a channel. The head may be coupled to the valve plate such that the passages cooperate with the other of the valve plate face and the head face to form chambers extending between and closing the first and second apertures of the valve plate.)

1. A multi-cylinder compressor or pump comprising:

a first cylinder housing including a first cylinder bore and a second cylinder housing including a second cylinder bore;

a motor having a drive shaft;

a first piston coupled to the drive shaft and received in the first cylinder bore and a second piston coupled to the drive shaft and received in the second cylinder bore;

a valve plate including a first cylinder portion, a second cylinder portion, and a third portion positioned between the first cylinder portion and the second cylinder portion, the valve plate further including a valve plate face having a first bore extending through the first cylinder portion and a second bore extending through the second cylinder portion, wherein the first cylinder portion of the valve plate is coupled to the first cylinder housing and the second cylinder portion of the valve plate is coupled to the second cylinder housing such that the first bore is in fluid communication with the first cylinder bore and the second bore is in fluid communication with the second cylinder bore;

a top cover comprising a top cover face; and

at least one wall extending from one of the valve plate face and the cap face to form a passage, wherein the cap is coupled to the valve plate such that the passage cooperates with the other of the valve plate face and the cap face to form a chamber extending between and closing the first aperture of the first cylinder portion and the second aperture of the second cylinder portion of the valve plate.

2. A multi-cylinder compressor or pump according to claim 1 wherein the valve plate is coupled to the first and second cylinder housings by a plurality of bosses of the first and second cylinder housings.

3. A multi-cylinder compressor or pump according to claim 2 wherein the head cover is coupled to the valve plate via fasteners.

4. A multi-cylinder compressor or pump according to claim 1 wherein one of the valve plate and the head cover defines an inlet port.

5. A multi-cylinder compressor or pump according to claim 1 wherein one of the valve plate and the head cover defines a discharge port.

6. A multi-cylinder compressor or pump according to claim 1 wherein the first cylinder housing defines a second chamber and the second cylinder housing defines a third chamber, wherein a third bore extends through the first piston such that the second chamber is in fluid communication with the first cylinder bore and a fourth bore extends through the second piston such that the third chamber is in fluid communication with the second cylinder bore.

7. A multi-cylinder compressor or pump according to claim 1 wherein the valve plate face further comprises a third aperture extending through the first cylinder portion and a fourth aperture extending through the second cylinder portion, wherein the at least one wall forms a second passage with the one of the valve plate face and the top cover face, wherein when the valve plate and the top cover are coupled together the second passage cooperates with the other of the valve plate face and the top cover face to form a second chamber extending between and closing the third aperture and the fourth aperture.

8. A multi-cylinder compressor or pump according to claim 7 wherein said at least one wall forms a third passage with said one of said valve plate face and said top cap face, wherein when said valve plate and said top cap are coupled together said third passage cooperates with said other of said valve plate face and said top cap face to form a third chamber, and wherein said third chamber is positioned between said first chamber and said second chamber.

9. A multi-cylinder compressor or pump according to claim 8 wherein the third chamber is at least partially lined with a sound reducing medium.

10. A multi-cylinder compressor or pump according to claim 1 wherein said valve plate further comprises a third bore and a fourth bore, wherein the third bore extends through the first cylinder portion in fluid communication with the first cylinder bore, the fourth bore extends through the second cylinder portion in fluid communication with the second cylinder bore, wherein the at least one wall and the one of the valve deck and the top cap face form a second channel and a third channel, wherein the second channel cooperates with the other of the valve plate face and the cap face to form a second chamber, and the third passageway cooperates with the other of the valve plate face and the top cover face to form a third chamber, wherein the third aperture is positioned in and enclosed by the second chamber and the fourth aperture is positioned in and enclosed by the third chamber.

11. A head assembly for a multi-cylinder compressor or pump having a first cylinder and a second cylinder, comprising:

a valve plate including a first cylinder portion, a second cylinder portion, and a third portion positioned between the first cylinder portion and the second cylinder portion, the valve plate further including a valve plate face having a first aperture extending through the first cylinder portion and a second aperture extending through the second cylinder portion;

a top cover comprising a top cover face; and

at least one wall extending from one of the valve plate face and the top cap face to form a passage, wherein the top cap is configured for coupling to the valve plate such that the passage cooperates with the other of the valve plate face and the top cap face to form a chamber extending between and closing the first aperture of the first cylinder portion and the second aperture of the second cylinder portion of the valve plate.

12. The head assembly of claim 11, wherein a groove is defined by one of the valve deck and the cap deck, and wherein the at least one wall cooperates with the groove.

13. The head assembly of claim 11, wherein one of the valve plate and the head cover defines an air intake port.

14. The head assembly of claim 11, wherein one of the valve plate and the head cover defines an exhaust port.

15. The head assembly of claim 11, wherein the valve plate further includes a third aperture extending through the first cylinder portion and a fourth aperture extending through the second cylinder portion, wherein the at least one wall and the one of the valve plate face and the cap face form a second passage, wherein when the valve plate and the cap are coupled together, the second passage cooperates with the other of the valve plate face and the cap face to form a second chamber extending between and closing the third aperture and the fourth aperture.

16. The head assembly of claim 15, wherein the at least one wall forms a third channel with the one of the valve plate face and the cap face, wherein the third channel cooperates with the other of the valve plate face and the cap face to form a third chamber when the valve plate and the cap are coupled together, and wherein the third chamber is positioned between the first chamber and the second chamber.

17. The head assembly of claim 16, wherein the third chamber is at least partially lined with a sound attenuating medium.

18. The head assembly of claim 11, wherein the first cylinder portion of the valve plate face further comprises a third aperture extending through the first cylinder portion of the valve plate and a fourth aperture extending through the second cylinder portion, wherein the at least one wall forms a second channel and a third channel with the one of the valve plate face and the top cap face, wherein the second channel cooperates with the other of the valve plate face and the top cap face to form a second chamber and the third channel cooperates with the other of the valve plate face and the top cap face to form a third chamber when the valve plate and the top cap are coupled together, and wherein the third aperture is positioned in the second chamber and enclosed by the second chamber and the fourth aperture is positioned in the third chamber, and is enclosed by the third chamber.

19. The head assembly of claim 11, wherein the at least one wall is integrally formed as one piece with the one of the valve plate and the head cover.

20. A multi-cylinder compressor or pump comprising:

a first cylinder housing defining a first cylinder bore and a second cylinder housing defining a second cylinder bore; and a head assembly coupleable to the first and second cylinder housings, the head assembly including a valve plate and a head cover configured to cooperate to form a chamber in fluid communication with the first and second cylinder bores, wherein the valve plate is positioned above both the first and second cylinder bores.

21. The head assembly of claim 11, wherein the at least one wall is formed independently of the one of the valve deck and the cap deck.

Technical Field

The present disclosure relates to compressors and pumps, and more particularly, to an improved head assembly for a compressor or pump.

Disclosure of Invention

In one embodiment, a multi-cylinder compressor or pump is provided that includes a first cylinder housing having a first cylinder bore, a second cylinder housing having a second cylinder bore, a motor having a drive shaft, a first piston coupled to the drive shaft and received in the first cylinder bore, and a second piston coupled to the drive shaft and received in the second cylinder bore. The multi-cylinder compressor or pump further comprises a valve plate comprising a first cylinder portion, a second cylinder portion and a third portion positioned between the first cylinder portion and the second cylinder portion. The valve plate also includes a valve plate face having a first bore extending through the first cylinder portion and a second bore extending through the second cylinder portion. The first cylinder portion of the valve plate is coupled to the first cylinder housing and the second cylinder portion of the valve plate is coupled to the second cylinder housing such that the first bore is in fluid communication with the first cylinder bore and the second bore is in fluid communication with the second cylinder bore. The multi-cylinder compressor or pump further includes a top cover including a top cover face and at least one wall extending from one of the valve plate face and the top cover face to form a channel. The head is coupled to the valve plate such that the passage cooperates with the other of the valve plate face and the head face to form a chamber extending between and closing the first bore of the first cylinder portion and the second bore of the second cylinder portion of the valve plate.

In one embodiment, a head assembly for a multi-cylinder compressor or pump having a first cylinder and a second cylinder is provided that includes a valve plate including a first cylinder portion, a second cylinder portion, and a third portion positioned to extend between the first cylinder portion and the second cylinder portion. The valve plate further includes a valve plate face having a first aperture in the first cylinder portion and a second aperture in the second cylinder portion. The head assembly also includes a cap having a cap face, and at least one wall extending from one of the valve plate face and the cap face to form a channel. The head is configured for coupling to the valve plate such that the channel cooperates with the other of the valve plate face and the head face to form a chamber extending between and closing the first bore of the first cylinder portion and the second bore of the second cylinder portion of the valve plate.

In one embodiment, a multi-cylinder compressor or pump is provided that includes a first cylinder housing defining a first cylinder bore and a second cylinder housing defining a second cylinder bore. The multi-cylinder compressor or pump further includes a head assembly coupleable to the first and second cylinder housings. The head assembly includes a valve plate and a head cover configured to cooperate to form a chamber in fluid communication with the first and second cylinder bores. The valve plate is positioned above both the first cylinder bore and the second cylinder bore.

Other features and aspects of the present disclosure will become apparent by consideration of the following detailed description and accompanying drawings.

Drawings

Fig. 1 is a perspective view of a compressor.

FIG. 2 is a cross-sectional view of the compressor of FIG. 1 taken along line 2-2.

Fig. 3 is a partially exploded view of the compressor of fig. 1.

Fig. 4 is an exploded view of a head assembly of the compressor of fig. 1.

FIG. 5 is a top view of a valve plate of the head assembly of FIG. 4.

Fig. 6 is a bottom view of a top cover of the head assembly of fig. 4.

FIG. 7 is an enlarged cross-sectional view of the compressor of FIG. 1 taken along line 7-7.

FIG. 8 is an enlarged cross-sectional view of the compressor of FIG. 1 taken along line 8-8.

FIG. 9 is an enlarged cross-sectional view of the compressor of FIG. 1 taken along line 9-9.

FIG. 10 is a partially exploded view of another head assembly.

FIG. 11 is a top view of a valve plate of the head assembly of FIG. 10.

Fig. 12 is a bottom view of a top cover of the head assembly of fig. 10.

Fig. 13 is a perspective cross-sectional view of the head assembly of fig. 10.

Fig. 14 is another perspective cross-sectional view of the head assembly of fig. 10.

FIG. 15 is a partially exploded view of another head assembly.

FIG. 16 is a top view of a valve plate of the head assembly of FIG. 15.

Fig. 17 is a bottom view of a top cover of the head assembly of fig. 15.

FIG. 18 is a perspective cross-sectional view of the overcap of FIG. 22, taken along the line 18-18.

FIG. 19 is a perspective cross-sectional view of the overcap of FIG. 15, taken along the line 19-19.

FIG. 20 is a perspective cross-sectional view of the overcap of FIG. 15, taken along the line 20-20.

Fig. 21 is a perspective view of another compressor.

FIG. 22 is a cross-sectional view of the compressor of FIG. 21 taken along line 22-22.

Fig. 23 is a partially exploded view of the compressor of fig. 21.

Fig. 24 is an exploded view of a head assembly of the compressor of fig. 21.

Fig. 25 is another view of the head assembly of fig. 24.

Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

Detailed Description

FIG. 1 shows a multi-cylinder air compressor 10 for oxygen concentration, which includes a housing assembly 14 and a head assembly 18. The housing assembly 14 includes a cylindrical thin-walled spacer or motor sleeve 22 located between the end housings 26 corresponding to the first and second cylinders 30, 34 of the compressor 10. The end housing 26 is preferably formed of a cast material such as aluminum. The motor sleeve 22 has perforations 38 adjacent opposite ends 42 of the motor sleeve 22 for air flow purposes. Head assembly 18 includes a valve plate 50 and a head manifold or head 54, and may further include a pair of pressure swing adsorption oxygen concentrators (not shown) mounted on head 54 for separating oxygen and nitrogen from the compressed air.

With additional reference to FIG. 2, the compressor 10 also includes an electric motor 62 having a through drive shaft 66 surrounded by the motor sleeve 22. Each of the end housings 26 includes a circumferential flange 70 having a relief 74 for receiving the opposite end 42 of the motor sleeve 22 to engage the end housing 26 to the motor sleeve 22. The bearing 78 supports the drive shaft 66 of the motor 62.

With continued reference to fig. 2 and 3, each of the end housings 26 includes a cylinder extension 86 for each of the cylinders 30, 34 of the compressor 10. The cylinder extension 86 has a support floor 90 that supports a cylinder sleeve 94 defining a cylinder bore 98. The support floor 90 has an opening 102. The cylinder extension 86 has a side wall 106 that terminates in a housing boss 110 to support and mount the valve plate 50 (FIG. 3). An O-ring 114 is mounted to the valve plate 50 between the valve plate 50 and the top edge of the cylinder sleeve 94, thereby sealing the top edge of the cylinder bore 98.

Compressor 10 also includes a piston 122 and an eccentric 126 associated with each of cylinders 30, 34 and mounted adjacent each of the opposite distal ends 130 of drive shaft 66. More specifically, the rod 134 of each piston 122 is mounted on a bearing 138 supported by the eccentric 126 such that the axis of the eccentric 126 is offset from the axis of the drive shaft 66. The eccentric 126 includes a counterweight 142. The piston 122 is positioned within each cylinder bore 98 of the cylinder sleeve 94 such that the rod 134 of the piston 122 extends through the opening 102 in the support floor 90. The piston 122 includes a peripheral seal 146 that seals with the cylinder bore 98 of the cylinder sleeve 94.

A fan 150 is mounted on each distal end of the drive shaft 66 within the hollow interior of the end housing 26 to draw air into the end housing 26 as the motor 62 rotates, thereby cooling the motor 62. Air may also be forced through openings 102 in the support floor 90 to cool the cylinder sleeve 94 and the piston 122.

With further reference to fig. 3, the valve plate 50 of the head assembly 18 includes first and second cylinder portions 162, 166 corresponding to the first and second cylinders 30, 34, and an intermediate portion 170 connecting the first and second cylinder portions 162, 166. Each of the cylinder portions 162, 166 has a support boss 174 that corresponds with the housing boss 110 on the end housing 26 and is supported by the housing boss 110.

The head 54 includes first and second cylinder portions 186, 190 corresponding to the first and second cylinders 30, 34 and an intermediate portion 194 therebetween. Each of the cylinder portions 186, 190 includes a mounting boss 198 supported by the support boss 174 of the valve plate 50. First fasteners 210 are threaded through mounting bosses 198 of head 54, support bosses 174 of valve plate 50, and into housing boss 110 to couple head 54, valve plate 50, and housing assembly 14. Second fasteners 214 are threaded through intermediate bosses 178 on intermediate portion 170 of valve plate 50 and corresponding intermediate bosses 180 on intermediate portion 194 of head 54 to provide additional clamping force between head 54 and valve plate 50 to prevent gas leakage around the locations where intermediate portions 170, 194 of head 54 and valve plate 50 meet when coupled together.

Referring to fig. 4, each of the first and second cylinder portions 186, 190 of the top cover 54 includes a sieve bed seat 222 and an oxygenator manifold 226 for mounting each of the pressure swing absorption oxygen concentrators (not shown). Solenoid valves (not shown) are mounted on each of the oxygenator manifolds 226 for controlling the flow of air to the oxygen concentrator and the flow of purge nitrogen out of the compressor 10.

Referring to fig. 4-5, the valve plate 50 includes a valve plate face or top surface 234 that extends across the first and second cylinder portions 162, 166 and the intermediate portion 170. The top surface 234 defines a groove 238 that includes an outer groove 242 extending around the periphery of the valve plate 50, an inner groove 246 extending within the periphery of the outer groove 242 on the top surface 234 and concentric with the outer groove 242, and a connecting groove 250 connecting the inner groove 246 and the outer groove 242 within the first and second cylinder portions 162, 166. The groove 238 supports a circuitous gasket 252 made of rubber or another suitable sealing material and defines an intake portion 254, an exhaust portion 258 and a purge or sound dampening portion 262. Intake portion 254 and exhaust portion 258 are defined by groove 238 so as to be continuous between first cylinder portion 162, intermediate portion 170, and second cylinder portion 166. The inner groove 246 defines a sound attenuating portion 262 to extend across the intermediate portion 170 such that the inner groove 246 and the connecting groove 250 bisect the outer groove 242 along a horizontal centerline a extending longitudinally between the first and second cylinder portions 162, 166. Therefore, the intake portion 254 and the exhaust portion 258 are located on opposite sides of the sound attenuation portion 262 and the connection groove 250. In an alternative embodiment, a single groove may bisect outer groove 242 along horizontal centerline a to define only intake portion 254 and exhaust portion 258 in place of sound attenuating portion 262 (i.e., similar to central groove 478 of fig. 15-20).

Valve plate 50 includes an intake port 270 in communication with intake portion 254 at an intake port 272. The valve plate 50 also includes a cylinder bore inlet aperture 274 located within the intake portion 254 defined in and extending through each of the first and second cylinder portions 162, 166, each of the first and second cylinder portions 162, 166 corresponding to each of the cylinders 30, 34. Each of the cylinder bore inlet apertures 274 has a corresponding cylinder bore inlet flapper valve 278 to allow intake air to enter the cylinder bore 98 from the intake portion 254, but not vice versa. The valve plate 50 also includes a cylinder bore outlet aperture 282 in the exhaust portion 258 defined in and extending through each of the first and second cylinder portions 162, 166, each of the first and second cylinder portions 162, 166 corresponding to each of the cylinders 30, 34. Each of the cylinder bore outlet apertures 282 has a corresponding cylinder bore outlet flapper valve 286 to allow exhaust air to exit the cylinder bore 98, but the reverse is not true. The vent section 258 also has a relief valve support recess 290 that receives a pressure relief valve or relief valve 294 (fig. 3). Sound attenuating portion 262 includes an exhaust port 298 that is centrally located within sound attenuating portion 262 through top surface 234 of valve plate 50.

Referring to FIG. 6, top cover 54 includes a top or inner bottom surface 306 and a series of continuous dividers or walls 310, dividers or walls 310 correspond to recesses 238 of valve plate 50 and extend generally vertically downward from bottom surface 306 of top cover 54. The series of walls 310 includes an outer wall 314 extending around the perimeter of the top cap 54, an inner wall 318 located within the outer wall 314, and a connecting wall 322 connecting the inner wall 318 and the outer wall 314 within the first and second cylinder portions 186, 190 of the top cap 54. The inner wall 318 includes first and second portions 319, 320. The series of walls 310 extend from the bottom surface 306 to form an intake passage 326, an exhaust passage 330, and a purge or sound damping passage 334. Like recess 238 of valve plate 50, inner wall 318 defines a sound damping passage 334 such that inner wall 318 and connecting wall 322 divide outer wall 314 along a horizontal centerline B extending longitudinally between first and second cylinder portions 186, 190. Therefore, the intake passage 326 and the exhaust passage 330 are located on opposite sides of the sound attenuation passage 334 and the connection wall 322. In an alternative embodiment, the connecting walls 322 may extend along the horizontal centerline B and meet to form a single wall that bisects the outer wall 314, thereby defining the intake and exhaust passages 326, 330, in place of the sound damping passage 334 (i.e., similar to the center wall 482 of fig. 15-20).

The series of walls 310 cooperate with recesses 238 such that when valve plate 50 and head 54 are coupled together, intake portion 254, exhaust portion 258, and sound attenuating portion 262 align with intake passage 326, exhaust passage 330, and sound attenuating passage 334, respectively, to form intake chamber 342, exhaust chamber 346, and integrated sound attenuating chamber 350, as shown in cross-section in fig. 8. The bottom edges of series of walls 310 compress circuitous gasket 252 within groove 238 to seal intake chamber 342, exhaust chamber 346, and muffler chamber 350 to inhibit leakage between top surface 234 of valve plate 50 and the bottom edge of wall 310 of head 54. The intake chamber 342 forms a fluid conduit that extends between the intake port 272 and the cylinder bore inlet hole 274 and closes the intake port 272 and the cylinder bore inlet hole 274. The exhaust chamber 346 forms a fluid conduit that extends between and closes off the cylinder bore outlet apertures 282. In the illustrated embodiment, the muffling chamber 350 is positioned between the intake chamber 342 and the exhaust chamber 346 such that the intake chamber 342 and the exhaust chamber 346 surround the muffling chamber 350 around the perimeter of the muffling chamber 350 defined by the inner wall 318. Thus, the first portion 319 of the inner wall 318 partially defines and is shared between the sound attenuation chamber 350 and the vent chamber 346, and the second portion 320 of the inner wall 318 partially defines and is shared between the sound attenuation chamber 350 and the intake chamber 342.

While in the illustrated embodiment, recess 238 is defined in top surface 234 of valve plate 50 and wall 310 extends downwardly from bottom surface 306 of head 54, in an alternative embodiment, wall 310 may extend upwardly from valve plate 50 and recess 238 may be defined by head 54. In other words, valve plate 50 may be a "bathtub" type design and head 54 may be a substantially flat cover. In such embodiments, wall 310 is integrally formed as a single piece with one of valve plate 50 and head 54. In still other embodiments, wall 310 may be a separate component fixedly coupled to one or both of valve plate 50 and head 54. In such embodiments, both valve plate 50 and head 54 may be of a flat plate design or a "bathtub" type design or any combination thereof. In further embodiments, some of the walls 310 may extend from the head 54, and some of the walls 310 may extend from the valve plate 50. In additional embodiments, the wall 310 is not associated with a groove in the mating surface, but is configured to contact the opposing aforementioned surface of the valve plate 50 or the head 54 with or without a gasket. Additionally, while the intake and exhaust ports 270, 298 are defined by the valve plate 50, in alternative embodiments, the intake and exhaust ports 270, 298 may each be defined by the head cover 54.

In any of these possible combinations, both valve plate 50 and head 54 may be formed by a die casting process that does not require a core to completely define the chamber within head 54 or valve plate 50 during casting. Thus, in addition to aluminum and other suitable materials, the overcap 54 may be made of plastic. Additionally, each of valve plate 50 and head 54 may be integrally formed from a single piece.

With continued reference to fig. 6 and 7, an exhaust outlet passage 358 is defined in the bottom surface 306 of each of the first and second cylinder portions 186, 190 of the top cover 54. As shown in fig. 7, each of the exhaust outlet passages 358 extends from the exhaust chamber 346 to a corresponding one of the oxygenator manifolds 226. As such, the exhaust outlet passages 358 are in fluid communication with the fluid conduit formed by the exhaust plenum 346.

Referring to fig. 8, a sieve bed channel 362 is defined by the top cover 54 in each of the first and second cylinder portions 186, 190. Sieve bed passage 362 extends from oxygenator manifold 226 to a sieve bed recess 366 defined by each of first and second vat portions 186, 190 adjacent sieve bed seat 222. Sieve bed recess 366 receives an adsorbent bed (e.g., a zeolite bed).

Referring to fig. 6 and 9, a sound damping inlet passage 370 is defined in each of the first and second cylinder portions 186, 190 of the head cover 54. A sound damping inlet passage 370 extends from the oxygenator manifold 226 to the sound damping chamber 350, as best shown in fig. 9. The muffling chamber 350 forms a fluid conduit between the muffling inlet passage 370 and the exhaust port 298.

Each of the muffling inlet passages 370 includes a bend 374 (fig. 9). In the illustrated embodiment, the bend 374 in the sound attenuating inlet passage 370 is approximately a right angle, but in some embodiments, the bend 374 in the sound attenuating inlet passage 370 may be between approximately 75 degrees and approximately 105 degrees. The sound damping inlet passage 370 is also positioned at an opposite end of the sound damping chamber 350, while the exhaust port 298 is centrally positioned within the sound damping portion 262 of the valve plate 50 within the sound damping chamber 350. The muffling chamber 350 forms a curved portion 376 where air exits each of the muffling inlet passages 370 and enters the muffling chamber 350 (fig. 2). In the illustrated embodiment, the curved portion 376 is a right angle bend, but may be between about 75 degrees and about 105 degrees in other embodiments.

The top cap 350 also includes a sound damping extension 352 in the middle portion 194 of the top cap 54 that defines a volume such that a larger volume is created in the sound damping chamber 350 (fig. 4). In some embodiments, the sound-attenuating medium may also be at least partially lined or positioned within the sound-attenuating chamber 350. In some embodiments, the muffling chamber 350 can include a plurality of baffles extending from any wall of the muffling chamber 350 that defines the top cap 54. In some embodiments, the filter media may be positioned within the sound attenuation chamber 350. In some embodiments, the sound attenuation chamber 350 may be used for heat exchange and insulation, and thus may include an insulating medium, such as an insulating foam. In an alternative embodiment, the inner wall 318 of the muffling chamber 350 may extend along the horizontal centerline B between the outer walls 314 in the first and second cylinder portions 186, 190. In other words, the connecting walls 322 may each be double-walled in communication with the sound-damping chamber 350 to lengthen the sound-damping chamber 350. In further alternative embodiments, the sound attenuation chamber 350 may be defined entirely by the valve plate 50 or the head 54, as shown in the embodiments of fig. 15-20. Sound-damping chamber 350 may also be formed in part by valve plate 50 or head 54 and may be formed entirely when a separate, separate cover is coupled thereto, rather than when valve plate 50 and head 54 are connected together. In any such embodiment, one or more muffling chambers may be disposed directly downstream and/or upstream of the intake port and/or the exhaust port, respectively.

Referring back to fig. 4 and 7-9, the solenoid valve is configured to control the flow of exhaust air from the exhaust chamber 346 to the sieve beds, and to control the flow of nitrogen exhausted or purged from the sieve beds to the muffling chamber 350. Specifically, when the solenoid valve is in the first position, the sound damping inlet passage 370 is blocked in the oxygenator manifold 226 such that only the exhaust outlet passage 358 and the sieve bed passage 362 are in fluid communication. When the solenoid valve is in the second position, the exhaust outlet passage 358 is blocked in the oxygenator manifold 226 such that the sieve bed passage 362 and the sound damping inlet passage 370 are in fluid communication through the oxygenator manifold 226.

The compressor 10 is assembled by axially positioning the motor 62 and the drive shaft 66 within the motor sleeve 22. An end housing 26 is coupled to each end of the motor sleeve 22. The eccentric 126, piston 122 and fan 150 are connected to opposite ends of the drive shaft 66. A cylinder sleeve 94 is seated on the support floor 90 of each of the cylinder extensions 86. The valve plate 50 is then positioned such that the first cylinder portion 162 is mounted over the first cylinder 30 and the second cylinder portion 166 is mounted over the second cylinder 34 with the intermediate portion 170 extending therebetween. An O-ring 114 is positioned between the top edge of each of the cylinder sleeves 94 and the valve plate 50. A circuitous gasket 252 fits into the recess 238 in the top surface 234 of the valve plate 50. The head 54 is mounted to the valve plate 50 such that each of the first cylinder portion 186, the second cylinder portion 190, and the intermediate portion 194 of the head 54 are aligned with the first cylinder portion 162, the second cylinder portion 166, and the intermediate portion 170 of the valve plate 50. The walls 310 defining the intake passage 326, the exhaust passage 330 and the sound-deadening passage 334 of the head cover 54 are aligned on the detour gasket 252 with the corresponding intake portion 254, exhaust portion 258 and sound-deadening portion 262 of the valve plate 50, forming respective intake chamber 342, exhaust chamber 346 and sound-deadening chamber 350. First fasteners 210 are then threaded through the aligned bosses 198, 174, 110 of the head cover 54, valve plate 50, and end housing 26, thereby coupling the head cover 54, valve plate 50, and end housing 26 together. Second fasteners 214 are also threaded through aligned intermediate bosses 178, 180 of valve plate 50 and head 54. As head 54 is coupled to valve plate 50, wall 310 of head 54 compresses circuitous gasket 252 within groove 238 of valve plate 50, thereby forming and sealing intake chamber 342, exhaust chamber 346, and sound attenuation chamber 350.

In operation, the motor 62 rotationally drives the drive shaft 66, causing the pistons 122 to reciprocate within the cylinder bores 98 of each of the cylinders 30, 34. During the downstroke of each of the pistons 122, air is drawn into the intake chamber 342 from the ambient through the intake port 270. Air is then drawn into the cylinder bores 98 of each of the first and second cylinders 30, 34, alternatively through the corresponding cylinder bore inlet apertures 274, depending on the direction of travel of the respective pistons 122, which is offset by the pair of eccentrics 126. The inlet flapper valve 278 admits air into the cylinder bore 98 through the cylinder bore inlet aperture 274, but prevents air from re-entering the intake chamber 342. Thereafter, air is compressed within the cylinder bore 98 by the upstroke of the piston 122 and forced out of the bore outlet aperture 282 through the outlet flapper valve 286 at an increased pressure. The outlet flapper valve 286 prevents compressed air from re-entering the cylinder bore 98. The compressed air exits the cylinder bore outlet apertures 282 of each of the first and second cylinders 30, 34 and enters the exhaust chamber 346. The compressed air, after exiting the cylinder bore 98 of each of the cylinders 30, 34 within the exhaust chamber 346, recombines (to an extent dependent on the rotational speed of the drive shaft 66), and flows from the exhaust chamber 346 to the oxygenator manifold 226 of each of the cylinders 30, 34 through each of the exhaust outlet passages 358 (fig. 7).

When the solenoid valve is in the first position, pressurized air flows through the sieve bed passages 362 into the sieve beds of the oxygen concentrator of each of the cylinder portions 186, 190. The pressurized air is then subjected to pressure swing absorption, such that the oxygen and nitrogen in the air are substantially separated. The solenoid valve periodically switches to the second position to permit purge nitrogen to flow from the sieve beds back to oxygenator manifold 226 through sieve bed passages 362. The purge nitrogen then flows from the manifold 226 into the muffler chamber 350 through the muffler inlet passage 370 of each of the first and second cylinder portions 186, 190. The bend 374 in the muffling inlet passage 370 and the bend 376 within the muffling chamber 350 provide a change in direction and a longer circuitous path for the travel of the exhaust gas, thereby promoting sound attenuation. The expanded volume of the muffling chamber 350 provides expansion space for the exhaust gas (e.g., nitrogen) exiting the muffling inlet channel 370, thereby facilitating muffling of the exhaust gas by expanding into the muffling chamber 350. The integration of the sound attenuation chamber 350 into the head assembly 18 and the location between the intake chamber 342 and the exhaust chamber 346 provides further sound attenuation. The purge nitrogen may also pass through a sound reducing medium positioned within the sound attenuation chamber 350 or lining the sound attenuation chamber 350 or alternatively around the baffle to provide additional sound reduction and sound attenuation. The baffles provide a more circuitous path for the exhaust gases to travel. The purge nitrogen gas combines within the sound damping chamber 350 and is discharged from the exhaust port 298 in the center of the valve plate 50 within the sound damping chamber 350.

The purge nitrogen in the muffling chamber 350 also reduces heat transfer between the gas flow in the intake chamber 342 and the gas flow in the exhaust chamber 346 by providing a layer of insulation therebetween. The temperature of the purge nitrogen in the muffling chamber 350 is lower than the compressed air in the exhaust chamber 346, and the purge nitrogen creates an isolating effect between the exhaust chamber 346 and the intake chamber 342 to prevent air in the exhaust chamber 346 that is higher than the air temperature in the intake chamber 342 from raising the air temperature in the intake chamber 342. Specifically, as shown in fig. 6, the first portion 319 of the inner wall 318 partially defines the exhaust chamber 346 and the second portion 320 of the inner wall 318 partially defines the intake chamber 342, thereby separating the exhaust chamber 346 and the intake chamber 342 by the width of the muffler chamber 350. This configuration further permits the muffling chamber 350 to act as a heat exchanger, providing thermal insulation between the exhaust chamber 346 and the air in the intake chamber 342. In particular, it is desirable to prevent the hot pressurized exhaust air from raising the temperature of the intake air, which is typically at ambient temperature, to improve efficiency. The gas passing through the sound attenuation chamber 350 is cooled and absorbs heat from the exhaust air in the exhaust chamber 346, thereby suppressing the exhaust air from increasing the temperature of the intake air. As previously mentioned, muffler chamber 350 may include an insulating material specifically to reduce heat transfer between intake chamber 342 and exhaust chamber 346.

Although in the illustrated embodiment, compressor 10 includes a pressure swing absorption oxygen concentrator configured for oxygen concentration, in alternative embodiments, compressor 10 and head assembly 18 may simply be configured for gas (e.g., air) compression. In this embodiment, header 54 does not include a solenoid valve or sieve bed seat 222 for mounting an oxygen concentrator. Accordingly, each of the first and second cylinder portions 186, 190 of the head cover 54 define a passage that fluidly communicates the vent chamber 346 and the muffler chamber 350. Thus, in operation, compressed air flows through the passages from the exhaust chamber 346 to the muffler chamber 350. The compressed air then exits the muffler chamber 350 through the exhaust port 298. Alternatively, the inner wall 318 may include one or more openings that place the exhaust chamber 346 in direct communication with the sound damping chamber 350 in place of the sound damping inlet passage 370 and the exhaust outlet passage 358. A series of baffles may be disposed within either or both of the exhaust chamber 346 and the muffler chamber 350 to provide a tortuous or circuitous path for the flow of the compressed air prior to exiting through the exhaust ports 298. The vent chamber 346 and the sound attenuation chamber 350 may optionally include an insulating material, a sound attenuating material, or a filter material.

While in the illustrated embodiment, the head assembly 18 is configured for single-stage parallel flow, in alternative embodiments, the groove 238 and corresponding wall 310 may be configured for any type of flow configuration (e.g., a multi-stage serial flow embodiment or a single exhaust chamber embodiment, as shown in fig. 10-14 and 21-25, respectively, and described below).

In an alternative embodiment, head assembly 18 may be reconfigured such that exhaust port 298 is an intake port that opens directly into a sound-damping chamber, such as sound-damping chamber 350, such that the flow through compressor 10 is substantially reversed. In this embodiment, air is drawn into the muffler chamber 350 through the intake port (i.e., the exhaust port 298). Air travels through the muffling chamber 350 to provide sound attenuation using the various methods described above. The muffler chamber 350 is in direct communication with the exhaust chamber 346, thereby reconfiguring the flapper valve 286 to allow air to enter the cylinder bore 98 from the exhaust chamber 346 via the aperture 282. In addition, the flapper valve 278 is reconfigured to allow compressed air to enter the intake chamber 342 through the aperture 274. Compressed air may flow out of the intake port 270 through the intake port 272.

Fig. 10-14 illustrate a head assembly 18a according to a multi-stage serial flow embodiment that may be used in place of head assembly 18 on compressor 10 of fig. 1-9. Thus, the housing assembly 14 will not be described in detail, and only the differences in the structure and manner of operation of the compressor 10 when using the head assembly 18a of fig. 10-14 will be described below. Similar components and features to the head assembly 18 of fig. 1-9 are identified with similar reference numerals, plus the letter "a," and will not be described in detail.

Referring to fig. 10, only second cylinder portion 190a of overcap 54a includes sieve bed base 222a and oxygenator manifold 226a, while first cylinder portion 186a of overcap 54a includes only cylinder cap 382.

Referring to fig. 10 to 11, the recess 238a in the top surface 234a of the valve plate 50a includes an outer recess 242a extending around the periphery of the valve plate 50a, an inner recess 246a located within the periphery of the outer recess 242a, and a first connecting recess 250a in the first and second cylinder portions 162a, 166a connecting the inner and outer recesses 246a, 242 a. The groove 238a also includes a second connecting groove 390 extending between the outer groove 242a and the inner groove 246a along a vertical centerline C of the intermediate portion 170a of the valve plate 50 a. The recess 238a defines a first stage intake portion 394, a first stage exhaust portion 398, a second stage intake portion 402, a second stage exhaust portion 406, and a sound attenuating portion 262 a. The first-stage intake portion 394 is defined by one of the outer groove 242a, the inner groove 246a, the first connecting groove 250a, and the second connecting groove 390 within the first cylinder portion 162 a. The first stage exhaust portion 398 and the second stage intake portion 402 are continuous with one another and are defined within the first and second cylinder portions 162a, 166a and the intermediate portion 170a by the outer groove 242a, the inner groove 246a and the first connecting groove 250a, forming an intermediate portion. The second-stage exhaust portion 406 is defined within the second cylinder portion 162a by one of the outer groove 242a, the inner groove 246a, the first connecting groove 250a, and the second connecting groove 390. In an alternative embodiment, a single groove may bisect the outer groove 242a along the horizontal centerline a to define only the first stage intake portion 394, the first stage exhaust portion 398, the second stage intake portion 402, and the second stage exhaust portion 406 in place of the sound attenuating portion 262 (i.e., similar to the central groove 478 of fig. 15-20).

The intake port 270a communicates with an intake port 272a defined in a first-stage intake portion 394 of the valve plate 50 a. A first bore inlet aperture 414 and a first bore outlet aperture 418 are defined in the first cylinder portion 162a to extend through the valve plate 50a for fluid communication with the cylinder bores 98a of the first cylinder 30a, each having a corresponding flapper valve (not shown). The first cylinder bore inlet aperture 414 is located in the first stage inlet portion 394 and the first cylinder bore outlet aperture 418 is located in the first stage exhaust portion 398. A second bore inlet aperture 422 and a second bore outlet aperture 426 are defined in the second cylinder portion 166a to extend through the valve plate 50a for fluid communication with the cylinder bores 98a of the second cylinder 34a, each having a corresponding flapper valve (not shown). A second bore inlet aperture 422 is located in the second stage intake portion 402 and a second bore outlet aperture 426 is located in the second stage exhaust portion 406. A relief valve support recess 290a is defined in the intermediate portion and receives a relief valve (relief valve 294 as shown in fig. 3). Although not shown, second stage exhaust portion 406 may also include a pocket for supporting an additional relief valve.

Referring to fig. 12, the wall 310a of the overcap 54a includes an outer wall 314a extending around the periphery of the overcap 54a, an inner wall 318a located within the periphery of the outer wall 314a, and a first connecting wall 322a connecting the inner wall 318a and the outer wall 314a within the first and second cylinder portions 186a, 190 a. The series of walls 310a also includes a second connecting wall 434 that extends between the inner wall 318a and the outer wall 314a along a vertical centerline D within the intermediate portion 194 a. The series of walls 310a and the floor 306a form a first stage intake passage 438, a first stage exhaust passage 442, a second stage intake passage 446, a second stage exhaust passage 450, and a sound-damping passage 334 a. Similar to valve plate 50a, a first-stage intake passage 438 is defined within first cylinder portion 186a by one of outer wall 314a, inner wall 318a, first connecting wall 322a, and second connecting wall 434. The first-stage exhaust passage 442 and the second-stage intake passage 446 are continuous with each other and defined by the outer wall 314a, the inner wall 318a, and the first connecting groove 250a within the first and second cylinder portions 186a, 190a and the intermediate portion 194a, thereby forming an intermediate passage. A second-stage exhaust passage 450a is formed in the second cylinder portion 250a by one of the outer wall 314a, the inner wall 318a, the first connecting wall 322a, and the second connecting wall 434.

The series of walls 310a correspond to the recesses 238a such that when the valve plate 50a and the head 54a are coupled together, the first stage intake portion 394, the first stage exhaust portion 398, the second stage intake portion 402, the second stage exhaust portion 406, and the sound attenuating portion 262 are aligned with the first stage intake passage 438, the first stage exhaust passage 442, the second stage intake passage 446, the second stage exhaust passage 450, and the sound attenuating passage 334, respectively, forming the first stage intake chamber 458, the first stage exhaust chamber 462, the second stage intake chamber 466, the second stage exhaust chamber 470, and the sound attenuating chamber 350a, respectively, as shown in fig. 13-14. The first stage intake chamber 458 extends between the intake port 272a and the first cylinder bore inlet aperture 414 and closes the intake port 272a and the first cylinder bore inlet aperture 414. Second stage exhaust chamber 470 closes second bore outlet aperture 426. The first stage exhaust chamber 462 and the second stage intake chamber 466 are continuous, forming an intermediate chamber that extends between and closes off the first and second cylinder bore exit apertures 418, 422. In an alternative embodiment, connecting walls 322a may extend along horizontal centerline B and meet to form a single wall that extends longitudinally across top cap 54a in place of sound damping chamber 350a (i.e., similar to central wall 482 of fig. 15-20).

With continued reference to FIG. 12, the muffling chamber 350a is generally located between the intermediate chamber, the first stage intake chamber 458 and the second stage exhaust chamber 470 such that the intermediate chamber, the first stage intake chamber 458 and the second stage exhaust chamber 470 surround the muffling chamber 350a around the perimeter of the muffling chamber 350a defined by the inner wall 318 a. Thus, the first portion 319a of the inner wall 318a partially defines the first stage intake chamber 458 and partially defines the second stage exhaust chamber 470, and the second portion 320a of the inner wall 318a partially defines an intermediate chamber, thereby separating the exhaust chamber 346 and the intake chamber 342 by the width of the muffler chamber 350 a. In this configuration, the muffler chamber 350a provides isolation between the first stage intake chamber 458, the intermediate chamber, and the second stage exhaust chamber 470.

With continued reference to fig. 12, the bottom surface 306a of the top cover 54a defines a single exhaust outlet passage 358a in the second cylinder portion 190a extending from the second stage exhaust chamber 470 to the oxygenator manifold 226 a. Bottom surface 306a also defines a single sound damping inlet passage 370a extending from oxygenator manifold 226a of second cylinder portion 190a to sound damping chamber 350 a.

In operation, during the downward stroke of the piston 122a of the first cylinder 30a, air is drawn into the first stage intake chamber 470 from the ambient through the intake port 270 a. Then, air is drawn into the cylinder bore 98a of the first cylinder 30a through the first cylinder bore inlet hole 414. A flapper valve corresponding to the first cylinder bore inlet aperture 414 allows air to enter the cylinder bore of the first cylinder 30a, but prevents air from re-entering the first stage intake chamber 470. The piston 122a of the first cylinder 30a then compresses the air to a first pressure, forcing the air out of the first cylinder bore exit aperture 418 and into the intermediate chambers (i.e., the first stage exhaust chamber 462 and the second stage intake chamber 466). The flapper valve corresponding to the first bore outlet aperture 418 allows air to exit the bore 98a of the first cylinder 30a into the intermediate chamber, but prevents air from re-entering the bore 98a of the first cylinder 30 a. The compressed air enters the cylinder bore 98a of the second cylinder 34a through the second cylinder bore inlet aperture 422. A flapper valve corresponding to the second cylinder bore inlet aperture 422 allows air to enter the cylinder bore 98a of the second cylinder 34a, but prevents air from re-entering the intermediate chamber. The air is then compressed by the piston 122a of the second cylinder 34a to a second pressure that is higher than the first pressure and forced out of the second bore outlet orifice 426 into the second stage exhaust chamber 470. A flapper valve corresponding to the second cylinder bore outlet aperture 426 allows air to exit the cylinder bore 98a of the second cylinder 34a into the second stage exhaust chamber 470, but prevents air from re-entering the cylinder bore 98a of the second cylinder 34 a. Air flows through the exhaust chamber outlet passage 358a to the oxygenator manifold 226a of the second bowl portion 190a of the top cap 54 a. When the solenoid valve is in the first position, compressed air flows through sieve bed passage 362a to sieve bed recess 366, where pressure swing absorption separates nitrogen and oxygen. When the solenoid valve is in the second position, purge nitrogen flows into the sound-deadening chamber 350a through the sound-deadening inlet passage 370a, optionally through a sound-deadening medium or another medium as previously described, and out of the exhaust port 298a in the center of the sound-deadening portion 262a of the valve plate 50 a.

Fig. 15-20 illustrate a head assembly 18b according to a multi-stage serial flow embodiment that may be used in place of head assembly 18 on compressor 10 of fig. 1-9. Thus, the housing assembly 14 will not be described in detail, and only the differences in the structure and manner of operation of the compressor 10 when using the head assembly 18b of fig. 15-20 will be described below. Similar components and features to the head assembly 18 of fig. 1-9 are identified with similar reference numerals, plus the letter "b," and will not be described in detail.

Referring to fig. 15-16, recess 238b in top surface 234b of valve plate 50b includes an outer recess 242b extending around the perimeter of valve plate 50b, and a single central recess 478 extending along a horizontal centerline a of valve plate 50b that bisects first cylinder portion 162b, intermediate portion 170b, and second cylinder portion 166b of top surface 234b to define an intake portion 254b and an exhaust portion 258 b. Accordingly, intake portion 254b and exhaust portion 258b are located on opposite sides of central recess 478.

The valve plate 50b includes a cylinder bore inlet hole 274b in the intake portion 254b defined in each of the first and second cylinder portions 162b, 166b corresponding to each of the cylinders 30, 34 and extending through each of the first and second cylinder portions 162b, 166b corresponding to each of the cylinders 30, 34. Each of the cylinder bore inlet apertures 274b has a corresponding cylinder bore inlet flapper valve (not shown) to allow intake air to enter the cylinder 98b from the intake portion 254b, but not vice versa. The valve plate 50b also includes a cylinder bore outlet aperture 282b in the exhaust portion 258b defined in each of the first and second cylinder portions 162b, 166b corresponding to each of the cylinders 30b, 34b and extending through each of the first and second cylinder portions 162b, 166b corresponding to each of the cylinders 30b, 34 b. Each of the cylinder bore outlet apertures 282b has a corresponding cylinder bore outlet flapper valve (not shown) to allow the exhaust air to exit the cylinder bore 98b, but the reverse is not true.

Referring to fig. 17-20, wall 310B of head 54B corresponds to recess 238B of valve plate 50B and includes an outer wall 314B extending around the periphery of head 54B and a central wall 482 within the periphery of outer wall 314B, the central wall 482 extending along a horizontal centerline B of head 54B that bisects first cylinder portion 186B, intermediate portion 194B, and second cylinder portion 194B to form intake passage 326B and exhaust passage 330B. Thus, the intake passage 326b and the exhaust passage 330b are located on opposite sides of the central wall 482.

The series of walls 310b correspond to grooves 328b such that when valve plate 50b and top cap 54b are coupled together, intake and exhaust portions 254b and 258b align with intake and exhaust passages 326b and 330b, respectively, forming intake and exhaust chambers 342b and 346b, respectively, as shown in fig. 19-20. The intake chamber 342b extends between and closes the cylinder bore inlet hole 274 b. The exhaust chamber 346b extends between and closes the bore outlet apertures 282 b.

With continued reference to fig. 17-20, cap 54b defines an intake passage 486 and an exhaust passage 490. An intake passage 486 extends from an intake passage inlet 494 to an intake passage outlet 498 defined in the inner bottom surface 306b within the intake passage 326b to communicate the ambient with the intake chamber 342b (fig. 18 and 20). Exhaust passage 490 extends from exhaust passage inlet 502 to exhaust passage outlet 506 to place exhaust chamber 346b in communication with the environment (fig. 18-19). The exhaust passage 490 or the intake passage 486 may be connected to a system or reservoir. The exhaust passage 490 and the intake passage 486 each define a volume that provides sound attenuation for the gas passing through the passages 486, 490. Alternatively, the sound-attenuating medium may be at least partially lined or positioned within one or both of the exhaust passage 490 and the intake passage 486. In some embodiments, one or both of the channels 486, 490 may include a plurality of baffles extending from any walls defining the channels 486, 490 of the cap 54. Accordingly, one or both of exhaust passage 490 and intake passage 486 may further function as a sound-damping chamber integrally formed with head cover 54 b. In some embodiments, a filter media may be positioned within one or both of the passages 486, 490.

In operation, air is drawn from the ambient into the intake passage 486 through the intake passage inlet 494 and then into the intake chamber 342b through the intake passage outlet 498 during the downstroke of the piston 122b of the first and second cylinders 30b, 34 b. Alternatively, the air passes through a sound reducing medium or another medium as previously described within the intake passage 486. Then, depending on the direction of travel of the respective piston 122b, air is alternately drawn into the cylinder bore 98b of each of the first and second cylinders 30b, 34b through the corresponding cylinder bore inlet aperture 274 b. The inlet flapper valve permits air to enter the cylinder bore 98b from the intake chamber 342b, but prevents air from entering the intake chamber 342b from the cylinder bore 98 b. Thereafter, the air is compressed within the cylinder bore 98b by the upstroke of the piston 122b and is pushed out of the corresponding cylinder bore outlet aperture 282b through the outlet flapper valve at an increased pressure. The outlet flapper valve prevents compressed air from re-entering the cylinder bore 98 b. The compressed air exits the cylinder bore outlet apertures 282b of each of the first and second cylinders 30b, 34b and enters the exhaust chamber 346 b. The compressed air, after exiting the cylinder bore 98b of each of the cylinders 30b, 34b within the exhaust chamber 346b, recombines (to an extent dependent on the rotational speed of the drive shaft 66 b) and flows from the exhaust chamber 346 into the exhaust passage 490 via the exhaust passage inlet 502. The compressed air passes through the exhaust passage 490 before exiting via the exhaust passage outlet 506. Alternatively, the air passes through a sound reducing medium or another medium as previously described within the exhaust passage 490.

Fig. 21-25 illustrate a head assembly 18c of a compressor 10c according to a single discharge chamber embodiment. Like parts and features are identified with like reference numerals, plus the letter "c" and will not be described in detail. Specifically, the housing assembly 14 is substantially identical to the housing assembly of fig. 1-9, except for several features described in detail below.

Referring to fig. 21-22, the end housings 26c each define an intake port 510. The housing assembly 14c also includes an end cap 514 coupled to each of the end housings 26c to form an air intake chamber 518 within each of the end housings 26 c. Each of the pistons 122c defines a cylinder bore inlet aperture 522 with a corresponding flapper valve (not shown) that allows air to enter the cylinder bore 98c during the downstroke of the piston 122c, but does not allow air during the upstroke.

Referring to fig. 23-25, the valve plate 50c includes a groove 238c extending around the outer periphery of the first and second cylinder portions 162c, 166c and the intermediate portion 170 c. The valve plate 50c has a top surface 234c and includes corresponding recesses and protrusions that extend downwardly into the valve plate 50c and cylinder bore 98 c. The recess 238c defines a continuous discharge portion 530 between the first and second cylinder portions 162c, 166c and the intermediate portion 170c of the valve plate 50 c. Cylinder bore outlet apertures 534 are defined in each of the first and second cylinder portions 162c, 166c so as to extend through the valve plate 50c for fluid communication with each of the cylinder bores, each of the cylinder bore outlet apertures 534 having a corresponding cylinder bore outlet flapper valve 542 (fig. 23). Exhaust port 538, which is in fluid communication with exhaust port 298c, extends from exhaust portion 530 in intermediate portion 170c of valve plate 50c to the atmosphere.

The top cap 54c includes an outer wall 314c that extends around the periphery of the first and second cylinder portions 186c, 190c and the middle portion 194c of the top cap 54c to define an exhaust passage 550. Outer wall 314c of head 54c corresponds to recess 238c of valve plate 50c such that when valve plate 50c and head 54c are coupled together, exhaust portion 530 and exhaust passage 550 form exhaust chamber 554. The exhaust chamber 554 extends between and closes off the exhaust ports 538 and the cylinder bore exit apertures 534 of the exhaust port 298 c. A gasket (not shown) may be received in the groove 238c and compressed by the outer wall 314c to seal the vent chamber 554.

In operation, during the downstroke of each of the pistons 122c, air is drawn into each of the intake chambers 518 from the ambient through the intake ports 510 of the end housing 26 c. Then, air is drawn into the cylinder bore 98c of each of the cylinders 30c, 34c through the cylinder bore inlet hole 522 and into the piston 122 c. The inlet flapper valve allows air to enter the cylinder bore 98c, but prevents air from re-entering the intake chamber 510. Air is compressed within the cylinder bore 98c during the upstroke of the piston 122 c. Forcing compressed air through the cylinder bore exit hole 534 into the exhaust chamber 554. The outlet flapper valve 542 allows air to enter the exhaust chamber 554, but prevents air from re-entering the cylinder bore 98 c. The compressed air from both the first and second cylinders 30c, 34c combines within an exhaust chamber 554 fluidly connecting the first and second cylinders 30, 34 c. The compressed air from both the first and second cylinders 30, 34c then exits the exhaust chamber 554 through the exhaust port 298 c.

Although not shown, a baffle may be positioned within the exhaust chamber 554 to provide a circuitous path for the compressed air to flow from the cylinder bore outlet aperture 534 to the exhaust port 298c, thereby providing sound attenuation. The baffle may extend downwardly from the top cover 54c or upwardly from the valve plate 50c between the intermediate portion 194c and the first cylinder portion 186c and the intermediate portion 194c and the second cylinder portion 190 c. Alternatively, the exhaust chamber 554 may include or be lined with a sound attenuating medium to provide sound attenuation to the compressed gas passing through the exhaust chamber 554 from the outlet aperture 534 to the exhaust port 298 c.

In further alternative embodiments, the valve plate and the head cover of the head assembly may have any arrangement that facilitates various flow configurations. In another embodiment, the head assembly may be configured with a pressure driven pump in a first cylinder and a vacuum driven pump in a second cylinder. That is, the first cylinder portions of the valve plate and the head cover have corresponding walls and grooves that together form the intake and exhaust chambers, and the second cylinder portions of the valve plate and the head cover have corresponding walls and grooves that together form the intake and exhaust chambers. In this configuration, the intake and exhaust chambers of each of the first and second cylinder portions are independent of each other such that one is a pressure driven pump and one is a vacuum driven pump. Alternatively, the first cylinder part may form only an exhaust chamber with intake air below the piston, and/or the second cylinder part may form only an intake chamber with exhaust air below the piston.

In another embodiment, the head assembly may be configured as a multi-stage compressor, with the intake air in the first cylinder below the piston. That is, the valve plate and head have corresponding walls and grooves that cooperate to form a first stage discharge chamber in the first cylinder portion and a second stage intake chamber in the second cylinder portion, the first and second stage discharge chambers being continuous with one another. The corresponding walls and grooves also form a second stage exhaust chamber in the second cylinder portion.

In yet another embodiment, the head assembly may be configured as a pressure/vacuum multi-stage compressor, wherein the intake air in the first cylinder is below the piston. That is, the valve plate and the head define corresponding walls and grooves that cooperate to form a first stage discharge plenum in the first cylinder portion and a second stage intake plenum in the second cylinder portion, the first stage discharge plenum and the second stage intake plenum being continuous with one another.

In yet another embodiment, a compressor is provided having a single cylinder housing with a single cylinder bore and a corresponding piston. The compressor also includes a head assembly having a valve plate and a head cover. The valve plate has an intake portion defined by a series of grooves, a discharge portion, and a sound attenuation portion positioned between the intake and discharge portions. The intake section has a cylinder bore inlet aperture extending through the valve plate, and the exhaust section has a cylinder bore outlet aperture extending through the valve plate. Each of the cylinder bore inlet and outlet apertures has a corresponding flapper valve. The head cover has walls extending from a head cover face, the walls forming an intake passage, a discharge passage, and a sound-deadening passage corresponding to the intake portion, the discharge portion, and the sound-deadening portion, so that the head cover can cooperate with the valve plate to form an intake chamber, a discharge chamber, and a sound-deadening chamber. The sound attenuation chamber in this configuration is surrounded on its periphery by the exhaust chamber and the intake chamber. The sound-damping chamber may contain or be lined with an insulating medium or a sound-damping medium. The top cover defines an intake port extending into the intake chamber and an exhaust port extending out of the sound attenuation chamber. The top cover also defines a passage extending from the exhaust chamber to the sound attenuation chamber. In operation, air is drawn into the intake chamber through the intake port prior to entering the cylinder bore through the cylinder bore inlet aperture. The air is compressed before being forced out of the cylinder bore exit orifice into the exhaust chamber. The air then flows through the passages into the provided sound attenuation chamber and then exits through the exhaust port. The header may include an oxygen concentrator such that the sweep nitrogen travels through the muffling chamber.

Although the head assembly of the illustrated embodiment is a dual cylinder compressor, in alternative embodiments, the head assembly may include any number of cylinder portions for a corresponding compressor having any number of cylinders. In addition, one of ordinary skill in the art will recognize that the present disclosure is equally applicable to pumps and other similar devices that include a head assembly.

While the above describes example embodiments of the present disclosure, these descriptions should not be viewed in a limiting sense. Rather, various changes and modifications can be made without departing from the scope of the disclosure.

Various features and advantages are set forth in the following claims.