阅读说明：本技术 活塞密封系统 (Piston sealing system ) 是由 E·D·达尔马斯 R·A·布洛姆 于 2018-03-30 设计创作，主要内容包括：公开了一种活塞和汽缸布置结构,其中,在活塞裙部的壁和/或汽缸上设置间隔开的凹穴的区域,以便在活塞和汽缸之间产生等效密封。可以呈具有多个竖向间隔开的行的图案来设置凹穴。(A piston and cylinder arrangement is disclosed in which areas of spaced pockets are provided on the wall of the piston skirt and/or the cylinder to create an equivalent seal between the piston and cylinder. The pockets may be arranged in a pattern having a plurality of vertically spaced rows.)

1. A sealing system, comprising:

a first structured surface;

an occlusion element having a first end, a second end, and an occlusion element surface extending between the first end and the second end;

a plurality of laterally spaced apart pockets arranged in a plurality of rows to form pocket areas on the first structural surface but not extending through the first structural surface or on the occlusion element surface but not extending through the occlusion element surface or on both the first structural surface and the occlusion element surface but not extending through both the first structural surface and the occlusion element surface; and

a working fluid provided at a first end of the obstruction element at an elevated pressure relative to a working fluid pressure at a second end of the obstruction element,

wherein the first structural surface is disposed proximate to and spaced a substantially uniform distance from the occlusion element surface; and

wherein an equivalent seal is created by the interaction of the working fluid with the pocket region.

2. The sealing system of claim 1, wherein the sealing system further comprises:

an equalization groove formed on the first structure surface but not extending through the first structure surface or in the pocket region on the occlusion element surface but not extending through the occlusion element surface, wherein the equalization groove is a continuous closed loop structure extending around a circumference of the first structure or occlusion element.

3. The sealing system of claim 1, wherein the plurality of laterally spaced pockets are of similar size and shape.

4. The sealing system of claim 1, wherein the plurality of laterally spaced pockets are of different sizes and shapes.

5. The sealing system of claim 1, wherein the plurality of laterally spaced pockets are arranged in a pattern having a plurality of rows of pockets and a plurality of columns of pockets.

6. The sealing system of claim 1, wherein the plurality of laterally spaced pockets each have a pocket mouth with a sharp edge formed at a junction of the pocket and the first structural surface or the obstruction element surface.

7. The sealing system of claim 1, wherein the first structural surface is provided by a cylinder wall and the obstruction element surface is provided by a skirt of a piston.

8. The sealing system of claim 7, wherein the cylinder wall is disposed in a cylinder of an internal combustion engine and the piston is an internal combustion engine piston.

9. The sealing system of claim 1, wherein the plurality of laterally spaced pockets each have a circular pocket mouth formed at a junction of the pocket and the first structural surface or the obstruction member surface.

10. The sealing system of claim 1, wherein the plurality of laterally spaced pockets each have a rectangular pocket mouth formed at a junction of the pocket and the first structural surface or the obstruction member surface.

11. The sealing system of claim 1, wherein one or more of the plurality of laterally spaced pockets have a converging portion and a diverging portion.

12. A sealing system, comprising:

a first structured surface;

an occlusion element having a first end, a second end, and an occlusion element surface extending between the first end and the second end; and

a plurality of spaced apart pockets arranged as pocket areas on the first structure surface but not extending through the first structure surface or the obstruction element surface but not extending through the obstruction element surface or both the first structure surface and the obstruction element surface but not extending through both the first structure surface and the obstruction element surface,

wherein the first structural surface is disposed proximate to and spaced a substantially uniform distance from the occlusion element surface.

13. The sealing system of claim 12, wherein the sealing system further comprises:

an equalization channel formed on the first structure surface but not extending through the first structure surface or in the pocket region of the obstruction element surface but not extending through the obstruction element surface, wherein the equalization channel is a continuous closed loop structure extending around the circumference of the first structure or obstruction element.

14. The sealing system of claim 12, wherein the plurality of spaced pockets are of similar size and shape.

15. The sealing system of claim 12, wherein the plurality of spaced pockets are of different sizes and shapes.

16. The sealing system of claim 12, wherein the plurality of spaced pockets are arranged in a pattern having a plurality of rows of pockets and a plurality of columns of pockets.

17. The sealing system of claim 12, wherein the plurality of spaced apart pockets each have a pocket mouth with a sharp edge formed at a junction of the pocket and the first structural surface or the obstruction element surface.

18. The sealing system of claim 12, wherein the first structural surface is provided by a cylinder wall and the obstruction element surface is provided by a skirt of a piston.

19. The sealing system of claim 18, wherein the cylinder wall is disposed in a cylinder of an internal combustion engine and the piston is an internal combustion engine piston.

20. The sealing system of claim 12, wherein the plurality of spaced apart pockets each have a circular pocket mouth formed at a junction of the pocket and the first structural surface or the obstruction member surface.

21. The sealing system of claim 12, wherein the plurality of spaced apart pockets each have a rectangular pocket mouth formed at a junction of the pocket and the first structural surface or the obstruction member surface.

22. The sealing system of claim 12, wherein one or more of the plurality of spaced pockets have a converging portion and a diverging portion.

23. An internal combustion engine, comprising:

an engine cylinder having a cylinder wall;

a piston disposed in the engine cylinder, the piston having a skirt and a head; and

a plurality of spaced apart pockets disposed as pocket areas on the piston skirt but not extending through the piston skirt or the engine cylinder but not extending through the engine cylinder or both the piston skirt and the engine cylinder but not extending through both the piston skirt and the engine cylinder.

24. The internal combustion engine of claim 23, wherein the internal combustion engine further comprises:

an equalization channel formed on the first structure surface but not extending through the first structure surface or in the pocket region on the occlusion element surface but not extending through the occlusion element surface, wherein the equalization channel is a continuous closed loop structure extending around a circumference of the first structure or occlusion element.

25. The internal combustion engine of claim 23, wherein the plurality of spaced pockets are of similar size and shape.

26. The internal combustion engine of claim 23, wherein the plurality of spaced pockets are of different sizes and shapes.

27. The internal combustion engine of claim 23, wherein the plurality of spaced pockets are arranged in a pattern having a plurality of rows and columns of pockets.

28. The internal combustion engine of claim 23, wherein the plurality of spaced apart pockets each have a pocket mouth with a sharp edge formed at a junction of the pocket and the first structural surface or the blocking element surface.

29. The internal combustion engine of claim 23, wherein the plurality of spaced apart pockets each have a circular pocket mouth formed at a junction of the pocket and the first structural surface or the blocking element surface.

30. The internal combustion engine of claim 23, wherein the plurality of spaced apart pockets each have a rectangular pocket mouth formed at a junction of the pocket and the first structural surface or the blocking element surface.

31. A method of sealing a first structural surface against a blocking element surface between a blocking element first end and a blocking element second end, wherein the first structural surface is disposed proximate to and spaced a substantially uniform distance from the blocking element surface, the method comprising:

providing a plurality of laterally spaced apart pockets arranged in a plurality of rows to form pocket regions on the first structural surface but not extending through the first structural surface or on the occlusion element surface but not extending through the occlusion element surface or on both the first structural surface and the occlusion element surface but not extending through both the first structural surface and the occlusion element surface;

providing a working fluid at the obstruction member first end; and

moving the obstruction member surface relative to the first structural surface to create an equivalent seal due to working fluid turbulence caused by the pocket region.

Technical Field

The present invention relates generally to systems and methods for forming a seal between a blocking element, such as a reciprocating piston, and a surface adjacent to the blocking element, such as a wall of a piston cylinder.

Background

Reciprocating piston and cylinder arrangements in internal combustion engines, pumps, etc. typically require sealing between the piston and the cylinder so that a pressure differential may exist between the two ends of the piston. This pressure differential allows the piston to provide a fluid pumping action useful in many things including pumps and internal combustion engines. A sufficiently sealed piston and cylinder arrangement may be used in, for example, two-stroke, four-stroke or multi-stroke internal combustion engines, free piston engines, heat engines, turbochargers, superchargers, compressors, pumps and vacuum cleaners.

It will be understood that reference herein to a "cylinder" is not limited to a chamber having a cylindrical shape or a circular cross-section. Conversely, the term "cylinder" refers to any chamber or cavity that can receive a piston having a profile adapted to allow the piston to seal against the side wall of the cylinder, but at the same time allow the piston to slide back and forth within the cylinder in a pumping motion.

An engine cylinder may include one or more intake ports and one or more exhaust ports that collectively allow gas to flow into and out of the engine cylinder, respectively. Engine valves, such as poppet valves, may be used to selectively open and close the intake and exhaust ports. The selective timed opening and closing of the intake and exhaust valves, in conjunction with the pumping motion of the engine piston and the introduction of fuel, may provide air/fuel feedstock to the engine cylinder for combustion and remove spent feedstock exhaust from the cylinder after combustion.

For example, existing engine pistons for otto or diesel cycle operation typically have a generally cylindrical shape. More specifically, a typical otto or diesel cycle engine piston may have a generally smooth cylindrical skirt with a circular cross-section that includes a circumferential recess for receiving one or more sealing piston rings. The piston and piston ring assembly is reciprocally slidable within the cylinder between a top dead center position and a bottom dead center position. The interface of the piston ring with the cylinder wall may be lubricated using, for example, engine oil.

Internal combustion engines almost universally require a liquid lubricant, such as engine oil, to lubricate the interface between the piston and the cylinder in which the piston moves back and forth in a reciprocating manner. Lubrication systems are often a critical task, and failure of a lubrication system can be catastrophic. The need for piston lubricants brings with it a number of disadvantages. The lubricant wears and becomes contaminated over time and therefore needs to be replaced, thereby increasing costs and causing inconvenience to the operation of the engine. Many lubricants require pumps and passages to reapply the lubricant to moving parts such as the engine pistons. The pumps and channels and other components of the active lubrication system need to function properly and seals need to be made between the interconnected components. As the seals deteriorate over time, lubrication system leaks occur naturally, and the pump leaks and wears, further increasing maintenance costs and inconvenience engine operation. Leakage can also allow lubricant to enter the combustion chamber, thereby interfering with combustion and fouling the fuel injector and spark or glow plug. The lubricant in the combustion chamber can also lead to harmful exhaust emissions. Leakage can also result in contamination of the lubricant with combustion byproducts. All of the above problems are associated with the use of lubricated pistons and all add to the failure mode and maintenance costs. Thus, there is a need for an internal combustion engine that relies less or not at all on piston lubrication.

Although embodiments of the present invention are not limited to use in internal combustion engines, such engines may benefit from the present invention because they routinely use a piston and cylinder arrangement in which the piston is sealed against the cylinder using one or more vertically spaced sealing piston rings disposed about the outer surface of the piston skirt. Many other devices besides internal combustion engines and pumps may include moving elements between which a seal needs to be formed. Embodiments of the present invention may be used for these applications as well.

Disclosure of Invention

It is therefore an object of some, but not all embodiments of the invention to provide a non-contact or semi-non-contact sealing system and method between a blocking element and an adjacent surface.

It is therefore an object of some, but not all embodiments of the invention to provide a non-contacting or semi-non-contacting sealing system and method between a piston (with or without piston rings) and a surrounding cylinder.

It is also an object of some, but not all embodiments of the invention to provide sealing systems and methods that reduce frictional losses due to contact between piston rings and surrounding cylinders by reducing or eliminating the use of piston rings.

It is also an object of some, but not necessarily all, embodiments of the invention to provide a sealing system and method that does not require the use of lubricant or requires less replacement of lubricant.

It is also an object of some, but not all embodiments of the invention to provide a low-wear sealing system and sealing method that produces less wear on components within the system, thereby reducing maintenance requirements and increasing reliability of the system.

It is also an object of some, but not all embodiments of the invention to reduce the number of parts required for sealing to reduce the cost of the system and the replacement parts inventory requirements.

It is also an object of some, but not all embodiments of the invention to provide improved heat transfer between the piston and the cylinder surface, thereby reducing the complexity of the cooling system and increasing the efficiency of the system.

It is also an object of some, but not all, embodiments of the present invention to provide a restorative, self-correcting centering action of a moving member, such as a reciprocating piston, within a cylinder.

These and other advantages of some, but not all embodiments of the invention will be apparent to those of ordinary skill in the art of internal combustion engines.

In response to the foregoing challenges, applicants have developed an innovative sealing system comprising: a first structured surface; an occlusion element having a first end, a second end, and an occlusion element surface extending between the first end and the second end; a plurality of laterally spaced apart pockets arranged in a plurality of rows to form pocket regions on the first structural surface but not extending through the first structural surface or on the occlusion element surface but not extending through the occlusion element surface or on both the first structural surface and the occlusion element surface but not extending through the first structural surface and the occlusion element surface; and a working fluid provided at the obstruction element first end at an elevated pressure relative to a working fluid pressure at the obstruction element second end, wherein the first structural surface is disposed proximate to and spaced a substantially uniform distance from the obstruction element surface; and wherein the equivalent seal is created by the interaction of the working fluid with the pocket region.

The applicant has further developed an innovative sealing system comprising: a first structured surface; and an occlusion element having a first end, a second end, and an occlusion element surface extending between the first end and the second end; and a plurality of spaced apart pockets provided as pocket regions on the first structural surface but not extending through the first structural surface or the occlusion element surface but not extending through the occlusion element surface or both the first structural surface and the occlusion element surface but not extending through both the first structural surface and the occlusion element surface, wherein the first structural surface is disposed in proximity to the occlusion element surface and spaced apart from the occlusion element surface by a substantially uniform distance.

The applicant has further developed an innovative internal combustion engine comprising: an engine cylinder having a cylinder wall; a piston disposed in an engine cylinder, the piston having a skirt and a head; and a plurality of spaced apart pockets arranged as pocket regions on the piston skirt but not extending through the piston skirt or the engine cylinder but not extending through the engine cylinder or both the piston skirt and the engine cylinder but not extending through both the piston skirt and the engine cylinder.

Applicants have further developed an innovative method of sealing a first structural surface against a blocking element surface between a blocking element first end and a blocking element second end, wherein the first structural surface is disposed proximate to and spaced a substantially uniform distance from the blocking element surface, the method comprising: providing a plurality of laterally spaced apart pockets arranged in a plurality of rows to form pocket regions on the first structural surface but not extending through the first structural surface or on the occlusion element surface but not extending through the occlusion element surface or on both the first structural surface and the occlusion element surface but not extending through both the first structural surface and the occlusion element surface; providing a working fluid at the obstruction member first end; the obstruction member surface is moved relative to the first structural surface to create an equivalent seal due to working fluid turbulence caused by the pocket region.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Drawings

To assist in understanding the invention, reference will now be made to the drawings, in which like reference numerals refer to like elements. The drawings are exemplary only, and should not be construed as limiting the invention.

FIG. 1 is a partial cross-sectional end view of an internal combustion engine cylinder and a side view of a piston disposed therein, wherein the piston is attached to a non-guided connecting rod and includes an external seal structure formed in accordance with a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional end view of an internal combustion engine cylinder and a side view of a piston disposed therein, wherein the piston is attached to a guide connecting rod and includes an external seal structure formed in accordance with a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of the piston and cylinder of FIG. 1 taken through cut line 3-3, wherein the piston includes an outer seal structure formed in accordance with a first embodiment of the present invention.

Fig. 4 is an isometric enlargement of a portion of the piston wall defined by cut line 4-4 in fig. 2, wherein the piston wall portion includes an external seal formed in accordance with the first and second embodiments of the present invention.

Figure 5 is an isometric view of a rectangular variation of a piston formed in accordance with a third embodiment of the present invention.

Figure 6 is an isometric view of a rectangular variation of a piston formed in accordance with a fourth embodiment of the present invention.

FIG. 7 is a top view of a rotary engine cylinder and rotor including an outer seal structure formed in accordance with a fifth embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Referring to FIG. 1, in a first embodiment of the invention, a cooperatively formed piston 36 and surrounding cylinder 38 are shown. The cylinder 38 may have a combustion chamber 21, the combustion chamber 21 having an upper end wall, which in this embodiment is somewhat rounded or arched, and a continuous side wall. One or more spark plugs, glow plugs, intake and exhaust valves, and associated ports may communicate with the combustion chamber 21. The engine crankcase may be disposed below the engine cylinder 38.

The piston 36 may include an upper end 50 or head, a lower end 51 remote from the upper end, and a sidewall or skirt 35 extending between the piston head and the lower end of the piston. Piston 36 may be attached to a non-guided connector rod 42, which non-guided connector rod 42 may in turn be connected to a crank 46, which crank 46 is connected to a crankshaft 44 in a crankcase.

The piston skirt 35 may have a circular cross-section when the piston head 50 is viewed from above looking down on the cylinder 38. The piston head 50 may be domed in a manner to mate with the upper end wall of the combustion chamber 21. The cylinder 38 may also have a circular shape when viewed from above. It is understood that in alternative embodiments, the cylinder 38, piston skirt 35, and piston head 50 may have a non-circular cross-sectional shape, such as a rectangle, when viewed from above.

The piston 36 may be disposed within the combustion chamber 21 of the cylinder 38 such that the piston skirt 35 is closely aligned with the side wall of the combustion chamber 21, but is evenly spaced from and parallel to the side wall of the combustion chamber 21. The upper and side walls of combustion chamber 21, along with piston head 50, may form a working space or compression zone 24 that may receive a working fluid. Piston 36 may be configured to reciprocally slide within combustion chamber 21 toward and away from the upper end wall.

Referring to fig. 1 and 3, the outer surface or face of the piston skirt 35 may have a plurality of recesses or pockets 22, the plurality of recesses or pockets 22 being separated by lands 23 formed therein and collectively forming a pocket area 25. Applicant regards the pockets 22 formed "on" the piston skirt 35 as meaning the same as those formed "in" the piston skirt 35. In both cases, the pocket 22 extends inwardly from the outermost surface of the piston skirt 35 surrounding the pocket. Preferably, but not necessarily, the pockets 22 may have similar shapes and sizes in terms of shape at the mouth, shape at the bottom, height, width, diameter, depth, and/or volume. Preferably, the piston skirt 35 is a hollow wall structure (i.e., not solid between opposing exterior points), and the pockets 22 are formed in the piston skirt, but do not extend through the piston skirt to the hollow interior of the piston 36. The pockets 22 in the region 25 may be arranged in at least one circumferential row or, more preferably, in a grid or array pattern of two or more spaced columns and rows of pockets. The number, shape, size and arrangement of the lands and pockets in region 25 shown in the drawings are chosen for ease of discussion and illustration and are not to be considered limiting.

The region 25 of the pocket 22 may extend in two dimensions (x and y) on a plane, or in two dimensions on the surface of a spatially curved object, such as a piston 35 having a circular cross-section. Each pocket 22 may be aligned with a pocket in an adjacent row and/or column, aligned with a pocket arranged in a row and/or column, thereby separating one or more intermediate rows and/or columns, or not aligned with each other. Preferably, the area 25 of the pockets 22 includes two or more pockets spaced apart from each other in the x-direction and two or more pockets spaced apart from each other in the y-direction. Further, it is preferred that the size or dimension of each pocket 22 at the mouth is significantly smaller than the size of the surface on which it is disposed (i.e., the size of the region 25) when measured in the x-direction or y-direction. More preferably, the dimension or size of each pocket 22 at the mouth is significantly smaller than the dimension of the surface on which it is disposed, as measured in the x-and y-directions. By "significantly less than" is meant that the dimension or size of each recess at the mouth is less than half, more preferably less than a quarter, of the dimension of the surface on which it is disposed, as measured in the x and/or x direction. Furthermore, the total surface area in the region 25 occupied by the lands 23 (e.g., the surface area of the piston skirt 35) preferably exceeds the total surface area attributable to the mouth of the pockets 22 in that region.

With reference to fig. 3, the arrangement of the pockets 22 and lands 23 in the appropriate sealing system area 25 on the face of the piston skirt 35 results in a seal or equivalent seal across a wide area of the piston skirt 35 from top to bottom. The seal or its equivalent may be created by a pressure differential of the working fluid between the piston head 50 and the piston lower end 51. As the piston 36 moves upward in the chamber 21, the pressure and temperature of the working fluid 26 in the working space 24 may rise and create a working fluid pressure differential between the head 50 and the lower piston end 51 of the piston 36. This pressure differential may cause the working fluid to flow in the space between the side wall of the piston skirt 35 and the side wall of the combustion chamber 21, i.e., in the seal gap, toward the lower end 51 of the piston 36. The flow of working fluid 26 through the seal gap may induce a local venturi effect at each pocket 22, which may increase the velocity of the working fluid 26 and decrease the pressure of the working fluid 26. The velocity and pressure variations of the working fluid 26 may depend on the actual small clearance distance between the side walls of the piston skirt 35 and the combustion chamber 21 and on the geometry and arrangement of the pockets 22.

With continued reference to fig. 3, the pocket 22 may preferably have a relatively sharp edge at the interface of the pocket mouth with the face of the piston skirt 35, i.e., at the interface with the platform 23. As the working fluid 26 flows past the sharp edges of the pockets 22, a reduction in local pressure is caused by turbulence. As a result, the working fluid 26 may expand, causing a temporary decrease in pressure and an increase in local turbulence. In addition, working fluid 26 flowing through and into each successive pocket 22 may begin a cycle, wherein each pocket 22 functions as a resonator (e.g., a helmholtz resonator), which causes working fluid to be drawn into the pocket 22 or expelled from the pocket 22 at a definable frequency, thereby creating further local turbulence.

The turbulence generated may depend on the physical properties of the working fluid 26 in the system as well as the diameter (or height and width), internal geometry, associated location and depth of each individual pocket 22 in the region 25. The turbulence generated may also depend on the actual small gap distance or sealing gap due to the ratio of the volume of space above each platform 23 to the volume of space above and inside each pocket 22. This local turbulence may interact with the flowing working fluid 26 and create a swirling motion that impedes further flow of the working fluid 26. The reduction in working fluid flow may temporarily reduce the resonance effect, which in turn may temporarily attenuate the local turbulence, thereby subsequently allowing the flow velocity of the working fluid 26 to temporarily increase again.

When the piston 36 is on the upward stroke, working fluid 26 that has passed over the uppermost row of pockets 22 (closest to the upper end of the piston 36) may next encounter pockets in an adjacent row of pocket regions 25 where the turbulence phenomenon repeats, but at a lower starting pressure. As the working fluid 26 flows through successive rows of the sealing system pocket region 25 with successive relatively reduced starting pressures, the process may repeat until the local pressure in the seal gap is sufficiently reduced (preferably, but not necessarily, to the pressure level of the working fluid contained in the cylinder 38 below the piston 36). The repeated cycling of the pressure drop from pocket 22 to pocket in region 25 may produce a seal or an effective equivalent seal because only a tolerable amount (or preferably none) of working fluid 26 will flow through a location where the local pressure in the seal gap is at or below the pressure of the working fluid in the space below piston 36. It is understood that when the amount of leakage of the working fluid allows the engine in which the equivalent seal is used to operate, this results in an "equivalent seal" having a tolerable level of leakage caused by a sufficient reduction in pressure across the face of the piston skirt 35.

The local turbulence at each successive pocket 22 may decrease over time due to the gradual leakage allowed by the resonant action of the pocket. Thus, the local turbulence may also depend on the rate of movement of the piston 36 relative to the side wall of the chamber 21, as this movement may be the cause of pressure variations around the piston 36 in the chamber. The effectiveness of the sealing system may require a fluctuating pressure of the working fluid 26 to maintain the effectiveness of the sealing system by providing a constant flow into and out of the pocket 22 to provide energy into the sealing system area 25.

The rate of seal system leakage may be modified by using different spacing patterns of lands 23 and pocket 22 geometries within the seal system pattern 25. The spacing of the lands 23 may be selected to cause the pockets 22 to provide reverse flow to the previous (upper) pocket, while the forward (lower) pocket may impede the flow of working fluid 26 to cause internally damped self-amplifying oscillations within the sealing system area 25.

In addition to the design parameters of each pocket 22, the effectiveness of the sealing system pattern 25 for a particular application may also depend on the outer dimensions of the sealing system area 25. Referring back to fig. 3, sealing efficiency may be improved by modifying the geometry of some or all of the pockets 22 to include a converging region 39 at the inner base of the pocket and a diverging region at the mouth of the pocket. The use of a converging region 39 and a larger diverging region to form a resonant cavity at the bottom of the pocket may create a de laval nozzle effect at the pocket, which may result in greater local turbulence due to the local supersonic working fluid 26 motion.

Referring to fig. 1 and 3, the piston 36 may self-center within the cylinder 38 as the pressure surrounding the piston tends to normalize at any given vertical point on the piston skirt 35. For example, when the actual small clearance distance (i.e., the seal clearance) between the piston 36 and the cylinder 38 is temporally unequal about the central axis, the total normalizing force may be generated by the pressure acting on the surface areas on opposite sides of the piston. This total normalized force may cause the piston 36 to be centrally positioned within the cylinder 38 with damped vibration about the central axis. The time required for the normalized force to return the piston to the center of the cylinder can be shortened by adding one or more equalization grooves 40. The equalization grooves 40 may be arranged on the area of the platform 23, or between the pockets 22, or both on the platform area and between the pockets, or in the side wall of the chamber 21 opposite the pockets, to allow a more even and rapid distribution of the forces on the surface using the sealing system.

An alternative embodiment of the invention is shown in fig. 2 and 4. Referring to fig. 2, the piston 36 is disposed in the cylinder 38 and includes a piston skirt 35 having a region 25 of pockets 22 and a piston head 46. The area 25 of the recess 22 is not provided with any equalization grooves. The piston 36 is connected to a crankshaft 44 by a crank 46, a connecting rod 42, and a crosshead 34. Crosshead 34 is slidably received in crosshead guide 33, which crosshead guide 33 allows crosshead 34 and piston 36 to move in a vertical direction while keeping piston 36 in a centered position with respect to combustion chamber 21. Fig. 4 shows in detail the portion 4-4 of the pocket area 25, wherein the pocket 22 and the platform 23 have relatively sharp engaging edges at the pocket mouth.

In an alternative embodiment of the present invention, the piston skirt 35 may not have an outer peripheral circular shape, but may be formed in any shape such as an oval shape, a rectangular shape, or the like, as long as any corners of the shape are rounded. For example, a third and fourth embodiment of the invention is shown in fig. 5 and 6, wherein the piston does not have a circular cross-section. Fig. 5 shows a rectangular piston 37 similar to the circular piston embodiment of fig. 1, the piston 37 including a pocket area 25 and an equalization groove 40 disposed on a piston skirt 50 between the piston head 50 and a piston lower end 51. The equalization channel 40 may extend around the circumference of the piston skirt 35 to form a continuous closed-loop structure that allows the pressure of the working fluid around the piston skirt to balance or equalize itself to be the same at all points. Fig. 6 shows a rectangular piston 37 similar to the circular piston embodiment of fig. 2, the piston 37 including a pocket area 25, but not including an equalization groove, the pocket area 25 being disposed on the piston skirt between the piston head 50 and the piston lower end 51.

A fifth embodiment of the invention is shown in fig. 7, which shows a partial cross-sectional view of a rotary engine housing and internal rotary engine components. The rotary engine housing may house the first rotatable vane 64, the second rotatable vane 74, the third rotatable vane 84, and the fourth rotatable vane 92, and the U-shaped supercharger boss 100, interconnected (e.g., hinged) together. Each of the vanes 64, 74, 84, 92 and the boss 100 may have regions 25 of pockets 22 separated by platforms 23 formed on an outer surface that rotates about a central axis relative to a flat sidewall (removed) of the rotating engine casing. The vanes 64, 74, 84, 92 and the boss 100 may be spaced from and parallel to the flat side wall of the rotary engine case such that an equivalent seal is provided between the inside of each vane which together defines the combustion chamber 21 and the outside of each vane which is remote from the inside as the vanes and boss rotate.

It is understood that the pistons, vanes, and other structures configured to form an equivalent seal with a surface such as a chamber wall (collectively "blocking elements") can be used not only in generators, but also in pumps and other devices in which a seal or equivalent seal is desired.

It is also understood that in alternative embodiments, the region 25 and/or equalization groove 40 described as a pocket 22 formed on or in a surface of the obstruction member may instead be formed on or in a surface opposite the obstruction member. It is also understood that in addition to being formed on or in a surface of the blocking element, the region 25 described as a pocket 22 formed on or in a surface of the blocking element may also be formed on or in a surface opposite the blocking element.

It is also understood that the foregoing structure may be used to provide a sealed system for fluids including, but not limited to, compressible fluids, gases, liquids, suspensions, plasma, and bose-einstein condensate.

It is also understood that the pocket 22 may have any shape at the mouth, at the bottom, and along the inner wall of the pocket extending between the mouth and the bottom, which is effective to produce the desired pressure reduction effect. For example, such shapes may be circular, annular, rectangular, square, trapezoidal, parallelogram, rhomboid, oval, elliptical, triangular, and polygonal. The cross-section of the equalization channel 40 may also have any of the aforementioned or other shapes, so long as they produce the desired pressure equalization effect. It is also understood that the pocket 22 may have a flat, rounded or contoured bottom away from the pocket mouth. The bottom of the flat pocket 22 may extend in a plane parallel to the plane in which the platform 23 surrounding the pocket extends. Alternatively, such a flat pocket bottom may be inclined and extend in a plane which is not parallel to the plane in which the surrounding platform extends.

It is also understood that in some embodiments, the pockets 22 may have beveled, chamfered or other broken/unsharpened edges at the junction of the pocket mouth and the surrounding platform.

As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The above-described elements are provided as illustrative examples of one technique for implementing the present invention. Those skilled in the art will recognize that many other embodiments are possible without departing from the invention as described in the claims. For example, the pockets and/or pattern of pockets need not be uniform and/or the lands need not be flat without departing from the intended scope of the invention. Furthermore, the pattern of pockets may be provided in the cylinder wall instead of and/or in addition to on the piston skirt. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention. It is intended that the present invention cover all such modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.