阅读说明：本技术 一种重油柱塞偶件 (Heavy oil plunger and barrel assembly ) 是由 侯旭洪 涂天华 刘惠娥 徐辉 栗东民 张朝磊 田梦江 于 2019-11-08 设计创作，主要内容包括：本方案涉及一种重油柱塞偶件,包括：柱塞套组件,其包括柱塞套,柱塞套上设置有向油道；柱塞组件,包括柱塞以及缝隙滤芯,缝隙滤芯和柱塞之间形成过滤缝隙；密封组件,包括密封块,密封块与柱塞之间形成有回油收集腔；柱塞套上还设置有轴向油道；高压重油经由柱塞和缝隙滤芯间进入,再经由过滤缝隙进行杂质过滤,经过杂质过滤后的高压重油流出至柱塞的外表面；流出至柱塞的外表面的高压重油一部分通过径向油道流出至燃油汇集区；另一部分流出至回油收集腔,流出至回油收集腔的高压重油通过轴向油道流出至燃油汇集区。上述方案可以改善柱塞偶件的受热状态,使柱塞套整体受热均衡；采用重油对柱塞表面进行润滑,减少润滑油的使用,节约能源。(This scheme relates to a heavy oil plunger matching parts, includes: the plunger sleeve assembly comprises a plunger sleeve, and an oil duct is arranged on the plunger sleeve; the plunger assembly comprises a plunger and a gap filter element, and a filtering gap is formed between the gap filter element and the plunger; the sealing assembly comprises a sealing block, and an oil return collecting cavity is formed between the sealing block and the plunger; the plunger sleeve is also provided with an axial oil duct; high-pressure heavy oil enters the plunger piston and the gap filter element, impurities are filtered through the filtering gap, and the high-pressure heavy oil after impurity filtering flows out to the outer surface of the plunger piston; part of the high-pressure heavy oil flowing out of the outer surface of the plunger flows out of the fuel oil gathering area through the radial oil duct; and the other part of the high-pressure heavy oil flows out of the oil return collection cavity, and the high-pressure heavy oil flowing out of the oil return collection cavity flows out of the fuel oil collection area through the axial oil duct. The scheme can improve the heating state of the plunger matching part, so that the plunger sleeve is heated uniformly; the surface of the plunger is lubricated by heavy oil, so that the use of lubricating oil is reduced, and energy is saved.)

1. A heavy oil plunger and barrel assembly, comprising:

the plunger sleeve assembly comprises a plunger sleeve (11), and a radial oil duct (112) communicated to a fuel oil collecting area (111) on the periphery of the plunger sleeve (11) is arranged on the plunger sleeve (11);

a plunger assembly comprising a plunger (21) inserted into the plunger sleeve (11) and partially passing through the plunger sleeve (11), and a slit filter element (22) installed in the plunger (21), a filter slit (213) being formed between the slit filter element (22) and the plunger (21);

the sealing assembly comprises a sealing block (31) which is sleeved on the part of the plunger (21) penetrating through the plunger sleeve (11) and is fixedly connected with the plunger sleeve (11), and an oil return collection cavity (32) is formed between the sealing block (31) and the plunger (21);

a plurality of axial oil ducts (113) which are uniformly distributed are further arranged on the plunger sleeve (11), one ends of the axial oil ducts (113) are respectively communicated with the fuel oil collecting area (111), and the other ends of the axial oil ducts are communicated with the return oil collecting cavity (32);

three ring grooves (2151, 2152) are formed in the outer surface of the plunger (21), and the three ring grooves (2151, 2152) are communicated to the inner wall of the plunger (21) through radial through holes formed in the plunger (21);

high-pressure heavy oil in a high-pressure oil chamber (115) above the plunger (21) enters through a space between the plunger (21) and the gap filter element (22), impurities are filtered through the filtering gap (213), and the high-pressure heavy oil after impurity filtering flows out to the outer surface of the plunger (21) through the radial through hole;

when the plunger (21) moves to enable a first ring groove (2151) positioned at the middle position in the three ring grooves (2151, 2152) to be communicated with a corresponding radial oil channel (114) on the plunger sleeve (11), a small part of high-pressure heavy oil flowing out of the outer surface of the plunger (21) flows out to the fuel oil collecting area (111) through the radial oil channel (112); most of the oil flows out to the return oil collecting cavity (32) through the radial oil passage (114) and then flows out to the fuel oil collecting area (111) through the axial oil passage (113);

when the plunger (21) moves to ensure that a first ring groove (2151) positioned at the middle position in the three ring grooves (2151 and 2152) is not communicated with a corresponding radial oil passage (114) on the plunger sleeve (11), most of high-pressure heavy oil flowing out of the outer surface of the plunger (21) flows out to the fuel oil collecting area (111) through the radial oil passage (112); and a small part of the oil flows out to the return oil collecting cavity (32) through the radial oil passage (114) and then flows out to the fuel oil collecting area (111) through the axial oil passage (113).

2. The heavy oil plunger and coupling member of claim 1,

an axial blind hole is formed in the upper end face of the plunger (21) along the axial direction, and the slit filter element (22) is inserted into and fixed in the axial blind hole from the upper end face part of the plunger (21);

an oil inlet channel (212) and an oil outlet channel (214) are formed between the plunger (21) and the gap filter element (22), and the filtering gap (213) is positioned between the oil inlet channel (212) and the oil outlet channel (214);

the three ring grooves (2151, 2152) are communicated to the oil outlet channel (214) through the radial through holes respectively;

high-pressure heavy oil in a high-pressure oil chamber (115) above the plunger (21) enters through the oil inlet channel (212) formed between the plunger (21) and the gap filter element (22), impurities are filtered through the filtering gap (213), and the high-pressure heavy oil filtered by the impurities flows out to the outer surface of the plunger (21) through the oil outlet channel (214) and the radial through hole (216).

3. The heavy oil plunger and barrel assembly of claim 2 wherein said plunger assembly further comprises:

and one end of the positioning pin (23) is inserted into the outer circumferential surface of one side of the plunger (21) and penetrates through the rear part of the slit filter element (22) to be exposed out of the outer circumferential surface of the other side of the plunger (21).

4. The heavy oil plunger and coupling member of claim 3,

the three ring grooves are respectively as follows: two first ring grooves (2151) positioned at the upper part of the plunger (21) and one second ring groove (2152) positioned at the lower part of the plunger (21);

the radial through-hole includes: two second radial through holes (2161) positioned at the upper part of the plunger (21) and a third radial through hole (2162) positioned at the lower part of the plunger (21), wherein the two first ring grooves (2151) are communicated with the two second radial through holes (2161) in a one-to-one correspondence manner, and the second ring grooves (2152) are communicated with the third radial through hole (2162);

the lower part of the slit filter element (22) is provided with a first radial through hole (216) communicated with the two oil outlet channels (214);

the first and the two third radial through holes (2162) are oppositely arranged;

one end of the positioning pin (23) is inserted into one of the third radial through holes (2162) from the outer surface of the plunger (21) and passes through the first radial through hole (216) and the rear part of the other third radial through hole (2162) to be exposed out of the second annular groove (2152).

5. The heavy oil plunger and coupling assembly of claim 4, wherein the third radial through hole (2162) disposed opposite the first radial through hole (216) has a larger bore diameter than the axial blind hole disposed in the plunger (21).

6. The heavy oil plunger and barrel assembly of claim 4 wherein said plunger sleeve assembly further comprises:

an oil return passage (114) communicated to the second ring groove (2152), the oil return passage (114) being communicated to the oil return collection cavity (32);

a throttling screw plug (12) which is arranged at the corner of the oil return channel (114) and is used for adjusting the flow of high-pressure heavy oil passing through the oil return channel (114);

wherein, a part of the high-pressure heavy oil flowing out of the outer surface of the plunger (21) flows into the return oil collecting cavity (32) through the return oil channel (114), and the other part of the high-pressure heavy oil flows into the radial oil passage (112) through a gap between the plunger (21) and the plunger sleeve (11) and further flows into the fuel oil collecting area (111);

the plug head of the throttling screw plug (12) is arranged to be a spherical surface or a conical surface.

7. The heavy oil plunger and coupling assembly of claim 1 wherein said seal assembly further comprises:

a seal ring (33) mounted between the seal block (31) and the plunger (21); and

a sealing gasket (34) mounted between the sealing block (31) and the plunger sleeve (11);

the sealing block (31), the sealing gasket (34) and the plunger sleeve (11) are connected through screws.

8. The heavy oil plunger and coupling member of claim 2, wherein the oil pressure of the high pressure heavy oil is between 120Mpa and 160 Mpa.

9. The heavy oil plunger and barrel assembly of any one of claims 1 to 8, wherein said heavy oil plunger and barrel assembly is applied to a marine low speed electromechanical control high pressure oil pump.

Technical Field

The invention relates to the field of high-pressure common rails of marine low-speed machines, in particular to a heavy oil plunger and barrel assembly.

Background

The fuel system is the heart of a marine engine, the high-pressure oil pump is a power source of the fuel system, the plunger and barrel assembly is an actuating mechanism of the high-pressure oil pump and is also the most precise mechanism in the high-pressure oil pump, and the service life of the plunger and barrel assembly often determines the service life of the whole pump. The low-speed machine for the ship often adopts heavy oil as a working medium, the viscosity of the heavy oil is up to 750Cst, the heavy oil needs to be heated to more than 150 ℃ during working, and meanwhile, the heavy oil contains a large amount of impurities. In the work, the plunger matching part is directly contacted with heavy oil, and the characteristics of high temperature, high viscosity, high impurity content and the like of the heavy oil can cause the following problems to the plunger matching part:

(1) in the traditional plunger and barrel assembly, a plunger cavity for compressing fuel oil is in more contact with flowing fuel oil, the temperature of the area nearby the plunger cavity is higher, the temperature of the part far away from the plunger cavity is lower, and the temperature difference of different positions is larger, so that the thermal deformation of the plunger and barrel assembly is irregular, the gap change of the plunger and barrel assembly is irregular, and the dynamic characteristic and the sealing are further influenced;

(2) the pressure of the plunger cavity is as high as 1500 bar, the impurity content of heavy oil is high, and the surface friction failure or excessive abrasion and even seizure of the plunger are easily caused.

Disclosure of Invention

The invention aims to provide a heavy oil plunger and barrel assembly to improve the heating state of the plunger and barrel assembly and ensure that the whole plunger sleeve is heated uniformly; and the surface of the plunger is lubricated by adopting heavy oil, so that the use of lubricating oil is reduced, and the effect of saving energy is achieved.

The technical scheme of the invention is as follows:

the invention provides a heavy oil plunger and barrel assembly, comprising:

the plunger sleeve assembly comprises a plunger sleeve, and a radial oil duct communicated to a fuel oil gathering area on the periphery of the plunger sleeve is arranged on the plunger sleeve;

a plunger assembly including a plunger inserted into and partially passing through a plunger sleeve and a slit filter element installed in the plunger, a filter slit being formed between the slit filter element and the plunger;

the sealing assembly comprises a sealing block which is sleeved on the part of the plunger penetrating through the plunger sleeve and is fixedly connected with the plunger sleeve, and an oil return collecting cavity is formed between the sealing block and the plunger;

the plunger sleeve is also provided with an axial oil duct communicated to the fuel oil collecting area, the plunger sleeve is provided with a plurality of axial oil ducts which are uniformly distributed, one end of each axial oil duct is communicated with the fuel oil collecting area, and the other end of each axial oil duct is communicated to the return oil collecting cavity;

three ring grooves are formed in the outer surface of the plunger and are communicated to the inner wall of the plunger through radial through holes formed in the plunger respectively;

high-pressure heavy oil in a high-pressure oil cavity above the plunger enters through the space between the plunger and the gap filter element, impurity filtration is carried out through the filtration gap, and the high-pressure heavy oil after impurity filtration flows out to the outer surface of the plunger through the radial through hole;

when the plunger moves to enable the three ring grooves, wherein a first ring groove positioned in the middle is communicated with a corresponding radial oil duct on the plunger sleeve, a small part of high-pressure heavy oil flowing out of the outer surface of the plunger flows out of the fuel oil collecting area through the radial oil duct; most of the oil flows out to the return oil collecting cavity through the radial oil duct and then flows out to the fuel oil collecting area through the axial oil duct;

when the plunger moves to enable the three ring grooves, and a first ring groove positioned in the middle is not communicated with a corresponding radial oil passage on the plunger sleeve, most of high-pressure heavy oil flowing out of the outer surface of the plunger flows out of the fuel oil gathering area through the radial oil passage; and a small part flows out to the return oil collecting cavity through the radial oil duct and then flows out to the fuel oil collecting area through the axial oil duct.

Preferably, the upper end surface of the plunger is axially provided with an axial blind hole, and the slit filter element is partially inserted into and fixed in the axial blind hole from the upper end surface of the plunger;

an oil inlet channel and an oil outlet channel are also formed between the plunger and the gap filter element, and the filtering gap is positioned between the oil inlet channel and the oil outlet channel;

the three ring grooves are communicated to the oil outlet channel through the radial through holes respectively;

and high-pressure heavy oil in a high-pressure oil cavity above the plunger enters through the oil inlet channel formed between the plunger and the gap filter element, then is subjected to impurity filtration through the filtration gap, and flows out to the outer surface of the plunger through the oil outlet channel and the radial through hole. Preferably, the plunger assembly further comprises:

and one end of the positioning pin is inserted into the outer circumferential surface of one side of the plunger, penetrates through the rear part of the slit filter core and is exposed out of the outer circumferential surface of the other side of the plunger.

Preferably, the first and second electrodes are formed of a metal,

the three ring grooves are respectively as follows: two first ring grooves positioned on the upper part of the plunger and one second ring groove positioned on the lower part of the plunger;

the radial through-hole includes: the plunger is provided with two second radial through holes positioned at the upper part of the plunger and one third radial through hole positioned at the lower part of the plunger, the two first ring grooves are communicated with the two second radial through holes in a one-to-one correspondence manner, and the second ring grooves are communicated with the third radial through holes;

the lower part of the gap filter element is provided with a first radial through hole which is communicated with the two oil outlet channels;

the first radial through hole and the two third radial through holes are oppositely arranged;

one end of the positioning pin is inserted into one of the third radial through holes from the outer surface of the plunger and passes through the first radial through hole and the rear part of the other third radial through hole to be exposed out of the second annular groove.

Preferably, the diameter of the third radial through hole arranged opposite to the first radial through hole is larger than that of the axial blind hole arranged in the plunger.

Preferably, the plunger sleeve assembly further comprises:

the oil return channel is communicated to the second annular groove and communicated to the oil return collecting cavity;

the throttling screw plug is arranged at the corner of the oil return channel and used for adjusting the flow of high-pressure heavy oil passing through the oil return channel;

one part of the high-pressure heavy oil flowing out of the outer surface of the plunger flows into the return oil collecting cavity through the return oil channel, and the other part of the high-pressure heavy oil flows into the radial oil channel through a gap between the plunger and the plunger sleeve and further flows into the fuel oil collecting area;

the plug head of the throttling plug screw is arranged to be a spherical surface or a conical surface.

Preferably, the seal assembly further comprises:

a seal ring mounted between the seal block and the plunger; and

the sealing gasket is arranged between the sealing block and the plunger sleeve;

the sealing block, the sealing gasket and the plunger sleeve are connected through screws.

Preferably, the oil pressure of the high-pressure heavy oil is between 120Mpa and 160 Mpa.

Preferably, the heavy oil plunger and barrel assembly is applied to a marine low-speed electromechanical control high-pressure oil pump.

The invention has the beneficial effects that:

(1) the plunger is internally provided with a slit filter element, the slit filter element and an axial blind hole in the plunger form a slit filter, the heavy oil with higher impurity content is filtered by utilizing the ultrahigh pressure (usually 150 Mpa) of the high-pressure heavy oil in a high-pressure oil cavity above the plunger, cleaner oil is formed and is supplied to the middle part and the lower surface of the plunger for lubrication, the use of lubricating oil is cancelled, and the effect of saving energy can be achieved. The fluid resistance formed by the lubricating oil with higher cleanliness on the outer surface of the plunger also reduces the oil quantity entering the outer surface of the plunger from the upper end of the plunger, and further reduces the probability of impurities entering the outer surface of the plunger from the upper end of the plunger.

(2) When the plunger moves to the bottom dead center, a certain amount of filtered high-temperature fuel oil flows through the whole plunger sleeve almost from the middle part of the plunger sleeve to the lower return oil collecting region and then to the fuel oil collecting region in the middle part of the plunger sleeve, so that the whole plunger sleeve is heated, the temperature distribution of the plunger is balanced, the non-uniform deformation caused by the uneven temperature distribution of the upper part and the lower part of the plunger sleeve is weakened, and the difficulty in plunger sleeve design and processing is reduced; and meanwhile, the plunger oil duct is cleaned once by the fuel oil in the cavity by each recycling pump, so that the heavy oil is prevented from being deposited and bonded in the oil return hole to cause blockage.

(3) According to the related calculation of fluid mechanics, when the hydraulic pressure between two axial points on the surface of the plunger is equal or has small difference, the liquid flow is difficult to form, and then an effective lubricating oil film is difficult to form. A plurality of fluid high-low pressure convection areas are formed on the surface of the plunger by controlling the relative positions of the plunger sleeve, the ring grooves on the plunger and the radial oil passage of the plunger sleeve, so that the surface liquid flow is enhanced, and the static pressure lubricating effect of the plunger is further enhanced.

(4) The plunger sleeve is characterized in that the plunger sleeve is provided with a fuel oil collecting area arranged in the middle of the plunger sleeve, a fuel oil collecting area arranged below the plunger sleeve and oil ducts uniformly distributed between the fuel oil collecting area and the fuel oil collecting area, and the oil ducts and corresponding spaces are symmetrically designed about the center of the plunger sleeve, so that the plunger sleeve is heated more uniformly when high-temperature heavy oil flows through the oil ducts.

(5) Throttling screw plugs with cylindrical heads are arranged at the middle part of the plunger sleeve and the oil hole at the lower dead point of the plunger, so that the flow flowing to the surface of the plunger oil duct can be controlled conveniently. The head of the corresponding outlet throttling screw plug can be designed into a conical surface or a spherical surface, and when the head is designed into the conical surface, the opening degree can be controlled by controlling the screwing depth of the screw plug.

(6) A sealing block assembly is arranged below the plunger sleeve, and a large oil return collecting space can be arranged between the sealing block and the gasket. The clearance between the plunger sleeve and the plunger needs to consider various reasons such as heavy oil impurities, high temperature and the like, so the accidental clearance of the plunger cannot be designed to be too small. However, the filtered fuel oil below the plunger piston is less in impurities, and the temperature of the plunger piston is lower than that of the plunger piston ultrahigh-pressure cavity accessory, so that the sealing block allows a smaller gap to be designed for sealing, and meanwhile, an O-shaped sealing ring is arranged in the sealing block, and the sealing effect is also enhanced. The heavy oil will not leak even when the heavy oil is switched to the light diesel oil mode;

(7) the gasket between the plunger sleeve and the sealing block is made of polytetrafluoroethylene or other heat-resistant oil-resistant wear-resistant rubber or plastic and other materials with lower hardness. The sealing effect is better when the gasket of sealed pad is softer, and secondly the softwood rigidity is little, allows the contact surface microcosmic floating when sealed piece and plunger bushing are compressed tightly to make sealed piece and plunger can automatic alignment function, and then subduct the additional load that the axiality error of well and plunger arouses after the installation of sealed piece.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic structural view of the plunger assembly of the present invention;

FIG. 3 is a schematic cross-sectional view of the present invention;

FIG. 4 is a schematic structural view of the plunger assembly of the present invention;

FIG. 5 is a schematic cross-sectional view of a plunger assembly of the present invention;

description of reference numerals: 11. a plunger sleeve; 111. a fuel oil gathering area; 112. a radial oil passage; 113. an axial oil passage; 114. an oil return passage; 115. a high pressure oil chamber; 12. a throttle plug screw; 13. an O-shaped ring; 21. a plunger; 22. a slit filter element; 212. an oil inlet channel; 213. filtering the gap; 214. an oil outlet channel; 2151. a first ring groove; 2152. a second ring groove; 216. a first radial through hole; 2161. a second radial through hole; 2162. a third radial through hole; 221, a boss; 23. positioning pins; 31. a sealing block; 32. an oil return collection cavity; 33. a seal ring; 34. sealing gaskets; 35. and (4) screws.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Referring to fig. 1 to 5, the present invention provides a heavy oil plunger and barrel assembly, comprising:

the plunger sleeve assembly comprises a plunger sleeve 11, a mounting through hole for mounting the plunger assembly is arranged in the plunger sleeve 11, a radial oil duct 112 communicated to a fuel oil collecting area 111 on the periphery of the plunger sleeve 11 is arranged on the plunger sleeve 11, and the radial oil duct 112 is communicated with the mounting through hole and the fuel oil collecting area 111 arranged on the outer peripheral surface of the plunger sleeve 11. A circumferential ring groove is respectively formed in the outer surface of the plunger sleeve 11 and located at the upper position and the lower position of the fuel oil collecting area 111, an O-ring 13 is installed in the circumferential ring groove, and the O-ring 13 can prevent heavy oil in the fuel oil collecting area 111 from leaking.

A plunger assembly including a plunger 21 inserted into the plunger sleeve 11 and partially penetrating through the plunger sleeve 11, as shown in fig. 1, a high-pressure oil chamber 115 is formed between an upper end surface of the plunger 21 and an upper end surface of the plunger sleeve 11, heavy oil of the electrically controlled high-pressure oil pump flows into the high-pressure oil chamber 115 when the electrically controlled high-pressure oil pump works, and fuel oil is compressed to form high-pressure oil when the plunger 21 moves upwards from a lower dead point; the lower end of the plunger 21 passes through the mounting through hole and is partially exposed at the lower end of the plunger sleeve 11, and since the plunger 21 needs to move up and down in the plunger sleeve 11 to realize fluid delivery, a clearance is required between the plunger 21 and the plunger sleeve 11 to ensure that the plunger 21 can slide relative to the plunger sleeve 11, that is, the plunger sleeve 11 and the plunger 21 are in clearance fit.

Referring to fig. 1, the plunger assembly further includes: and a slit filter element 22 installed in the plunger 21, wherein a filter slit 213 is formed between the slit filter element 22 and the plunger 21, an axial blind hole is axially opened on the upper end surface of the plunger 21, and the slit filter element 22 is partially inserted into and fixed in the axial blind hole from the upper end surface of the plunger 21. In order to enable the plunger assembly to have a gap filtering effect, in the present embodiment, the oil inlet passage 212 and the oil outlet passage 214 are formed between the gap core 22 and the plunger 21 by machining on the gap core 22, the filter gap 213 is provided between the oil inlet passage 212 and the oil outlet passage 214, and the oil inlet passage 212 and the oil outlet passage 214 are provided independently of each other. Wherein, there are 2 respectively oil inlet channels 212 and oil outlet channels 214, 2 oil inlet channels 212 and 2 oil outlet channels 214 are respectively arranged symmetrically about the axial center line of the gap filter core 22. One end of the oil inlet channel 212 is communicated to the upper end face of the slit filter element 22, and the other end is not communicated to the lower end face of the slit filter element 22; one end of the oil outlet passage 214 communicates with the lower end surface of the slit filter element 22, and the other end does not communicate with the upper end surface of the slit filter element 22. The high-pressure heavy oil in the high-pressure oil chamber 115 enters through the oil inlet passage 212, the high-pressure heavy oil entering the oil inlet passage 212 is subjected to impurity filtration through the filtration gap 213, and the relatively clean heavy oil after impurity filtration flows out to the oil outlet passage 214. That is, a slotted filter is formed between the slotted insert 22 and the walls of the axial blind bore in the plunger 21. After the heavy oil flows out to the oil outlet passage 214, in order to lubricate the outer circumferential surface of the plunger 21, a radial through hole communicating with the outer circumferential surface of the plunger 21 and the oil outlet passage 214 needs to be provided at a position where the outer circumferential surface of the plunger 21 and the oil outlet passage 214 are opposite to each other, and the heavy oil inside the plunger 21 can be guided out to the outer circumferential surface of the plunger 21 by means of the radial through hole. For the lubrication of the outer circumferential surface of the plunger 21, the plunger 21 is lubricated by the original heavy oil in the system without using special lubricating oil, so that the effect of saving energy can be achieved.

Meanwhile, in order to enhance the lubricating effect on the outer surface of the plunger 21, in the present embodiment, the lengths of the oil inlet passage 212 and the oil outlet passage 214 should be set long enough to allow the fuel to sufficiently enter the outer surface of the plunger 21, and specifically, the lengths of the oil inlet passage 212 and the oil outlet passage 214 may be set to be greater than 1/2, etc., which is the axial length of the slit filter 22.

Preferably, in order to uniformly distribute the heavy oil flowing out through the radial through-holes 216 over the outer circumferential surface of the plunger 21, three ring grooves are formed in the outer surface of the plunger 21, each of which is connected to the oil outlet passage 214 through one or more radial through holes 216, when the plunger 21 moves upwards from the vicinity of the lower dead point, the first ring groove 2151 formed in the middle of the outer surface of the plunger is misaligned with the corresponding radial oil passage 114 on the plunger sleeve (i.e., the radial oil passage 114 is not communicated with the first ring groove 2151 located in the middle), high-pressure heavy oil in the high-pressure oil chamber 115 above the plunger 21 passes through the plunger 21 and form between the gap filter core 22 the oil inlet 212 gets into, again the via filter gap 213 and carry out impurity filtering, high-pressure heavy oil after impurity filtering passes through oil outlet 214 with radial through hole 216 flows out to in the three ring grooves that set up on the surface of plunger 21. The heavy oil flowing into the ring groove is high-pressure oil, the heavy oil in the radial oil passage 112 on the plunger sleeve 11 is low-pressure return oil, and the high-pressure oil and the low-pressure return oil form a fluid high-low pressure convection area on the outer circumferential surface of the plunger 21, so that a thicker oil film is formed, and a better lubricating effect is achieved. Thus, most of the heavy oil flowing out through the radial through-hole is retained in the ring groove, and a small portion of the heavy oil in the ring groove can flow in the gap between the plunger 21 and the plunger sleeve 11, so that the inner surface of the plunger sleeve 11 is lubricated. Here, although there is a certain gap between the plunger 21 and the plunger barrel 11, since the filtered high-pressure heavy oil is filled in the gap between the plunger 21 and the plunger barrel 11, the unfiltered high-pressure heavy oil in the high-pressure oil chamber 115 can be prevented from directly flowing in from the gap between the plunger 21 and the plunger barrel 11.

When the plunger 21 is communicated with the corresponding influence oil passage 114 on the plunger sleeve 11 from the vicinity of the lower dead point, the first annular groove 2151 arranged at the middle position of the outer surface of the plunger 21 enters through the oil inlet passage 212 formed on the slit filter element 22, impurities are filtered through the filtering slit 213 and flow to the two oil outlet passages 214, a part of the fuel in the oil outlet passage 214 flows into the two first annular grooves 2151 through the two second radial through holes 2161, the fuel in the upper first annular groove 2151 flows into the fuel collecting area 111 through the radial oil passage 112, and the fuel in the lower first radial annular groove 2151 flows into the return oil collecting cavity 32 through the return oil passage 114; meanwhile, a small portion of the fuel in the oil outlet passage 214 flows into the return-oil collection chamber 32 through the clearance between the plunger 21 and the plunger barrel 11, and the fuel in the return-oil collection chamber 32 flows into the fuel collection area 111 through the axial oil passage 113.

Specifically, the first ring groove 2151 and the second ring groove 2152 are chamfered at both side edges thereof at an angle of 1 ~ 10 °, and after the plunger 21 is mounted on the plunger sleeve 11, the chamfered arrangement allows a small-angle convergent wedge shape to be formed between the ring grooves (the first ring groove 2151 and the second ring groove 2152) and the inner wall of the plunger sleeve 11, and in operation, the outer surface of the plunger 21 and the radial oil passage 112 provided on the plunger sleeve 11 generate a convergent wedge shape in the relative movement direction of heavy oil, thereby enhancing the squeezing effect in dynamic pressure lubrication, and forming a thicker lubricating oil film on the outer surface of the plunger 21, thereby optimizing the lubricating effect on the outer surface of the plunger 21. if the chamfered arrangement is made large (for example, about 45 ° or 90 °), the lubricating effect on the outer surface of the plunger 21 may be poor, and even the scraping effect may be generated on the respective friction surfaces of the ring grooves (the first ring groove 2151 and the second ring groove 2152), thereby accelerating the seizure thereof, and, in the case, the plunger 21 in this embodiment, the chamfered arrangement is designed at a 90 ° chamfer, thereby reducing the possibility of the residual oil particles adhering to the plunger 21, which may be left on the inner surface of the plunger 21, and thus reducing the possibility of the residual impurities (including the heavy oil particles) which may be left on the plunger 21, and which may be.

The sealing assembly comprises a sealing block 31 which is sleeved on the part of the plunger 21 penetrating through the plunger sleeve 11 and is fixedly connected with the plunger sleeve 11, and an oil return collecting cavity 32 is formed between the sealing block 31 and the plunger 21; specifically, the seal assembly further comprises: a seal ring 33 installed between the seal block 31 and the plunger 21, wherein the seal ring 33 can prevent the heavy oil in the return oil collection cavity 32 from leaking; and a sealing gasket 34 installed between the sealing block 31 and the plunger sleeve 11; the sealing block 31, the sealing gasket 34 and the plunger sleeve 11 are connected through a screw 35. The clearance between the plunger barrel 11 and the plunger 21 needs to be designed to be small for various reasons such as heavy oil impurities, high temperature and the like. In this embodiment, the temperature of the filtered heavy oil passing through the lower part of the matching part of the plunger 21 is lower than the temperature near the high-pressure oil chamber 115 above the plunger 21, so that the sealing block 31 allows a smaller gap to be designed for sealing, and the sealing effect is enhanced because the sealing block 31 is internally provided with the O-ring 33. There is no leakage even when the heavy oil is switched to the light diesel mode. The sealing gasket 34 is made of polytetrafluoroethylene or other materials with low hardness, such as heat-resistant oil-resistant rubber or plastic, the sealing effect is good when the sealing gasket 34 is soft, the rigidity of the soft materials is low, and the contact surface is allowed to float microscopically when the sealing block 31 and the plunger sleeve 11 are compressed, so that the sealing block 31 and the plunger 21 can be automatically aligned, and the additional load caused by the coaxiality error between the middle hole of the sealing block 31 and the plunger 21 after the sealing block 31 is installed is eliminated.

In order to recover the heavy oil in the return oil collection cavity 32, as shown in fig. 1, a plurality of axial oil passages 113 are further disposed on the plunger sleeve 11, and one end of each of the plurality of axial oil passages 113 is communicated with the fuel oil collecting area 111, and the other end is communicated with the return oil collection cavity 32.

In the above embodiment of the present application, as shown in fig. 4, when the plunger 21 moves upward near the bottom dead center to communicate the first ring groove 2151 in the middle of the plunger with the corresponding radial oil passage 114 on the plunger sleeve, the high-pressure heavy oil in the high-pressure oil chamber 115 above the plunger 21 enters through the space between the plunger 21 and the slit filter core 22, and then is filtered by the filter gap 213, and the high-pressure heavy oil after being filtered by the impurities flows out to the outer surface of the plunger 21, specifically, the high-pressure heavy oil flows into the oil inlet passage 212 from the high-pressure oil chamber 115, and then is filtered by the filter gap 213, and the high-pressure heavy oil after being filtered by the impurities flows out to the second radial through hole 2161 and the third radial through hole 2162 through the oil outlet passage 214, and finally flows out to the first ring groove 2151 and the second ring groove 2152 on the outer circumference of the; a part of the high-pressure heavy oil flowing out to the outer surface of the plunger 21 flows out to the fuel oil collecting area 111 through the radial oil passage 112; the other part of the high-pressure heavy oil flows out of the return oil collecting cavity 32, and the high-pressure heavy oil flowing out of the return oil collecting cavity 32 flows out of the fuel oil collecting area 111 through the axial oil passage 113, specifically, the high-pressure heavy oil flowing out of the return oil collecting cavity 32 flows in through a gap between the plunger 21 and the plunger sleeve 11, and further flows in through the return oil passage 114, and the flow rate flowing through the return oil passage 114 is more when the plunger is near the bottom dead center.

In order to prevent the slit filter element 22 from moving inside the plunger 21, as shown in fig. 1, the plunger assembly further includes:

and one end of the positioning pin 23 is inserted into the outer circumferential surface of one side of the plunger 21, penetrates through the rear part of the slit filter core 22 and is exposed out of the outer circumferential surface of the other side of the plunger 21.

Specifically, referring to fig. 1, three ring grooves are respectively: two first ring grooves 2151 in an upper portion of the plunger 21 and one second ring groove 2152 in a lower portion of the plunger 21; the radial through-hole includes: two second radial through holes 2161 located at the upper part of the plunger 21 and a third radial through hole 2162 located at the lower part of the plunger 21, wherein the two first ring grooves 2151 are correspondingly communicated with the two second radial through holes 2161 one by one, and the second ring grooves 2152 are communicated with the third radial through holes 2162; the lower part of the slit filter element 22 is provided with a first radial through hole 216 communicated with the two oil outlet channels 214; the first radial through hole 216 and the two third radial through holes 2162 are oppositely arranged; one end of the positioning pin 23 is inserted into one of the third radial through holes 2162 from the outer surface of the plunger 21 and passes through the first radial through hole 216 and the rear portion of the other third radial through hole 2162 to be exposed out of the second ring groove 2152.

Moreover, the aperture of the third radial through hole 2162 opposite to the first radial through hole 216 is larger than the aperture of the axial blind hole provided in the plunger 21, and the two ends of the positioning pin 23 are spherical surfaces, so that when the positioning pin 23 axially moves in the third radial through hole 2162, heavy oil is filled between the spherical surface of the positioning pin 23 and the inner wall of the plunger sleeve 11, and the hydrodynamic effect separates the spherical surface of the positioning pin 23 from the inner wall of the plunger sleeve 11, thereby reducing the wear of the friction surface (spherical surface at the end) of the positioning pin 23. And, locating pin 23 and third radial through-hole 2162 clearance fit, clearance fit's mode has been convenient for the dismouting of this locating pin 23, because the high-pressure heavy oil that this embodiment used need carry out many times test operation, and quick assembly disassembly can only be realized to clearance fit's mode. Preferably, when the plunger 21 moves to the bottom dead center, the radial oil passage 112 communicates with one of the second radial through holes 2161 located above in two of the second radial through holes 2161. Thus, the high-pressure heavy oil that has entered the upper one of the second radial oil passages 2161 can flow out to the fuel oil collecting area 111 through the radial oil passage 112.

Preferably, referring to fig. 1 and 3, the plunger sleeve assembly further comprises:

an oil return passage 114 communicated to the second ring groove 2152, the oil return passage 114 being communicated to the oil return collection chamber 32;

the throttling screw plug 12 is arranged at the corner of the oil return channel 114 and used for adjusting the flow of high-pressure heavy oil passing through the oil return channel 114, and the throttling screw plug 12 is arranged to facilitate the control of the flow from the inside of the plunger 21 to the oil return channel 114 at the time of bottom dead center(To the oil passage surfaces of the plunger 21).

A part of the high-pressure heavy oil flowing out of the outer surface of the plunger 21 flows into the return oil collecting chamber 32 through the return oil passage 114, and another part of the high-pressure heavy oil flows into the radial oil passage 112 through a gap between the plunger 21 and the plunger sleeve 11, and then flows into the fuel oil collecting area 111;

the plug head of the throttle plug screw 12 is designed to be a spherical surface or a conical surface, and when the plug head is designed to be a conical surface, the opening degree can be controlled by controlling the screwing depth of the throttle plug screw 12.

For the high-pressure heavy oil in the present embodiment, the oil pressure of the high-pressure heavy oil is between 120Mpa and 160 Mpa.

In addition, for the present embodiment, the number of the oil return passages 114 and the radial oil passages 112 connecting the fuel oil collecting area 111 and the return oil collecting area is plural, and the plural oil return passages 114 and the plural radial oil passages 112 are uniformly distributed in the radial direction.

Preferably, the heavy oil plunger and barrel assembly is applied to a marine low-speed electromechanical control high-pressure oil pump.

In summary, the invention has the following technical effects:

(1) the plunger 21 is internally provided with a slit filter element 22, the slit filter element 22 and an axial blind hole in the plunger 21 form a slit filter, heavy oil with high impurity content is filtered by using the ultrahigh pressure (usually 150 Mpa) of the high-pressure heavy oil in the high-pressure oil cavity 115 above the plunger 21, cleaner oil is formed and is supplied to the middle part and the lower surface of the plunger 21 for lubrication, the use of lubricating oil is eliminated, and the effect of saving energy can be achieved. The fluid resistance formed on the outer surface of the plunger 21 by the lubricating oil with high cleanliness will also reduce the amount of oil entering the outer surface of the plunger 21 from the upper end of the plunger 21, thereby reducing the probability of impurities entering the outer surface of the plunger 21 from the upper end of the plunger 21.

(2) When the plunger 21 runs to the vicinity of the bottom dead center and the first ring groove 2151 in the middle of the plunger 21 is communicated with the radial oil duct 114 on the plunger sleeve 11, a certain amount of filtered high-temperature fuel oil flows through the entire plunger sleeve 11 from the middle of the plunger sleeve 11 to the lower return oil collecting region 32 and then to the fuel oil collecting region 111 in the middle of the plunger sleeve 11, so that the whole plunger sleeve 11 is heated, the temperature distribution of the plunger 21 is balanced, the non-uniform deformation caused by the uneven temperature distribution of the upper and lower parts of the plunger sleeve 11 is weakened, and the design and processing difficulty of the plunger sleeve 11 is reduced; meanwhile, the plunger 21 oil duct is cleaned once by fuel oil in the cavity by each recycling pump, so that the heavy oil is prevented from being deposited and bonded in the oil return hole to cause blockage.

(3) According to the fluid mechanics related calculation, when the hydraulic pressures between two axial points on the surface of the plunger 21 are equal or have small difference, the liquid flow is difficult to form, and then an effective lubricating oil film is difficult to form. A plurality of fluid high-low pressure convection areas are formed on the surface of the plunger 21 by controlling the relative positions of the plunger sleeve 11, the ring grooves (the first ring groove 2151 and the second ring groove 2152) on the plunger 21 and the radial oil passage 112 of the plunger sleeve 11, so that the surface liquid flow is enhanced, and the static pressure lubricating effect of the plunger 21 is further enhanced.

(4) Because the oil ducts and the corresponding spaces are designed symmetrically about the center of plunger sleeve 11, plunger sleeve 11 is heated more uniformly when high-temperature heavy oil flows through the oil ducts.

(5) The throttling screw plug 12 with a cylindrical head part is arranged at the middle part of the plunger sleeve 11 and the oil hole at the bottom dead center of the plunger 21, so that the flow rate from the inside of the plunger to the oil return passage 114 (instead of flowing to the surface of the oil passage of the plunger 21) at the bottom dead center of A25 can be conveniently controlled. The head of the corresponding throttling screw plug 12 can be designed into a conical surface or a spherical surface, and when the head is designed into the conical surface, the opening degree can be controlled by controlling the screwing depth of the throttling screw plug 12.

(6) A sealing block 31 assembly is arranged below the plunger sleeve 11, and a large return oil collecting space can be formed between the sealing block 31 and the gasket. The clearance between the plunger sleeve 11 and the plunger 21 needs to be considered for heavy oil impurities, high temperature and other reasons, so the occasional clearance of the plunger 21 cannot be designed to be too small. However, the plunger 21 has less impurities in the filtered fuel oil below the plunger, and the temperature of the filtered fuel oil is lower than that of the ultrahigh-pressure cavity accessory of the plunger 21, so that the sealing block 31 allows a smaller gap to be designed for sealing, and meanwhile, the sealing effect is enhanced because the O-shaped sealing ring 33 is arranged in the sealing block 31. The heavy oil will not leak even when the heavy oil is switched to the light diesel oil mode;

(7) the gasket between the plunger sleeve 11 and the sealing block 31 is made of polytetrafluoroethylene or other heat-resistant oil-resistant wear-resistant rubber or plastic with low hardness. The sealing effect is better when the gasket of the sealing gasket is softer, and secondly, the rigidity of the soft material is small, and when the sealing block 31 and the plunger sleeve 11 are compressed, the contact surface is allowed to float microscopically, so that the sealing block 31 and the plunger 21 can have an automatic alignment function, and the additional load caused by the coaxiality error of the middle hole and the plunger 21 after the sealing block 31 is installed is further reduced.

In conclusion, the plunger and barrel assembly can effectively reduce the sensitivity of plunger and barrel assembly to heavy oil pollution, and improve the overall reliability of the high-pressure oil pump; the plunger coupling assembly can improve the heating state of the plunger coupling assembly to ensure that the whole plunger sleeve is heated evenly, and improves the collection design of leakage oil of the plunger to ensure that the whole structure is compact; and the surface of the plunger 21 is lubricated by adopting fuel oil, so that waste caused by waste oil formed by mixing the fuel oil and the lubricating oil is eliminated. Thereby improving the reliability and the economy of the system.

While only one or more embodiments of the invention have been described herein, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms without departing from the spirit or scope thereof. Accordingly, the present examples and embodiments are to be considered as illustrative and not restrictive, and various modifications and substitutions may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.