Oil return structure of an aluminum swashplate type large displacement compressor

Abstract

This utility model relates to the field of compressor technology, and in particular to an oil return structure for an aluminum swashplate type large displacement compressor, comprising: a compression working assembly including a rotating shaft with an oil outlet channel along its length, and multiple oil outlet holes on its outer wall communicating with the oil outlet channel; a cylinder body with a working chamber in the middle, fitted onto the compression working assembly, with the rotating shaft passing through the cylinder body; an oil storage pool on one side of the cylinder body; and end caps, one on each of the two end faces of the cylinder body; wherein the cylinder body is divided into a first oil return section and a second oil return section; the first oil return section has a first oil return hole channel communicating from the joint surface between the first oil return section and the end cap to the working chamber; the second oil return section has a second oil return hole channel communicating from the joint surface between the second oil return section and the end cap to the oil storage pool. This utility model effectively improves the oil circulation effect within the compressor, enhances the lubrication effect, and improves the oil return function.

Description

Technical Field

[0001] This utility model relates to the field of compressor technology, and in particular to an oil return structure for an aluminum swashplate type large displacement compressor. Background Technology

[0002] As a core component of automotive air conditioning systems, especially in compressors specifically designed for buses, the performance of the oil return mechanism of the swashplate compressor directly affects lubrication efficiency and overall reliability. During compressor operation, lubricating oil needs to circulate back to the compression chamber with the refrigerant for lubrication and cooling of critical moving parts, such as the main shaft bearing, swashplate, and piston. In traditional designs, the rotating shaft typically has a central oil passage and supplies oil to the bearing area through radial oil holes. However, efficiently recovering the lubricating oil splashed onto both ends of the compressor housing and achieving precise diversion—partially reusing the lubricating oil and partially collecting and storing it—remains a technical challenge for improving lubrication efficiency and lifespan.

[0003] In existing technologies, the oil return scheme of swashplate compressors has significant shortcomings. Most designs rely on a single oil return channel, which leads to oil stagnation in the end cover area far from the oil return port. Lubricating oil splashed onto the inside of the end cover cannot be effectively recovered. Especially when the compressor is installed at an angle, oil accumulates on the non-oil return side end cover, causing insufficient bearing lubrication and localized overheating. The oil return channels are usually concentrated in the middle or bottom of the cylinder block, which cannot collect oil from the end cover mating surface area nearby. The oil needs to flow a long distance to enter the oil return channel, which increases flow resistance and the risk of stagnation. Under high-speed conditions, this can easily lead to delayed oil return and weakened lubrication.

[0004] Therefore, there is a need for an oil return structure in an aluminum swashplate compressor with optimized oil return path and enhanced lubrication effect. Utility Model Content

[0005] In view of at least one of the above technical problems, the present invention provides an oil return structure for an aluminum swashplate type large displacement compressor, which adopts a cylinder segmented double oil return channel design, and uses an oil collection and directional diversion mechanism near the end cap joint surface to quickly guide the stagnant oil into the lubrication area and oil storage pool, significantly improving the oil film coverage stability and continuous lubrication capability of key moving parts.

[0006] This utility model provides an oil return structure for an aluminum swashplate type large displacement compressor, including:

[0007] A compression working assembly includes a rotating shaft with an oil outlet channel along its length and multiple oil outlet holes on its outer wall that communicate with the oil outlet channel.

[0008] The cylinder body has a working chamber in the middle and is fitted onto the compression working assembly. The rotating shaft passes through the cylinder body. An oil storage tank is provided on one side of the cylinder body.

[0009] End caps are installed on both end faces of the cylinder body;

[0010] The cylinder body is divided into a first oil return section and a second oil return section; the first oil return section has a first oil return hole channel, which connects the first oil return section and the end cover to the working chamber; the second oil return section has a second oil return hole channel, which connects the second oil return section and the end cover to the oil storage tank.

[0011] In some embodiments of this utility model, one end of the first oil return hole channel near the end cover is close to the axis of the rotating shaft, and the other end is connected to the bottom of the working chamber.

[0012] In some embodiments of this utility model, an oil return extension section is provided on the end face of the second oil return section. The oil return extension section extends from the end face of the second oil return section near the axis of the rotating shaft toward the second oil return hole channel and is connected thereto.

[0013] In some embodiments of this utility model, the compression working assembly further includes a swashplate, a plane bearing, and a needle roller bearing sleeved on the rotating shaft.

[0014] In some embodiments of this utility model, the swashplate is disposed in the middle section of the rotating shaft, and one of the planar bearing and one of the needle roller bearing are disposed on each side of the swashplate.

[0015] In some embodiments of this utility model, the two planar bearings abut against the two end faces of the swashplate, and the two needle roller bearings are close to the end caps on both sides.

[0016] In some embodiments of this utility model, multiple oil outlet holes are respectively provided for the planar bearing or the needle roller bearing.

[0017] In some embodiments of this utility model, the compression working assembly further includes a plurality of assembly cavities opened in the cylinder body, extending from the first oil return section to the second oil return section along the axis of rotation within the cylinder body.

[0018] In some embodiments of this utility model, a piston is installed in the assembly cavity, and the piston is provided with a ball socket.

[0019] In some embodiments of this utility model, ball heads are provided on both sides of the swash plate, and the ball heads are adapted to the ball sockets.

[0020] The beneficial effects of this utility model are as follows: By opening a first oil return hole channel directly connected to the bottom of the working chamber at the joint surface between the first oil return section and the end cover, this utility model achieves the purpose of quickly introducing the lubricating oil retained at the far end into the lubrication area of ​​the working chamber, thereby improving the uniformity and continuity of the oil film coverage of the spindle bearing, swashplate, and piston moving pair, and effectively avoiding abnormal wear and overheating failure caused by local oil shortage; by opening a second oil return hole channel connected to the oil storage pool at the joint surface between the second oil return section and the end cover, this utility model achieves the purpose of actively separating excess lubricating oil and establishing a controllable storage mechanism, thereby improving the stability of the system oil quantity and reuse efficiency, and effectively preventing oil churning loss and decreased cooling efficiency caused by excessive retention of lubricating oil at the end cover. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the present invention;

[0023] Figure 2 This is a cross-sectional schematic diagram of the oil return structure of the aluminum swash plate type large displacement compressor in an embodiment of this utility model.

[0024] Figure 3 This is a schematic diagram of the structure of a portion of the compression working components in the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the end face structure of the first oil return section in the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the present invention.

[0026] Figure 5 This is a schematic cross-sectional view of the end face of the first oil return section in the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the end face structure of the second oil return section in the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the present invention.

[0028] Figure 7 This is a schematic cross-sectional view of the end face of the first oil return section in the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the present invention.

[0029] Figure 8This is a schematic diagram of the piston structure in the oil return structure of the aluminum swashplate type large displacement compressor in this utility model embodiment;

[0030] Figure 9 This is a side view schematic diagram of the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the utility model;

[0031] Figure 10 This is a front view schematic diagram of the oil return structure of the aluminum swashplate type large displacement compressor in the embodiment of this utility model;

[0032] Figure 11 This is a top view schematic diagram of the oil return structure of the aluminum swashplate type large displacement compressor in this embodiment of the present invention.

[0033] Reference numerals: 1. Compression working assembly; 11. Rotary shaft; 11a. Oil outlet channel; 11b. Oil outlet hole; 12. Swashplate; 12a. Ball head; 13. Flat bearing; 14. Needle roller bearing; 15. Assembly cavity; 16. Piston; 16a. Ball socket; 2. Cylinder block; 21. Working chamber; 22. Oil reservoir; 23. First oil return section; 23a. First oil return hole channel; 24. Second oil return section; 24a. Second oil return hole channel; 24b. Oil return extension section; 3. End cap. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0035] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] Bus air conditioning compressors need to run continuously for long periods of time every day in high summer temperatures and full-load scenarios, and the compressors are under high load for a long time. Traditional designs have a single oil return channel, and the lubricating oil splashed on the inside of the end cover is easy to accumulate. Especially when installed at an angle, oil accumulates on the non-oil return side end cover, resulting in insufficient lubrication of key components such as bearings and swashplates, extremely high local temperatures, wear, and even cylinder scoring. Therefore, this utility model was designed.

[0038] like Figures 1 to 8 The oil return structure of the aluminum swashplate type large displacement compressor shown includes:

[0039] The compression working assembly 1 includes a rotating shaft 11, with an oil outlet channel 11a opened along the length direction of the rotating shaft 11, and multiple oil outlet holes 11b opened on the outer wall and communicating with the oil outlet channel 11a.

[0040] The cylinder body 2 has a working chamber 21 in the middle, preferably including a medium pressure chamber and an oil storage chamber, and is fitted on the compression working assembly 1. The rotating shaft 11 passes through the cylinder body 2; an oil storage pool 22 is opened on one side of the cylinder body 2.

[0041] End caps 3 are installed on both end faces of the cylinder body 2, and can be divided into front caps and rear caps. Preferably, a valve plate assembly can be provided on the mating surface of the first oil return section 23 and the end cap 3, and on the mating surface of the second oil return section 24 and the end cap 3. This helps to enhance the connection stability between the cylinder body 2 and the end cap 3, reduce structural deformation caused by vibration or impact, improve the sealing effect of the cylinder body 2 and the end cap 3, prevent lubricating oil leakage and the intrusion of external contaminants, and at the same time help to dissipate the heat generated inside and improve heat dissipation efficiency.

[0042] The cylinder body 2 is divided into a first oil return section 23 and a second oil return section 24. The first oil return section 23 has a first oil return hole channel 23a, which connects the first oil return section 23 to the working chamber 21 from the joint surface of the first oil return section 23 and the end cover 3. The second oil return section 24 has a second oil return hole channel 24a, which connects the second oil return section 24 to the oil storage pool 22 from the joint surface of the second oil return section 24 and the end cover 3.

[0043] In the actual operation of the swashplate 12 compressor, the traditional oil return mechanism has significant shortcomings. Most designs rely on a single oil return channel, which makes it difficult to effectively recover the lubricating oil splashed inside the end cover 3. Especially when the compressor is installed at an angle, oil tends to accumulate on the non-oil return side end cover 3, resulting in insufficient bearing lubrication and local overheating. At the same time, traditional oil return channels are mostly concentrated in the middle or bottom of the cylinder 2, and the oil needs to flow a long distance to enter the channel. Under high-speed conditions, the oil return is easily delayed due to high flow resistance and long residence time, which directly weakens the lubrication effect.

[0044] In this embodiment, the cylinder block 2 is divided into a first oil return section 23 and a second oil return section 24, with oil return channels of different functions opened in each section. The first oil return channel 23a of the first oil return section 23 directly connects from the end cover 3 mating surface to the bottom of the working chamber 21. This design shortens the oil flow path. The lubricating oil that was originally stuck inside the end cover 3 does not need to travel a long distance and can quickly flow into the working chamber 21 through the proximal channel, directly replenishing the oil film for the swashplate 12, piston 16 and other moving parts and the main shaft bearing. This significantly shortens the circulation time of the oil from the end cover 3 to the lubrication area, reduces retention loss, avoids abnormal wear and overheating failure caused by lack of oil, and enables the lubricating oil to circulate more efficiently, improving the oil film renewal speed of key components. The degree and coverage uniformity; while the second oil return channel 24a of the second oil return section 24 connects from the end cover 3 joint surface to the oil storage pool 22. When the compressor is running at high speed or under variable operating conditions, the lubricating oil supplied by the oil outlet channel 11a may exceed the immediate lubrication demand. For example, when the lubrication consumption is reduced under low speed conditions, the excess oil will no longer remain in the end cover 3 to interfere with the circulation. The excess lubricating oil is actively separated and stored through the second oil return channel 24a. This not only prevents excessive oil from remaining in the end cover 3 and causing oil churning loss, but also avoids energy loss caused by churning when there is too much lubricating oil, thus reducing the refrigeration efficiency. It also establishes a controllable oil reserve mechanism for the system, ensuring that the lubrication area can still be continuously supplied with oil under high speed or variable operating conditions, thus balancing the oil volume fluctuation in the circulation.

[0045] In some embodiments of this utility model, such as Figure 4 and Figure 5 As shown, the first oil return channel 23a is close to the axis of the rotating shaft 11 at one end near the end cover 3, and the other end is connected to the bottom of the working chamber 21.

[0046] The design of the first oil return channel 23a, with its proximal end close to the axis of the rotating shaft 11, covers the oil accumulation area inside the end cover 3. When the compressor is running, the high-speed rotation of the rotating shaft 11 will cause lubricating oil to splash. The area inside the end cover 3 near the axis of the rotating shaft 11, that is, near the center of rotation, is where oil is most likely to accumulate due to centrifugal force or splashing. Traditional oil return holes are far from this area and cannot effectively collect this part of the oil. However, the proximal end of the first oil return hole is located in this area, which is equivalent to opening a channel directly at the oil retention point. The oil no longer needs to take a long detour and can flow into the oil return hole nearby, which greatly shortens the flow distance, reduces flow resistance and retention risk, and allows the oil to enter the circulation more promptly.

[0047] Moreover, the bottom of the working chamber 21 is the main lubrication area for the swash plate 12, piston 16 motion pair and main shaft bearing mentioned later. Traditional oil return holes are located off-center, so the oil needs to diffuse again to reach these areas. However, the far end of the first oil return hole is directly connected to the bottom of the working chamber 21, which is equivalent to delivering the recovered oil to the core area that needs the most lubrication. The oil can directly participate in the formation of oil film without secondary flow, which significantly improves the timeliness of lubrication.

[0048] In some embodiments of this utility model, such as Figure 6 and Figure 7 As shown, an oil return extension section 24b is provided on the end face of the second oil return section 24. The oil return extension section 24b extends from the end face of the second oil return section 24 near the axis of the rotating shaft 11 toward the second oil return hole channel 24a and is connected.

[0049] Traditional oil return holes are directly located on the end face of cylinder block 2, with their inlet position far from the axis of rotation shaft 11. However, the actual oil accumulation area inside end cover 3 is concentrated near the axis. The oil return extension section 24b extends from a position near the axis of rotation shaft 11 to the second oil return hole channel 24a, effectively creating a guide channel between the oil accumulation point and the oil return hole. The oil no longer needs to flow a long distance from near the axis to the edge of the oil return hole, but instead flows directly into the oil return hole through the extension section. The path is shorter and the resistance is lower, significantly improving the oil collection efficiency. This allows excess oil to be more thoroughly guided into the oil storage tank 22, avoiding ineffective oil retention inside end cover 3. This ensures that the oil storage tank 22 can effectively store, collect, and recycle oil, enabling the system to maintain a stable oil supply under different operating conditions.

[0050] In some embodiments of this utility model, such as Figure 2 and Figure 3 As shown, the compression working assembly 1 also includes a swashplate 12, a plane bearing 13, and a needle roller bearing 14 mounted on the rotating shaft 11.

[0051] Based on the above embodiment, the swash plate 12 is located in the middle section of the rotating shaft 11, and a plane bearing 13 and a needle roller bearing 14 are each provided on both sides of the swash plate 12.

[0052] As the core of the compressor's power conversion, the swashplate 12 converts the rotational motion of the rotating shaft 11 into the reciprocating motion of the piston 16. During operation, it must withstand the bidirectional axial thrust generated by the reciprocating motion of the piston 16 and the radial bending moment caused by the lateral force generated by the tilt angle of the swashplate 12. The traditional arrangement of single-sided bearings or single bearings will cause one side of the swashplate 12 to bear concentrated loads, while the other side will wobble due to lack of support, exacerbating local wear. In this embodiment, the swashplate 12 is centrally located with a set of planar bearings 13 and needle roller bearings 14 on each side, which is equivalent to establishing a bidirectional balanced support for the swashplate 12. The planar bearings 13 on both sides of the swashplate 12 mainly bear the axial thrust, and the thrust is evenly distributed to the rotating shaft 11 and the cylinder 2 through large-area contact. The similarly symmetrically arranged needle roller bearings 14 mainly bear the radial bending moment, and the lateral force is dispersed through the line contact of multiple needle rollers. This division of load and symmetrical bearing avoids the off-center load problem caused by unilateral force in traditional designs. The stress on the contact surface between the swashplate 12 and the bearings is greatly reduced, and the wear rate is significantly slowed down. The symmetrical planar bearings 13 and needle roller bearings 14 work together to keep the axis of the rotating shaft 11 stable during high-speed rotation. The movement trajectories of the swashplate 12 and piston 16 are more precise, and the vibration and noise of the compressor during operation are greatly reduced. At the same time, the additional friction loss caused by sway is reduced, and the energy conversion efficiency is improved.

[0053] Please refer to Figure 3 In some embodiments of this utility model, two planar bearings 13 abut against the two end faces of the swashplate 12, and two needle roller bearings 14 are close to the end caps 3 on both sides.

[0054] Two planar bearings 13 are tightly fitted to the two end faces of the swashplate 12, which is equivalent to establishing a two-way buffer layer for the end face of the swashplate 12. Regardless of whether the axial thrust comes from above or below, it can be directly distributed to the rotating shaft 11 and the cylinder block 2 through the planar bearings 13 on the corresponding side. The end face of the swashplate 12 is subjected to more uniform force, and the risk of deformation is greatly reduced. Since the planar bearings 13 are symmetrically arranged on both sides of the swashplate 12, the oil can cover the contact surface between the planar bearings 13 and the swashplate 12 from two directions at the same time. The oil film of the left planar bearing 13 is directly supplied by the left oil outlet 11b, and the oil film of the right planar bearing 13 is replenished by the right oil outlet 11b and the return oil. This two-way lubrication mechanism solves the problem of uneven oil film caused by the arrangement of planar bearings 13 on one side in the traditional design. The contact surface between the planar bearings 13 and the swashplate 12 is always wrapped with a uniform oil film, the friction coefficient and temperature rise are significantly reduced, and the lubrication effect is improved from local coverage to full and continuous.

[0055] In some embodiments of this utility model, such as Figure 3 As shown, multiple oil outlet holes 11b are respectively provided for the plane bearing 13 or the needle roller bearing 14.

[0056] The rotating shaft 11 has an oil outlet channel 11a along its length. Lubricating oil enters from the oil outlet channel 11a and is compressed by the internal and external oil pump gears located near the end cover 3 as the rotating shaft 11 rotates. The lubricating oil is then supplied from the oil outlet channel 11a through the oil outlet hole 11b to the swashplate 12, the flat bearing 13, and the needle roller bearing 14, thereby realizing the lubrication and oil return functions of the compressor parts and improving the lubrication efficiency and effect.

[0057] The thrust bearing 13 directly abuts against the end face of the swashplate 12. Its core lubrication area is the contact surface between the bearing raceway and the swashplate 12, requiring a continuous oil film to prevent dry friction. The oil outlet 11b of the thrust bearing 13 ensures the stable formation of the axial oil film. The oil directly enters the raceway gap of the thrust bearing 13, forming a uniform oil film on the contact surface without additional flow, significantly reducing the wear rate of the end faces of the thrust bearing 13 and the swashplate 12. The needle roller bearing 14 is located near the end cover 3. Its core lubrication area is the contact line between the needle rollers and the inner and outer rings, requiring oil to penetrate into the tiny gaps to form lubrication. The oil outlet 11b of the needle roller bearing 14 achieves radial lubrication coverage. The oil directly enters the contact area of ​​the inner ring of the needle rollers, quickly penetrating the entire raceway. The contact surface between the needle rollers and the inner and outer rings is always wrapped with an oil film, avoiding local high temperatures caused by insufficient oil. This design effectively enhances the lubrication effect for the thrust bearing 13 and the needle roller bearing 14.

[0058] In some embodiments of this utility model, such as Figure 2 As shown, the compression working assembly 1 also includes multiple assembly cavities 15 opened in the cylinder 2, which are opened from the first oil return section 23 to the second oil return section 24 along the axis of the rotating shaft 11 in the cylinder 2, ensuring that the movement trajectory of the piston 16 is strictly aligned with the axis of the rotating shaft 11, and avoiding piston 16 jamming or cylinder rubbing noise caused by sway.

[0059] In some embodiments of this utility model, such as Figure 8 As shown, a piston 16 is installed in the assembly cavity 15, and the piston 16 is provided with a ball socket 16a. Ball heads 12a are provided on both sides of the swashplate 12, and the ball heads 12a are adapted to the ball sockets 16a.

[0060] Based on the above embodiments, refer to Figure 2 and Figure 8 Ball heads 12a are provided on both sides of the swash plate 12, and the ball heads 12a are adapted to the ball sockets 16a.

[0061] The adaptive connection between the piston 16 ball socket 16a and the swashplate 12 ball head 12a achieves flexible buffering of motion transmission. In traditional rigid hinges, when the swashplate 12 rotates, force needs to be transmitted through the sliding of the pin and the hole. When the tilt angle of the swashplate 12 changes, the contact point shifts, which can cause local stress concentration, easily leading to pin breakage or hole wall crushing. However, the ball joint connection allows the relative movement of the swashplate 12 and piston 16 to be finely adjusted in any direction through the spherical contact of the ball head 12a and the ball socket 16a. The force transmission is more uniform, and the friction coefficient of the spherical contact is reduced, reducing frictional heat generation and making the movement smoother.

[0062] Moreover, the position of the assembly cavity 15 extending from the first oil return section 23 to the second oil return section 24 precisely covers the main circulation path of the lubricating oil. The first oil return section 23 recovers the splashed oil from the top of the cylinder 2, and the second oil return section 24 stores the oil in the bottom oil reservoir 22. When the piston 16 reciprocates, the contact area between the ball socket 16a and the ball head 12a generates negative pressure due to the movement, which draws the lubricating oil in the assembly cavity 15 into the spherical gap, forming a dynamic oil film. This mechanism solves the problem of lubrication blind spots caused by the closed structure of traditional rigid hinges. The spherical contact area is always protected by the oil film, reducing the wear rate and effectively improving the lubrication effect.

[0063] Piston ring scoring is a common fault in traditional compressors. During long-term operation, the piston rings and cylinder wall of ordinary aluminum alloy or cast iron cylinders experience intense friction due to high-frequency reciprocating motion, with local temperatures potentially exceeding 200°C, leading to rupture of the lubricating oil film. This direct metal-to-metal contact causes microscopic cutting, gradually forming visible grooves. Scoring not only widens the cylinder wall clearance, increasing refrigerant leakage, but also increases motion resistance due to jamming, and can even cause secondary faults such as crankshaft wear due to metal debris entering the lubrication system. It is a core pain point restricting the lifespan and stability of compressors.

[0064] In some embodiments of this utility model, the swash plate 12 is made of high-silicon aluminum alloy and its surface is treated with hard anodizing and molybdenum disulfide. The high-silicon aluminum alloy has a lower density than conventional cast iron, making it lighter. Due to the dispersion strengthening effect of silicon particles, the matrix is ​​harder and has excellent wear resistance. On this basis, the hard anodizing treatment further generates an oxide film on the surface, forming a rigid protective layer to resist the high-frequency impact when the swash plate 12 contacts the plane bearing 13 and the ball joint 12a contacts the ball socket 16a. The molybdenum disulfide solid lubricating film forms a lubrication buffer layer on the oxide film surface, reducing the coefficient of friction between the swash plate 12 and the plane bearing 13, avoiding local high temperatures caused by dry friction, and effectively improving the overall life of the swash plate 12.

[0065] Based on the above embodiments, the piston 16 structure adopts a surface coating of Teflon (polytetrafluoroethylene). Teflon has excellent self-lubricating properties and chemical stability. When the piston 16 reciprocates in the cylinder bore, the sliding friction between the Teflon coating and the cylinder bore wall is significantly reduced, and more energy is used to compress the refrigerant, directly increasing the cooling capacity. At the same time, the low surface energy characteristics of the coating reduce the adhesion of refrigerant to the surface of the piston 16, avoiding the decrease in compression efficiency caused by refrigerant retention.

[0066] Based on the above embodiments, the cylinder block 2 is made of high-silicon aluminum alloy. The thermal expansion coefficient of the high-silicon aluminum alloy is highly matched with that of the piston 16 (high-silicon aluminum alloy or Teflon coating). During compressor operation, the gap between the cylinder bore and the piston 16 changes less, effectively reducing refrigerant leakage. At the same time, the wear resistance of the high-silicon aluminum alloy cylinder bore is much improved compared to ordinary aluminum alloy. After long-term operation, the cylinder bore dimensional stability is better, and the fitting precision with the piston 16 is maintained, further ensuring the continuous stability of the cooling capacity. Moreover, the high-silicon aluminum alloy structure stabilizes the cylinder wall gap, keeping the volumetric efficiency at an excellent level for a long time. This improvement not only means an increase in the actual intake volume under the same input power, but also reduces compression power loss by reducing leakage, achieving the dual benefits of enhanced reliability and optimized performance.

[0067] Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An oil return structure of an aluminum swash plate type large capacity compressor, characterized by comprising: include: The compression working assembly (1) includes a rotating shaft (11), the rotating shaft (11) having an oil outlet channel (11a) along its length, and having multiple oil outlet holes (11b) on its outer wall that communicate with the oil outlet channel (11a); The cylinder body (2) has a working chamber (21) in the middle, which is fitted onto the compression working assembly (1), and the rotating shaft (11) passes through the cylinder body (2); an oil storage tank (22) is provided on one side of the cylinder body (2); End caps (3) are installed on both end faces of the cylinder body (2); The cylinder body (2) is divided into a first oil return section (23) and a second oil return section (24). The first oil return section (23) has a first oil return hole channel (23a) that connects the first oil return section (23) to the working chamber (21) through the joint surface between the first oil return section (23) and the end cover (3). The second oil return section (24) has a second oil return hole channel (24a) that connects the second oil return section (24) to the oil storage tank (22) through the joint surface between the second oil return section (24) and the end cover (3).

2. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 1, characterized in that, The first oil return hole channel (23a) is located near the axis of the rotating shaft (11) at one end near the end cover (3), and the other end is connected to the bottom of the working chamber (21).

3. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 1, characterized in that, An oil return extension section (24b) is provided on the end face of the second oil return section (24). The oil return extension section (24b) extends from the end face of the second oil return section (24) near the axis of the rotating shaft (11) toward the second oil return hole channel (24a) and is connected.

4. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 1, characterized in that, The compression working assembly (1) also includes a swashplate (12), a plane bearing (13), and a needle roller bearing (14) fitted on the rotating shaft (11).

5. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 4, characterized in that, The swash plate (12) is located in the middle section of the rotating shaft (11), and the planar bearing (13) and the needle roller bearing (14) are each located on both sides of the swash plate (12).

6. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 5, characterized in that, The two planar bearings (13) abut against the two end faces of the swashplate (12) respectively, and the two needle roller bearings (14) are close to the end caps (3) on both sides respectively.

7. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 6, characterized in that, The plurality of oil outlet holes (11b) are respectively provided for the planar bearing (13) or the needle roller bearing (14).

8. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 5, characterized in that, The compression working assembly (1) also includes a plurality of assembly cavities (15) opened in the cylinder (2), which are opened from the first oil return section (23) to the second oil return section (24) along the axis of the rotation shaft (11) in the cylinder (2).

9. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 8, characterized in that, A piston (16) is installed in the assembly cavity (15), and the piston (16) is provided with a ball socket (16a).

10. The oil return structure of the aluminum swashplate type large displacement compressor according to claim 9, characterized in that, Ball heads (12a) are provided on both sides of the swash plate (12), and the ball heads (12a) are adapted to the ball sockets (16a).

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