Oil supply mechanism and compressor

Abstract

The utility model relates to the technical field of compressors, in particular to an oil supply mechanism and a compressor, the oil supply mechanism is applied to the compressor, the compressor comprises a main shaft and an impeller arranged at one end of the main shaft, the oil supply mechanism comprises an end cover assembly and an axial bearing pack, and the end cover assembly is arranged at the end, away from the impeller, of the main shaft; the end cover assembly is provided with an oil supply passage and an oil inlet communicated with the oil supply passage; the axial bearing set is arranged in the end cover assembly and comprises a second bearing fixedly arranged on the periphery of the main shaft. The axial bearing pack further comprises a first bearing, a first bearing gap is formed between the first bearing and the second bearing, and the first bearing gap is communicated with the oil supply passage; and / or the axial bearing pack further comprises a third bearing, a second bearing gap is formed between the third bearing and the second bearing, and the second bearing gap is communicated with the oil supply passage. The oil supply mechanism can reduce transmission of high temperature to the composite bearing, reduce abrasion of the composite bearing and improve operation reliability of the centrifugal compressor.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to an oil supply mechanism and a compressor. Background Art

[0002] Compared with conventional refrigeration compressors, existing centrifugal heat pump compressors have more complex working conditions and higher internal temperatures in the compressors, which places strict requirements on some key materials such as composite bearings and motor bearings. However, conventional centrifugal heat pump compressor designs usually use composite bearings to radially bear the weight of the shaft system and axially bear the axial force to ensure the reliability of the shaft system operation. However, in high-temperature centrifugal heat pump compressors, the impeller outlet temperature can reach 120°C or even higher, resulting in the composite bearings close to the impeller position having to withstand the high temperature transmitted from the impeller, especially the axial bearing surface of the composite bearing. Therefore, higher requirements are placed on the material of the axial bearing surface of the composite bearing to ensure the normal operation of the compressor. However, the bearing surface material of existing composite bearings is difficult to withstand such high temperatures, which will cause the bearing surface to wear severely under the action of high temperature, affecting the reliability of the centrifugal compressor operation. Utility Model Content

[0003] The present application provides an oil supply mechanism and a compressor, wherein the oil supply mechanism can reduce the transmission of high temperature to the composite bearing, alleviate the wear of the composite bearing, and improve the reliability of the operation of the centrifugal compressor.

[0004] In the first aspect, the present application provides an oil supply mechanism, which is applied to a compressor. The compressor includes a main shaft and an impeller arranged at one end of the main shaft. The oil supply mechanism includes: an end cover assembly, which is arranged at the end of the main shaft away from the impeller, and the end cover assembly is provided with an oil supply passage and an oil inlet connected to the oil supply passage, and the oil inlet is connected to an external oil supply device; and an axial bearing group, which is arranged in the end cover assembly, and the axial bearing group includes a second bearing fixedly arranged on the outer periphery of the main shaft; wherein the axial bearing group also includes a first bearing, the first bearing is sleeved on the outer periphery of the main shaft, and is located on the side of the second bearing facing the impeller, a first load-bearing gap is formed between the first bearing and the second bearing, and the first load-bearing gap is connected to the oil supply passage; and / or, the axial bearing group also includes a third bearing, the third bearing is sleeved on the outer periphery of the main shaft, and is located on the side of the second bearing facing away from the impeller, a second load-bearing gap is formed between the third bearing and the second bearing, and the second load-bearing gap is connected to the oil supply passage.

[0005] In one possible implementation, a first groove is provided at one end of the first bearing facing the second bearing, and a first load-bearing gap is formed between the first groove and the second bearing; and / or a second groove is provided at one end of the third bearing facing the second bearing, and a second load-bearing gap is formed between the second groove and the second bearing.

[0006] In a possible implementation, a plurality of first grooves are provided, and the plurality of first grooves are spaced apart along the circumference of the first bearing; and / or a plurality of second grooves are provided, and the plurality of second grooves are spaced apart along the circumference of the third bearing.

[0007] In a possible implementation, the first groove is provided to extend in a radial direction of the first bearing, and the second groove is provided to extend in a radial direction of the third bearing.

[0008] In one possible implementation, the first bearing is provided with a first oil inlet hole along its own axial direction, and the first groove is connected to the oil supply passage through the first oil inlet hole; the third bearing is provided with a second oil inlet hole along its own axial direction, and the second groove is connected to the oil supply passage through the second oil inlet hole.

[0009] In a possible implementation, an annular groove is provided on the outer peripheral surface of the first bearing, and the first oil inlet hole is connected to the oil supply passage through the annular groove.

[0010] In a possible implementation, an oil distribution groove is provided on the inner surface of the first bearing, and the oil distribution groove is connected to the annular groove through a connecting hole on the first bearing.

[0011] In one possible implementation, the end cover assembly includes an end cover body and a cover plate connected to the end cover body, a closed cavity is formed between the third bearing and the cover plate, and the second oil inlet hole is connected to the oil supply passage through the closed cavity.

[0012] In one possible implementation, the outer peripheral surface of the first bearing is provided with a first oil unloading port connected to the first groove, and the outer peripheral surface of the third bearing is provided with a second oil unloading port connected to the second groove, and the first oil unloading port and the second oil unloading port are connected to the oil return passage on the end cover assembly.

[0013] In one possible implementation, the oil supply passage includes: a first oil supply passage, connected to the first load-bearing gap; and a second oil supply passage, arranged in parallel with the first oil supply passage, the second oil supply passage connected to the second load-bearing gap; wherein, a regulating valve is provided on the first oil supply passage and / or the second oil supply passage, and the regulating valve is used to adjust the oil inlet amount into the first oil supply passage and the second oil supply passage.

[0014] In a possible implementation, a side of the first bearing facing the second bearing is made of heat-insulating material or is provided with a heat-insulating layer, and a side of the third bearing facing the second bearing is made of heat-insulating material or is provided with a heat-insulating layer.

[0015] In a second aspect, an embodiment of the present application provides a compressor, comprising: a main shaft; an impeller, arranged at one end of the main shaft; a composite bearing, arranged on the outer peripheral side of the main shaft and adjacent to the impeller; and the above-mentioned oil supply mechanism, the oil supply mechanism being arranged at the end of the main shaft away from the impeller.

[0016] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0017] The oil supply mechanism and compressor provided in the embodiment of the present application form a first load-bearing gap between the first bearing and the second bearing, so that the lubricating oil in the oil supply passage enters the first load-bearing gap, which is used to bear the axial force of the main shaft toward the impeller. A second load-bearing gap is formed between the second bearing and the third bearing, so that the lubricating oil in the oil supply passage enters the second load-bearing gap, which is used to bear the axial force of the main shaft in the direction away from the impeller. The axial bearing group is away from the high-temperature end of the main shaft and has a lower temperature, which can effectively reduce the impact of high temperature, reduce the transmission of high temperature to the composite bearing, reduce the wear of the composite bearing, and improve the reliability of the operation of the centrifugal compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0021] Figure 1 A schematic structural diagram of an oil supply mechanism and a main shaft provided in an embodiment of the present application;

[0022] Figure 2 for Figure 1 A local enlarged structural diagram of point A;

[0023] Figure 3 A schematic structural diagram of a compressor provided in an embodiment of the present application;

[0024] Figure 4 A schematic diagram of a planar structure of a first bearing facing a second bearing provided in an embodiment of the present application;

[0025] Figure 5 A schematic diagram of the three-dimensional structure of a first bearing provided in an embodiment of the present application;

[0026] Figure 6A schematic structural diagram of a plane of a third bearing facing the second bearing provided in an embodiment of the present application;

[0027] Figure 7 for Figure 6 Schematic diagram of the local enlarged structure at point B.

[0028] Description of reference numerals:

[0029] 1. Spindle;

[0030] 2. Impeller;

[0031] 3. End cover assembly; 31. Oil supply passage; 311. First oil supply passage; 312. Second oil supply passage; 32. Oil inlet; 33. End cover body; 34. Cover plate; 35. Regulating valve; 36. Oil return passage;

[0032] 4. Axial bearing assembly; 41. First bearing; 411. First groove; 412. First oil inlet; 413. Ring groove; 414. Oil distribution groove; 415. Connecting hole; 416. First oil unloading port; 417. Oil guide groove; 42. Second bearing; 43. Third bearing; 431. Second groove; 432. Second oil inlet; 433. Second oil unloading port;

[0033] 5. Sealed cavity;

[0034] 6. Composite bearings. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0036] The disclosure below provides many different embodiments or examples for implementing different configurations of the present invention. To simplify the disclosure of the present invention, the components and configurations of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or configurations discussed.

[0037] For ease of description, spatially relative terms may be used herein to describe the relative position or movement of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," "above," "front," "back," and the like. Such spatially relative terms are intended to include different orientations of the device in use or operation other than the orientation depicted in the figures. For example, if the device in the figures undergoes a positional flip or a change in posture or a change in motion, then these directional indications will also change accordingly. For example, an element described as "below" or "below" another element or feature will subsequently be oriented as "above" or "above" another element or feature. Thus, the example term "below" can include both above and below orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein will be interpreted accordingly.

[0038] Figure 1 A schematic structural diagram of an oil supply mechanism and a main shaft provided in an embodiment of the present application;

[0039] Figure 2 for Figure 1 A local enlarged structural diagram of point A; Figure 3 A schematic structural diagram of a compressor provided in an embodiment of the present application; Figure 4 A schematic diagram of a planar structure of a first bearing facing a second bearing provided in an embodiment of the present application; Figure 5 A schematic diagram of the three-dimensional structure of a first bearing provided in an embodiment of the present application; Figure 6 A schematic structural diagram of a plane of a third bearing facing the second bearing provided in an embodiment of the present application; Figure 7 for Figure 6 Schematic diagram of the local enlarged structure at point B.

[0040] like Figure 1-Figure 7 As shown, an embodiment of the present application provides an oil supply mechanism, which is applied to a compressor. The compressor includes a main shaft 1 and an impeller 2 arranged at one end of the main shaft 1. The oil supply mechanism includes: an end cover assembly 3 and an axial bearing group 4.

[0041] The end cover assembly 3 is arranged at the end of the main shaft 1 away from the impeller 2. The end cover assembly 3 is provided with an oil supply passage 31 and an oil inlet 32 connected to the oil supply passage 31. The oil inlet 32 is connected to an external oil supply device.

[0042] The axial bearing group 4 is disposed in the end cover assembly 3 , and the axial bearing group 4 includes a second bearing 42 fixedly disposed on the outer periphery of the main shaft 1 .

[0043] The axial bearing assembly 4 further includes a first bearing 41, which is sleeved around the outer circumference of the main shaft 1 and located on the side of the second bearing 42 facing the impeller 2. A first load-bearing gap is formed between the first bearing 41 and the second bearing 42, and the first load-bearing gap is connected to the oil supply passage 31. And / or, the axial bearing assembly 4 further includes a third bearing 43, which is sleeved around the outer circumference of the main shaft 1 and located on the side of the second bearing 42 facing away from the impeller 2. A second load-bearing gap is formed between the third bearing 43 and the second bearing 42, and the second load-bearing gap is connected to the oil supply passage 31.

[0044] Specifically, the first load-bearing gap is an annular structure arranged around the main shaft 1. The outer periphery of the first load-bearing gap is relatively sealed by the abutment of the ends of the first bearing 41 and the second bearing 42, so that the lubricating oil can be retained in the first load-bearing gap. As the main shaft moves axially, a small amount of lubricating oil will seep out from the four sides of the first load-bearing gap, and then new lubricating oil will be replenished into the first load-bearing gap through the oil supply passage 31.

[0045] The second load-bearing gap is an annular structure arranged around the main shaft 1. The outer periphery of the second load-bearing gap is relatively sealed by the abutment between the end portions of the third bearing 43 and the second bearing 42, so that the lubricating oil can be retained in the second load-bearing gap. As the main shaft moves axially, a small amount of lubricating oil will seep out from around the second load-bearing gap, and new lubricating oil will be replenished into the second load-bearing gap through the oil supply passage 31.

[0046] In the present application, a first load-bearing gap is formed between the first bearing 41 and the second bearing 42, so that the lubricating oil in the oil supply passage 31 enters the first load-bearing gap to bear the axial force of the main shaft 1 toward the impeller 2. A second load-bearing gap is formed between the second bearing 42 and the third bearing 43, so that the lubricating oil in the oil supply passage 31 enters the second load-bearing gap to bear the axial force of the main shaft 1 in the direction away from the impeller 2. The axial bearing group 4 is away from the high-temperature end of the main shaft 1 and has a lower temperature, which can effectively reduce the impact of high temperature. The composite bearing 6 located at the high-temperature end of the main shaft 1 does not need to bear the axial force of the main shaft 1, thereby reducing the transmission of high temperature to the composite bearing 6, reducing the wear of the composite bearing 6, and improving the reliability of the operation of the centrifugal compressor.

[0047] In another embodiment, a first load-bearing gap is formed between the first bearing 41 and the second bearing 42, so that the lubricating oil in the oil supply passage 31 enters the first load-bearing gap to bear the axial force of the main shaft 1 toward the impeller 2, while the axial force of the main shaft 1 away from the impeller 2 is still borne by the existing composite bearing 6. Compared with the existing technology, the composite bearing 6 only needs to bear the axial force in the direction away from the impeller 2, which also reduces the heat transfer from the main shaft 1 to the composite bearing 6.

[0048] In another embodiment, a second load-bearing gap is formed between the second bearing 42 and the third bearing 43, so that the lubricating oil in the oil supply passage 31 flows into the second load-bearing gap to bear the axial force of the main shaft 1 in the direction away from the impeller 2, while the axial force of the main shaft 1 toward the impeller 2 is still borne by the existing composite bearing 6. Compared with the prior art, the composite bearing 6 only needs to bear the axial force toward the impeller 2, which also reduces the heat transfer from the main shaft 1 to the composite bearing 6.

[0049] In current high-temperature centrifugal heat pump compressors, the exhaust temperature is high, with the impeller 2 outlet temperature reaching 120°C or even higher. This causes the composite bearing 6 near the impeller 2 to withstand the high temperature transmitted from the impeller 2, especially the axial bearing surface of the composite bearing 6. Therefore, higher requirements are placed on the material of the axial bearing surface of the composite bearing 6 to ensure the normal operation of the compressor. However, the existing bearing surface material of the composite bearing 6 is difficult to withstand such high temperatures, which leads to severe wear of the bearing surface under the influence of high temperatures, affecting the reliability of the centrifugal compressor.

[0050] In the embodiment of the present application, the axial force of the main shaft 1 is carried by the axial bearing group 4, so that the composite bearing 6 adjacent to the impeller 2 does not need to bear the axial force of the main shaft 1. The composite bearing 6 only needs to bear the radial weight of the main shaft 1. The composite bearing 6 has no axial contact with the main shaft 1, thereby reducing the contact area and heat transfer effect between the main shaft 1 and the composite bearing 6, and to a certain extent lowering the temperature of the composite bearing 6, thereby reducing the wear of the composite bearing 6 under high-temperature conditions. The axial bearing group 4 is far away from the main heat-generating part of the main shaft 1 and has a lower temperature. Lubricating oil is pumped into the first bearing gap between the first bearing 41 and the second bearing 42 to bear the forward axial force of the main shaft 1 (toward the impeller 2); lubricating oil is pumped into the second bearing gap between the second bearing 42 and the third bearing 43 to bear the backward axial force of the main shaft 1 (away from the impeller 2), thereby ensuring normal operation of the compression system.

[0051] Specifically, the first bearing 41 and the third bearing 43 are fixedly mounted within the end cover assembly 3 and are used to support the rear end of the main shaft 1, that is, to bear the radial weight of the end of the main shaft 1 away from the impeller 2. The composite bearing 6 supports the front end of the main shaft 1, that is, to bear the radial weight of the end of the main shaft 1 adjacent to the impeller 2. The second bearing 42 is fixedly mounted on the main shaft 1 and is used to bear the axial force of the main shaft 1 by pumping lubricating oil into the first bearing gap between the first bearing 41 and the second bearing 42, and the second bearing gap between the second bearing 42 and the third bearing 43. This achieves the bearing of the radial and axial forces of the compressor main shaft 1, while ensuring that the composite bearing 6 adjacent to the high-temperature end of the main shaft 1 does not need to be in axial contact with the main shaft 1, reducing the amount of heat transferred from the main shaft 1 to the composite bearing 6, thereby reducing wear of the composite bearing 6 and ensuring the reliability of the compressor. Among them, the first bearing 41 is a motor bearing, the second bearing 42 is a thrust bearing, and the third bearing 43 is a thrust bearing.

[0052] The first and third bearings 41, 43 are fixedly mounted within the end cap assembly 3. The second bearing 42 is fixedly connected to the main shaft 1 and positioned between the first and third bearings 41, 43. The main shaft 1 drives the second bearing 42 in rotation. The spacing between the first and third bearings 41, 43 is slightly greater than the axial length of the second bearing 42. This ensures that any axial movement of the main shaft 1 is supported by the lubricating oil in the first and second bearing gaps. This also prevents relative sliding friction between the first and second bearings 41, 42, and between the second and third bearings 42, 43, effectively protecting the first, second, and third bearings 41, 42, 43.

[0053] After the lubricating oil is pumped into the first and second load gaps, it is easily thrown out from around the first and second load gaps as the second bearing 42 rotates, thereby affecting the amount of lubricating oil retained in the first and second load gaps. To address the above problem, the present application provides the following embodiments.

[0054] like Figure 2 、 4 -6, in some embodiments, a first groove 411 is provided at one end of the first bearing 41 facing the second bearing 42, and a first load-bearing gap is formed between the first groove 411 and the second bearing 42; a second groove 431 is provided at one end of the third bearing 43 facing the second bearing 42, and a second load-bearing gap is formed between the second groove 431 and the second bearing 42.

[0055] In the present application, by providing a first groove 411 on the end surface of the first bearing 41 facing the second bearing 42, a first load-bearing gap is formed between the first groove 411 and the second bearing 42. After the lubricating oil is pumped into the first groove 411, the first bearing 41 and the second bearing 42 are isolated. This can better maintain the lubricating oil in the first load-bearing gap, reduce the friction between the first bearing 41 and the second bearing 42, and at the same time play a role in bearing the axial force of the main shaft 1. By providing a second groove 431 on the end surface of the third bearing 43 facing the second bearing 42, a second load-bearing gap is formed between the second groove 431 and the second bearing 42. After the lubricating oil is pumped into the second groove 431, the second bearing 42 and the third bearing 43 are isolated. This can better maintain the lubricating oil in the second load-bearing gap, reduce the friction between the second bearing 42 and the third bearing 43, and at the same time play a role in bearing the axial force of the main shaft 1.

[0056] like Figure 4-6 As shown, in some embodiments, a plurality of first grooves 411 are provided, and the plurality of first grooves 411 are arranged at intervals along the circumference of the first bearing 41 ; a plurality of second grooves 431 are provided, and the plurality of second grooves 431 are arranged at intervals along the circumference of the third bearing 43 .

[0057] In the present application, multiple first grooves 411 are provided, and multiple first grooves 411 are spaced apart along the circumference of the first bearing 41 on the end surface of the first bearing 41, thereby ensuring uniform distribution of lubricating oil between the first bearing 41 and the second bearing 42, thereby improving the uniformity and effectiveness of bearing the forward axial force of the main shaft 1. Multiple second grooves 431 are provided, and multiple second grooves 431 are spaced apart along the circumference of the third bearing 43 on the end surface of the third bearing 43, thereby ensuring uniform distribution of lubricating oil between the second bearing 42 and the third bearing 43, thereby improving the uniformity and effectiveness of bearing the backward axial force of the main shaft 1.

[0058] Specifically, the multiple first grooves 411 have the same structure and are evenly disposed on the end surface of the first bearing 41 . The multiple second grooves 431 have the same structure and are evenly disposed on the end surface of the third bearing 43 .

[0059] Optionally, the first groove 411 may include a first shape and a second shape, and the first groove 411 of the first shape and the second groove 411 of the second shape are spaced apart. The second groove 431 may also include a first shape and a second shape, and the first groove 431 of the first shape and the second groove 431 of the second shape are spaced apart.

[0060] Of course, the first groove 411 can also include a variety of shapes, such as strips, arcs, circles, ellipses, etc., as long as they are evenly arranged on the end face of the first bearing 41 along the circumference of the first bearing 41, it can be ensured that the lubricating oil in the multiple first grooves 411 can be evenly distributed between the first bearing 41 and the second bearing 42.

[0061] Similarly, the second groove 431 can also include a variety of shapes, such as strips, arcs, circles, ellipses, etc., as long as they are evenly arranged on the end face of the third bearing 43 along the circumference of the third bearing 43, it can be ensured that the lubricating oil in the multiple second grooves 431 can be evenly distributed between the second bearing 42 and the third bearing 43.

[0062] In a specific embodiment, the end face of the first bearing 41 facing the second bearing 42 is a load-bearing surface, which is used to bear the forward axial force of the main shaft 1. The load-bearing surface of the first bearing 41 is provided with 12 first grooves 411 and 12 pads. The 12 pads and the 12 first grooves 411 are arranged at intervals, that is, each first groove 411 is located between two adjacent pads, so that the 12 first grooves 411 are arranged at intervals, thereby ensuring that the lubricating oil is evenly distributed between the first bearing 41 and the second bearing 42.

[0063] Specifically, the side of the pad facing the second bearing is a wedge-shaped surface, allowing lubricating oil to be distributed between the pad and the second bearing 42. Specifically, the lubricating oil is distributed not only within the first groove 411 but also between the pad and the second bearing, thereby supporting the forward axial force of the spindle. Furthermore, the wedge-shaped structure of the pad allows the distribution of lubricating oil between the first and second bearings 41, 42 to gradually decrease from the center toward the periphery, further enhancing the retention of lubricating oil and, consequently, the ability to support the forward axial force of the spindle 1. By configuring the pad as a wedge-shaped surface, the contact area between the first and second bearings is reduced, thereby reducing sliding friction between them.

[0064] Of course, the number of the first grooves 411 and the tiles can also be other numbers, which can be adjusted according to actual conditions.

[0065] In a specific embodiment, the end face of the third bearing 43 facing the second bearing 42 is a load-bearing surface for bearing the backward axial force of the main shaft 1. The load-bearing surface of the third bearing 43 is provided with 12 second grooves 431 and 12 pads. The 12 pads and the 12 second grooves 431 are arranged at intervals, that is, each second groove 431 is located between two adjacent pads, so that the 12 second grooves 431 are arranged at intervals, thereby ensuring that the lubricating oil can be evenly distributed between the second bearing 42 and the third bearing 43.

[0066] Specifically, the side of the shoe facing the second bearing is a wedge-shaped surface, so that the lubricating oil can be distributed between the shoe and the second bearing 42, that is, the lubricating oil is not only distributed in the second groove 431, but also distributed between the shoe and the second bearing, for bearing the rearward axial force of the main shaft, and due to the wedge-shaped surface structure of the shoe, the distribution of the lubricating oil between the third bearing 43 and the second bearing 42 can also be made to gradually decrease from the center to the surrounding area, further improving the retention effect of the lubricating oil, and thereby improving the bearing effect of the rearward axial force of the main shaft 1.

[0067] Of course, the number of the second grooves 431 and the tiles can also be other numbers, which can be adjusted according to actual conditions.

[0068] like Figure 4-6 As shown, in some embodiments, the first groove 411 is provided to extend along the radial direction of the first bearing 41 , and the second groove 431 is provided to extend along the radial direction of the third bearing 43 .

[0069] In the present application, the first groove 411 extends radially along the first bearing 41, so that during the rotation of the second bearing 42, the centrifugal force can drive the lubricating oil in the first groove 411 to fill the first groove 411, thereby ensuring that the lubricating oil can be fully distributed in the first groove 411, further ensuring the effectiveness of bearing the axial force of the main shaft 1. The second groove 431 extends radially along the third bearing 43, so that during the rotation of the second bearing 42, the centrifugal force can drive the lubricating oil in the second groove 431 to fill the second groove 431, thereby ensuring that the lubricating oil can be fully distributed in the second groove 431, further ensuring the effectiveness of bearing the axial force of the main shaft 1.

[0070] Specifically, the first groove 411 is a strip-shaped structure extending radially along the first bearing 41. After the lubricating oil enters the first groove 411 of the strip structure, it can be filled with the first groove 411 under the action of centrifugal force. The second groove 431 is a strip-shaped structure extending radially along the third bearing 43. After the lubricating oil enters the second groove 431, it can be filled with the second groove 431 under the action of centrifugal force.

[0071] Optionally, the first groove 411 may extend in a straight line or arc that forms an angle with the radial direction of the first bearing 41 . The second groove 431 may extend in a straight line or arc that forms an angle with the radial direction of the third bearing 43 .

[0072] like Figure 2 As shown, in some embodiments, the first bearing 41 is provided with a first oil inlet hole 412 along its own axial direction, and the first groove 411 is connected to the oil supply passage 31 through the first oil inlet hole 412; the third bearing 43 is provided with a second oil inlet hole 432 along its own axial direction, and the second groove 431 is connected to the oil supply passage 31 through the second oil inlet hole 432.

[0073] In the present application, the lubricating oil in the oil supply passage 31 passes through the first bearing 41 from one end of the first bearing 41 through the first bearing 41 to the first groove 411 through the first oil inlet hole 412, and is used to bear the forward axial force of the main shaft 1. By passing the lubricating oil from the side of the first bearing 41 away from the second bearing 42 into the first groove 411, the occupation of the bearing surface of the first bearing 41 is reduced, and the bearing effect of the forward axial force of the main shaft 1 is further guaranteed. The lubricating oil in the oil supply passage 31 passes through the third bearing 43 from one end of the third bearing 43 through the second oil inlet hole 432 to the second groove 431, and is used to bear the backward axial force of the main shaft 1. By passing the lubricating oil from the side of the third bearing 43 away from the second bearing 42 into the second groove 431, the occupation of the bearing surface of the third bearing 43 can be reduced, and the bearing effect of the backward axial force of the main shaft 1 can be further guaranteed.

[0074] In some embodiments, an annular groove 413 is provided on the outer peripheral surface of the first bearing 41 , and the first oil inlet hole 412 is connected to the oil supply passage 31 through the annular groove 413 .

[0075] In the present application, an annular groove 413 is provided on the outer peripheral surface of the first bearing 41, and the annular groove 413 is connected to a plurality of first oil inlet holes 412. The plurality of first oil inlet holes 412 are parallel to the axial direction of the first bearing 41. The lubricating oil in the oil supply passage 31 first enters the annular groove 413 and fills the annular groove 413 under the action of pressure, and then enters the plurality of first grooves 411 through the plurality of first oil inlet holes 412 respectively, so that the lubricating oil in the plurality of first grooves 411 maintains the same pressure, thereby further improving the bearing effect of the forward axial force of the main shaft 1.

[0076] Moreover, by providing an annular groove 413 communicating with the plurality of first oil inlet holes 412 , while ensuring balanced distribution of lubricating oil, the structure is relatively simple, facilitating the processing and forming of the first bearing 41 .

[0077] Specifically, the first bearing 41 includes a first section and a second section along its own axial direction. The diameter of the first section is smaller than the diameter of the second section. The annular groove 413 is set in the first section, and the first groove 411 is set on the end face of the second section. It can not only ensure the fitting area between the second bearing 42 and the bearing effect of the forward axial force of the main shaft 1, but also reduce the processing depth of the annular groove 413, so that the annular groove 413 can be connected with the center of the first groove 411 close to the first bearing 41, so that the lubricating oil entering the first groove 411 can be dispersed to the surroundings under the action of centrifugal force, that is, it is hot and covers the first groove 411.

[0078] Among them, a step surface facing the impeller 2 is formed between the first section and the second section of the first bearing 41, and a limiting step that cooperates with the above-mentioned step surface is provided in the end cover assembly 3. The first bearing 41 realizes axial limitation through the cooperation between the step surface and the limiting step, so that the first bearing 41 cannot move forward (that is, the end of the main shaft with the impeller), thereby enabling the first bearing 41 to effectively bear the forward axial force of the second bearing 42 and the main shaft 1.

[0079] In some embodiments, an oil distribution groove 414 is provided on the inner surface of the first bearing 41 , and the oil distribution groove 414 is connected to the annular groove 413 through a connecting hole 415 on the first bearing 41 .

[0080] In the present application, part of the lubricating oil entering the annular groove 413 enters the first groove 411 through the first oil inlet hole 412, and the other part enters the oil distribution groove 414 through the connecting hole 415, and then is distributed between the main shaft 1 and the first bearing 41 through the oil distribution groove 414, forming an oil film on the radial contact surface of the main shaft 1 and the first bearing 41, which plays a role in radially supporting the weight of the main shaft 1. In addition, it can also lubricate the main shaft 1 and the first bearing 41.

[0081] Specifically, the oil distribution groove 414 is an annular structure, so that the oil entering the oil distribution groove 414 can be fully distributed between the main shaft 1 and the first bearing 41, and under the rotation of the main shaft 1, the gap between the main shaft 1 and the first bearing 41 is fully filled.

[0082] Because the first bearing 41 also bears the radial weight of the main shaft, the axial length of the first bearing 41 is longer than the axial length of the third bearing 43. The third bearing 43 is only used to bear the rearward axial force of the main shaft 1, and its bearing surface is mainly concentrated on the end surface facing the second bearing 42. Therefore, the length of the third bearing can be appropriately reduced, reducing the space occupied by the end cover assembly 3.

[0083] The communicating hole 415 is provided along the radial direction of the first bearing 41 , with one end communicating with the annular groove 413 and the other end communicating with the oil distribution groove 414 .

[0084] In a specific embodiment, an oil guide groove 417 is axially provided on the inner surface of the first bearing 41, and the oil guide groove 417 is connected to the oil distribution groove, so that the lubricating oil entering the oil distribution groove can flow along the oil guide groove 417, and then the lubricating oil can flow axially in the gap between the first bearing 41 and the main shaft 1, thereby ensuring that the lubricating oil can be fully filled between the first bearing 41 and the main shaft 1.

[0085] There are multiple oil guide grooves 417 , which are evenly distributed along the circumference of the inner surface of the first bearing, thereby further improving the uniformity of the distribution of the lubricating oil between the first bearing 41 and the main shaft 1 .

[0086] Specifically, the cross-section of the oil guide groove 417 is triangular, and the opening of the oil guide groove 417 toward the main shaft 1 is of a gradually expanding design, which can not only transport the lubricating oil in the axial direction, but also effectively increase the coverage area of the oil guide groove 417 on the main shaft 1, so that the lubricating oil in the oil guide groove 417 adheres to the surface of the main shaft 1 and enters the gap between the main shaft 1 and the first bearing 41 as the main shaft 1 rotates, filling the gap between the first bearing 41 and the main shaft 1, thereby achieving a lubricating effect and ensuring the bearing effect of the first bearing 41 on the radial gravity of the main shaft 1.

[0087] In some embodiments, the end cover assembly 3 includes an end cover body 33 and a cover plate 34 connected to the end cover body 33 , a closed cavity 5 is formed between the third bearing 43 and the cover plate 34 , and the second oil inlet hole 432 is connected to the oil supply passage 31 through the closed cavity 5 .

[0088] In the present application, a space for accommodating the axial bearing group 4 is formed between the end cover body 33 and the cover plate 34, the first bearing 41 is fixed in the space, the cover plate 34 is assembled and fixed to the end cover body 33, and the third bearing 43 and the cover plate 34 are interference fit to form a closed cavity 5, which prevents the lubricating oil from falling into the end cover cavity through the gap between the third bearing 43 and the cover plate 34 and returning to the oil tank through the return oil passage 36, thereby ensuring the oil storage amount required for the normal operation of the third bearing 43 and avoiding the problem of abnormal operation of the compressor caused by wear of the bearing surface of the third bearing 43.

[0089] Specifically, lubricating oil enters the sealed cavity between the cover plate 34 and the third bearing 43 through the oil supply passage 31, and then enters the second groove 431 through the second oil inlet hole 432. The sealed cavity has an annular structure, allowing the lubricating oil in the sealed cavity 5 to enter the multiple second grooves 431 through the multiple second oil inlet holes 432, ensuring uniform distribution of the lubricating oil within the multiple second grooves 431, thereby ensuring the effectiveness of bearing the rearward axial force of the main shaft 1.

[0090] In the present application, by creating an interference fit between the third bearing 43 and the cover plate 34 to form a sealed cavity 5, the lubricating oil in the oil supply passage enters the sealed cavity 5 and is evenly distributed. The oil then enters the plurality of second grooves 431 through the plurality of second oil inlet holes 432, thereby evenly distributing the lubricating oil within the plurality of second grooves 431. Furthermore, even lubricating oil can be uniformly supplied to the plurality of second grooves 431 without machining corresponding annular grooves on the third bearing 43, facilitating the machining and forming of the third bearing 43.

[0091] Specifically, a first limiting boss is provided on one end of the third bearing 43 facing the cover plate 34, and a second limiting boss is provided on the other end of the cover plate 34 facing the third bearing 43. The second limiting boss cooperates with the first limiting boss to limit and fix the third bearing 43. It can not only limit the third bearing 43 in the axial direction so that the third bearing 43 will not move away from the impeller 2, but also limit the third bearing 43 in the radial direction, thereby ensuring the stability of the third bearing 43, and then ensuring the stability of the relative position between the third bearing 43 and the second bearing 42, and ensuring the bearing effect of the third bearing 43 on the second bearing 42 and the backward axial force of the main shaft 1.

[0092] In some embodiments, the outer peripheral surface of the first bearing 41 is provided with a first oil unloading port 416 connected to the first groove 411, and the outer peripheral surface of the third bearing 43 is provided with a second oil unloading port 433 connected to the second groove 431. The first oil unloading port 416 and the second oil unloading port 433 are connected to the oil return passage 36 on the end cover assembly 3.

[0093] In the present application, the first oil unloading port 416 is provided at the outer end of the first groove 411, and the first oil inlet 32 is connected to the portion of the first groove 411 away from the first oil unloading port 416, so that the lubricating oil entering the first groove 411 can fully fill the first groove 411 under the action of centrifugal force, and then enter the oil return passage 36 through the first oil unloading port 416 and return to the oil tank. The second oil unloading port 433 is provided at the outer end of the second groove 431, and the second oil inlet 32 is connected to the portion of the second groove 431 away from the second oil unloading port 433, so that the lubricating oil in the second groove 431 can fully fill the second groove 431 under the action of centrifugal force, and then enter the oil return passage 36 through the second oil unloading port 433 and return to the oil tank. The normal amount and pressure of the lubricating oil in the first groove 411 and the second groove 431 are ensured, thereby ensuring the bearing effect of the axial force of the main shaft 1.

[0094] Specifically, the first oil unloading port 416 and the second oil unloading port 433 are small ports that are much smaller than the width of the first groove 411 and the second groove 431, thereby maintaining the pressure and oil storage volume of the lubricating oil in the first groove 411 and the second groove 431, thereby ensuring that the lubricating oil can effectively bear the axial force of the main shaft 1.

[0095] In some embodiments, the first oil unloading port 416 is provided at the end of the first groove 411 away from the main shaft 1, and an opening is provided at the end of the first groove 411 adjacent to the main shaft 1, so that part of the lubricating oil in the first groove 411 can enter the gap between the first bearing 41 and the main shaft 1 through the opening, thereby lubricating the first bearing 41 and the main shaft 1, making it easier for the first bearing 41 to bear the radial gravity of the main shaft 1.

[0096] In some embodiments, the second oil unloading port 433 is arranged at the end of the second groove 431 away from the main shaft 1, and an opening is provided at the end of the second groove 431 adjacent to the main shaft 1, so that part of the lubricating oil in the second groove 431 can enter the gap between the third bearing 43 and the main shaft through the opening, thereby lubricating the third bearing 43 and the main shaft 1.

[0097] In some embodiments, the oil supply passage 31 includes: a first oil supply passage 311, connected to the first load-bearing gap; and a second oil supply passage 312, arranged in parallel with the first oil supply passage 311, and the second oil supply passage 312 is connected to the second load-bearing gap; wherein, a regulating valve 35 is provided on the first oil supply passage 311 and / or the second oil supply passage 312, and the regulating valve 35 is used to adjust the amount of oil entering the first oil supply passage 311 and the second oil supply passage 312.

[0098] In the present application, by setting up a first oil supply passage 311 and a second oil supply passage 312 in parallel, the amount of lubricating oil distributed in the first oil supply passage 311 and the second oil supply passage 312 can be adjusted by the regulating valve 35 to better cope with the changes in the axial force of the compressor main shaft 1. Specifically, when the compressor is running, if the internal axial force of the compressor is forward, the first bearing 41 not only needs to bear the gravity of the main shaft 1, but also needs to bear the forward axial force of the main shaft 1, while the third bearing 43 is equivalent to having no effect. In this case, the oil intake of the second oil supply passage 312 can be appropriately reduced to ensure the oil storage required for the normal operation of the first bearing 41. If the internal axial force of the compressor is backward, the first bearing 41 only needs to bear the gravity of the main shaft 1 and does not need to bear the axial force of the main shaft 1. The third bearing 43 bears the backward axial force of the main shaft 1. In this case, the oil intake of the second oil supply passage 312 can be appropriately increased to ensure the oil storage required for the normal operation of the third bearing 43.

[0099] Specifically, the end cap assembly 3 also includes an external pipeline, which forms the aforementioned second oil supply passage 312. One end of the external pipeline is connected to the end cap body 33 via a shutoff valve, and the other end is connected to the cover plate 34 via a shutoff valve. The two shutoff valves are regulating valves 35, which are used to distribute the amount of lubricating oil entering the first oil supply passage 311 and the second oil supply passage 312. The external pipeline is a copper tube and is connected to the end cap body 33 and the cover plate 34 via a shutoff valve, facilitating assembly.

[0100] The direction and magnitude of the axial force of the main shaft 1 can be determined by disassembling and inspecting the actual compressor and using calculation and analysis software. Later, the regulating valve 35 can be adjusted accordingly based on the operating conditions of the compressor. When the axial force of the main shaft 1 is directed forward, the oil flow through the first oil supply passage 311 is increased, and the amount of lubricating oil pumped in is adjusted according to the magnitude of the forward axial force, ensuring that the forward axial force of the main shaft 1 can be effectively supported. When the axial force of the main shaft 1 is directed backward, the amount of lubricating oil pumped into the second oil supply passage 312 is increased, and the amount of lubricating oil pumped in is adjusted according to the magnitude of the backward axial force, ensuring that the backward axial force of the main shaft 1 can be effectively supported.

[0101] Optionally, a sensor can be provided to detect the axial force of the spindle 1. The sensor can detect the direction and magnitude of the axial force of the spindle 1. When the axial force of the spindle 1 is forward, the amount of lubricating oil pumped into the first oil supply passage 311 is increased, and the amount of lubricating oil pumped into the first oil supply passage 311 is adjusted according to the magnitude of the forward axial force of the spindle 1, so that the lubricating oil in the first load-bearing gap can effectively bear the forward axial force of the spindle 1. When the axial force of the spindle 1 is backward, the amount of lubricating oil pumped into the second oil supply passage 312 is increased, and the amount of lubricating oil pumped into the second oil supply passage 312 is adjusted according to the magnitude of the backward axial force of the spindle 1, so that the lubricating oil in the second load-bearing gap can effectively bear the backward axial force of the spindle 1.

[0102] In some embodiments, a side of the first bearing 41 facing the second bearing 42 is made of heat-insulating material or provided with a heat-insulating layer, and a side of the third bearing 43 facing the second bearing 42 is made of heat-insulating material or provided with a heat-insulating layer.

[0103] In the present application, by using heat-insulating materials or providing heat-insulating layers on the bearing surfaces of the first bearing 41 and the third bearing 43, heat can be further prevented from being transferred to the first bearing 41 and the third bearing 43, thereby reducing the temperature rise of the first bearing 41 and the third bearing 43, and thereby protecting the first bearing 41 and the second bearing 42.

[0104] Specifically, the bearing surfaces of the first bearing 41 and the third bearing 43 can be made of materials with low thermal conductivity, such as stainless steel and ceramics. Among them, ceramics not only have low thermal conductivity but also high structural strength, which can effectively ensure the service life of the bearing surfaces.

[0105] The oil supply mechanism forms a first load-bearing gap between the first bearing 41 and the second bearing 42, so that the lubricating oil in the oil supply passage 31 enters the first load-bearing gap to bear the axial force of the main shaft 1 toward the impeller 2. By forming a second load-bearing gap between the second bearing 42 and the third bearing 43, the lubricating oil in the oil supply passage 31 enters the second load-bearing gap to bear the axial force of the main shaft 1 in the direction away from the impeller 2. The axial bearing group 4 is away from the high-temperature end of the main shaft 1 and has a lower temperature, which can effectively reduce the impact of high temperature. The composite bearing 6 located at the high-temperature end of the main shaft 1 does not need to bear the axial force of the main shaft 1, thereby reducing the transmission of high temperature to the composite bearing 6, reducing the wear of the composite bearing 6, and improving the reliability of the operation of the centrifugal compressor.

[0106] like Figure 3 As shown, an embodiment of the present application provides a compressor, comprising: a main shaft 1; an impeller 2, arranged at one end of the main shaft 1; a composite bearing 6, arranged on the outer peripheral side of the main shaft 1 and adjacent to the impeller 2; and the above-mentioned oil supply mechanism, which is arranged at the end of the main shaft 1 away from the impeller 2.

[0107] In this application, the compressor is a high-temperature centrifugal heat pump compressor with complex operating conditions. The temperature at the impeller 2 is high, and the working environment of the front composite bearing 6 is harsh. By allowing the front composite bearing 6 to bear only the gravity of the main shaft 1, while concentrating the axial force of the main shaft 1 on the rear axial bearing group 4, the axial bearing group 4 is farther away from the impeller 2 and has a lower temperature, and is used to bear the axial force caused by the pressure difference inside the compressor. This ensures the normal operation of the compressor, while reducing the impact of high temperature on the composite bearing 6, reducing the wear of the composite bearing 6, and improving the operational reliability of the entire compressor.

[0108] This compressor has a simple structure, is highly applicable to heat pump compressors, is easy to implement, and can largely ensure the normal operation of the composite bearing 6 and the axial bearing group 4, thereby improving the operating reliability of the compressor.

[0109] Specifically, in the present application, the radial gravity of the main shaft 1 is mainly borne by the front composite bearing 6 and the rear first bearing 41, and the axial force of the main shaft 1 is borne by the axial bearing group 4. Specifically, lubricating oil is pumped into the first load-bearing gap between the first bearing 41 and the second bearing 42 to bear the forward axial force of the main shaft 1, and lubricating oil is pumped into the second load-bearing gap between the third bearing 43 and the second bearing 42 to bear the backward axial force of the main shaft 1.

[0110] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0111] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0112] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An oil supply mechanism, applied to a compressor, comprising a main shaft (1) and an impeller (2) arranged at one end of the main shaft (1), characterized in that: The oil supply mechanism comprises: an end cover assembly (3) disposed at an end of the main shaft (1) away from the impeller (2), the end cover assembly (3) being provided with an oil supply passage (31) and an oil inlet (32) communicating with the oil supply passage (31), the oil inlet (32) being connected to an external oil supply device; and An axial bearing group (4) is arranged in the end cover assembly (3), and the axial bearing group (4) includes a second bearing (42) fixedly arranged on the outer periphery of the main shaft (1); The axial bearing group (4) further comprises a first bearing (41), the first bearing (41) being sleeved on the outer periphery of the main shaft (1) and being located on the side of the second bearing (42) facing the impeller (2), a first load-bearing gap being formed between the first bearing (41) and the second bearing (42), and the first load-bearing gap being connected to the oil supply passage (31); and / or the axial bearing group (4) further comprises a third bearing (43), the third bearing (43) being sleeved on the outer periphery of the main shaft (1) and being located on the side of the second bearing (42) facing away from the impeller (2), a second load-bearing gap being formed between the third bearing (43) and the second bearing (42), and the second load-bearing gap being connected to the oil supply passage (31).

2. The oil supply mechanism according to claim 1, characterized in that: A first groove (411) is provided at one end of the first bearing (41) facing the second bearing (42), and the first bearing gap is formed between the first groove (411) and the second bearing (42); and / or, A second groove (431) is provided at one end of the third bearing (43) facing the second bearing (42), and the second bearing gap is formed between the second groove (431) and the second bearing (42).

3. The oil supply mechanism according to claim 2, characterized in that: A plurality of the first grooves (411) are provided, and the plurality of the first grooves (411) are arranged at intervals along the circumference of the first bearing (41); and / or, A plurality of the second grooves (431) are provided, and the plurality of the second grooves (431) are spaced apart along the circumference of the third bearing (43).

4. The oil supply mechanism according to claim 2 or 3, characterized in that: The first groove (411) is arranged to extend radially of the first bearing (41), and the second groove (431) is arranged to extend radially of the third bearing (43).

5. The oil supply mechanism according to claim 2 or 3, characterized in that: The first bearing (41) is provided with a first oil inlet hole (412) along its own axial direction, and the first groove (411) is connected to the oil supply passage (31) through the first oil inlet hole (412); and / or, The third bearing (43) is provided with a second oil inlet hole (432) along its own axial direction, and the second groove (431) is connected to the oil supply passage (31) through the second oil inlet hole (432).

6. The oil supply mechanism according to claim 5, characterized in that: An annular groove (413) is provided on the outer peripheral surface of the first bearing (41), and the first oil inlet hole (412) is connected to the oil supply passage (31) through the annular groove (413).

7. The oil supply mechanism according to claim 6, characterized in that: An oil distribution groove (414) is provided on the inner surface of the first bearing (41), and the oil distribution groove (414) is connected to the annular groove (413) through a connecting hole (415) on the first bearing (41).

8. The oil supply mechanism according to claim 5, characterized in that: The end cover assembly (3) comprises an end cover body (33) and a cover plate (34) connected to the end cover body (33); a sealed cavity (5) is formed between the third bearing (43) and the cover plate (34); and the second oil inlet hole (432) is connected to the oil supply passage (31) through the sealed cavity (5).

9. The oil supply mechanism according to claim 2, characterized in that: The outer peripheral surface of the first bearing (41) is provided with a first oil unloading port (416) communicating with the first groove (411), and the outer peripheral surface of the third bearing (43) is provided with a second oil unloading port (433) communicating with the second groove (431). The first oil unloading port (416) and the second oil unloading port (433) are communicated with the oil return passage (36) on the end cover assembly (3).

10. The oil supply mechanism according to claim 1, characterized in that: The oil supply passage (31) includes: A first oil supply passage (311) communicating with the first load-bearing gap; and A second oil supply passage (312) is provided in parallel with the first oil supply passage (311), and the second oil supply passage (312) is connected to the second bearing gap; The first oil supply passage (311) and / or the second oil supply passage (312) are provided with a regulating valve (35), and the regulating valve (35) is used to regulate the amount of oil entering the first oil supply passage (311) and the second oil supply passage (312).

11. The oil supply mechanism according to claim 1, characterized in that: The side of the first bearing (41) facing the second bearing (42) is made of heat-insulating material or provided with a heat-insulating layer, and the side of the third bearing (43) facing the second bearing (42) is made of heat-insulating material or provided with a heat-insulating layer.

12. A compressor, characterized in that: include: spindle (1); An impeller (2) is arranged at one end of the main shaft (1); a composite bearing (6) disposed on the outer peripheral side of the main shaft (1) and adjacent to the impeller (2); and The oil supply mechanism according to any one of claims 1 to 11, wherein the oil supply mechanism is arranged at an end of the main shaft (1) away from the impeller (2).

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