Bearing lubricating structure and vacuum pump

Abstract

The utility model provides a bearing lubricating structure and a vacuum pump. The bearing lubricating structure comprises an assembly part, a bearing and an oil stirring rotating shaft. An oil storage space is arranged on one side of the assembly part. The assembly part is provided with an assembly hole. The oil stirring rotating shaft penetrates through the assembly hole and extends into the oil storage space, and the bearing is fixed between the assembly part and the oil stirring rotating shaft in an abutting mode. The assembly part is provided with a first oil inlet channel and a second oil inlet channel, the bearing comprises a first end face and a second end face which are oppositely arranged, and inlets of the first oil inlet channel and the second oil inlet channel are communicated with the oil storage space. An outlet of the first oil inlet channel faces the first end face, and an outlet of the second oil inlet channel faces the second end face. Lubricating oil in the oil storage space can lubricate the two end faces of the bearing at the same time through the first oil inlet channel and the second oil inlet channel, and the lubricating and cooling effects of the bearing lubricating structure are improved.

Description

Technical Field

[0001] The present application relates to the technical field of lubrication structures, and in particular to a bearing lubrication structure and a vacuum pump. Background Art

[0002] Bearings are an important component in modern mechanical equipment and are widely used in equipment such as vacuum pumps. The main function of bearings is to support mechanical rotating bodies, reduce friction, and ensure their rotation accuracy.

[0003] The lubrication effect of the traditional bearing lubrication structure is insufficient, resulting in a short life of the bearing. Taking the dry vacuum pump as an example, the dry vacuum pump generally adopts splash lubrication, which throws the lubricating oil from the inside of the oil tank through the gears and the oil-slinging plate, and the lubricating oil splashes to the bearing for lubrication and cooling, but the lubricating oil directly splashed into the bearing is limited. Utility Model Content

[0004] The present application provides a bearing lubrication structure and a vacuum pump to solve related technical problems.

[0005] The present application provides a bearing lubrication structure, including an assembly, a bearing and an oil stirring shaft;

[0006] An oil storage space is provided on one side of the assembly, and an assembly hole is provided on the assembly. The oil stirring shaft passes through the assembly hole and extends into the oil storage space. The bearing is abutted and fixed between the assembly and the oil stirring shaft.

[0007] The assembly is provided with a first oil inlet passage and a second oil inlet passage, the bearing comprises a first end face and a second end face arranged opposite to each other, and the inlets of the first oil inlet passage and the second oil inlet passage are connected to the oil storage space;

[0008] The outlet of the first oil inlet passage faces the first end surface, and the outlet of the second oil inlet passage faces the second end surface.

[0009] Furthermore, the assembly includes a base, a mounting seat fixed to the base, and a pressure plate assembled to the mounting seat, and the bearing is disposed in the mounting seat.

[0010] Furthermore, the base and the pressure plate are respectively located on two sides of the mounting seat, the first oil inlet passage is arranged between the base and the mounting seat, and the second oil inlet passage is arranged between the mounting seat and the pressure plate.

[0011] Furthermore, the mounting seat includes a main body and a flange located at one end of the main body, and the flange is connected and fixed to the base and the pressure plate.

[0012] Further, the flange includes a first surface facing the base and a second surface facing the pressing plate;

[0013] The first surface is provided with a first groove, the first groove forms at least a part of the first oil inlet passage, and / or the second surface is provided with a second groove, the second groove forms at least a part of the second oil inlet passage.

[0014] Further, the first surface is provided with a first groove, the mounting seat includes an outer side surface between two ends, the outer side surface is provided with a flow channel connected to the first groove, and the first groove and the flow channel form the first oil inlet channel.

[0015] Further, the second surface is provided with a second groove; the pressure plate includes a third surface facing the second surface, the third surface is provided with a third groove arranged in alignment with the second groove, and the second groove and the third groove form the second oil inlet channel.

[0016] Further, the circumferential width of the first slot and / or the second slot gradually decreases in the radial direction toward the center of the circle.

[0017] Furthermore, the flow channel is provided with an oil inlet section and an oil guide section which are connected at the end, the oil inlet section extends in the radial direction of the bearing, and the oil guide section extends in the axial direction of the bearing.

[0018] Furthermore, the mounting seat is in the shape of a hollow cylinder, and the mounting seat includes a continuous side wall abutting against the outer ring of the bearing.

[0019] Furthermore, the assembly is provided with a first oil return channel and a second oil return channel, the outlets of the first oil return channel and the second oil return channel are connected to the oil storage space, the inlet of the first oil return channel is arranged toward the first end face, and the inlet of the second oil return channel is arranged toward the second end face.

[0020] Furthermore, the inner wall of the assembly hole is provided with grooves on both sides in the axial direction of the bearing.

[0021] The present application also provides a vacuum pump, comprising the above-mentioned bearing lubrication structure.

[0022] The technical solution provided by the present application can at least achieve the following beneficial effects: since the outlet of the first oil inlet channel is toward the first end face and the outlet of the second oil inlet channel is toward the second end face, under the rotation of the oil stirring shaft, the lubricating oil can lubricate the two end faces of the bearing at the same time, so that the lubrication and cooling of the bearing are optimized, the service life of the bearing is extended, and the reliability of the bearing is improved.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and, together with the description, serve to explain the principles of the specification.

[0025] Figure 1 is a partial cross-sectional view of a vacuum pump in an exemplary embodiment of the present application;

[0026] Figure 2 yes Figure 1 A partial cross-sectional view of the vacuum pump in another section;

[0027] Figure 3 yes Figure 1 A front view of the vacuum pump;

[0028] Figure 4 is a structural diagram of a mounting base in an exemplary embodiment of the present application;

[0029] Figure 5 yes Figure 4 The structural diagram of the middle mounting seat from the front view;

[0030] Figure 6 yes Figure 4 The structural diagram of the middle mounting seat from the back side;

[0031] Figure 7 yes Figure 4 A cross-sectional view of the middle mounting seat;

[0032] Figure 8 It is a structural diagram of a pressing plate in an exemplary embodiment of the present application.

[0033] Description of the accompanying drawings: assembly part, 10; oil storage space, 100; assembly hole, 101; groove, 1011; first oil inlet passage, 102; second oil inlet passage, 103; first oil return passage, 104; second oil return passage, 105; base, 11; connecting part, 111; accommodating part, 112; mounting seat, 12; main body, 121; outer side, 1211; flow channel, 1212; first through port, 1213; second through port, 1214; bottom wall, 1215 ; flange, 122; first surface, 1221; second surface, 1222; first groove, 1223; second groove, 1224; notch, 1225; pressure plate, 13; limiting portion, 131; third surface, 1311; third groove, 1312; assembly portion, 132; bearing, 20; first end face, 201; second end face, 202; oil stirring shaft, 30; shaft body, 31; gear, 32; oil throwing plate, 33; oil retaining ring, 40; housing, 60. DETAILED DESCRIPTION

[0034] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this specification. Instead, they are merely examples of devices and methods consistent with some aspects of this specification as detailed in the appended claims.

[0035] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Unless otherwise defined, the technical terms or scientific terms used in this specification should be understood by people with ordinary skills in the field to which this application belongs. The words "first", "second" and similar words used in this specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantitative limit, but indicate that there is at least one. "Multiple" or "several" means two and more than two. Unless otherwise specified, words such as "front", "rear", "lower" and / or "upper" are only for the convenience of explanation and are not limited to one position or one spatial orientation. Words such as "include" or "comprise" mean that the elements or objects appearing in front of "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, and can include electrical connections, whether direct or indirect.

[0036] The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms of "a", "the" and "the" used in this specification and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0037] Next, the embodiments of this specification are described in detail.

[0038] At present, the lubrication effect of the bearing lubrication structure is poor and the life of the bearing is short. Taking a dry vacuum pump as an example, a traditional dry vacuum pump generally adopts splash lubrication, where the lubricating oil is thrown out from the inside of the oil tank through gears and an oil-slinging plate, and the lubricating oil is splashed to the bearing for lubrication and cooling, but the lubricating oil directly splashed into the bearing is limited. The present application provides a bearing lubrication structure to solve the related technical problems.

[0039] like Figure 1 and Figure 2As shown, the present application provides a bearing lubrication structure, including an assembly 10, a bearing 20 and an oil stirring shaft 30. An oil storage space 100 is provided on one side of the assembly 10, and an assembly hole 101 is provided on the assembly 10. The oil stirring shaft 30 extends into the oil storage space 100 through the assembly hole 101, and the bearing 20 is fixed between the assembly 10 and the oil stirring shaft 30.

[0040] The assembly 10 is provided with a first oil inlet passage 102 and a second oil inlet passage 103, and the bearing 20 includes a first end face 201 and a second end face 202 arranged opposite to each other. The inlets of the first oil inlet passage 102 and the second oil inlet passage 103 are connected to the oil storage space 100, and the outlet of the first oil inlet passage 102 faces the first end face 201, and the outlet of the second oil inlet passage 103 faces the second end face 202.

[0041] Since the outlet of the first oil inlet passage 102 faces the first end face 201 and the outlet of the second oil inlet passage 103 faces the second end face 202 , the end faces on both sides of the bearing 20 can be lubricated, thereby improving the lubrication effect of the bearing lubrication structure and extending the life of the bearing 20 .

[0042] During operation, the oil stirring shaft 30 rotates, and the lubricating oil in the oil storage space 100 is stirred, splashed, and enters the first oil inlet passage 102 and the second oil inlet passage 103. The lubricating oil in the first oil inlet passage 102 flows to the first end face 201. The lubricating oil in the second oil inlet passage 103 flows to the second end face 202. The first end face 201 and the second end face 202 are both lubricated with lubricating oil, and the lubrication and cooling of the bearing 20 are optimized.

[0043] In one embodiment, if Figures 1 to 3 As shown, the assembly 10 may be provided with a first oil return passage 104 and a second oil return passage 105. The outlets of the first oil return passage 104 and the second oil return passage 105 are connected to the oil storage space 100. The inlet of the first oil return passage 104 is arranged toward the first end surface 201, and the inlet of the second oil return passage 105 is arranged toward the second end surface 202.

[0044] By setting up the oil return channel, the bearing lubrication structure of the present application can perform circulating lubrication, avoid lubricating oil accumulation, and reduce the oil stirring power. The temperature of the lubricating oil will increase after passing through the bearing 20. When it enters the oil storage space 100 through the oil return channel, it will mix with the low-temperature lubricating oil. The oil stirring shaft 30 will then send the lubricating oil with a lower temperature into the bearing 20, which can improve the lubrication and cooling effect of the bearing 20.

[0045] In one embodiment, if Figure 1 and Figure 2As shown, the inner wall of the assembly hole 101 is provided with grooves 1011 on both sides of the bearing 20 in the axial direction. The grooves 1011 are arranged on the path of the first oil return passage 104 and the second oil return passage 105, which can reduce the oil level when the lubricating oil accumulates and reduce the impact load on the retainer of the bearing 20.

[0046] like Figure 1 As shown, the assembly 10 may include a base 11, a mounting seat 12 and a pressure plate 13. The mounting seat 12 is fixed to the base 11. The pressure plate is assembled to the mounting seat 12. The bearing 20 is arranged in the mounting seat 12. By arranging multiple parts to assemble the bearing 20, the manufacturing difficulty is reduced.

[0047] In order to ensure that the bearing 20 and the oil stirring shaft 30 can be installed smoothly, the base 11, the mounting seat 12 and the pressure plate 13 are provided with a coaxial hole structure. The hole structure of the base 11, the mounting seat 12 and the pressure plate 13 forms an assembly hole 101 for installing the bearing 20. The diameters of the hole structures on the base 11, the mounting seat 12 and the pressure plate 13 may be different to form a step structure that abuts against each other, which can improve the installation strength of the bearing lubrication structure. In other embodiments, the assembly 10 may be an integrated component, and the assembly hole 101 is a through hole provided on the assembly 10, which can improve manufacturing efficiency.

[0048] In the embodiment where the assembly 10 is provided with the first oil return passage 104 and the second oil return passage 105, the first oil return passage 104 may be a groove structure at the bottom of the base 11, the groove structure is connected with the assembly hole 101, and the lubricating oil at the first end surface 201 may flow into the oil storage space 100 through the groove structure. The second oil return passage 105 may be formed by a hole structure on the pressing plate 13, the hole structure of the pressing plate 13 is connected with the oil storage space 100, and the lubricating oil on the second end surface 202 may return to the oil storage space 100 through the bottom of the hole structure on the pressing plate 13.

[0049] In one embodiment, the base 11 and the pressure plate 13 can be located on both sides of the mounting seat 12, respectively, the first oil inlet channel 102 is arranged between the base 11 and the mounting seat 12, and the second oil inlet channel 103 is arranged between the mounting seat 12 and the pressure plate 13. The two oil inlets are arranged close to the mounting seat 12, so that the overall bearing lubrication structure is more compact, and the splashing lubricating oil is easier to enter the first oil inlet channel 102 and the second oil inlet channel 103, thereby improving the lubrication effect. The first oil inlet channel 102 and the second oil inlet channel 103 are arranged on both sides of the mounting seat 12, so as to avoid mutual interference between the first oil inlet channel 102 and the second oil inlet channel 103 and reduce the manufacturing difficulty.

[0050] In other embodiments, the first oil inlet channel 102 and the second oil inlet channel 103 can be arranged on the same side of the mounting seat 12, the bearing lubrication structure as a whole can be more compact, and the lubricating oil can more easily enter the first oil inlet channel 102 and the second oil inlet channel 103, further enhancing the lubrication capacity of the bearing lubrication structure.

[0051] like Figure 3 and Figure 4 As shown, the base 11 includes a connecting portion 111 and a receiving portion 112. The connecting portion 111 is plate-shaped. The receiving portion 112 is formed by protruding from the connecting portion 111. The mounting seat 12 extends into the receiving portion 112 and is fixed, which can improve the fixing strength of the mounting seat 12.

[0052] In one embodiment, the mounting seat 12 may be in a hollow cylindrical shape, and the mounting seat 12 includes a continuous side wall that abuts against the outer ring of the bearing 20. The cylindrical mounting seat 12 can abut against the outer ring of the bearing 20 in a circumferential direction to provide full support, prevent the outer ring of the bearing 20 from having an unsupported suspended portion, avoid the outer ring of the bearing 20 from being subjected to periodic pressure, and reduce the risk of fatigue failure of the bearing 20.

[0053] In one embodiment, if Figure 1 and Figure 4 As shown, the mounting base 12 may include a main body 121 and a flange 122 located at one end of the main body 121. The flange 122 is connected and fixed to the base 11 and the pressing plate 13 to improve the fixing strength. The flange 122 can be fixed to the connecting portion 111 by screws to facilitate disassembly and assembly. In other embodiments, the fixing method of the base 11, the mounting base 12 and the pressing plate 13 is not limited.

[0054] like Figures 4 to 6 As shown, the main body 121 includes an outer side surface 1211 between two ends. The two ends of the main body 121 are respectively provided with a first through hole 1213 and a second through hole 1214. The diameter of the first through hole 1213 is greater than the diameter of the second through hole 1214. When the bearing 20 is installed, the bearing 20 passes through the first through hole 1213 and abuts against the bottom wall 1215, which has a high assembly efficiency.

[0055] like Figure 4 As shown, the flange 122 includes a first surface 1221 facing the base 11 and a second surface 1222 facing the pressure plate 13. In one embodiment, the first surface 1221 may be provided with a first groove 1223, and the first groove 1223 forms at least a portion of the first oil inlet passage 102. In another embodiment, the second surface 1222 may be provided with a second groove 1224, and the second groove 1224 forms at least a portion of the second oil inlet passage 103. The flange 122 may be provided with only the first groove 1223, or only the second groove 1224. The flange 122 may also be provided with both the first groove 1223 and the second groove 1224.

[0056] By providing a groove on the flange 122 to form a corresponding oil inlet passage, the flange 122 can play a fixing role and an oil inlet role, thereby improving the compactness of the bearing lubrication structure, avoiding the addition of an additional oil guide structure, and reducing the manufacturing cost. In the embodiment where the flange 122 is provided with both the first groove 1223 and the second groove 1224, the first oil inlet passage 102 and the second oil inlet passage 103 are both provided on the flange 122, further improving the compactness of the bearing lubrication structure and reducing the manufacturing cost.

[0057] In an embodiment where the first surface 1221 is provided with a first slot 1223, the circumferential width of the first slot 1223 may gradually decrease in the radial direction toward the center of the circle. In an embodiment where the second surface 1222 is provided with a second slot 1224, the circumferential width of the second slot 1224 may gradually decrease in the radial direction toward the center of the circle. The trumpet-shaped slot can improve the lubrication effect. On the one hand, the entrances of the first oil inlet channel 102 and the second oil inlet channel 103 have a large size, which facilitates the entry of lubricating oil. On the other hand, the path of the lubricating oil gradually narrows, which is conducive to the accumulation of lubricating oil and its flow to the end face of the bearing 20.

[0058] In the embodiment where the first surface 1221 is provided with the first groove 1223, the outer side surface 1211 may be provided with a flow channel 1212 connected to the first groove 1223, and the first groove 1223 and the flow channel 1212 form the first oil inlet channel 102. The outer side surface 1211 and the first surface 1221 are the outer surfaces of the mounting seat 12, and the grooves and the flow channels are provided on the outer surfaces at the same time, which can reduce the difficulty of processing.

[0059] like Figure 7 As shown, the flow channel 1212 may be provided with a connected oil inlet section 1216 and an oil guide section 1217 at the end. The oil inlet section 1216 extends in the radial direction of the bearing 20, and the oil guide section 1217 extends in the axial direction of the bearing 20. By providing the oil inlet section 1216 and the oil guide section 1217, the lubricating oil can be more accurately guided to the end surface of the bearing 20, further improving the lubrication effect of the bearing lubrication structure.

[0060] like Figure 8 As shown, the pressure plate 13 may include a limiting portion 131 and an assembly portion 132 located at one end of the limiting portion 131. The limiting portion 131 is formed by protruding from the assembly portion 132. The pressure plate 13 may be screwed to the flange 122 through the assembly portion 132. The limiting portion 131 abuts against the side surface of the bearing 20 to limit and fix the bearing 20.

[0061] like Figure 4 and Figure 8As shown, the pressure plate 13 includes a third surface 1311 facing the second surface 1222. The third surface 1311 can be set at the limiting portion 131. In the embodiment where the second surface 1222 is provided with a second groove 1224, the third surface 1311 is provided with a third groove 1312 arranged in alignment with the second groove 1224, and the second groove 1224 and the third groove 1312 form a second oil inlet channel 103. The second oil inlet channel 103 is formed by two aligned grooves, which increases the inlet width of the second oil inlet channel 103, increases the oil intake, and improves the lubrication effect.

[0062] like Figure 1 As shown, the bearing 20 of the present application can be a double-row bearing with a large load-bearing capacity and service life. The first oil inlet channel 102 and the second oil inlet channel 103 lubricate the rollers of the two rows of the bearing 20 respectively. The specific type of the bearing 20 is not limited. The oil stirring shaft 30 may include a shaft body 31, a gear 32 assembled to the shaft body 31, and an oil-slinging plate 33. The stirring of the gear 32 and the rotation of the oil-slinging plate 33 drive the lubricating oil in the oil storage space 100 to splash. The gear 32 and the oil-slinging plate 33 synchronously throw oil, which can increase the amount of splashing lubricating oil.

[0063] like Figure 1 As shown, the present application also provides a vacuum pump, including the above-mentioned bearing lubrication structure. Since the bearing lubrication structure has a good lubrication effect, the vacuum pump of the present application has a high reliability. The vacuum pump of the present application can be a dry vacuum pump, and the specific type is not limited.

[0064] The vacuum pump further includes an oil retaining ring 40 and a housing 60. The oil retaining ring 40 is used to block the lubricating liquid to prevent leakage. When the lubricating oil passes through the oil retaining ring 40, it can be thrown out radially to avoid entering the rotor cavity of the vacuum pump. The oil storage space 100 is formed by the housing 60.

[0065] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Moreover, the above embodiments can complement each other in the absence of conflict. Although the present application has been disclosed as a preferred embodiment as above, it is not used to limit the present application. Any technician familiar with this profession can make some changes or modify the technical content disclosed above to an equivalent implementation method with equivalent changes without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification made to the above implementation method based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A bearing lubrication structure, characterized in that: include: Assemblies, bearings and churning shafts; An oil storage space is provided on one side of the assembly, and an assembly hole is provided on the assembly. The oil stirring shaft passes through the assembly hole and extends into the oil storage space. The bearing is abutted and fixed between the assembly and the oil stirring shaft. The assembly is provided with a first oil inlet passage and a second oil inlet passage, the bearing comprises a first end face and a second end face arranged opposite to each other, and the inlets of the first oil inlet passage and the second oil inlet passage are connected to the oil storage space; The outlet of the first oil inlet passage faces the first end surface, and the outlet of the second oil inlet passage faces the second end surface.

2. The bearing lubrication structure according to claim 1, characterized in that: The assembly comprises a base, a mounting seat fixed to the base, and a pressing plate assembled to the mounting seat, and the bearing is arranged in the mounting seat.

3. The bearing lubrication structure according to claim 2, characterized in that: The base and the pressure plate are respectively located on two sides of the mounting seat, the first oil inlet passage is arranged between the base and the mounting seat, and the second oil inlet passage is arranged between the mounting seat and the pressure plate.

4. The bearing lubrication structure according to claim 2, characterized in that: The mounting seat comprises a main body and a flange located at one end of the main body, and the flange is connected and fixed to the base and the pressing plate.

5. The bearing lubrication structure according to claim 4, characterized in that: The flange includes a first surface facing the base and a second surface facing the pressure plate; The first surface is provided with a first groove, the first groove forms at least a part of the first oil inlet passage, and / or the second surface is provided with a second groove, the second groove forms at least a part of the second oil inlet passage.

6. The bearing lubrication structure according to claim 5, characterized in that: The first surface is provided with a first groove, the mounting seat includes an outer side surface between two ends, the outer side surface is provided with a flow channel connected to the first groove, and the first groove and the flow channel form the first oil inlet channel.

7. The bearing lubrication structure according to claim 5, characterized in that: The second surface is provided with a second groove; the pressure plate includes a third surface facing the second surface, the third surface is provided with a third groove arranged in alignment with the second groove, and the second groove and the third groove form the second oil inlet channel.

8. The bearing lubrication structure according to claim 5, characterized in that: The circumferential width of the first slot and / or the second slot gradually decreases in the radial direction toward the center of the circle.

9. The bearing lubrication structure according to claim 6, characterized in that: The flow channel is provided with an oil inlet section and an oil guide section which are connected at the end. The oil inlet section extends in the radial direction of the bearing, and the oil guide section extends in the axial direction of the bearing.

10. The bearing lubrication structure according to claim 2, characterized in that: The mounting seat is in the shape of a hollow cylinder and comprises a continuous side wall abutting against the outer ring of the bearing.

11. The bearing lubrication structure according to claim 1, characterized in that: The assembly is provided with a first oil return passage and a second oil return passage, the outlets of the first oil return passage and the second oil return passage are connected to the oil storage space, the inlet of the first oil return passage is arranged toward the first end surface, and the inlet of the second oil return passage is arranged toward the second end surface.

12. The bearing lubrication structure according to claim 1, characterized in that: The inner wall of the assembly hole is provided with grooves on both sides of the bearing in the axial direction.

13. A vacuum pump, characterized in that: include: A bearing lubrication structure as claimed in any one of claims 1 to 12.

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