Bearing and compressor

Abstract

A bearing (10) is provided with a cylindrical base material (12) and a resin layer (14). The resin layer (14) is joined to the inner peripheral surface (C1) of the base material (12), and the resin layer (14) is provided with a plurality of grooves (MG) along a direction intersecting the extension direction (Z) of a shaft member housed on the inner peripheral surface (C1) side of the base material (12) on the surface facing the surface (C2) of the shaft member. The resin layer (14) contains a synthetic resin (16) and an additive (18) dispersed in the synthetic resin (16). The average particle diameter of the additive (18) is smaller than the depth (d) of the groove portion (MG).

Description

Technical Field

[0001] The present invention relates to a bearing and a compressor. Background Art

[0002] Conventionally, from the viewpoint of improving the anti-seizure property by oil retention, there is known a structure in which a groove is formed on the surface of the inner peripheral surface of a cylindrical bearing. For example, a structure in which a groove is formed on a bearing layer on a substrate is disclosed. In addition, a structure using a resin layer containing an additive such as graphite as a bearing layer provided on a substrate is disclosed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 5683571

[0006] Patent Document 2: Japanese Patent Application Publication No. 2018-193521 Summary of the invention

[0007] Problems to be solved by the invention

[0008] The groove is formed by cutting a resin material layer provided on a substrate. However, due to the influence of additives contained in the resin layer, it is sometimes difficult to form a groove of a target shape. Therefore, in the prior art, a normal groove may not be formed, and the anti-seizure property is insufficient.

[0009] An object of the present invention is to provide a bearing and a compressor capable of improving anti-seizure performance.

[0010] Solutions for solving problems

[0011] In order to solve the above-mentioned problems and achieve the purpose, the bearing of the present invention comprises: a cylindrical substrate; and a resin layer, which is bonded to the inner circumferential surface of the substrate, and the resin layer is provided with a plurality of grooves along a direction intersecting the extension direction of the shaft member on the surface of the opposite side to the shaft member, wherein the shaft member is accommodated on the inner circumferential surface side of the substrate, and the resin layer contains a synthetic resin and an additive dispersed in the synthetic resin, and the average particle size of the additive is smaller than the depth of the groove.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to improve the anti-seizure property. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A It is an explanatory diagram of an example of the overall structure of the bearing according to the embodiment.

[0015] Figure 1BIt is an explanatory diagram of an example of the overall structure of the bearing according to the embodiment.

[0016] Figure 2 This is an enlarged cross-sectional view of an example of a bearing.

[0017] Figure 3A This is an explanatory diagram of an example of a method for producing a bearing.

[0018] Figure 3B This is an explanatory diagram of an example of a method for producing a bearing.

[0019] Figure 4 This is an explanatory diagram of an example of a conventional comparative bearing.

[0020] Figure 5 is a schematic diagram of an example of a compressor.

[0021] Figure 6 This is a diagram for explaining the seizure resistance test. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of a bearing and a compressor according to the present invention will be described in detail with reference to the drawings.

[0023] The bearing of this embodiment comprises a cylindrical substrate and a resin layer. The resin layer is bonded to the inner peripheral surface of the substrate. In the resin layer, a plurality of grooves are provided on the surface of the opposite side to the shaft member along a direction intersecting the extension direction of the shaft member, wherein the shaft member is accommodated on the inner peripheral surface side of the substrate. The resin layer contains a synthetic resin and an additive dispersed in the synthetic resin. The average particle size of the additive is smaller than the depth of the groove.

[0024] In the bearing of this embodiment, the average particle size of the additive contained in the resin layer is smaller than the depth of the groove portion. Therefore, the groove portion of the bearing of this embodiment can be easily formed, and the anti-seizure property can be improved.

[0025] The reason why the above effect is achieved is not clear, but is presumed as follows. However, the present invention is not limited to the following presumption.

[0026] It is believed that if the average particle size of the additive contained in the resin layer is greater than the depth of the groove, it may be difficult to form a groove of a target shape. In addition, it is believed that if the average particle size of the additive contained in the resin layer is greater than the depth of the groove, the detached portion formed due to the detachment of the additive during processing of the groove will form a large defect in the shape of the groove, and sometimes the groove of the target shape cannot be formed. If it is difficult to form a groove of the target shape, it is believed that the bearing performance including anti-bite performance cannot be stably exerted, and there will be problems with the quality of the bearing product. In addition, it is believed that if the average particle size of the additive contained in the resin layer is greater than the depth of the groove, it may be impossible to maintain the specified groove shape when sliding relative to the shaft member.

[0027] On the other hand, it is speculated that if the average particle size of the additive contained in the resin layer is smaller than the depth of the groove portion, the groove portion of the target shape will be properly formed. In addition, it is speculated that by forming the groove portion of the target shape, the appropriate oil film retention force of the lubricating oil in the groove portion can be achieved, the lubrication performance can be improved, and the anti-seizure property can be improved.

[0028] Hereinafter, the bearing and the compressor according to the present embodiment will be described in detail.

[0029] Figure 1A and Figure 1B It is an explanatory diagram of an example of the overall structure of the bearing 10 according to the present embodiment. Figure 1A This is a cross-sectional view of the bearing 10 cut along a direction intersecting with the extending direction Z of the bearing 10 . Figure 1B This is an appearance diagram when the bearing 10 is visually checked from a direction intersecting with the extending direction Z of the bearing 10 .

[0030] The bearing 10 includes a base material 12 and a resin layer 14 .

[0031] The substrate 12 is a cylindrical member. In the present embodiment, the substrate 12 is described as an example in which the substrate 12 is a cylindrical member. It should be noted that the substrate 12 may be a cylindrical member, and is not limited to a cylindrical member.

[0032] The substrate 12 is a member for accommodating the shaft member 30 on the inner circumferential surface C1 side thereof. The shaft member 30 is a rod-shaped member that is long in the extension direction Z. In the present embodiment, the extension direction Z of the substrate 12 is consistent with the extension direction Z of the shaft member 30 as an example for explanation. It should be noted that the extension direction Z of the substrate 12 and the extension direction Z of the shaft member 30 may not be consistent.

[0033] The resin layer 14 is a layer bonded to the inner peripheral surface C1 of the base material 12. A plurality of grooves MG are provided on the surface of the resin layer 14 on the side of the opposing surface C2 to the shaft member 30 along a direction intersecting the extension direction Z of the shaft member 30. The grooves MG along the direction intersecting the extension direction Z refer to the grooves MG extending along the direction intersecting the extension direction Z.

[0034] The groove MG may be provided along a direction intersecting the extension direction Z of the shaft member 30, and may be any of a direction orthogonal to the extension direction Z and a direction inclined at an angle less than 90° relative to the orthogonal direction. In the present embodiment, the groove MG is provided along a direction orthogonal to the extension direction Z of the shaft member 30, that is, a circumferential direction Q of the cylindrical bearing 10 as an example for explanation. In addition, the groove MG may be formed continuously in a spiral shape from one end to the other end in the extension direction Z in the resin layer 14. It should be noted that a plurality of grooves MG which are discontinuous with each other may be provided on the resin layer 14 from one end side of the extension direction Z toward the other end side.

[0035] Next, the bearing 10 will be described in detail.

[0036] Figure 2 It is an enlarged cross-sectional view of an example of the bearing 10 .

[0037] The bearing 10 is a laminate of a base material 12 and a resin layer 14 formed on the base material 12 .

[0038] The substrate 12 is a layer for imparting mechanical strength to the bearing 10. The substrate 12 may be referred to as a backing or a backing layer. For example, a metal plate such as Fe alloy, Cu, or Cu alloy can be used as the substrate 12.

[0039] At least a portion of the contact surface side of the substrate 12 with the resin layer 14 may also be composed of a sintered layer. The sintered layer is a sintered body of metal powder and is a porous layer having a plurality of pores. The metal powder constituting the sintered layer may be the same metal as the substrate 12 or a metal or material different from the substrate 12. By adopting a structure having a sintered layer, the adhesion between the substrate 12 and the resin layer 14 can be improved.

[0040] As described above, the resin layer 14 is a layer bonded to the inner peripheral surface C1 of the base material 12. As described above, the groove portion MG is provided on the surface of the resin layer 14 on the side facing the surface C2 of the shaft member 30.

[0041] The groove portion MG is a micron-order fine and precise groove processed portion formed on the surface of the resin layer 14. The groove portion MG may be referred to as a micro groove or a micro groove.

[0042] The shape of the groove portion MG is not limited. The groove portion MG may be any shape that can retain the lubricating oil supplied when the bearing 10 is driven to rotate, and can retain the oil between the groove portion MG and the shaft member 30 .

[0043] Figure 2In the embodiment, as an example, the cross-sectional shape of the groove portion MG is shown to be V-shaped. However, the cross-sectional shape of the groove portion MG is not limited to the V-shape. For example, the cross-sectional shape of the groove portion MG may be U-shaped, or may be composed of a flat bottom and a pair of sidewall portions erected relative to the bottom.

[0044] The depth d and width of the groove MG are not limited. The depth d and width of the groove MG may be sufficient to retain the lubricating oil supplied during the rotational drive of the bearing 10 and to retain the oil between the shaft member 30 .

[0045] The depth d of the groove MG indicates the distance between the bottom B of the groove MG and the top T of the peak of the groove MG in the thickness direction of the resin layer 14. The width of the groove MG indicates the distance between the centers of the bottoms B of adjacent grooves MG.

[0046] The depth d of the groove MG is, for example, in the range of 4.0 μm or more and 7.0 μm or less, but is not limited to this range. In addition, the width of the groove MG is, for example, in the range of 0.045 mm or more and 0.145 mm or less, preferably in the range of 0.075 mm or more and 0.095 mm or less, but is not limited to this range. Furthermore, the groove MG is continuously formed in the width direction.

[0047] The resin layer 14 is a layer having a resin material as a main component. Specifically, the resin layer 14 is composed of a synthetic resin 16 and an additive 18 dispersed in the synthetic resin 16 .

[0048] The composition of the synthetic resin 16 is not limited. From the viewpoint of improving wear resistance, etc., the composition of the synthetic resin 16 is preferably composed of a heat-resistant resin.

[0049] For example, the synthetic resin 16 includes PTFE (polytetrafluoroethylene). In the present embodiment, a state in which particulate PTFE, that is, PTFE particles 16A are dispersed in the synthetic resin 16 is described as an example.

[0050] The content of the PTFE particles 16A in the synthetic resin 16 is not limited. For example, the content of the PTFE particles 16A in the synthetic resin 16 is preferably 5% by volume or more and 30% by volume or less, more preferably 10% by volume or more and 25% by volume or less, and particularly preferably 12% by volume or more and 20% by volume or less.

[0051] When the content of the PTFE particles 16A in the synthetic resin 16 is within the above range, the friction coefficient of the resin layer 14 can be reduced. In addition, the PTFE particles 16A have high heat resistance and are not easy to melt or decompose. Therefore, by adopting a structure containing PTFE particles 16A in the synthetic resin 16, the friction coefficient of the resin layer 14 can be effectively reduced. That is, by containing PTFE particles 16A, the anti-seizure property of the bearing 10 can be further improved.

[0052] The average particle size of the PTFE particles 16A is not limited. The average particle size of the PTFE particles 16A can be either greater than the depth d of the groove MG or less than the depth d of the groove MG. Specifically, the average particle size of the PTFE particles 16A is preferably, for example, 1.0 μm or more and 25.0 μm or less, more preferably 1.0 μm or more and 15.0 μm or less, and particularly preferably 0.2 μm or more and 12.0 μm or less.

[0053] When the average particle size of the PTFE particles 16A is within the above range, the total surface area of ​​the PTFE particles 16A dispersed in the synthetic resin 16 increases. Therefore, even if the content of the PTFE particles 16A is a relatively small content within the above range, the friction coefficient of the resin layer 14 can be reduced and the anti-seizure property can be improved.

[0054] The average particle size of PTFE particles 16A represents the average primary particle size of PTFE particles 16A. Average primary particle size refers to the cumulative 50% particle size of the volume average particle size. Scanning electron microscope (SEM) can be used in the determination of the average particle size of PTFE particles 16A. It can be that the particles of PTFE particles 16A are observed by SEM with an appropriate magnification (for example, about 5000 times), the diameter of 100 primary particles is measured and the volume is calculated, and the cumulative 50% particle size is set to the average primary particle size. It should be noted that when the particles of PTFE particles 16A are not spherical, the average value of the major diameter and the minor diameter is regarded as the diameter of the primary particle.

[0055] The shape of PTFE particle 16A is not limited. For example, the shape of PTFE particle 16A can also be any one of spherical and ellipsoidal. In addition, the preparation method of PTFE particle 16A is not limited. For example, PTFE particle 16A can use any one of PTFE particles prepared by suspension polymerization, PTFE particles prepared by emulsion polymerization, and regenerated PTFE particles.

[0056] Moreover, the synthetic resin 16 may also be a composition further including one or more selected from the following: PI (polyimide), PAI (polyamideimide), PBI (polybenzimidazole), PA (polyamide), phenol, epoxy, POM (polyacetal), PEEK (polyetheretherketone), PE (polyethylene), PPS (polyphenylene sulfide) and PEI (polyetherimide).

[0057] Furthermore, from the viewpoint of strengthening the bonding with the additive 18 , the synthetic resin 16 may further contain a silane coupling agent.

[0058] Next, the additive 18 will be described.

[0059] The additive 18 is a substance for improving the characteristics of the resin layer 14. In the present embodiment, the additive 18 refers to a substance other than the resin. That is, the additive 18 does not contain a resin.

[0060] The average particle size of the additive 18 of this embodiment is smaller than the depth d of the groove MG. For example, the average particle size of the additive 18 must be smaller than 1 times the depth d of the groove MG, preferably smaller than 3 / 4 times the depth d of the groove MG, and more preferably smaller than 1 / 2 times the depth d of the groove MG.

[0061] It is believed that if the average particle size of the additive 18 is smaller than the depth d of the groove MG, the groove MG of the target shape will be appropriately formed when the bearing 10B is manufactured. It is believed that by appropriately forming the groove MG of the target shape, an appropriate lubricant retention force can be obtained by the groove MG, and the anti-seizure property can be improved.

[0062] The average particle size of the additive 18 can be measured by the following method. Specifically, for example, an electron image is obtained by photographing a cross section along the extension direction Z of the resin layer 14 using an electron microscope at an appropriate magnification (for example, 1000 times). Then, the area of ​​the additive 18 included in the obtained electron image is measured by a general image analysis method according to the type of the additive 18, and the area is converted into an average diameter assuming a circle. Through these processes, the average particle size of each type of the additive 18 can be obtained.

[0063] Specifically, at least one of graphite 20 and clay 22 is contained as the additive 18 .

[0064] When the additive 18 contains the graphite 20 , it is possible to improve the anti-seizure property of the resin layer 14 .

[0065] As described above, the average particle size of the additive 18 such as the graphite 20 may be smaller than the depth d of the groove MG. For example, it is assumed that the depth d of the groove MG is in the range of 4.0 μm or more and 7.0 μm or less. In this case, the average particle size of the graphite 20 is preferably, for example, 1.0 μm or more and less than 4.0 μm, and preferably 1.0 μm or more and less than 2.0 μm.

[0066] The content of graphite 20 in synthetic resin 16 is not limited. For example, the content of graphite 20 in synthetic resin 16 is preferably 1 volume % or more and less than 15 volume %, more preferably 3 volume % or more and 12 volume % or less, and particularly preferably 5 volume % or more and less than 9 volume %.

[0067] When the content of the graphite 20 in the synthetic resin 16 is within the above range, the lipophilicity of the resin layer 14 can be increased, thereby further improving the anti-seizure property.

[0068] The shape of the graphite 20 is not limited. For example, the shape of the graphite 20 may be either flaky or spherical. It should be noted that the shape of the graphite 20 is preferably flaky.

[0069] Flake-like means that the shape is in the shape of flakes. The flake-shaped graphite 20 is a crystal having a thickness in the C-axis direction perpendicular to the AB surface and stacked with many AB surfaces (hexagonal mesh plane, basal surface) that are flatly unfolded by regularly forming a mesh structure with carbon atoms. The binding force generated by the van der Waals force between the stacked AB surfaces is much smaller than the binding force in the in-plane direction of the AB surface, so shearing is easy to occur between the AB surfaces. Therefore, relative to the unfolding of the AB surface, the thickness of the flaky graphite 20 in the stacking direction is thinner, and the whole is in the shape of a thin plate.

[0070] The flaky graphite 20 generates shear between the AB planes when subjected to external force, thereby functioning as a solid lubricant. Therefore, by using the flaky graphite 20 as the graphite 20 dispersed in the synthetic resin 16, the seizure resistance of the resin layer 14 can be further improved.

[0071] Furthermore, from the viewpoint of reducing the friction coefficient, the graphite 20 preferably has a high degree of graphitization. For example, the graphitization degree of the graphite 20 is preferably 95% or more, and more preferably 99% or more.

[0072] The clay 22 is any Al2O3-SiO2-H2O clay mineral. The clay 22 may be calcined clay. When the additive 18 contains the clay 22, the wear resistance of the resin layer 14 can be improved.

[0073] As described above, the average particle size of the clay 22 only needs to be smaller than the depth d of the groove portion MG. For example, it is assumed that the depth d of the groove portion MG is in the range of 4.0 μm to 7.0 μm. In this case, the average particle size of the clay 22 is preferably, for example, 2.0 μm to 4.0 μm, and preferably 2.0 μm to less than 3.5 μm.

[0074] The content of the clay 22 in the synthetic resin 16 is not limited. The content of the clay 22 in the synthetic resin 16 is, for example, preferably 1% by volume or more and 5% by volume or less, and more preferably 1% by volume or more and 3% by volume or less. When the content of the clay 22 is within the above range, the wear resistance of the resin layer 14 can be improved and the reduction in fatigue resistance can be suppressed.

[0075] (Bearing Manufacturing Method)

[0076] The bearing 10 of the present embodiment is produced, for example, through the following steps.

[0077] Figure 3A and Figure 3B It is an explanatory diagram of an example of a method for manufacturing the bearing 10 .

[0078] like Figure 3A As shown, the resin material layer 15 is formed by applying the constituent material of the resin layer 14 having the above-described constitution on the substrate 12 (resin material layer forming step). Then, the resin material layer 15 formed on the substrate 12 is dried. The coating conditions and the drying conditions may be known conditions.

[0079] Then, the groove processing step is performed. In the groove processing step, the surface of the resin material layer 15 is cut along the cut surface CS of the groove MG of the target shape by moving the tip of the cutting tool along the surface of the resin material layer 15. Figure 3B As shown in FIG. 1 , a bearing 10 including a resin layer 14 having a groove portion MG formed therein is produced.

[0080] The formation of the groove portion MG is not limited to the formation by cutting the resin material layer 15 with a cutting tool. For example, the groove portion MG may be formed by etching, rolling, or the like.

[0081] Here, the resin material layer 15 contains an additive 18. In some cases, the larger the relative size of the additive 18 contained in the resin material layer 15 to the groove portion MG is, the more difficult it is to process the groove portion MG. However, as described above, in this embodiment, the average particle size of the additive 18 is smaller than the depth d of the groove portion MG. Therefore, in this embodiment, even if the resin material layer 15 contains the additive 18, the groove portion MG can be easily formed.

[0082] When the groove portion MG is formed, the additive 18 may fall off from the resin layer 14 due to cutting of the resin material layer 15, etc., and a fall-off portion F may be formed on the surface of the resin layer 14 (see Figure 3B ). However, as described above, in the present embodiment, the average particle size of the additive 18 is smaller than the depth d of the groove MG. Therefore, even if a falling portion F is formed on the surface of the resin layer 14 due to the falling of the additive 18 when the groove MG is formed, the shape of the groove MG in the bearing 10 of the present embodiment is substantially maintained in the target shape (see Figure 3B ). That is, in the present embodiment, it is possible to produce the bearing 10 having the groove portion MG having a suppressed shape defect rate relative to the target shape (ie, a normal shape).

[0083] On the other hand, in a conventional bearing in which the average particle size of the additive 18 is equal to or larger than the depth d of the groove portion MG, it may be difficult to form the groove portion MG in a target shape.

[0084] Figure 4 1 is an explanatory diagram of an example of a comparative bearing 1000. In the comparative bearing 1000, the average particle size of additives 19 such as graphite 21 and clay 23 dispersed in the synthetic resin 16 of the comparative resin layer 17 is greater than the depth d of the groove MG. Therefore, in the comparative bearing 1000, the relative size of the additive 19 with respect to the groove MG is large, and it is sometimes difficult to process the groove MG on the surface of the resin material layer of the comparative resin layer 17.

[0085] In the comparative bearing 1000, the additive 19 may fall off when forming the groove portion MG, and the resulting fall-off portion F may be relatively large relative to the groove portion MG, resulting in the groove portion MG being greatly deformed from the target shape (see FIG. Figure 4 ). Therefore, it is considered that in the comparative bearing 1000, a normal groove portion MG cannot be provided, and it is difficult to exert stable bearing performance, and there will be problems in quality as a bearing product.

[0086] On the other hand, the average particle size of the additive 18 of the bearing 10 of the present embodiment is smaller than the depth d of the groove portion MG. Therefore, in the present embodiment, even if the resin material layer 15 contains the additive 18, the groove portion MG can be easily formed. Figure 3B As shown, it is considered that the shape defect rate of the bearing 10 of this embodiment relative to the target shape of the groove portion MG is smaller than that of the conventional comparative bearing 1000, and the bearing 10 having the groove portion MG closer to or consistent with the target shape can be manufactured.

[0087] Therefore, in the present embodiment, it is considered that by forming the groove portion MG in a target shape, an appropriate lubricant oil retaining force by the groove portion MG can be obtained, and the anti-seizure property of the bearing 10 can be improved.

[0088] (compressor)

[0089] Next, an example of application of the bearing 10 will be described. The bearing 10 is used, for example, as a bushing in a fuel injection pump, various bearings, or a compressor.

[0090] Figure 5 2 is a schematic diagram of an example of a compressor 40 . The compressor 40 is an example of an application of the bearing 10 . Figure 5 Scroll compressors are shown as an example. Scroll compressors are used to compress gases such as refrigerant gas in air conditioners for automobiles, homes, railways, or businesses.

[0091] The compressor 40 has a cylindrical housing 41 with both ends closed. For example, the center of the housing 41 is arranged along the z-axis. The z-axis direction is consistent with the direction parallel to the vertical direction. The +z direction is the vertical direction, and it is sometimes referred to as the upper direction for explanation. The -z direction is the anti-vertical direction, and it is sometimes referred to as the lower direction for explanation.

[0092] A suction pipe 44 for sucking in the atmosphere is provided above the housing 41 (in the -z direction). A discharge pipe 46 for discharging the compressed air stored in the chamber 45 in the housing 41 is provided on the side of the housing 41. Inside the housing 41, a bearing 10 fixed to the housing 41 and a shaft member 30 rotatably supported by the bearing 10 are arranged in the direction along the z-axis. That is, Figure 5 , as an example, the extending direction Z of the shaft member 30 and the bearing 10 coincides with the z-axis direction which is parallel to the vertical direction. Figure 5 In the description, the compressor 40 is described as a vertical compressor as an example.

[0093] A fixed scroll member 47 having spiral blades is fixed above the housing 41 of the compressor 40. A movable scroll member 48 having spiral blades in a direction opposite to that of the fixed scroll member 47 is arranged below the fixed scroll member 47 and opposite to the fixed scroll member 47. The movable scroll member 48 forms a compression chamber together with the fixed scroll member 47.

[0094] The shaft member 30 has a crank pin 30A as an upper portion. When the shaft member 30 is driven to rotate by a motor 43 provided inside the housing 41, the crank pin 30A rotates. The crank pin 30A is accommodated in a pin receiving portion 48A provided on the lower side of the movable scroll member 48, and rotates the movable scroll member 48 by rotating itself.

[0095] When the movable scroll 48 rotates, the air sucked from the suction pipe 44 flows into the compression chamber formed by the movable scroll 48 and the fixed scroll 47, is compressed, and is stored in the chamber 45. The compressor 40 discharges the compressed air stored in the chamber 45 from the discharge pipe 46 to the outside.

[0096] Generally speaking, in the compressor 40 (air conditioning compressor) that compresses the refrigerant, the refrigerant contains lubricating oil (refrigeration oil), and the lubricating oil is supplied to each bearing 10 through the circulation of the refrigerant. In the stopped state, the refrigerant does not circulate, so the lubricating oil is not supplied. Therefore, from the stop to the initial start, the lubrication of the bearing 10 is only performed by the oil held (adhered) between the bearing 10 and the shaft member 30.

[0097] When the compressor 40 is started, the shaft member 30 is driven to rotate by lubrication by the oil held between the bearing 10 and the shaft member 30. If the oil is exhausted before the refrigerant circulates, seizure may occur.

[0098] In the bearing 10 of the present embodiment, the groove portion MG is provided on the surface C2 of the resin layer 14 that faces the shaft member 30 .

[0099] Therefore, the oil retention force of the lubricating oil entering the gap between the bearing 10 and the shaft member 30 is increased by the groove portion MG provided in the resin layer 14. Therefore, it is considered that when the compressor 40 is started, the resin layer 14 of the bearing 10 and the shaft member 30 are lubricated, and the oil depletion and seizure of the shaft member 30 at the initial stage of the rotation start can be suppressed.

[0100] Therefore, it is considered that the compressor 40 including the bearing 10 of the present embodiment can achieve improved anti-seizure performance.

[0101] It should be noted that in Figure 5 , the compressor 40 is shown as a vertical compressor as an example. However, the compressor 40 may also be a horizontal compressor arranged in a direction where the extension direction Z of the shaft member 30 and the bearing 10 coincides with the horizontal direction. In addition, the compressor 40 may also be arranged in a direction where the extension direction Z of the shaft member 30 and the bearing 10 intersects with both the horizontal direction and the vertical direction.

[0102] It should be noted that the timing of forming the groove portion MG is not limited. For example, the groove portion MG may be formed before the bearing 10 is assembled to the compressor 40. That is, the compressor 40 may be manufactured by assembling the bearing 10 formed with the groove portion MG to the compressor 40.

[0103] In addition, the groove MG may be formed by performing a groove processing step on the resin material layer 15 after the bearing 10 having the resin material layer 15 without the groove MG is assembled to the compressor 40. As described above, the average particle size of the additive 18 contained in the resin material layer 15 of the bearing 10 of the present embodiment is smaller than the depth d of the groove MG to be formed. Therefore, in the present embodiment, even if the additive 18 is contained in the resin material layer 15, the groove MG can be easily formed. That is, in the present embodiment, even in the case where the groove MG is formed after the bearing 10 is assembled to the compressor 40, the groove MG of the target shape can be easily and accurately formed.

[0104] [Example]

[0105] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

[0106] Test pieces having the following resin layer 14 and comparative resin layer were prepared, and the seizure resistance of these test pieces was evaluated.

[0107] - Preparation of test pieces -

[0108] As the substrate 12, a steel plate (SPCC (cold rolled steel plate) (JIS)) with a thickness of 1.5 mm was prepared. In addition, a solution of the constituent material of the resin layer 14 was prepared by adding the additives shown in Examples 1 to 3 of Table 1 to the synthetic resin of the composition shown in Examples 1 to 3 of Table 1. Then, the solution was applied to the substrate 12 by a doctor blade coating method. After coating, it was dried in the range of room temperature to about 200°C for 60 minutes to 90 minutes. Then, the temperature was raised to about 300°C and fired for 30 minutes to 90 minutes. Through these steps, a resin material layer 15 was formed on the substrate 12. Moreover, the surface of the resin material layer 15 was cut along the cut surface CS of the groove MG of the target shape by moving the tip of the cutting tool along the surface of the resin material layer 15. The target shape is set to a depth d4.0μm of the groove MG, a width of the groove MG of 0.075μm, and a V-shaped cross-sectional shape.

[0109] Through these treatments, test pieces of the resin layer 14 of each of Examples 1 to 3 were produced.

[0110] In addition, in addition to using the synthetic resins and additives shown in Comparative Examples 1 to 3 in Table 1 as the constituent materials of the comparative resin layer 17, the test pieces of the comparative resin layer 17 of Comparative Examples 1 to 3 were prepared in the same manner as the resin layer 14 of Examples 1 to 3.

[0111] It should be noted that as graphite, graphite in a flaky state with a graphitization degree of 99% was used, and as clay, clay having a structural formula of Al2O3·2SiO2 was used.

[0112] [Table 1]

[0113]

[0114] [Table 2]

[0115]

[0116] -evaluate-

[0117] - Anti-seizure -

[0118] The anti-seizure properties of the test pieces of the examples and the test pieces of the comparative examples were evaluated. Figure 6 The test machine shown is carried out.

[0119] Figure 6 1 is an explanatory diagram of the anti-seizure test. The groove portion MG side of the test piece corresponding to the resin layer 14 or the comparative resin layer 17 is arranged opposite to the shaft member 30, and 45 mg of lubricating oil is applied to the surface of the groove portion MG side. Then, the anti-seizure property is evaluated by rotating the shaft member 30 while applying a load. The evaluation is performed under the following conditions.

[0120] Testing machine: Occlusal testing machine (refer to Figure 6 )

[0121] Load: 5Mpa

[0122] Rotation speed (circumferential speed): 2m / s

[0123] Test temperature (atmosphere temperature): 40°C

[0124] Material of shaft member 30: SCM415 (Hv500 or above)

[0125] Surface roughness Ra of the shaft member 30: 0.15 μm

[0126] Lubricating oil: liquid paraffin (viscosity: 4.4×10 －3 Pa·s)

[0127] Lubrication method: Apply 45mg of lubricating oil

[0128] Oil gap: 100μm

[0129] ·Seizure determination: time (seconds) required from the start of the rotation drive of the shaft member 30 until the friction torque reaches 4.8 N·m

[0130] The shaft member 30 is rotated under the above conditions, and the time (seconds) required from the start of the rotation drive of the shaft member 30 to the friction torque reaching 4.8 N·m is measured as the elapsed time until bite. The elapsed time until bite refers to the time required from the start of the rotation drive of the shaft member 30 to the occurrence of bite. The measurement results are shown in Table 1. In Table 1, the longer the elapsed time until bite, the higher the anti-seizure property, that is, the better the anti-seizure property.

[0131] - Evaluation of improvement in anti-seizure performance achieved by the groove portion MG -

[0132] As shown in Table 1, all the test pieces of the examples with the groove MG had longer elapsed time until seizure than the test piece of the comparative example without the groove MG. Therefore, the following evaluation result was obtained: the test piece of the resin layer 14 of the example had higher seizure resistance than the test piece of the comparative resin layer 17 of the comparative example.

[0133] ―Determination of groove shape processability―

[0134] The shape workability of the groove portion MG was evaluated for the test pieces of the example and the test pieces of the comparative example.

[0135] As shown in Table 2, when the Gr particle size is smaller than the depth of the groove MG, the shape defect rate of the groove shape is small (normal shape). In addition, as shown in Table 2, when the Gr particle size is larger than the depth of the groove MG, the shape defect rate of the groove shape is large (abnormal shape).

[0136] Specifically, for the test pieces of the embodiment and the test pieces of the comparative example, the surfaces of the groove portions MG of the bearing 10 and the comparative bearing 1000 were traced along the extension direction Z by a roughness measuring device (SE-3400 manufactured by Kosaka Laboratory) to obtain a surface shape enlargement curve of the groove portion MG along the extension direction Z. Then, for the test pieces of the embodiment and the test pieces of the comparative example, an average value av of the depth d of each of the plurality of groove portions MG included in the surface shape enlargement curve and a standard deviation σ of the depth d of the groove portion MG were calculated.

[0137] Furthermore, for each of the test pieces of the embodiment and the test pieces of the comparative example, among the plurality of grooves MG included, the grooves MG having a depth d within the range of the standard deviation σ×1 / 2 relative to the average value av were considered normal, and the grooves MG having a depth d outside the range were considered defective. Furthermore, for each of the test pieces of the embodiment and the test pieces of the comparative example, when the ratio of the grooves MG judged to be defective among the plurality of grooves MG included was 20% or more, the shape of the grooves MG was determined to be abnormal. Furthermore, for each of the test pieces of the embodiment and the test pieces of the comparative example, when the ratio of the grooves MG judged to be defective among the plurality of grooves MG included was less than 20%, the shape of the grooves MG was determined to be normal, and when the ratio of the defective grooves MG was 20% or more, the shape was determined to be abnormal. The determination results are shown in Tables 1 and 2.

[0138] Moreover, as shown in Table 2, all the test pieces of the examples were judged to have normal shapes of the groove portion MG. On the other hand, all the test pieces of the comparative examples were judged to have abnormal shapes of the groove portion MG.

[0139] It should be noted that the various materials and their compositions used in the above-mentioned embodiments are only examples, and the present invention is not limited thereto. The resin layer 14 of the present invention may further contain inevitable impurities, etc. In addition, the specific structure of the bearing 10 is not limited to Figure 1A to Figure 2 The structure shown as an example in etc.

[0140] Description of Reference Numerals

[0141] 10: bearings;

[0142] 12: substrate;

[0143] 14: resin layer;

[0144] 16: Synthetic resin;

[0145] 16A: PTFE particles;

[0146] 18: Additives;

[0147] 20: Graphite;

[0148] 22: clay;

[0149] 40: Compressor.

Claims

1. A bearing having: a cylindrical substrate; and A resin layer is bonded to the inner peripheral surface of the base material, and the resin layer has a plurality of grooves on the surface of the resin layer facing the shaft member in a direction intersecting with the extending direction of the shaft member, wherein The shaft member is accommodated on the inner peripheral surface side of the base material, the resin layer includes a synthetic resin and an additive dispersed in the synthetic resin, The average particle size of the additive is smaller than the depth of the groove.

2. The bearing according to claim 1, wherein: The additive includes at least one of graphite and clay.

3. The bearing according to claim 2, wherein: The average particle size of the graphite is greater than 1.0 μm and less than 4.0 μm, The average particle size of the clay is greater than 2.0 μm and less than 3.5 μm, The depth of the groove is not less than 4 μm and not more than 7 μm.

4. The bearing according to claim 1, wherein: The synthetic resin contains polytetrafluoroethylene particles.

5. A compressor comprising the bearing according to claim 1.

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