JP2017036712A - Semi-spherical shoe of swash plate type compressor and swash plate type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semi-spherical shoe having lubricative resin layers which can possess characteristics corresponding to those of a swash plate and a piston.SOLUTION: A semi-spherical shoe 4 used in a swash plate type compressor uses a hard member as a base material 5, resin layers 6 are formed on a surface of a plane part 4b which slides with a swash plate, and on a surface of a spherical part 4a which slides with a piston, and the resin layer 6b of the plane part 4b and the resin layer 6a of the spherical part 4a are composed of different resin compositions. The resin layer 6a of the spherical part is lower than the resin layer 6b in hardness, and soft.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hemispherical shoe for converting a rotary motion of a swash plate into a reciprocating motion of a piston interposed between a swash plate and a piston in a swash plate type compressor used for an air conditioner for automobiles and the like.

  In the swash plate compressor, a hemispherical shoe is slid on a swash plate that is fixed at right angles and obliquely so as to be directly fixed to a rotating shaft or indirectly via a connecting member in a housing in which refrigerant exists. Through this hemispherical shoe, the rotational movement of the swash plate is converted into the reciprocating movement of the piston to compress and expand the refrigerant. There are two types of swash plate compressors: a double swash plate type that uses a double-headed piston to compress and expand refrigerant on both sides, and a single swash plate type that uses a single-headed piston to compress and expand refrigerant only on one side. There is a thing. In addition, the hemispherical shoes include those that slide only on one side of the swash plate and those that slide on both sides of the swash plate. In these swash plate type compressors, sliding with a large relative speed of 20 m or more per second occurs on the sliding surface of the swash plate and the hemispheric shoe, and the hemispheric shoe is used in a very severe environment.

  As for lubrication, the lubricating oil is diluted while dissolved in the refrigerant, circulates in the housing, and is supplied to the sliding portion in the form of a mist. However, when the operation is resumed from the operation suspension state, the lubricating oil is washed away by the liquefied refrigerant, and the sliding surface between the swash plate and the hemispherical shoe at the start of the operation becomes a dry state without the lubricating oil, and is burned. There is a problem that sticking is likely to occur.

  As a means for preventing this seizure, for example, a polyether ether ketone (PEEK) resin film is directly formed on at least sliding surfaces of a swash plate and a hemispherical shoe by an electrostatic powder coating method (see Patent Document 1). There has been proposed a thermoplastic polyimide coating containing a solid lubricant formed by an electrostatic powder coating method (see Patent Document 2).

  Further, in order to ensure high slidability under high speed and high temperature conditions, a binder made of PEEK resin at at least one sliding contact portion of the swash plate, hemispherical shoe and piston, and a solid lubricant dispersed in the binder The thing which formed the sliding layer which becomes (refer patent document 3) is proposed.

JP 2002-180964 A JP 2003-049766 A JP 2002-039062 A

  In the prior art, in order to improve the lubrication characteristics of the swash plate and the hemispherical shoe, as described above, a method of forming the sliding surface of the swash plate and the hemispherical shoe with a lubricating coating has been proposed. There was no formation of a lubricious coating on the hemispherical shoe, even though a lubricious coating was formed on the plate.

  This is because the hemispherical shoe is very small compared to the swash plate, and it is difficult to form a lubricious coating (lubricating resin layer) on the flat surface portion that slides with the swash plate and the spherical surface portion that slides with the piston. This is probably because of this. This is easily inferred from the fact that none of Patent Documents 1 to 3 has a specific description of forming a lubricious coating on a hemispherical shoe. In addition, since the hemispherical shoe has a small sliding area with the swash plate and also receives sliding with the spherical seat of the piston, it is speculated that the durability of the lubricating coating is not sufficiently obtained by frictional heat. The Further, since the sliding surface of the hemispherical shoe has a high surface pressure, the lubricating coating is required to have a high level in terms of strength. Furthermore, it is considered that the materials of the swash plate and the piston are different.

  In addition, the swash plate with a lubricating coating is not only strict in terms of flatness, parallelism and thickness accuracy of the sliding surface, but also has a low coating cost due to the large coating area of the lubricating coating made of expensive materials. There is a problem that you can not.

  The present invention has been made to address these problems, and an object of the present invention is to provide a hemispherical shoe having a lubricating resin layer that can have characteristics corresponding to each of the swash plate and the piston. In addition, to provide a hemispherical shoe with sufficient durability that does not cause seizure even in a dry state without lubricating oil at the start of operation, does not deteriorate lubrication characteristics due to frictional heat generation, and does not peel off the resin layer. With the goal. Furthermore, it aims at providing the swash plate type compressor which uses this hemispherical shoe.

  The hemispherical shoe of the swash plate compressor according to the present invention has a hemispherical shoe attached to a swash plate mounted at a right angle and obliquely so as to be fixed directly to a rotating shaft or indirectly through a connecting member in a housing in which a refrigerant exists. A swash plate compressor hemisphere shoe that slides and converts the rotational movement of the swash plate into a reciprocating movement of the piston through the hemisphere shoe to compress and expand the refrigerant. A resin layer is provided on the surface of the flat part that slides with the swash plate and the surface of the spherical part that slides with the piston, and the resin layer of the flat part is different from the resin layer of the spherical part. It is the resin layer which consists of a resin composition, It is characterized by the above-mentioned.

  The spherical resin layer has a lower hardness than the flat resin layer.

  The planar resin layer includes a carbon-based material, and the spherical resin layer does not include a carbon-based material.

  Each of the planar resin layer and the spherical resin layer is an injection-molded body of the resin composition. Further, the molded body that becomes the resin layer of the flat surface portion and the molded body that becomes the resin layer of the spherical surface portion are integrated with the base material interposed therebetween.

  In addition, a hollow portion is provided in the central axis portion of the base material, and leg portions provided on each molded body of the molded body A that becomes the resin layer of the flat surface portion and the molded body B that becomes the resin layer of the spherical surface portion. The molded body A and the molded body B are integrated with the base material sandwiched between the outer peripheral portions of the molded bodies and the outer peripheral portions of the molded bodies. To do.

  The swash plate type compressor of the present invention slides a hemispherical shoe on a swash plate attached at right angles and obliquely so as to be fixed directly to a rotating shaft or indirectly through a connecting member in a housing in which refrigerant exists. A swash plate compressor that compresses and expands the refrigerant by converting the rotational movement of the swash plate into a reciprocating movement of the piston through the hemispheric shoe, and the hemispheric shoe is the hemispheric shoe of the present invention. To do.

  The hemispherical shoe of the swash plate compressor of the present invention has a resin composition in which the resin layer formed on the surface of the flat portion sliding with the swash plate and the surface of the spherical portion sliding with the piston has a hard member as a base material. It is a resin layer made of material. For this reason, even if the materials of the swash plate and the piston, which are the sliding counterparts of the hemispherical shoe, are different from each other, the corresponding resin layers should be formed separately for the anti-swash plate and for the piston. Is possible. As a result, it is possible to prevent the life of the resin layer of either the swash plate and the piston or of the flat surface portion and the spherical surface portion from becoming uneven. In addition, by forming the resin layer with engineering plastics with excellent lubricity and heat resistance and high mechanical strength, seizure does not occur even in a dry state without lubricating oil at the start of operation, and lubrication characteristics due to frictional heat generation The durability is sufficiently ensured without lowering or peeling of the resin layer.

  Since the spherical resin layer has a lower hardness and is softer than the flat resin layer, when the iron material is selected for the swash plate and the aluminum material is selected for the piston, the flat surface and spherical surface of the resin layer are selected. The difference in the wear characteristics of the parts is reduced. In addition, since the carbon layer material is included in the resin layer in the plane portion and the carbon layer material is not included in the resin layer in the spherical surface portion, the sliding between the swash plate made of iron material and the piston made of aluminum material is performed. In movement, wear of each resin layer and the counterpart material is suppressed to a low level.

  Since the resin layer of the plane portion and the resin layer of the spherical portion are each an injection-molded body of the resin composition, they can be easily formed as resin layers having various shapes and sizes according to the hemispherical shoe. Moreover, it is excellent in mass productivity and the quality is stable.

  In addition, since the molded body that becomes the resin layer of the planar portion and the molded body that becomes the resin layer of the spherical portion are integrated with the base material interposed therebetween, adhesion between the base material and the resin layer is improved. In particular, the resin layer can be easily formed on the hemispherical shoe by being integrated by fitting.

  In addition, a hollow portion is provided in the central axis portion of the base material, and leg portions provided on each molded body of the molded body of the flat surface portion and the molded body of the spherical surface portion are fitted into the hollow portion, and The outer peripheral parts are elastically fitted to each other, and the molded part of the flat part and the molded part of the spherical part are integrated with the base material interposed therebetween, so that the integration of the base material and the resin layer is easy. Excellent layer adhesion.

  Since the swash plate compressor according to the present invention includes the above-described hemispherical shoe, the swash plate and the piston sliding with the hemispherical shoe can remove the lubricating coating. This makes it possible to provide a low-priced swash plate compressor, which is functionally equivalent.

It is sectional drawing which shows an example of the swash plate type compressor of this invention. It is a longitudinal cross-sectional view which expands and shows the hemispherical shoe of FIG. It is a longitudinal cross-sectional view which shows the other example of a hemispherical shoe. It is a longitudinal cross-sectional view which shows the other example of a hemispherical shoe. It is a longitudinal cross-sectional view which shows the other example of a hemispherical shoe. It is the front view and top view which show an example of the base material which provided the recessed part for rotation prevention of a molded object. It is the front view and top view which show the other example of the base material which provided the recessed part for rotation prevention of a molded object.

  An embodiment of a swash plate compressor according to the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an example of a swash plate compressor of the present invention. The swash plate type compressor shown in FIG. 1 uses carbon dioxide gas as a refrigerant, and is a double swash plate type. In this swash plate compressor, a hemispherical shoe 4 that slides on both sides of the swash plate 3 is used to rotate the swash plate 3 that is obliquely mounted so as to be directly fixed to the rotary shaft 2 in the housing 1 in which refrigerant exists. Through the reciprocating motion of the double-headed piston 9. Then, the refrigerant is compressed and expanded on both sides of each piston 9 in the cylinder bore 10 formed at equal intervals in the circumferential direction of the housing 1. The rotary shaft 2 that is rotationally driven at high speed is supported by a needle roller bearing 11 in the radial direction and supported by a thrust needle roller bearing 12 in the thrust direction. In this configuration, the swash plate 3 may be fixed to the rotary shaft 2 indirectly via a connecting member. Moreover, the aspect attached rather than diagonally may be sufficient.

  Each piston 9 is formed with a recess 9 a so as to straddle the outer periphery of the swash plate 3, and a hemispherical shoe 4 is seated on a spherical seat 13 formed on the axially opposed surface of this recess 9 a, The swash plate 3 is supported so as to be movable relative to the rotation of the swash plate 3. Thereby, conversion from the rotational movement of the swash plate 3 to the reciprocating movement of the piston 9 is performed smoothly. The hemispherical shoe 4 slides with the swash plate 3 on the flat surface and slides with the piston 9 (spherical seat 13) on the spherical surface.

  The structure of the hemispherical shoe of the present invention will be described in detail with reference to FIG. FIG. 2 is a longitudinal sectional view showing an example of the hemispherical shoe of the present invention. The hemispherical shoe 4 includes a spherical part 4a constituting a part of a sphere, a flat part 4b having a shape obtained by cutting the spherical part on a side opposite to the spherical part 4a, and an outer periphery connecting the spherical part 4a and the flat part 4b. It has a substantially hemispherical structure with a portion 4c. The hemispherical shoe 4 has a circular planar shape. The overall shape of the hemispherical shoe 4 is a shape in which one bottom surface of the cylindrical body is a convex shape constituting a part of the hemisphere. The overall shape of the hemispherical shoe 4 is not limited to this, and it is sufficient that it has at least a flat surface portion that slides with the swash plate and a spherical surface portion that slides with the piston.

  The hemispherical shoe 4 is made of a hard member made of metal or the like as a base material 5, and a resin layer 6 is provided on the surface of the flat surface portion 4 b that slides with the swash plate and the surface of the spherical surface portion 4 a that slides with the piston (spherical seat). ing. The resin layer 6 is a resin molded body. Of the resin layer, the resin layer 6a is provided on the surface of the spherical surface portion 4a, and the resin layer 6b is provided on the surface of the flat surface portion 4b.

  The resin layer 6b of the flat surface portion 4b and the resin layer 6a of the spherical surface portion 4a are resin layers made of different resin compositions. That is, the resin composition that is the material of the resin layer 6b of the flat surface portion 4b is different from the resin composition that is the material of the resin layer 6a of the spherical surface portion 4a. Here, the “different resin composition” means a case where the base resin is the same but the compounding material is different, or a case where the base resin and the compounding material are the same even though the compounding ratio is different, and the same resin composition. It means not. This is because different members in the hemispherical shoe in which the flat part is a swash plate and the spherical part is a piston are different members. The swash plate mating plane part has a large momentum because the swash plate rotates while oscillating, and the spherical part slides with the spherical part of the piston so that the momentum is small. This is because there is a difference in the mating material of the iron-based material and the piston of the aluminum-based material. For the spherical part and the flat part of the hemispherical shoe, materials suitable for the respective momentum and the mating material should be selected. In the hemispherical shoe of the present invention, since the resin layer of the spherical portion and the resin layer of the flat portion are made of different resin compositions, it is possible to improve the operation efficiency of the swash plate compressor.

  In addition, by forming these resin layers with engineering plastics with excellent lubricity, heat resistance and high mechanical strength, seizure does not occur even in a dry state without lubricating oil at the start of operation, and frictional heat generation occurs. As a result, there is no deterioration in the lubrication characteristics and no peeling of the resin layer, and sufficient durability is ensured. The synthetic resin (base resin) for forming the resin layer is not particularly limited as long as it can ensure the lubrication characteristics and heat resistance required for the hemispherical shoe. For example, polyphenylene sulfide (PPS) resin, polyamideimide (PAI) ) Resin, polyether ether ketone (PEEK) resin, polyimide (PI) resin, phenol resin and the like. Each of these synthetic resins may be used alone or may be a polymer alloy in which two or more kinds are mixed. Among these, PAI resin, PEEK resin, and PI resin excellent in heat resistance and wear resistance are preferable, and PEEK resin excellent in fatigue characteristics and fluidity during injection molding is particularly preferable. These synthetic resins may be blended with carbon fiber, glass fiber, mica, talc and the like for the purpose of improving mechanical strength and wear resistance. In addition, for the purpose of reducing friction and improving seizure at the time of oil exhaustion, a solid lubricant such as polytetrafluoroethylene (PTFE) resin, graphite, molybdenum disulfide may be blended. The handling of carbon-based materials (also referred to as carbon-based compounding materials) such as carbon fibers and graphite to be blended with the base resin will be described later.

  Because the momentum is different between the flat part and the spherical part, the spherical part has less momentum than the flat part, so the hardness of the resin layer of the spherical part is lower and softer than the resin layer of the flat part. Wear of the flat surface portion and the spherical surface portion, and the swash plate and the piston can be kept low. Here, “hardness” is a hardness generally used for resin moldings such as Rockwell hardness and Shore hardness, and the hardness level is a comparison when the hardness is measured according to the same measurement standard.

  For example, if the same base resin is used, (1) a configuration in which carbon fiber is blended in the resin composition of the planar resin layer and aramid fiber is blended in the resin composition of the spherical resin layer; 2) A structure in which graphite is blended in the resin composition of the resin layer of the plane portion and PTFE resin is blended in the resin composition of the resin layer of the spherical surface portion. It becomes possible to make the wear of the spherical surface portion, the swash plate and the piston uniform. In addition, by adding a carbon-based material (carbon fiber or graphite) to the resin composition of the flat surface resin layer, the wear resistance of the flat surface resin layer having a large momentum is improved and the resin layer of the spherical surface portion is improved. By not adding a carbon-based material to the resin composition, it is possible to prevent wear of a piston made of an aluminum-based material.

  In the hemispherical shoe 4 shown in FIG. 2, the resin layer 6 b of the flat surface portion 4 b and the resin layer 6 a of the spherical surface portion 4 a are formed as separate molded bodies with the base material 5 interposed therebetween. Due to such a structure, it is easy to form a resin layer on the hemispherical shoe. In particular, the quality is stabilized by making each resin layer a separate injection-molded body. In addition, since injection molding applies pressure to the resin composition in a molten state, the resin layer is densely formed, and load resistance and wear resistance are increased. In addition, when forming a resin layer by injection molding, you may machine to a desired dimension after injection molding besides injection molding to a desired dimension by injection molding.

  In the hemispherical shoe 4 shown in FIG. 2, a resin layer 6 is provided so as to cover almost the entire surface of the substrate 5. In the case where the diameter of the hemispherical shoe is about 10 mm (5 to 15 mm), the thickness of the resin layer 6 covering the outside of the base material 5 is about 0.1 to 0.7 mm, and the shape of the base material 5 is the hemispherical shoe 4. It is a shape along the whole shape. For this reason, the base material 5 has a spherical surface portion 5a, a flat surface portion 5b, and an outer peripheral portion 5c corresponding to the spherical surface portion 4a, the flat surface portion 4b, and the outer peripheral portion 4c of the hemispherical shoe 4, respectively. It is preferable to make the resin layer as thin as the above-mentioned range since the frictional heat easily escapes from the frictional sliding surface to the substrate side and is difficult to store heat.

  A hemispherical shoe with improved heat dissipation will be described with reference to FIG. FIG. 3 is a longitudinal sectional view showing a hemispherical shoe having a substrate exposed portion. As shown in FIG. 3, the hemispherical shoe 4 is formed with a resin layer 6 on the sliding surface of the base material 5 that directly contacts the swash plate and the piston, and is covered with a resin layer at other locations. The exposed portion 17 is not provided. Specifically, the outer peripheral portion 5c of the substrate 5 is exposed without being covered with the resin layer. Thus, by exposing a part of the base material, the frictional heat generated at the sliding part can be easily radiated from the exposed part.

  In the hemispherical shoe 4 shown in FIGS. 2 and 3, each resin layer is fixed in close contact with the base material 5. As a fixing method, any method such as adhesion, welding, and fitting can be adopted. As a preferred embodiment, it is preferable that the molded body that becomes the resin layer 6 b of the flat surface portion 4 b and the molded body that becomes the resin layer 6 a of the spherical surface portion 4 a are integrated with the base material 5 interposed therebetween. In the hemispherical shoe 4 shown in FIG. 2, the outer peripheral portion of the resin layer 6a and the outer peripheral portion of the resin layer 6b are fixed and integrated by the fixing method or the like at the position of the outer peripheral portion 4c of the hemispherical shoe 4. . Thereby, it is excellent in the adhesiveness of a base material and a resin layer.

  An example of the fixing method of the resin layer with respect to a base material is demonstrated based on FIG. 4 and FIG. 4 and 5 are both longitudinal sectional views showing a hemispherical shoe in which the resin layer of the spherical portion and the flat portion is integrated, FIG. 4 is a fitting type, and FIG. 5 is a welding type. In addition, the right figure in FIG. 4 is a longitudinal cross-sectional view, and the left figure is the exploded view.

  In the hemispherical shoe 4 shown in FIG. 4, a hollow portion 7 is provided in the central axis portion of the base material 5. The molded body that becomes the resin layer 6b of the flat surface portion 4b has a rod-like leg portion 6d on the central axis on the non-sliding side. Similarly, the molded body to be the resin layer 6a of the spherical surface portion 4a has a rod-like leg portion 6c on the central axis on the non-sliding side. These leg portions 6 c and 6 d are press-fitted into the hollow portion 7 of the base material 5. Moreover, in the hemispherical shoe 4 of this form, the outer peripheral portion of the molded body that becomes the resin layer 6b of the flat surface portion 4b and the outer peripheral portion of the molded body that becomes the resin layer 6a of the spherical surface portion 4a are elastically fitted. Specifically, a concave portion 8a is provided on the outer peripheral portion of one molded body, and a convex portion 8b corresponding to the concave portion 8b is provided on the outer peripheral portion of the other molded body. The convex portion 8b on the outer peripheral portion of the other molded body is combined with 8a and elastically fitted (snap fit). 8 in the figure is an elastic fitting part. In addition, the uneven | corrugated relationship in an elastic fitting part may be contrary to the case shown to this figure. Thereby, the compacts are firmly fixed in a state where the base material is held in a sandwich shape at both the central shaft portion and the outer peripheral portion. As a result, the resin layer of the flat surface portion and the spherical surface portion is integrated with the base material of the hemispherical shoe interposed therebetween, and the adhesion between the base material and the resin layer is improved.

  In the hemispherical shoe 4 shown in FIG. 5, the resin layer 6b of the flat surface portion 4b and the resin layer 6a of the spherical surface portion 4a are formed of separate molded bodies with the base material 5 sandwiched therebetween, and the outer peripheral portion of each molded body is formed. The configuration is the same as that of the hemispherical shoe shown in FIG. 4 except that there is no elastic fitting portion (uneven portion). In this embodiment, the outer peripheral end surface of the molded body that becomes the resin layer 6b of the flat surface portion 4b and the outer peripheral edge surface of the molded body that becomes the resin layer 6a of the spherical surface portion 4a are bonded together by ultrasonic welding. Specifically, first, a rod-shaped leg portion 6d of the molded body that becomes the resin layer 6b of the flat surface portion 4b and a rod-shaped leg portion 6c of the molded body that becomes the resin layer 6a of the spherical surface portion 4a are formed into the hollow portion of the base material 5. Press fit into 7. The ends of the rod-like leg portions 6c and 6d are bonded together by ultrasonic welding, and the outer peripheral end surface of the molded body that becomes the resin layer 6b of the flat surface portion 4b and the molded body that becomes the resin layer 6a of the spherical surface portion 4a. The outer peripheral end face is bonded by ultrasonic welding. 14 in the figure is an ultrasonic welding part. Thereby, the molded bodies are firmly bound and fixed in a state where the base material is held in a sandwich shape at both the central shaft portion and the outer peripheral portion, and the adhesion between the base material and the resin layer is improved.

  In either case of FIG. 4 and FIG. 5, the fixing location between the molded body that becomes the resin layer 6b of the flat surface portion 4b and the molded body that becomes the resin layer 6a of the spherical surface portion 4a is located at the outer peripheral portion 4c of the hemispherical shoe. doing. The outer peripheral portion 4c is a portion that is not slidably contacted with the piston or the swash plate, unlike the spherical portion or the flat portion. For this reason, there is no concern that the sliding characteristics are adversely affected by joining the two members by elastic fitting or ultrasonic welding at the location so that the joint portion is positioned on the sliding contact surface.

  Since hemispherical shoes are used in extremely harsh environments, the resin layer (molded product) is relative to the substrate when abnormal heat generation occurs for some reason and the adhesion between the substrate and the resin layer decreases. May rotate. In order to prevent this, it is preferable to form a recess for preventing rotation of the molded body with respect to the base material on the surface of the base material on which each molded body is provided.

  The groove | channel formed radially as one form of such a recessed part is demonstrated based on FIG. 6A is a front view of the base material, and FIG. 6B is a bottom view of the base material (viewed from the plane portion side). As shown in FIGS. 6A and 6B, grooves 15 that are concave portions are formed on the surface of the base material 5 radially from the central axis of the base material. The groove 15 is formed on the base material surface of both the flat surface portion 5b and the spherical surface portion 5a. Four radial grooves 15 in the flat portion 5b are arranged at equal angles (90 degrees) with respect to the central axis, and the four grooves have the same shape. Similarly, the four radial grooves 15 in the spherical surface portion 5a are also arranged in a radial distribution from the central axis of the base material.

  A groove formed in the axial direction as another form of the recess will be described with reference to FIG. Fig.7 (a) is a front view of a base material, FIG.7 (b) is a bottom view (figure seen from the plane part side) of a base material. As shown in FIGS. 7A and 7B, an axial groove 16 is formed on the outer diameter surface of the substrate 5 (the surface of the outer peripheral portion 5c). Four axial grooves 16 are arranged at equal angles (90 degrees) with respect to the center axis of the base material, and the four grooves have the same shape.

  The resin layer (molded body) of the flat surface portion and the resin layer (molded body) of the spherical surface portion have convex portions corresponding to these grooves on the contact surface with the base material. A groove which is a concave portion of the material is fitted. Thereby, relative rotation of the resin layer with respect to the substrate can be prevented. The convex part of the resin layer (molded body) has a shape complementary to the groove which is a concave part, and can be easily formed at the time of injection molding of each molded body.

  When the radial groove is formed, it is easy to form on the base material, and since the resin layer cannot have a thin portion, the strength of the resin layer can be prevented from being reduced, and the resin layer can be prevented from cracking. When the axial groove is formed, the incorporation of the molded body into the base material is improved at the same time as preventing rotation.

  Moreover, in the form which provides the groove | channel of an axial direction, it is preferable to set it as the structure which arrange | positions the above-mentioned elastic fitting part in this groove part (refer FIG. 4). By disposing the above-described elastic fitting portion in the groove portion, the thickness of the concave portion and the convex portion to be elastically fitted can be increased, cracking of the elastic fitting portion can be prevented, and strong bonding is possible. .

  It is preferable that 2 to 8 grooves are formed on each surface of the base material (for the surface of the spherical surface portion 5a and the surface of the flat surface portion 5b for 15 and for the surface of the outer peripheral portion 5c for 16). If there is one evenly distributed radial groove, the position of the center of gravity of the base material deviates from the central axis, which may cause some adverse effects on the movement of the hemispherical shoe. Moreover, it becomes difficult to form a groove | channel clearly with respect to the base-material surface as it is nine or more.

  The depth of the groove is preferably 0.2 to 1.3 mm at the deepest portion. By setting the depth of the groove of the base material to 0.2 to 1.3 mm, it is possible to reliably prevent relative rotation due to the displacement of the resin layer with respect to the base material. If it is shallower than 0.2 mm, the convex portion of the resin layer corresponding to the groove may get over the groove. On the other hand, if it is deeper than 1.3 mm, there is a risk that, when forming the convex portion of the corresponding resin layer, an injection molding sink may occur on the resin layer surface on the back side of the convex portion. In addition, since the radial groove is formed at a position corresponding to the spherical and planar resin layers that are sliding surfaces, the depth is 0.2 to 1 in order to avoid the above-described adverse effect when it is too deep. More preferably, it is 0.0 mm.

  The edge portion of the groove with the substrate surface is preferably a sharp edge. That is, it is preferable not to chamfer the edge portion of the groove with the substrate surface. When chamfering is provided at the edge portion of the groove, the convex portion of the resin layer corresponding to the groove easily gets over the groove.

  The hemispherical shoe of the present invention is prepared by preparing a molded body that becomes a resin layer of a planar portion and a molded body that becomes a resin layer of a spherical portion with respect to the base material of the hemispherical shoe made of a hard material. And, it becomes possible to manufacture by sandwiching the base material of the hemispherical shoe in a sandwich shape with the molded body of the spherical portion and fitting (snap fitting) with the snap.

  Examples of the material of the hard member used as the base material of the hemispherical shoe of the present invention include metals, ceramics, and hard synthetic resins. When a metal is used for the hard member, a molten metal or a sintered metal manufactured by pressing, machining, die casting or the like can be used. In particular, the substrate is preferably made of sintered metal because of a good balance of productivity, strength, cost, and the like. Examples of the molten metal include steels such as bearing steel (SUJ1-5, etc.), chromium molybdenum steel, carbon steel for mechanical structure, mild steel, stainless steel, or high speed steel, aluminum, aluminum alloy, copper, copper alloy Is mentioned. Examples of the sintered metal include iron, copper iron, copper, and stainless steel. In addition, the density when the base material is a sintered metal is preferably 0.7 to 0.9 in terms of the theoretical density ratio of the material. The thermal conductivity of can be sufficiently secured.

  The surface of the resin layer serving as a sliding surface with the swash plate or the piston may be polished after the resin layer is molded or after being fixed to the substrate. The polishing process eliminates variations in individual height dimensions and improves accuracy. The surface roughness Ra of the surface of the resin layer is preferably adjusted to 0.05 μm to 1.0 μm (JIS B0601). By setting it within this range, the real contact area on the sliding surface of the resin layer sliding with the swash plate or the piston is increased, the actual surface pressure can be lowered, and seizure can be prevented. If the surface roughness Ra is less than 0.05 μm, the supply of lubricating oil to the sliding surface is insufficient. If the surface roughness Ra exceeds 1.0 μm, the real contact area on the sliding surface will decrease, resulting in high local pressure. There is a risk of seizure. More preferably, the surface roughness Ra is 0.1 μm to 0.5 μm.

  Oil pockets and dynamic pressure grooves may be formed on the surface of the resin layer serving as the sliding surface with the swash plate or the piston in addition to the above-described hollow portion in order to supplement the lubricating action during lean lubrication. Examples of the shape of the oil pocket include a spot-like or streak-like recess. Examples of the spot shape or the stripe shape include a parallel straight line shape, a lattice shape, a spiral shape, a radial shape, and a ring shape. The depth of the oil pocket can be determined as appropriate below the thickness of the resin layer.

  The swash plate type compressor in which the hemispherical shoe of the present invention is used is a swash plate that is fixed to the rotating shaft directly or indirectly through a connecting member at right angles and obliquely in a housing where refrigerant exists. This is a swash plate type compressor that compresses and expands the refrigerant by sliding a hemispherical shoe and converting the rotational motion of the swash plate into a reciprocating motion of the piston through the hemispherical shoe. By using the hemispherical shoe (with a resin layer) of the present invention for this swash plate compressor, the lubricating coating can be removed from the swash plate and the piston sliding with the hemispherical shoe. In other words, the surface of the swash plate or the like can be incorporated in the swash plate compressor and slid with the hemispherical shoe while the polished surface of the base material remains unchanged. Therefore, it is possible to provide a low-cost swash plate compressor that is functionally equivalent. In addition, even in a dry state without lubricating oil at the start of operation, seizure on the sliding surface of the hemispherical shoe does not occur, and there is no deterioration in lubrication characteristics due to frictional heat generation and exfoliation of the resin layer. It becomes a long-life swash plate compressor. In particular, since the resin layer using the resin composition suitable for the respective momentum and the counterpart material is formed on the spherical surface portion and the flat surface portion of the hemispherical shoe, the operation efficiency of the swash plate compressor is excellent.

  The sliding surface of the swash plate and the hemispherical shoe of the piston may be provided with a resinous lubrication film, but sufficient sliding characteristics can be exhibited without the lubrication film. is there.

  Since the hemispherical shoe of the swash plate compressor of the present invention has a lubricating resin layer that can have characteristics corresponding to each of the swash plate and the piston, either the swash plate or the piston, or the flat surface portion or the spherical surface portion. It is possible to prevent the life of the resin layer from becoming uneven, and seizure does not occur even in a dry state where there is no lubricating oil at the start of operation. Durability is sufficiently ensured. Therefore, it can be used for various swash plate compressors, and in particular, it can also be used suitably for recent swash plate compressors that use carbon dioxide gas or HFC1234yf as a refrigerant and have a high-speed and high-load specification (for example, the surface pressure exceeds 8 MPa).

DESCRIPTION OF SYMBOLS 1 Housing 2 Rotating shaft 3 Swash plate 4 Hemispherical shoe 5 Base material 6 Resin layer 7 Hollow part 8 Elastic fitting part 9 Piston 10 Cylinder bore 11 Needle roller bearing 12 Thrust needle roller bearing 13 Spherical seat 14 Ultrasonic welding part 15 Radial Groove 16 Axial groove

Claims (7)

In the housing in which the refrigerant is present, the hemispherical shoe is slid on a swash plate mounted at right angles and obliquely so as to be directly fixed to the rotating shaft or indirectly through the connecting member, and the hemispherical shoe is passed through the hemispherical shoe. A hemispherical shoe for a swash plate type compressor that compresses and expands the refrigerant by converting the rotational movement of the swash plate into the reciprocating movement of the piston,
The hemispherical shoe has a hard member as a base material, and a resin layer is provided on the surface of the flat portion that slides with the swash plate and the surface of the spherical portion that slides with the piston,
The flat plate portion resin layer and the spherical portion resin layer are resin layers made of different resin compositions, respectively.   The hemispherical shoe for a swash plate compressor according to claim 1, wherein the spherical resin layer has a lower hardness than the flat resin layer.   The hemisphere of a swash plate compressor according to claim 1 or 2, wherein the resin layer of the flat surface portion includes a carbon-based material, and the resin layer of the spherical surface portion does not include a carbon-based material. Shoe.   4. The swash plate compressor according to claim 1, wherein each of the planar resin layer and the spherical resin layer is an injection-molded body of the resin composition. 5. Hemisphere shoe.   5. The hemisphere of a swash plate compressor according to claim 4, wherein the molded body that becomes the resin layer of the flat surface portion and the molded body that becomes the resin layer of the spherical surface portion are integrated with the base material interposed therebetween. Shoe. A hollow portion is provided in the central axis portion of the base material,
The leg portions provided on each molded body of the molded body to be the resin layer of the flat surface portion and the molded body to be the resin layer of the spherical surface portion are fitted into the hollow portion, and the outer peripheral portions of the molded bodies are 6. The molded body that is elastically fitted so as to be a resin layer of the flat surface portion and a molded body that is a resin layer of the spherical surface portion are integrated with the base material interposed therebetween. Hemispherical shoe for swash plate compressor. In the housing in which the refrigerant is present, the hemispherical shoe is slid on a swash plate mounted at right angles and obliquely so as to be directly fixed to the rotating shaft or indirectly through the connecting member, and the hemispherical shoe is passed through the hemispherical shoe. A swash plate type compressor that compresses and expands refrigerant by converting the rotational movement of the swash plate into the reciprocating movement of the piston,
The swash plate type compressor, wherein the hemispherical shoe is the hemispherical shoe according to any one of claims 1 to 6.

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