JP2013036339A - Rotation stopping mechanism of wobble plate of swash plate type variable displacement compressor and constant velocity universal joint constituting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve lubricity, durability, and strength, and to reduce costs by achieving compatibility to a lubricant and adaptation to high temperature use environment, even during use under lean lubrication in a swash plate type variable displacement compressor.SOLUTION: In a rotation stopping mechanism 36 of a wobble plate 18 of a swash plate type variable displacement compressor 1, the rotation stopping mechanism of the wobble plate comprises a constant velocity universal joint 21. The constant velocity universal joint includes: an outer joint member 22 in which a plurality of track grooves are formed in an inner circumferential surface; an inner joint member 23 in which a plurality of track grooves mated with the track grooves of the outer joint member are formed on an outer circumferential surface; a plurality of balls 24 interposed between the track grooves of the outer joint member and the track grooves of the inner joint member to transmit torque; and retainers 25 retaining the balls and provided at the inner circumferential surface of the outer joint member 22 and the outer circumferential surface of the inner joint member. The outer joint member is mounted on the wobble plate. The inner joint member is mounted on a central shaft 30. The retainer is made of resin.

Description

  The present invention relates to an anti-rotation mechanism for a rocking plate of a swash plate type variable capacity compressor and a constant velocity universal joint constituting the same.

A swash plate type variable capacity compressor is provided with a drive shaft that is rotatably supported by a housing, a swash plate that is connected to the drive shaft, rotates, and can be tilted with respect to the drive shaft, and a bearing is attached to the swash plate via a bearing. A rocking plate coupled and blocked from rotating, a piston coupled to the rocking plate and reciprocating in the axial direction of the drive shaft, and a central shaft supported by the housing for supporting the rocking plate Are the main components. In order to prevent the rotation of the swing plate, a detent mechanism is provided, and a structure in which a constant velocity universal joint is used as this detent mechanism is described in Patent Document 1, for example. In this detent mechanism, the constant velocity universal joint is arranged at the center of the swing plate,
The outer joint member is attached to the swing plate, and the inner joint member is attached to the central shaft.

  The constant velocity universal joints that constitute the rocking plate detent mechanism are used under lean lubrication in a swash plate type variable capacity compressor, so each sliding part of the constant velocity universal joint or between the ball and the track groove is used. There is little supply of this lubricant, and it is in a harsh state in terms of lubricity and durability. In Patent Document 1, a measure for supplying the lubricant is not taken, and lubricity, durability, etc. are not sufficient. Further, in a swing plate type variable capacity compressor that requires high-speed rotation, the sliding speed of each sliding portion of the constant velocity universal joint also increases, so that countermeasure is required.

  On the other hand, in order to improve lubricity and durability, a constant velocity universal joint made of a resin material has been proposed. For example, Patent Document 2 describes a double offset type sliding constant velocity universal joint that is made of self-lubricating resin to reduce slide resistance. As a constant velocity universal joint used under lean lubrication in a plate type variable capacity compressor, it does not focus on problems in terms of compatibility (oil resistance), durability and strength with a lubricant.

JP 2006-200405 A Japanese Utility Model Publication No. 8-320026

  In view of the above problems, the present invention is compatible with a lubricant and used in a high-temperature environment even in use under lean lubrication in a swash plate type variable capacity compressor, and improves lubricity, durability and strength. At the same time, it is an object of the present invention to provide a rocking plate detent mechanism capable of reducing the cost and a constant velocity universal joint constituting the same.

  As a result of various studies to achieve the above object, the present inventors have determined that the cage is a lubricant and a constant velocity universal joint that constitutes a detent mechanism for the swing plate of the swash plate type variable capacity compressor. The new idea of forming with resin that is compatible with compatibility and high temperature use environment and contributes to improvement of lubricity, durability and strength.

  As technical means for achieving the above-mentioned object, the present invention includes a drive shaft rotatably supported by a housing, and a slant that is connected to the drive shaft and rotates and tiltable with respect to the drive shaft. A plate, a swing plate connected to the swash plate via a bearing and prevented from rotating, a piston connected to the swing plate and reciprocating in the axial direction of the drive shaft, and the swing plate An anti-rotation mechanism for a rocking plate of a swash plate type variable displacement compressor having a central shaft supported by the housing for supporting, wherein the anti-rotation mechanism for the rocking plate is constituted by a constant velocity universal joint. The constant velocity universal joint includes an outer joint member in which a plurality of track grooves are formed on the inner peripheral surface, and an inner joint member in which a plurality of track grooves that are paired with the track grooves of the outer joint member are formed on the outer peripheral surface; Track groove and inner joint portion of the outer joint member A plurality of balls that are interposed between the track grooves and transmit torque, and retainers that hold the balls and are disposed on the inner peripheral surface of the outer joint member and the outer peripheral surface of the inner joint member. The outer joint member is attached to the swing plate, the inner joint member is attached to the central shaft, and the cage is made of resin.

  With the above configuration, the swash plate type variable capacity compressor swing plate detent mechanism and the constant velocity universal joints that make it compatible with lubricants and high temperature usage environments even when used under lean lubrication In addition, lubricity, durability and strength can be improved. Further, the cage can be mass-produced with high productivity, and the cost can be reduced. As a result, it is possible to improve the durability and cost of the swash plate type variable capacity compressor.

  By using a thermoplastic resin as the resin for forming the cage, it can be mass-produced with high productivity by injection molding, which is advantageous in terms of manufacturing cost. Further, since a smooth surface can be obtained without any grinding or turning marks by machining, it is advantageous from the viewpoint of frictional wear.

  The resin forming the cage preferably has a glass transition point of 100 ° C. or higher in consideration of the usage environment of the swash plate type variable capacity compressor and the physical properties of the resin. In the case of an amorphous resin, there is little decrease in physical properties up to the glass transition point, and the amorphous resin having a glass transition point of less than 100 ° C. has poor compatibility with the polyalkylene glycol (PAG) that is a lubricant, It is difficult to ensure durability, and when the ambient temperature is higher than the glass transition point, the physical properties are drastically deteriorated, which is not suitable for use.

  The thermoplastic resin is preferably a crystalline resin, and the melting point is preferably 200 ° C. or higher. The higher the melting point, the higher the heat resistance of the crystalline resin, and the heat resistance strength up to the vicinity of the melting point, heat resistance creep, heat resistance stability, fatigue resistance and mechanical strength are excellent. In addition, since the resin surface has a strong crystal structure and excellent wear resistance, the life of the rotation prevention mechanism can be extended.

  A reinforcing material can be added to the resin forming the cage. Thereby, further strength and toughness are imparted, which is advantageous.

  A solid lubricant can be added to the resin forming the cage. Thereby, the lubrication performance can be further improved. Only one type of solid lubricant may be added, or two or more types may be mixed and added.

  By forming an infinite number of minute concave depressions on the surface of the cage, the lubricating oil is easily held on the surface, which is advantageous for sliding under lean lubrication. As a method for forming an infinite number of minute concave recesses, it can be formed by barrel processing or tumbler processing in the final step after forming the cage. However, the present invention is not limited to this, and shot peening can be used. Moreover, a desired surface shape can be given to the mold surface at the time of injection molding, and it can be transferred to the cage surface to form a dent.

  The lubricant used in the anti-rotation mechanism of the swing plate of the swash plate type variable capacity compressor is preferably polyalkylene glycol (PAG). PAG is compatible with a refrigerant generally used in a car air conditioner compressor and is preferable as a lubricant coexisting with the refrigerant.

  As the constant velocity universal joint, a Rzeppa type fixed constant velocity universal joint is preferable. As a result, the rotation between the ball and the track groove can be smoothly prevented, and the rocking motion is performed at the spherical contact portions of the outer joint member, the cage and the inner joint member, so that stable rocking without vibration is achieved. Exercise is realized.

  According to the present invention, the anti-rotation mechanism of the rocking plate of the swash plate type variable capacity compressor and the constant velocity universal joint constituting the same are compatible with the lubricant and used in a high temperature environment even when used under lean lubrication. It can be adapted to improve lubricity, durability and strength. Further, the cage can be mass-produced with high productivity, and the cost can be reduced. As a result, it is possible to improve the durability and cost of the swash plate type variable capacity compressor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an overall structure of a rocking plate rotation preventing mechanism and a swash plate type variable capacity compressor of a swash plate type variable capacity compressor according to a first embodiment of the present invention. It is a figure which shows the constant velocity universal joint which comprises the rotation prevention mechanism of 1st Embodiment. It is a figure which shows the outer joint member of a constant velocity universal joint. It is a figure which shows the inner side coupling member of a constant velocity universal joint. It is a figure which shows the holder | retainer of a constant velocity universal joint. It is a figure which shows the inner side coupling member of the constant velocity universal joint which comprises the anti-rotation mechanism of the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  A rotation preventing mechanism for a rocking plate of a swash plate type variable displacement compressor according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view showing the overall structure of a swash plate type variable capacity compressor. In the swash plate type variable displacement compressor 1, a front housing 2, a cylinder block 3 as a middle housing, and a rear housing 4 indicated by a two-dot chain line behind the front housing 2 are integrated by fastening means (not shown) to form a housing of the compressor 1. ing. In the cylinder block 3, a plurality of (for example, five) cylinder bores 5 are formed so as to be arranged approximately evenly around the center line A. Although not shown, a discharge chamber as a substantially annular space is formed inside the rear housing 4, and a suction chamber is formed as a space in the center portion.

  The drive shaft 6 receives rotational power from an external power source (for example, an engine), and a rotor 7 is integrally attached so as to be orthogonal to the drive shaft 6. The rotor 7 may be an integral part of the drive shaft 6. The arm portion 8 is formed so as to protrude rearward from a part near the outer periphery of the rotor 7. The arm portion 8 is provided with a long hole 15 that operates as a cam. The drive shaft 6 is rotatably supported by a front housing 2 which is a part of the housing via radial rolling bearings 9 and 10, and the rear surface of the rotor 7 integrally attached to the drive shaft 6 is thrust-rolled. The bearing 11 is also supported so as to be rotatable in the thrust direction. A seal device 12 is provided between the radial rolling bearings 9 and 10 to prevent fluid from leaking from the periphery of the drive shaft 6 to the outside.

  The swash plate 13 is generally annular and includes an arm portion 14 protruding forward from a part thereof. The arm portion 14 is provided with a pin 16 and is inserted into and engaged with a long hole 15 provided in the arm portion 8 of the rotor 7 attached to the drive shaft 6. The link mechanism 17 is constituted by these portions, and the swash plate 13 can rotate together with the drive shaft 6 and can be inclined and tilted with respect to the drive shaft 6 and the rotor 7. On the swash plate 13, a substantially annular swing plate 18 that is prevented from rotating by means described later and only swings is supported via a radial rolling bearing 19 and a thrust rolling bearing 20.

  The outer joint member 22 of the constant velocity universal joint 21 is press-fitted into the inner peripheral hole of the swing plate 18 and is positioned and fixed by a retaining ring 26. An inner ring of the radial rolling bearing 19 is incorporated in the small diameter portion 27 of the swing plate 18 and is positioned and fixed by a retaining ring 28. The outer ring of the radial rolling bearing 19 is incorporated in the inner peripheral hole 29 of the swash plate 13 and is positioned and fixed at its shoulder.

  A central shaft 30 that supports the swash plate 13 and the swing plate 18 is supported by the cylinder block 3 so as not to rotate in a state that coincides with the axis A of the drive shaft 6. Specifically, a male spline 31 is formed at the large diameter portion of the central shaft 30 and is engaged with the female spline 32 at the central portion of the cylinder block 3. As a result, the center shaft 8 is prevented from rotating with respect to the cylinder block 3, but is supported by the cylinder block 3 so as to be movable in the axial direction. A female spline 34 of the inner joint member 23 of the constant velocity universal joint 21 is fitted to a male spline 33 formed at the shaft end of the central shaft 30, and is positioned and fixed in the axial direction by a retaining ring 35. The constant velocity universal joint 21 includes an outer joint member 22, an inner joint member 23, a torque transmission ball 24, and a cage 25. The torque transmission ball 24 held by the cage 25 is engaged with each track groove of the outer joint member and the inner joint member 23, and torque can be transmitted in a state where the operating angle is taken.

  As an outline of the detent mechanism of the present embodiment, the outer joint member 22 of the constant velocity universal joint 21 is attached and fixed to the swing plate 18, while the inner joint member 23 is attached and fixed to the central shaft 30, and the swing plate An anti-rotation mechanism 36 for preventing the rotation 18 is configured. Although the rocking plate 18 swings together with the swash plate 13 by the rotation preventing mechanism 36, it can be stopped so as not to rotate regardless of the rotational motion of the swash plate 13.

  The same number of spherical recesses 37 as the cylinder bores 5 are provided in the periphery of the swing plate 18, and correspondingly the spherical end portions 39 formed at one ends of the connecting rods 38 are fitted. ing. The piston 40 slidably inserted into the cylinder bore 5 is also provided with a spherical recess 41 and a spherical end 42 formed at the other end of the connecting rod 38 is fitted.

  Although the illustration of the inside of the rear housing 4 is omitted, the outline is as follows. As described above, a discharge chamber as a substantially annular space is formed inside the rear housing 4, and a suction chamber is formed as a space in the center portion. A valve plate is interposed between the cylinder block 3 and the rear housing 4, and a discharge port and a suction port are opened in the valve seat at positions corresponding to the cylinder bores 5. A suction valve is disposed at each suction port and is closed from the cylinder bore side, while a discharge valve is disposed at each discharge port and is closed from the discharge chamber side. In addition, a control valve is attached to the rear end portion of the rear housing 4 and is controlled by the control device to generate fluid pressure. This is introduced as a control pressure into a control pressure chamber inside the chlorofluorocarbon housing 2 in which the swash plate 13 and the swing plate 18 are arranged, and the tilt angle of the swing plate 18 is controlled.

  The operation of the swash plate type variable displacement compressor 1 having the above configuration will be described. When the drive shaft 6 is rotationally driven by an external power source, the swash plate 13 connected to the rotor 7 of the drive shaft 6 via the arm portion 8, the long hole 15, the pin 16, and the arm portion 14 is driven. It rotates with the shaft 6. However, the oscillating plate 18 is supported on the swash plate 13 via a radial rolling bearing 19 and a thrust rolling bearing 20, and a constant velocity universal joint 21 whose central portion forms a detent mechanism 36. The rocking plate 18 does not rotate because it is supported by the central shaft 30 that does not rotate, and the rocking plate 18 performs only rocking motion with an amplitude corresponding to the inclination angle. Thereby, a plurality of pistons 40 connected to the swing plate 18 via the connecting rod 38 reciprocate in the cylinder bore 5. As a result, among the working chambers 43 formed on the top surfaces of the plurality of pistons 40, those in the suction process are enlarged to a low pressure, and therefore are in the suction chamber (not shown) in the rear housing 4. The refrigerant flows into the working chamber 43. On the contrary, since the working chamber 43 formed on the top surface of the piston 40 in the pressure feeding process is reduced, the refrigerant in the inside is compressed to a high pressure and discharged into a discharge chamber (not shown). The discharge amount of the compressor 1 per rotation of the drive shaft 6 is approximately proportional to the stroke length of the piston 40 determined by the inclination angles of the swash plate 13 and the swing plate 18. In the operation state of the compressor 1 as described above, the rolling bearing, the constant velocity universal joint, and the sliding portions of the respective constituent members are under severe lubrication conditions by a small amount of lubricant in the compressor 1. Specifically, polyalkylene glycol (PAG) is used as the lubricant. PAG is compatible with the refrigerant and coexists with the refrigerant. Under such lubrication conditions, the constant velocity universal joint 21 constituting the detent mechanism 36 of the present embodiment has a retainer 25, which is a constituent member thereof, formed of resin, so that lubrication performance is ensured. be able to.

  The details of the constant velocity universal joint constituting the rocking plate detent mechanism according to the first embodiment of the present invention will be described with reference to FIGS. A constant velocity universal joint 21 shown in FIG. 2 is an enlargement of the constant velocity universal joint 21 shown in FIG. 2A is a longitudinal sectional view of the constant velocity universal joint 21, and FIG. 2B is a front view. This constant velocity universal joint 21 is a Rzeppa type constant velocity universal joint which is a fixed type constant velocity universal joint. The constant velocity universal joint 21 includes an outer joint member 22, an inner joint member 23, a torque transmission ball 24, and a cage 25. Six track grooves 51 are formed on the spherical inner peripheral surface 50 of the outer joint member 22 at equal intervals in the circumferential direction and along the axial direction. On the spherical outer peripheral surface 52 of the inner joint member 23, track grooves 53 that are paired with the track grooves 51 of the outer joint member 22 are formed at equal intervals in the circumferential direction and along the axial direction. Six balls 24 that transmit torque are interposed between the track grooves 51 of the outer joint member 22 and the track grooves 53 of the inner joint member 23. A cage 25 that holds the ball 24 is disposed between the spherical inner peripheral surface 50 of the outer joint member 22 and the spherical outer peripheral surface 52 of the inner joint member 23. The feature of this embodiment is that the cage 25 is made of resin, and details will be described later. The outer joint member 22, the inner joint member 23, and the ball 24 are formed of a commonly used melted material. The outer joint member 22 is formed in an annular shape, and its outer peripheral surface is cylindrical, and is press-fitted into the inner peripheral hole of the swing plate 18 as shown in FIG. Further, the female spline 34 of the inner joint member 23 is fitted to the male spline 33 of the center shaft 30 as shown in FIG.

  As shown in FIG. 2, the centers of curvature of the spherical inner peripheral surface 50 of the outer joint member 22 and the spherical outer peripheral surface 52 of the inner joint member 23 are both formed at the center O of the joint. On the other hand, the center of curvature B of the track groove 51 of the outer joint member 22 and the center of curvature C of the track groove 53 of the inner joint member 23 are offset by an equal distance in the axial direction with respect to the center O of the joint. . As a result, when the joint takes an operating angle, the ball 24 is always guided on a plane that bisects the angle formed by the two axes of the outer joint member 22 and the inner joint member 23, and rotates at a constant speed between the two axes. Torque is transmitted. Since the anti-rotation mechanism 36 of the swing plate 18 is configured by using such a function of the constant velocity universal joint 21, the ball 24 is connected to the outer joint member 22 and the inner joint member according to the inclination angle of the swing plate 18. The swing plate 18 can be smoothly prevented from rotating by reciprocating while being engaged with the track grooves 51 and 53 of the track 23. Further, since the swing motion of the swing plate 18 is performed at the joint center 0 of the constant velocity universal joint 21 and is performed at the spherical contact portions of the outer joint member 22, the retainer 25 and the inner joint member 23, the vibration is stable. Oscillating motion is realized.

  The main structural members of the constant velocity universal joint 21 of this embodiment are shown in FIGS. FIG. 3 is a single view of the outer joint member 22. 3A is a vertical cross-sectional view, and FIG. 3B is a cross-sectional view taken along the line DD in FIG. 3A. FIG. 4 is a single view of the inner joint member 23. FIG. 4B is a front view, and FIG. 4A is a longitudinal sectional view taken along line EE in FIG. 4B. The notch 54 shown in FIG. 4A is for assembling the inner joint member 23 in the pocket 55 (see FIG. 5) of the retainer 25 when the inner joint member 23 is assembled in the retainer 25. It is. FIG. 5 is a single view of the cage 25. 5A is a longitudinal sectional view of the central surface of the pocket 55 (the GG line in FIG. 5B), and FIG. 5B is a transverse sectional view along the FF line in FIG. 5A. It is.

  The outer joint member 22 shown in FIG. 3 is formed of a molten material. Specifically, for example, S45C to S55C material, which is carbon steel for mechanical structure, is used. Six track grooves 51 are formed on the spherical inner peripheral surface 50 of the outer joint member 22 at equal intervals in the circumferential direction and along the axial direction. The spherical inner peripheral surface 50 and the track groove 51 are finished by grinding or turning after quenching.

  The inner joint member 22 shown in FIG. 4 is also formed of a molten material, and specifically, for example, an SCr material or an SCM material that is a case-hardened steel is used. Six track grooves 53 are formed on the spherical outer peripheral surface 52 of the inner joint member 23 at equal intervals in the circumferential direction and along the axial direction. The spherical outer peripheral surface 52 and the track groove 53 are finished by grinding or turning after quenching. The inner joint member 23 is formed with a female spline 34 into which a male spline 33 (see FIG. 1) of the central shaft 30 is fitted.

  Next, the cage 25 which is a feature of the present embodiment will be described with reference to FIG. The cage 25 is formed with a spherical outer peripheral surface 56 that fits with the spherical inner peripheral surface 50 of the outer joint member 22 and a spherical inner peripheral surface 57 that fits with the spherical outer peripheral surface 52 of the inner joint member 23. Six pockets for holding the balls 24 (not shown) are provided at equal intervals in the circumferential direction. The cage 25 having such a shape is formed of a resin, and even when the swash plate type variable capacity compressor is used under dilute lubrication, the compatibility with the lubricant and the high temperature use environment are met. The strength is improved.

  As the resin forming the cage 25, a thermoplastic resin capable of injection molding is preferable. By using a thermoplastic resin, it can be mass-produced with high productivity by injection molding, which is advantageous in terms of manufacturing cost. Further, since a smooth surface can be obtained without any grinding or turning marks by machining, it is advantageous from the viewpoint of frictional wear.

  Thermoplastic resins include crystalline resins and amorphous resins. Examples of crystalline resins are polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polybutylene naphthalate. (PBN), polycyclohexane dimethylene terephthalate (PCT), polyethylene terephthalate (PTFE), liquid crystal polymer (LCP), and the like are exemplified, but not limited thereto. Moreover, these can also be used independently and can also be used in mixture of 2 or more types. A crystalline resin is preferably applied to the cage 25 of the constant velocity universal joint 21 according to the present embodiment, and in that case, the melting point is preferably 200 ° C. or higher. The higher the melting point, the higher the heat resistance of the crystalline resin, and the heat resistance strength up to the vicinity of the melting point, heat resistance creep, heat resistance stability, fatigue resistance and mechanical strength are excellent. In addition, since the resin surface has a strong crystal structure and excellent wear resistance, the life of the rotation prevention mechanism can be extended.

  Examples of the amorphous resin include, but are not limited to, polyetherimide (PEI), polyamideimide (PAI), polycarbonate (PC), polyethersulfone (PES), polyimide (PI), and the like. It is not a thing. Moreover, these can also be used independently and can also be used in mixture of 2 or more types.

  The resin forming the cage 25 preferably has a glass transition point of 100 ° C. or higher in consideration of the usage environment of the swash plate type variable capacity compressor and the physical properties of the resin. In the case of an amorphous resin, there is little decrease in physical properties up to the glass transition point, and the amorphous resin having a glass transition point of less than 100 ° C. has poor compatibility with the polyalkylene glycol (PAG) that is a lubricant, It is difficult to ensure durability, and when the ambient temperature is higher than the glass transition point, the physical properties are drastically deteriorated, which is not suitable for use.

  Addition of a reinforcing material to the resin forming the cage 25 is advantageous because it provides further strength and toughness. Examples of the reinforcing material include fibers, powders, cloths, etc., and these may be used alone or in combination. Examples of the fibers include glass fibers, carbon fibers, aramid fibers, boron fibers, various whiskers and the like. Examples of the powder include silica, carbon black, calcium carbonate, talc, mica, carillon, iron oxide, glass beads, and phosphate compounds.

  The above resin itself has self-lubricating properties, but a solid lubricant can be added to further improve the lubricating performance. Examples of solid lubricants include molybdenum disulfide, tungsten disulfide, melamine cyanurate, PTFE powder, boron nitride, and graphite. These solid lubricants may be added alone or in combination of two or more.

The surface of the cage 25 is formed with an infinite number of minute concave recesses to form a minute rough surface, whereby the lubricating oil is easily held on the surface, which is advantageous for sliding under lean lubrication. This minute rough surface has a recess area ratio in the range of 5 to 20% of the entire surface of the cage 25, and the average area of the recess is within a range of 30 to 100 μm ² when arranged except for an equivalent circular diameter of 3 μmφ or less. It has become. The parameter Rymax is set within the range of 0.4 to 1.0. When Rymax is out of the range of 0.4 to 1.0, the area ratio of the depression exceeds 20%, and the average area exceeds 100 μm ² , the effective contact length decreases and the lubricity effect tends to decrease. is there. Here, Rymax is the maximum value of the maximum height for each reference length (ISO 4287: 1997). Further, when the surface roughness of the minute rough surface is represented by the parameter Rqni, the value of Rqni is set to 0.05 to 0.09, the axial surface roughness Pqni (L) and the circumferential surface roughness Rqni (C ) Pqni (L) / Rqni (C) is set to 1.0 or less. The parameter Sk value is set to −1.6 or less. Here, the parameter Rqni is the square root of the value obtained by integrating the square of the height deviation from the roughness center line to the roughness curve in the section of the measured length and averaging the section. It is also called (ISO 4287: 1997). The parameter Sk value refers to the degree of distortion (skewness) of the surface roughness distribution curve (ISO 4287: 1997), and is a standard statistic for knowing the asymmetry of the uneven distribution.

The measurement methods and conditions of the parameters Rymax and Ryni are exemplified as follows. In addition, although the measured value of one place of the spherical outer peripheral surface 56 of the cage | basket 25 and the spherical inner peripheral surface 57 is reliable as a representative value, it is good to measure two places which oppose a diameter direction, for example.
Parameter calculation standard: JIS B 0601: 1994 (Surfcom JIS 1994)
Cut-off type: Gaussian Measurement length: 5λ
Cut-off wavelength: 0.25mm
Measurement magnification: × 10000
Measurement speed: 0.30 mm / s
Measurement location: Number of measurements in the central portion of the axial width of the spherical inner and outer peripheral surfaces of the cage 25: 2
Measuring device: Surface roughness measuring device Surfcom 1400A (Tokyo Seimitsu Co., Ltd.)

In order to perform the quantitative measurement of the indentation, the surface of the cage 25 is enlarged, and the image can be quantified from the image by a commercially available image analysis system. The white portion of the image is analyzed as a flat surface portion, and the minute depression is analyzed as a black portion. For example, when analyzed using Pierce's LA-525 image analysis system, the density of the original image is first clarified with an emphasis filter, and then an equivalent circle diameter of 3 μmφ or less, which is a very fine black portion, is removed with a noise eraser. . The size, distribution, and area ratio of the minute dents left after removal by the noise eraser are obtained, and the surface of the cage 25 is evaluated. The measurement conditions in that case are as follows, for example. Further, the area ratio and the average area of the dents can be reliable as a representative value even if the measured values at one place are the same as the above-described parameters Rymax and Ryni.
Field of view: 826 μm × 620 μm
Measurement location: Central side constant of axial width of spherical inner and outer peripheral surface of cage 25: 2

  As a surface processing method for forming a micro rough surface having a micro concave recess, it can be formed by special barrel processing or tumbler processing in the final process after the cage 25 is formed. However, the present invention is not limited to this, and shot peening may be used. Also, a similar convex shape may be provided on the mold surface during injection molding, and transferred during molding.

  Next, a second embodiment will be described based on FIG. Fig.6 (a) is a longitudinal cross-sectional view of the inner joint member in this embodiment, FIG.6 (b) is a front view. This embodiment is different from the first embodiment in that the inner joint member 23 is formed of a metal sintered body. Parts having the same functions as those of the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 6, the inner joint member 23 is formed of a metal sintered body, and the track grooves 53 are formed on the spherical outer peripheral surface 52 at equal intervals in the circumferential direction and along the axial direction by a molding die in a compacting process. Is formed. The sintered metal body is composed of an iron-based alloy metal powder as a main component and is composed of an alloyed powder containing at least chromium and molybdenum. After sintering the green compact, a hardened layer is formed on the surface by heat treatment. As a result, accuracy, mechanical strength, and durability are ensured. Further, the inner joint member 23 can be mass-produced with high productivity, which is advantageous in terms of manufacturing cost. Further, by imparting an appropriate porosity to the sintered metal forming the inner joint member 23, the lubrication performance of the spherical contact portion with the resin cage 25 is further improved. Others are the same as those described above in the first embodiment, and thus description thereof is omitted.

  Examples of the present invention and comparative examples will be described below. In the constant velocity universal joint 21 constituting the detent mechanism of the first embodiment, the example is a resin material in which a retainer 25 is a polyether ether ketone (PEEK) and a reinforcing material is added to 30% of carbon fiber (CF). The injection molded. However, in this example, the surface of the cage that was not subjected to the micro-roughening treatment of the fine concave shape was used (glass transition point 143 ° C., melting point 343 ° C., measured according to JIS K7121). In the comparative example, a cage was made of an SCr420 material as a melting material, and carburizing, quenching, and tempering were performed. The surface hardness was Hv700.

(Evaluation test and test results)
The examples and comparative examples were evaluated. As the Rzeppa type constant velocity universal joint of FIG. 2 subjected to the evaluation test, NTN BJ75 was used, and the resin-made cage of the example and the molten-material cage of the comparative example were incorporated therein. The outer joint member was made of S53C material, the inner joint member was made of molten material of SCr420 material, and the balls were steel balls. In this evaluation test, an outer joint member, an inner joint member, a ball, and a cage were incorporated in order to approximate the lubrication conditions in the swash plate type variable capacity compressor, and after connecting the shaft to the inner joint member, When sealing between the outer periphery of the shaft with a boot, an amount of PAG (polyalkylene glycol) corresponding to 10% of the joint space volume was sealed as a lubricant.
Test conditions are shown below.
Torque: 80Nm
Joint angle: 6 degrees The rotational speed was increased by 1000 rpm every 30 minutes from 4000 rpm, and the rotational speed at which seizure occurred was defined as the seizure limit rotational speed. The results are shown in Table 1. In the comparative example, seizure occurred at 6000 rpm, and the operation became impossible, but in the example, the continuous operation was possible even after the operation at 8000 rpm.

  In each of the above embodiments, the case where the Zepper type fixed type constant velocity universal joint is applied to the rotation preventing mechanism has been described. However, the present invention is not limited to this, for example, an undercut free type fixed type constant velocity universal joint, Furthermore, a sliding type constant velocity universal joint can also be applied.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the scope of the present invention. The scope of the present invention is not limited to patents. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1 Swash plate type variable capacity compressor 2 Front housing 3 Cylinder block 4 Rear housing 5 Cylinder bore 6 Drive shaft 7 Rotor 8 Arm part 9 Radial rolling bearing 10 Radial rolling bearing 11 Thrust rolling bearing 13 Swash plate 14 Arm part 17 Link mechanism 18 Oscillation Plate 19 Radial rolling bearing 20 Thrust rolling bearing 21 Constant velocity universal joint 22 Outer joint member 23 Inner joint member 24 Torque transmission ball 25 Cage 30 Center shaft 36 Non-rotating mechanism 38 Connecting rod 40 Piston 43 Working chamber 50 Spherical inner peripheral surface 51 Track groove 52 Spherical outer peripheral surface 53 Track groove 56 Spherical outer peripheral surface 57 Spherical inner peripheral surface B Center of curvature C Center of curvature O Joint center

Claims (12)

A drive shaft rotatably supported by the housing, a swash plate that is connected to the drive shaft, rotates, and can be tilted with respect to the drive shaft, and is connected to the swash plate via a bearing to prevent rotation. A slanting plate including a swinging plate, a piston coupled to the swinging plate and reciprocating in the axial direction of the drive shaft, and a central shaft supported by the housing for supporting the swinging plate. In the rotation prevention mechanism of the swing plate of the plate variable capacity compressor,
The anti-rotation mechanism of the swing plate is composed of a constant velocity universal joint, and the constant velocity universal joint includes an outer joint member having a plurality of track grooves formed on the inner peripheral surface, and a track of the outer joint member on the outer peripheral surface. An inner joint member in which a plurality of track grooves paired with the groove are formed; a plurality of balls which are interposed between the track grooves of the outer joint member and the track grooves of the inner joint member; And a cage disposed on the outer peripheral surface of the outer joint member and the outer peripheral surface of the inner joint member, wherein the outer joint member is attached to the swing plate, and the inner joint A rotation preventing mechanism for a rocking plate of a swash plate type variable capacity compressor, wherein a member is attached to the central shaft and the cage is made of resin.   2. The anti-rotation mechanism of the swing plate of the swash plate type variable capacity compressor according to claim 1, wherein the resin forming the cage is a thermoplastic resin.   The rotation stop mechanism of the swing plate of the swash plate type variable capacity compressor according to claim 1 or 2, wherein the thermoplastic resin is a crystalline resin.   The rotation stop mechanism of the rocking plate of the swash plate type variable capacity compressor according to any one of claims 1 to 3, wherein a glass transition point of the resin forming the cage is 100 ° C or higher.   The swash plate type variable capacity compressor according to claim 3, wherein the crystalline resin has a melting point of 200 ° C or higher.   The rotation preventing mechanism for the swing plate of the swash plate type variable capacity compressor according to any one of claims 1 to 5, wherein a reinforcing material is added to the resin forming the cage.   The rotation preventing mechanism for the swing plate of the swash plate type variable capacity compressor according to any one of claims 1 to 6, wherein a solid lubricant is added to the resin forming the cage.   The said retainer is formed by injection molding, The rotation prevention mechanism of the rocking | fluctuation plate of the swash plate type variable capacity compressor as described in any one of Claims 1-7 characterized by the above-mentioned.   9. The rotation preventing mechanism for a swing plate of a swash plate type variable capacity compressor according to claim 1, wherein a minute concave recess is formed on the surface of the cage.   The rotation stopper of the swing plate of the swash plate type variable capacity compressor according to any one of claims 1 to 9, wherein the lubricant used in the swash plate type variable capacity compressor is polyalkylene glycol. mechanism.   The said constant velocity universal joint is a Rzeppa type fixed type constant velocity universal joint, The rotation prevention mechanism of the rocking | fluctuation plate of the swash plate type variable capacity compressor as described in any one of Claims 1-10 characterized by the above-mentioned.   The constant velocity universal joint which comprises the anti-rotation mechanism of the rocking | fluctuation plate of the swash plate type variable capacity compressor as described in any one of Claims 1-11.

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