JP2007198249A - Swash plate compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swash plate compressor securing good lubricating performance at a sliding part in a crank chamber and a cylinder bore without accompanied by enlargement, accurately controlling displacement in a case of a variable displacement type, reducing power consumption and improving durability. <P>SOLUTION: A spherical surface bearing 28a opening toward the crank chamber 20 is formed on an end part of a piston 28 of the swash plate compressor. An inner circumference wall and an outer circumference wall are provided on a surface in a cylinder block side of a swash plate 52, and the inner circumference wall and the outer circumference wall partition an annular shape cam surface 86. A shoe 88 is arranged between the inner circumference wall and the outer circumference wall and the shoe 88 is connected to a head 92 fitted in the spherical surface bearing 28a via a rod 90. An outward flange part 78a and an inward flange part 80b project out of the inner wall surface and the outer wall surface. The flange parts 78a, 80b retains the shoe 88 on the cam surface 86 with forming a slit 82 allowing passage of the rod 90. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a swash plate compressor, and more particularly to a swash plate compressor suitable for a compressor of a refrigeration circuit using CO ₂ as a refrigerant.

For example, a swash plate compressor applied to a compressor of a refrigeration circuit includes conversion means for converting the rotational motion of the rotating shaft into the reciprocating motion of a piston.
Specifically, the conversion means includes a swash plate disposed in the crank chamber, and the swash plate is penetrated by the rotation shaft and is rotatable integrally with the rotation shaft. The outer periphery of the swash plate is positioned in a recess formed at the end of the piston. The recess is defined by a pair of seats spaced apart in the axial direction of the piston and a bridge connecting the seats, and a pair of hemispherical shoes are arranged in the pair of seats. The shoe is in sliding contact with the outer periphery of the swash plate, and the rotational movement of the swash plate is converted into the reciprocating motion of the piston through the shoe.

And this type of swash plate compressor includes a variable displacement type. In the variable displacement swash plate compressor, a hinge is provided on the back of the swash plate (see, for example, Patent Document 1). The hinge allows the swash plate to tilt with respect to the rotating shaft while keeping the top dead center of the piston constant, and adjusts the pressure (back pressure) in the crank chamber to adjust the stroke of the piston.
Japanese Patent Laid-Open No. 2003-083244

By the way, the sliding part inside the swash plate compressor is lubricated by the lubricating oil contained in the working fluid. Therefore, a sufficient amount of lubricating oil is held in the compressor, and a part of the lubricating oil is accumulated at the bottom of the crank chamber. In the swash plate compressor, the parts requiring lubrication are 1) the engaging portion between the piston and the swash plate, 2) the bearing, 3) the fitting surface between the piston and the cylinder bore, and 4) the shaft seal device. In the conventional swash plate type compressor, the piston reciprocates due to the rotation of the swash plate and rocks the lubricating oil in the crank chamber, but it cannot be said that the lubricating oil has reached the points 1) to 4). If the lubricating oil collected at the bottom of the crank chamber is scooped up and can be supplied in a concentrated manner at a required location, even if the compressor is heated to a high temperature by compressing CO ₂ as a working fluid, the compressor It is possible to prevent a decrease in durability.

In addition, if the lubricating oil can be splashed up, the amount of lubricating oil retained in the compressor can be reduced, and when the compressor is applied to a refrigeration circuit, the amount of lubricating oil circulating in the refrigeration circuit can be reduced. Can also be reduced. If the amount of lubricating oil circulating in the refrigeration circuit decreases, the refrigeration capacity of the refrigeration circuit is improved.
Further, if the lubricating oil can always be held on the sliding portion, the lubricity improves without needing to splash the lubricating oil.

However, in the compressor of Patent Document 1, the outer peripheral portion of the swash plate and the inner peripheral surface of the crank chamber are separated by a distance corresponding to at least the thickness of the bridge. The accumulated lubricating oil cannot be splashed up. For this reason, another device is required to splash the lubricating oil, and the compressor becomes large.
Moreover, in the compressor of patent document 1, since the outer peripheral part of a swash plate is flat, lubricating oil escapes by rotation of a swash plate, and oil is always hold | maintained at the sliding part between a swash plate and a shoe. It is not possible.

  On the other hand, in the compressor of Patent Document 1, the stroke (discharge capacity) of the piston is adjusted by increasing / decreasing the back pressure (crank chamber pressure), but the stroke is not determined solely by the back pressure, but is reciprocating. It also changes depending on the inertial force of the piston based on the above and the moment (gyro effect) that the swash plate tends to be perpendicular to the rotation axis based on the centrifugal force corresponding to the rotational speed. When the rotational speed of the rotating shaft is high, the inertial force of the piston increases, and the control accuracy decreases in the direction in which the discharge capacity increases. Since an undesired increase in the discharge capacity leads to an increase in power consumption and a decrease in durability due to an increase in stress on the parts, it is preferable that the discharge capacity is controlled with high accuracy.

For that purpose, the moment of the gyro effect may be increased so as to cancel the inertial force of the piston. More specifically, the outer diameter of the swash plate is increased or the mass distribution of the swash plate is changed to the inner circumference. What is necessary is just to thicken an outer peripheral part so that it may become large in an outer peripheral side rather than the side.
However, in the compressor of Patent Document 1, it is impossible to increase the diameter of the swash plate due to the existence of the bridge of the piston. Further, since the outer peripheral portion of the swash plate is sandwiched between the shoes, it is impossible to make the outer peripheral portion thicker.

The present invention has been made based on the above-mentioned circumstances, and its object is to ensure good lubricity at the sliding portion in the crank chamber and the cylinder bore without increasing the size, and to reduce power consumption. Another object of the present invention is to provide a swash plate compressor that has excellent durability and is suitable for a refrigeration circuit using, for example, a CO ₂ refrigerant.
Another object of the present invention is to provide a variable displacement swash plate compressor in which the discharge capacity is controlled with high accuracy, resulting in reduced power consumption and improved durability.

  To achieve the above object, according to the present invention, a rotating shaft extending in a crank chamber, a cylinder block having a plurality of cylinder bores substantially parallel to the rotating shaft, pistons inserted into the cylinder bores, and the crank A spherical bearing formed at an end portion of the piston on the chamber side and opened toward the crank chamber; a swash plate which is penetrated by the rotation shaft and is rotatable integrally with the rotation shaft; and the cylinder block side A shoe provided concentrically on the surface of the swash plate and disposed between the inner and outer peripheral walls defining an annular cam surface within the surface, and between the inner and outer peripheral walls and in sliding contact with the cam surface A rod connected to the shoe and projecting from the shoe to the opposite side of the cam surface; a spherical head provided at the tip of the rod and fitted to the spherical bearing; and the inner wall surface and A swash plate compressor, comprising an outward flange and an inward flange that hold the shoe on the cam surface while projecting from an outer wall surface toward each other and forming a slit that allows the rod to pass therethrough. (Claim 1).

As a preferred embodiment, the swash plate compressor further includes a hinge provided on a back surface of the swash plate and supporting the swash plate so as to be tiltable with respect to the rotation shaft, and each piston rotates the swash plate. Accordingly, when it matches the circumferential position of the hinge, it is positioned at a fixed top dead center.
As a preferred aspect, the swash plate further includes an annular portion that integrally projects from the outer periphery of the swash plate toward the cylinder block.

As a preferred aspect, the swash plate further includes a counterweight in an outer peripheral area that is diametrically separated from the hinge, and the counterweight extends from the annular portion toward the cylinder block. A cylindrical portion is included (claim 4).
As a preferred embodiment, the swash plate compressor further includes a wear-resistant plate interposed between the swash plate and the shoe.

As a preferred embodiment, the swash plate compressor compresses CO ₂ as a working fluid.

In the swash plate compressor according to the first aspect of the present invention, the shoe is formed on the cam surface by the inner peripheral wall and the outer peripheral wall provided on the surface of the swash plate, the outward flange and the inward flange protruding from the peripheral wall. Retained. The shoe is coupled to the piston via a rod and a head fitted to the spherical bearing.
For this reason, in this compressor, there is no member that obstructs the increase in the diameter of the swash plate, and the increase in the diameter of the swash plate causes the lubricating oil accumulated at the bottom of the crank chamber to jump up, improving the lubricity. Further, the inner peripheral wall, the outer peripheral wall, the outward flange and the inward flange keep the lubricating oil always around the shoe, thereby improving the lubricity. As a result, power consumption is reduced and durability is improved.

  In the swash plate compressor according to claim 2, the swash plate is a variable capacity swash plate compressor supported to be tiltable with respect to the rotation shaft. In this compressor, there is no member that obstructs the increase in the diameter of the swash plate or the increase in the thickness of the outer periphery, and the increase in the diameter of the swash plate or the increase in the thickness of the outer periphery increases the moment of the gyro effect. The control accuracy of the discharge capacity during rotation is improved. As a result, in this compressor, power consumption is reduced, stress applied to parts is reduced, and durability is improved.

In the swash plate compressor according to the third aspect, the lubricating oil is efficiently splashed by the annular portion of the swash plate protruding to the cylinder block side, and the lubricity is further improved.
Further, in this compressor, the rigidity of the swash plate having a large diameter is ensured by the annular portion of the swash plate. For this reason, even when subjected to a compression reaction force, the flatness of the cam surface of the swash plate is ensured, and the shoe does not hit the cam surface. As a result, oil film breakage between the cam surface and the shoe is prevented, and lubricity is further improved.

In the swash plate compressor according to the fourth aspect, since the counterweight is formed on the outer periphery, the counterweight is reduced in size. Further, more lubricating oil is splashed up by the semi-cylindrical counterweight, and the lubricity is further improved.
In the swash plate compressor according to the fifth aspect, since the shoe slides on the wear-resistant plate, the durability can be easily increased. That is, as the surface roughness of the surface on which the shoe slides is smaller, the oil film breakage is prevented and the durability of the compressor is improved, but when the shoe is slid on a wear resistant plate separate from the swash plate, It is easy to polish the surface of the wear-resistant plate to reduce its surface roughness. As a result, the durability of the compressor is easily increased.

In the swash plate compressor according to the sixth aspect, since CO ₂ is compressed as a working fluid, the temperature in the crank chamber and the cylinder bore is higher than that in the case of compressing chlorofluorocarbon, and the sliding conditions at the sliding portion are severe. . However, in this compressor, since the lubricity at the sliding portion is improved, seizure at the sliding portion is prevented, and a decrease in durability is prevented.

1A and 1B show a variable capacity swash plate compressor according to an embodiment. FIG. 1A shows a state in which the discharge capacity is maximum, and FIG. 1B shows a discharge capacity. The minimum state is shown. The compressor is installed such that the vertical direction in FIG. 1 coincides with the vertical direction.
The compressor includes a casing (front housing) 10 that constitutes a part of the housing. The casing 10 includes a large diameter cylindrical portion 12, and a small diameter cylindrical portion 16 is integrally connected to an end wall 14 of the large diameter cylindrical portion 12. A cylinder block 18 is disposed at the end of the large-diameter cylindrical portion 12 opposite to the end wall 14, and the cylindrical portion of the cylinder block 18 is fitted inside the end of the large-diameter cylindrical portion 12. A crank chamber 20 is defined between one end face of the cylinder block 18 and the end wall 14 of the large diameter cylindrical portion 12.

  An end surface of the large-diameter cylindrical portion 12 of the casing 10 abuts against a flange portion of the cylinder block 18 via an annular gasket (not shown), and a circular gasket (not shown) is attached to the other end surface of the cylinder block 18. A cylinder head is disposed via the valve plate. The casing 10, the cylinder block, and the cylinder head 21 are connected by a plurality of connecting bolts.

A suction port and a discharge port (not shown) are formed on the peripheral wall of the cylinder head 21, and a suction chamber 22 and a discharge chamber 24 in which these suction and discharge ports are opened are defined in the cylinder head 21. Yes.
The suction chamber 22 communicates with each cylinder bore 26 of the cylinder block 18 via a suction reed valve (not shown), and always communicates with the crank chamber 20 through the low pressure side communication passage. A part of the low-pressure side communication path is defined in a bearing hole formed in the center of the cylinder block 18.

  The discharge chamber 24 communicates with each cylinder bore 26 of the cylinder block 18 via a discharge reed valve (not shown). On the other hand, a high pressure side communication path (not shown) extending from the discharge chamber 24 to the crank chamber 20 extends, and an electromagnetic control valve (not shown) is inserted in the high pressure side communication path. The electromagnetic control valve is built in the cylinder block 18 and opens and closes the high-pressure side communication passage based on a control signal from the outside, thereby connecting and disconnecting the discharge chamber 24 and the crank chamber 20.

A piston 28 is inserted into each cylinder bore 26 of the cylinder block 18 from the crank chamber 20 side so as to freely reciprocate, and a tail portion of the piston 28 projects into the crank chamber 20.
Power for reciprocating motion is transmitted to the tail portion of the piston 28. For this purpose, the compressor has an electromagnetic clutch 30 that receives power from a power source such as an engine.

  More specifically, the drive rotor 32 that constitutes the drive side unit of the electromagnetic clutch 30 is rotatably supported on the outside of the small diameter cylindrical portion 16 via a bearing. A groove is formed on the outer periphery of the drive rotor 32, and a drive belt is wound around the groove. A solenoid is disposed in the drive rotor 32, and the solenoid is fixed to the end wall 14 by a bracket.

  A friction material is attached to the end face of the drive rotor 32, and an armature plate 34 is disposed in the vicinity of the end face of the drive rotor 32. The armature plate 34 constitutes a driven side unit of the electromagnetic clutch 30, and an outer ring 36 rivet-coupled to the back surface of the armature plate 34 is connected to a wheel 40 via an elastic member 38. The elastic member 38 allows the armature plate 34 to be pressed against the end face of the drive rotor 32 by the electromagnetic force of the solenoid. A hub is integrally formed at the center of the wheel 40, and the hub is splined to the outer end portion of the rotating shaft 42 protruding from the small diameter cylindrical portion.

The rotating shaft 42 passes through the small diameter cylindrical portion 16, the shaft hole of the end wall 14 and the crank chamber 20, and extends to the bearing hole of the cylinder block 18. The inner end portion of the rotating shaft 42 is rotatably supported by a roller bearing and a thrust bearing in the bearing hole.
A rotor 44 is fixed to the central portion of the rotating shaft 42, and the rotor 44 has an annular disk portion. The disk part faces the end wall 14 through a thrust bearing 46, and a boss part is integrally formed on the inner edge of the disk part. The boss portion of the rotor 44 is fitted to the rotating shaft 42, and a roller bearing 48 is disposed between the boss portion and the inner peripheral surface of the shaft hole of the end wall 14. Accordingly, the central portion of the rotating shaft 42 is rotatably supported by the roller bearing 48 and the thrust bearing 46.

A lip seal 50 is disposed in the small-diameter cylindrical portion 16 on the wheel 68 side of the roller bearing 48, and the lip seal 50 partitions the crank chamber 20 in an airtight manner.
A portion of the rotating shaft 42 extending between the rotor 44 and the cylinder block 18 passes through the center of the annular swash plate 52. The swash plate 52 is connected to the rotor 44 via a hinge 54 so as to be tiltable, and can rotate integrally with the rotor 44. The hinge 54 has two arms that protrude from the swash plate 52 and the rotor 44 each other, and a hinge pin 56 is bridged between the arms of the rotor 44. The hinge pin 56 passes through a long hole 58 formed in each arm of the swash plate 52.

  As shown in FIG. 2, a cylindrical swash plate boss 62 is integrally formed on the inner peripheral edge of the swash plate 52, and the swash plate boss 62 protrudes toward the cylinder block 18. A sleeve 64 is disposed between the inner peripheral surface of the swash plate boss 62 and the rotary shaft 42, and the sleeve 64 is pin-coupled to the swash plate boss 62 using a tilting pin 66 parallel to the hinge pin 56. The sleeve 64 is slidably fitted to the rotating shaft 42, and a compression coil spring 68 is inserted between the sleeve 64 and the rotor 44, and the compression coil spring 68 is connected to the sleeve 64. It is biased toward the cylinder block 18.

  A cylindrical rim 70 is integrally formed on the outer peripheral edge of the swash plate 52, and the rim 70 also protrudes toward the cylinder block 18. The inner peripheral surface of the rim 70 is stepped with a step, and the inner diameter of the rim 70 is smaller on the swash plate 52 side than the step on the cylinder block 18 side. The outer diameter of the rim 70 is substantially equal to the outer diameter of the cylindrical portion of the cylinder block 18, and the outer peripheral surface of the rim 70 is located near the inner peripheral surface of the large-diameter cylindrical portion 12 of the casing 10.

However, as shown in FIG. 3, the outer peripheral surface of the rim 70 includes a curved surface region 72 in a region where the arm of the hinge 54 is formed in the circumferential direction so as to allow the tilting of the swash plate 52.
Also, as shown in FIG. 4, a semi-cylindrical first counterweight 74 is integrally formed at the tip of the rim 70, and the first counterweight 74 is diametrically aligned with the hinge 54, that is, the curved region 72. Are separated. On the other hand, as shown in FIG. 5, a wedge-shaped second counterweight 76 is integrally formed on the surface of the swash plate 52 on the rotor 44 side so as to be separated from the hinge 54 in the diameter direction.

  Referring to FIG. 2 again, a retainer is fixed between the swash plate boss 60 and the rim 70 which are concentric with each other. The retainer has an inner ring 78 and an outer ring 80, and the inner ring 78 is fitted to the outer peripheral surface of the swash plate boss 60. The inner ring 78 includes a boss portion 78a that fits to the outer peripheral surface of the swash plate boss 60 and abuts against the swash plate 52. From the portion of the boss portion 78a near the swash plate 52 toward the outer ring 80 on the radially outer side. The outward flange 78b protrudes integrally. A predetermined interval is secured between the outward flange portion 78b and the swash plate 52 by a part of the boss portion 78a on the swash plate 52 side, while between the outward flange portion 78b and the boss portion 78a, Reinforced by a rib portion 78c opposite to the swash plate 52. The rib portion 78c is formed in a tapered shape such that the outer diameter decreases as the rib portion 78c moves away from the outward flange portion 78b.

  The outer ring 80 includes a boss portion 80a that fits to the inner peripheral surface of the rim 70 and abuts against a step on the inner peripheral surface. From the portion of the boss portion 80a that abuts on the step, the radially outward flange portion An inward flange 80b projects toward 78b. A space between the inward flange portion 80b and the boss portion 80a is reinforced by a rib portion 80c opposite to the step. The rib portion 80c is formed in a tapered shape so that the inner diameter increases as the rib portion 80c moves away from the inward flange portion 80b.

  The distance between the inward flange 80b and the swash plate 52 secured by the portion of the rim 70 closer to the swash plate 52 than the step is equal to the distance between the outward flange 78b and the swash plate 52, and the outward flange 78b. The inward flange 80b defines an annular slit 82 having a constant width between the outer peripheral edge and the inner peripheral edge. The outward flange 78b and the inward flange 80b define an annular cam groove 84 between the swash plate 52 and the cam groove 84 in the plane of the swash plate 52 on the cylinder block 18 side. An annular cam surface 86 is defined as the bottom surface. The inner peripheral wall of the cam groove 84 is formed by the boss portion 78 a of the inner ring 78, and the outer peripheral wall of the cam groove 84 is formed by the rim 70.

A plurality of disc-shaped shoes 88 are arranged in the cam groove 84, and the outer diameter of the shoes 88 is larger than the opening width of the slit 82 so as to be held in the cam groove 84. However, the outer diameter of the shoe 88 is smaller than the width of the cam groove 84 so that a predetermined space is secured between the inner and outer peripheral walls of the cam groove 84 and the outer peripheral surface of the shoe 88.
The shoe 88 has a circular sliding contact surface that is in sliding contact with the cam surface 86, and a cylindrical rod 90 having a smaller diameter than the opening width of the slit 82 is coaxially and integrally formed on the back surface of the shoe 88. On the back surface of the shoe 88, an annular surface is defined around the rod 90, and the annular surface is in sliding contact with the inner surfaces of the outward flange portion 78b and the inward flange portion 80b.

  The rod 90 passes through the slit 82 and extends toward the cylinder block 18, that is, the piston 28, and a spherical head 92 is integrally formed at the tip of the rod 90. These heads 92 are positioned concentrically about the axis of the swash plate 52, and more than half of each head 92 is positioned between the inner ring 78 and the outer ring 80. Further, when viewed in the axial direction of the swash plate 52, the center point 92 a of each head coincides with the center of the tilt pin 66. The inclination angle θ of the swash plate is defined as an angle formed by a plane perpendicular to the rotation axis 42 and a virtual plane where the center point 92a of the head is positioned.

  Here, a spherical bearing 28a is formed on the tail portion of the piston 28 described above, the spherical bearing 28a opens toward the swash plate 52 in the axial direction of the piston 28, and the inner surface has a spherical shape. The head 92 integrated with the shoe 88 is rotatably fitted to the spherical bearing 28a. That is, the shoe 88, the rod 90, and the head 92 constitute one connecting member. The opening edge of the spherical bearing 28a is caulked so as to reduce the opening diameter in order to prevent the head 92 from coming off.

Hereinafter, the operation of the above-described compressor will be described.
When the electromagnetic clutch 30 is turned on, power from the outside is transmitted to the rotating shaft 42 via the electromagnetic clutch 30 and the rotating shaft 42 rotates. The rotational motion of the rotary shaft 42 is converted into reciprocating motion of the piston 28 via conversion means, that is, the rotor 44, the hinge 54, the swash plate 52, the shoe 88, the rod 90, the head 92, and the spherical bearing 28a.

Based on the reciprocating motion of each piston 28, in the compressor, a working process such as refrigerant in the suction chamber 22 is sucked into the cylinder bore 26 via the suction reed valve, and the working fluid is compressed in the cylinder bore 26. A series of processes including a compression step and a discharge step in which the compressed working fluid is discharged into the discharge chamber 24 via the discharge reed valve is performed.
The discharge amount (discharge capacity) of the refrigerant discharged from the compressor by this process can be adjusted by opening and closing the high-pressure side communication path using an electromagnetic control valve. That is, as the pressure (back pressure) in the crank chamber 20 increases or decreases, the stroke of each piston 28 increases or decreases. Specifically, the lower the back pressure, the longer the stroke, and conversely, the higher the back pressure, the shorter the stroke.

1A shows a state in which the discharge capacity is maximum, and FIG. 1B shows a state in which the discharge capacity is minimum.
Referring to FIG. 2, the inclination angle θ of the swash plate 52 increases and decreases to allow the stroke to change, and the swash plate 52 tilts around the tilt pin 66. At this time, the sleeve 64 moves along the rotation shaft 42, and the hinge pin 56 of the hinge 54 slides in the long hole 58. Thereby, even if the swash plate 52 tilts, the top dead center of the piston 28 does not change, and only the bottom dead center changes. That is, as the swash plate 52 rotates, the piston that matches the circumferential position of the hinge 54 is positioned at the top dead center, and the piston that matches the first counterweight is positioned at the bottom dead center.

The tilt pin 66 guides the tilt of the swash plate 52, but the resultant force center of the compression reaction force applied from the piston 28 to the swash plate 52 is located in the vicinity of the hinge 54 and supports the swash plate 52. Is the hinge 54. As the swash plate 52 tilts, the shoe 88 slightly slides in the radial direction in the cam groove 84.
In the swash plate compressor described above, the shoe 88 is held in a cam groove 84 provided on the surface of the swash plate 52. The shoe 88 is coupled to the piston 28 via a rod 90 and a head 92 fitted to the spherical bearing 28a.

  For this reason, in this compressor, there is no member like a conventional bridge of the piston that obstructs an increase in the diameter of the swash plate 52, and the lubricating oil collected at the bottom of the crank chamber 20 due to the increase in the diameter of the swash plate 52. Bounces up and improves lubricity. Further, the lubricating oil is always held around the shoe 88 in the cam groove 84, which also improves the lubricity. The improved lubricity allows the compressor to reduce power consumption and improve durability, while inexpensive materials can be used for the swash plate 52 and the shoe 88. Cost is reduced.

  Further, in the above-described swash plate compressor, there is no member that obstructs the increase in the diameter of the swash plate 52 or the increase in the thickness of the outer peripheral portion, and the gyro effect is achieved by increasing the diameter of the swash plate 52 or increasing the thickness of the outer peripheral portion. The moment is increased, and the control accuracy of the discharge capacity is improved especially at high speed rotation. As a result, in this compressor, power consumption is reduced, stress applied to the component parts is reduced, and durability is improved.

Further, in the above-described swash plate compressor, the lubricating oil is efficiently splashed by the rim 70 of the swash plate 52 protruding to the cylinder block 18 side, and the lubricity is further improved.
At the same time, in this compressor, the rim 70 of the swash plate 52 ensures rigidity even for the swash plate 52 having a large diameter. For this reason, even when the compression reaction force is received, the flatness of the cam surface 86 of the swash plate 52 is ensured, and the shoe 88 does not hit the cam surface 86. As a result, oil film breakage between the cam surface and the shoe 88 is prevented, and lubricity is further improved.

Furthermore, in this swash plate type compressor, since the first and second counterweights 74 and 76 are formed on the outer peripheral portion of the swashplate 52, the counterweights 74 and 76 are reduced in size. Further, the semi-cylindrical first counterweight 74 causes more lubricating oil to be splashed up, further improving the lubricity.
As shown in FIG. 2, the tip of the first counterweight 74 moves along the inner peripheral surface of the large-diameter cylindrical portion 12 as the swash plate 52 tilts, so that the lubricating oil is always splashed up. Can do.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, although the working fluid compressed by the compressor is not particularly limited, this compressor is suitable for CO ₂ compression because of improved lubricity. When CO ₂ is compressed as the working fluid, the temperatures in the crank chamber 20 and the cylinder bore 26 are higher than when compressing chlorofluorocarbon or the like, and the sliding conditions at the sliding portion are severe. However, in this compressor, since the lubricity at the sliding portion is improved, it is between the swash plate 52 and the shoe 88, between the piston 28 and the cylinder bore 26, and further at the sliding portion such as a bearing. The seizure of is prevented, and the durability is prevented from being lowered.

Although the compressor of one embodiment was installed horizontally, the compressor may be installed diagonally or vertically. However, in order to improve lubricity more, it is preferable to install horizontally.
In the compressor according to the embodiment, the cylinder bore 26 and the rotation shaft 42 are parallel, but the cylinder bore may be slightly inclined as long as it is substantially parallel to the rotation shaft 42.
In the compressor of one embodiment, the top dead center may not be changed, but the top dead center may be changed. In addition, since the top dead center does not change, the compressor of one Embodiment is suitable for compressing a compressible fluid.

In the compressor according to the embodiment, although the shoe 88 slides with respect to the swash plate 52, as shown in FIG. 6, the wear resistant plate 94 is disposed between the swash plate 52 and the shoe 88. The shoe 88 may be slid with respect to the surface of the wear-resistant plate 94.
Here, as the surface roughness of the surface on which the shoe 88 slides is smaller, oil film breakage is prevented and the durability of the compressor is improved. When the shoe 88 is slid on a wear-resistant plate 94 that is separate from the swash plate 52, the surface of the wear-resistant plate 94 is polished and finished even if the rim 70 is formed integrally with the swash plate 52. It is easy to reduce the surface roughness, and the durability of the compressor can be easily increased.

In addition, the range of selection of the material of the swash plate 52 is expanded by sliding the shoe 88 on the wear plate 94. In addition, heat treatment of the swash plate 52 for improving wear resistance is not necessary, and deformation of the swash plate 52 due to heat treatment is also prevented. As a result, it is easy to ensure the flatness of the wear-resistant plate 94 on which the shoe 88 slides.
Finally, although the compressor of one embodiment was a variable capacity type, it may of course be a fixed capacity type.

It is a figure which shows the longitudinal cross-section of the variable capacity | capacitance type reciprocating fluid machine which concerns on one Embodiment, (a) is the state when discharge capacity is the maximum, (b) has shown the state when discharge capacity is the minimum. . It is the figure which expanded and showed a part of swash plate of FIG.1 (b), and its periphery. It is a figure which shows the piston connected via the connection member to the swash plate and swash plate of FIG.1 (b). It is the figure which looked at FIG. 3 from diagonally forward. It is the figure which looked at FIG. 3 from diagonally backward. It is a figure for demonstrating the abrasion-resistant board arrange | positioned between a swash plate and a shoe.

Explanation of symbols

20 Crank chamber 28 Piston 28a Spherical bearing 42 Rotating shaft 52 Swash plate 60 Swash plate boss 70 Rim 78 Inner ring 78a Boss portion 78b Outward flange 80 Outer ring 80b Inward flange 82 Slit 84 Cam groove 86 Cam surface 88 Shoe 90 Rod 92 head

Claims (6)

A rotating shaft extending through the crank chamber;
A cylinder block having a plurality of cylinder bores substantially parallel to the rotation axis;
A piston inserted into each cylinder bore;
A spherical bearing formed at an end portion of the piston on the crank chamber side and opened toward the crank chamber;
A swash plate that is penetrated by the rotating shaft and rotatable integrally with the rotating shaft;
An inner peripheral wall and an outer peripheral wall that are concentrically provided on a surface of the swash plate on the cylinder block side and define an annular cam surface in the surface;
A shoe disposed between the inner peripheral wall and the outer peripheral wall and in sliding contact with the cam surface;
A rod connected to the shoe and protruding from the shoe to the opposite side of the cam surface;
A spherical head provided at the tip of the rod and fitted into the spherical bearing;
A slant comprising an outward ridge and an inward ridge projecting toward each other from the inner wall surface and the outer wall surface, and holding the shoe on the cam surface while forming a slit allowing passage of the rod. Plate type compressor. A hinge that is provided on the back surface of the swash plate and supports the swash plate so as to be tiltable with respect to the rotation axis;
2. The swash plate compressor according to claim 1, wherein each piston is positioned at a fixed top dead center when the piston is aligned with a circumferential position of the hinge as the swash plate rotates.   The swash plate compressor according to claim 2, wherein the swash plate further includes an annular portion that integrally protrudes from an outer periphery of the swash plate toward the cylinder block. The swash plate further includes a counterweight in an outer peripheral region spaced from the hinge in the diameter direction,
The swash plate compressor according to claim 3, wherein the counterweight includes a semi-cylindrical portion extending from the annular portion toward the cylinder block.   The swash plate compressor according to claim 3, further comprising a wear-resistant plate interposed between the swash plate and the shoe. Swash plate type compressor according to any one of claims 1 to 5, characterized in that compressing the CO ₂ as the working fluid.

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