JP2007192137A - Reciprocating fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating fluid machine having a small and reliable thrust bearing device. <P>SOLUTION: The reciprocating fluid machine is provided with a thrust plate 102 opposing to the tip face of a rotating shaft 72; a spring hole 106 having an opening end opened on the tip face of the rotating shaft 72; a compression coil spring 108 arranged in the spring hole 106; and a ball 110 energized toward the thrust plate 102 by the compression coil spring 108 while being guided by the inner peripheral face of the spring hole 106, and having a hemispherical face brought into point contact with the thrust plate 102. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reciprocating fluid machine.

  The reciprocating fluid machine is used as a compressor of a refrigeration circuit, for example. The plurality of cylinder bores formed in the cylinder block of the reciprocating fluid machine are opened at an end face of the cylinder block facing the crank chamber, and a bearing hole is opened at the end face at the center of the cylinder bore. . In the bearing hole, the tip of a rotating shaft extending in the crank chamber is positioned, and the tip of the rotating shaft is rotatably supported by a radial bearing and a thrust bearing arranged in the bearing hole. The rotating motion of the rotating shaft is converted by the converting means into a linear motion of a piston inserted into the cylinder bore, whereby the working fluid in the cylinder bore is compressed (for example, Patent Document 1).

Specifically, in the thrust bearing applied to the compressor of Patent Document 1, a recess is formed in the tip surface of the rotating shaft, and the ball is in line contact with the recess. A compression coil spring is disposed on the opposite side of the rotation shaft across the ball, and the compression coil spring urges the ball toward the recess of the rotation shaft.
JP 11-315782 A

  However, in the thrust bearing applied to the compressor of Patent Document 1, the compression coil spring is disposed on the opposite side of the rotating shaft across the ball, and the thrust bearing is increased in size. In addition, since the ball makes line contact with both the compression coil spring and the recess of the rotating shaft, a torsional moment is applied to the compression coil spring through the ball, and the compression coil spring may be damaged.

  The present invention has been made based on the above-described circumstances, and an object of the present invention is to provide a reciprocating fluid machine including a small-sized and highly reliable thrust bearing device.

  In order to achieve the above object, according to the present invention, a cylinder block having a bearing hole opened in a crank chamber and a plurality of cylinder bores concentrically formed around the bearing hole, and reciprocally movable in the cylinder bore. An inserted piston; a rotating shaft extending through the crank chamber and having a tip surface positioned in the bearing hole; conversion means for converting the rotational motion of the rotating shaft into a reciprocating motion of the piston; and the rotating shaft The thrust plate is opposed to the front end surface of the rotation shaft, the striation hole having an open end opened to the front end surface of the rotating shaft, the compression coil spring disposed in the striation hole, and the inner peripheral surface of the striation hole. And a contact member that is biased toward the thrust plate by the compression coil spring and has a hemispherical surface that makes point contact with the thrust plate. Reciprocating fluid machine is provided, wherein the door (claim 1).

In a preferred aspect, the contact member is a sphere (claim 2).
As a preferred aspect, the thrust plate is disposed in a communication path that connects the crank chamber and the inside of the cylinder head, and has a communication hole that forms a part of the communication path.

In the reciprocating fluid machine according to claim 1 of the present invention, the slewing hole is formed in the rotating shaft, and the compression coil spring is disposed in the splaying hole. For this reason, it is not necessary to secure a space corresponding to the length of the compression coil spring in the bearing hole, and the thrust bearing device can be miniaturized and the fluid machine can be miniaturized.
Further, in this reciprocating fluid machine, the contact member is in point contact with the thrust plate, and the relative rotational speed between the contact member and the thrust plate is substantially zero when viewed at the point contact portion. It is. For this reason, a torsional moment is not applied to the compression coil spring, damage such as buckling of the compression coil spring is prevented, and the reliability of the thrust bearing device is improved.

In the reciprocating fluid machine according to the second aspect, the contact member is formed of a spherical body, and the thrust bearing device can be reduced in size and improved in reliability with a simple configuration.
According to the reciprocating fluid machine of claim 3, even if the thrust bearing device has the thrust plate, the variable capacity type reciprocating fluid machine can be configured with a simple structure by forming the communication hole in the thrust plate. Realized.

  FIG. 1 shows a variable capacity swash plate compressor as a reciprocating fluid machine according to an embodiment. The compressor includes a casing (front housing) 12 that forms part of the housing 10. The casing 12 includes a large-diameter cylindrical portion 14, and a small-diameter cylindrical portion 18 is integrally connected to an end wall 16 of the large-diameter cylindrical portion 14. A substantially cylindrical cylinder block 20 is fitted inside the portion of the large-diameter cylindrical portion 14 on the side opposite to the end wall 16, and the one end face of the cylinder block 20 and the end wall 16 of the large-diameter cylindrical portion 14 are connected to each other. A crank chamber 22 is defined between them.

  A cylinder head 24 is disposed at the opening end of the large-diameter cylindrical portion 14 of the casing 12 via a gasket (not shown), and the cylinder head 24 is coupled to the casing 12 by a plurality of bolts 26. A valve plate 28 is sandwiched between the cylinder head 24 and the other end surface of the cylinder block 20 via a cylinder gasket (not shown). The cylinder block 20 is coupled to the cylinder head 24 by a plurality of inner bolts 30. Has been.

A suction port and a discharge port (not shown) are formed on the outer peripheral wall of the cylinder head 24, and a suction chamber 32 and a discharge chamber 34 in which the suction and discharge ports are opened are defined inside the cylinder head 24. ing. An electromagnetic control valve 36 is accommodated in the cylinder head 24.
The suction chamber 32 communicates with each cylinder bore 38 of the cylinder block 20 via a suction reed valve (not shown), and always communicates with the crank chamber 22 through the low pressure side communication passage 40.

The discharge chamber 34 communicates with each cylinder bore 38 via a discharge reed valve (not shown), and reference numeral 42 is attached to a valve retainer of the discharge reed valve. The valve retainer 42 is fixed to the center of the valve plate 28 by a bolt 44, and the head of the bolt 44 is positioned in a bolt space 46 formed in the cylinder block.
On the other hand, the discharge chamber 34 communicates with the crank chamber 22 through the high-pressure side communication passage 47. The electromagnetic control valve 36 is inserted in the high pressure side communication passage 47 and opens and closes the high pressure side communication passage 47 based on a control signal from an external control device (not shown).

A piston 48 is reciprocally inserted into each cylinder bore 38 of the cylinder block 20 from the crank chamber 22 side, and a tail portion of the piston 48 projects into the crank chamber 22.
Power for reciprocating the piston 48 is transmitted to the tail portion of the piston 48. For this purpose, the compressor has an electromagnetic clutch 50 that intermittently receives power from the outside.

  More specifically, the drive rotor 52 constituting the drive side unit of the electromagnetic clutch 50 is rotatably supported via the ball bearing 54 on the outside of the small diameter cylindrical portion 18. A groove is formed on the outer periphery of the drive rotor 52, and a belt is wound around the drive rotor 52 and a power source such as an engine. A solenoid 56 is disposed in the drive rotor 52, and the solenoid 56 is fixed to the end wall 16 via a bracket 58.

  A friction material 60 is embedded in the end surface of the drive rotor 52, and an armature plate 62 constituting a driven side unit of the electromagnetic clutch 50 is disposed in the vicinity of the end surface of the drive rotor 52. An annular outer wheel 64 is riveted to the back surface of the armature plate 62. The outer wheel 64 is connected to the inner wheel 68 via an elastic member 66, and the elastic member 66 allows the armature plate 62 to be attracted to the end surface of the drive rotor 52 by the electromagnetic force of the solenoid 56. A hub 70 is integrally formed at the center of the inner wheel 68, and the hub 70 is splined to the base end portion of the rotating shaft 72 inside the small diameter cylindrical portion 18.

  The rotating shaft 72 extends through the small diameter cylindrical portion 18, the shaft hole of the end wall 16, and the crank chamber 22. A rotor 74 is fixed to the central portion of the rotating shaft 72, and the rotor 74 has an annular disk portion. The disk part faces the end wall 16 through a thrust bearing 76, and a boss part is integrally formed on the inner edge of the disk part. The boss portion is fitted to the rotating shaft 72, and a roller bearing 78 is disposed between the boss portion and the inner peripheral surface of the shaft hole of the end wall 16.

A lip seal 80 is disposed in the shaft hole of the end wall 16 on the hub 70 side of the roller bearing 78. The lip seal 80 partitions the crank chamber 22 in an airtight manner.
A portion of the rotating shaft 72 extending between the rotor 74 and the cylinder block 20 passes through an annular swash plate boss 82, and the swash plate boss 82 is connected to a disk portion of the rotor 74 via a hinge 84. An annular swash plate 86 is fitted to the swash plate boss 82, and the swash plate 86 can tilt with respect to the rotation shaft 72 and can rotate together with the rotation shaft 72.

Here, a recess opening toward the rotation shaft 72 is formed in the tail portion of each piston 48, and a pair of hemispherical shoes 88 are disposed in the recess. The shoe 88 is in sliding contact with the outer periphery of the swash plate 86 in the recess, and the swash plate 86 and the piston 48 are connected via the shoe 88.
The tip of the rotating shaft 72 is positioned in the bearing hole 90 of the cylinder block 20 as shown in an enlarged manner in FIG.

The bearing hole 90 has an open end that opens to one end face of the cylinder block 20 and is positioned at the center of the cylinder bore 38 that is formed concentrically. The bearing hole 90 has a predetermined depth and is parallel to each cylinder bore 38. A roller bearing 92 is disposed between the inner peripheral surface of the bearing hole 90 and the outer peripheral surface of the distal end portion of the rotating shaft 72.
A filter hole 96 having a diameter smaller than that of the bearing hole 90 is opened on the inner end surface 94 of the bearing hole 90. Therefore, the inner end surface 94 of the bearing hole 90 has an annular shape. The filter hole 96 is filled with a filter 98, and the filter hole 96 and the bolt space 46 of the cylinder block 20 communicate with each other through the orifice passage 100 having a smaller diameter than the filter hole 96 and the bolt space 46. is doing.

A thrust plate 102 having a slightly smaller diameter than the bearing hole 90 is disposed on the inner end surface 94 of the bearing hole 90, and a plurality of through holes 104 are formed in the thrust plate 102. The through holes 104 are located slightly inside the inner edge of the inner end face 94 and are arranged at equal intervals in the circumferential direction.
Therefore, the low-pressure side communication passage 40 communicating between the crank chamber 22 and the suction chamber 32 described above includes the clearance of the roller bearing 92, the through hole of the thrust plate 102, the filter 98, the orifice channel 100, and the bolt space 46. It is out.

  The thrust plate 102 is opposed to the tip surface of the rotating shaft 72 with a gap of a predetermined size. On the other hand, a round hole 106 (striking hole) having a predetermined depth formed coaxially with the tip of the rotating shaft 72 is opened at the leading end surface of the rotating shaft 72. 108 is arranged. One end of the compression coil spring 108 is in contact with the bottom surface of the strip hole 106 as a strip base, while the other end of the compression coil spring 108 is in front contact with the ball 110. The ball 110 has a diameter substantially equal to the inner diameter of the striating hole 106, and most of the ball 110 is located in the striating hole 106. However, the ball 110 is urged toward the thrust plate by the compression coil spring 109, and the apex of the ball 110 protruding from the opening end of the striation hole 106 is in point contact with the thrust plate 102.

Hereinafter, the operation of the above-described compressor will be described.
When the electromagnetic clutch 50 is turned on, power from the outside is transmitted to the rotating shaft 72 via the electromagnetic clutch 50, and the rotating shaft 72 is rotated. The rotational motion of the rotary shaft 72 is converted into reciprocating motion of the piston 48 via the conversion means, that is, the rotor 74, the hinge 84, the swash plate boss 82, the swash plate 86 and the shoe 88. Based on the reciprocating motion of each piston 48, in the compressor, a working process such as refrigerant in the suction chamber 32 is sucked into the cylinder bore 38 through the suction reed valve, and the working fluid is compressed in the cylinder bore 38. A series of processes including a compression step and a discharge step in which the compressed working fluid is discharged into the discharge chamber 34 through the discharge reed valve is performed.

The discharge amount of the refrigerant discharged from the compressor by this process can be adjusted by opening and closing the high-pressure side communication passage 47 by the electromagnetic control valve 36. That is, as the pressure (back pressure) in the crank chamber 22 increases and decreases, the stroke length of each piston 48 increases or decreases.
During the rotation of the rotating shaft 72, the radial load applied to the end wall 16 and the cylinder block 20 is supported by roller bearings 78 and 92. The compression reaction force from the piston 48 is supported by the thrust bearing 76.

  On the other hand, although it is smaller than the compression reaction force, the axial load applied to the cylinder block from the tip of the rotating shaft 72 due to the on-operation of the electromagnetic clutch 50 or the like is the thrust of the thrust bearing device disposed in the splaying hole 106. Supported by plate 102. The thrust plate 102 is brought into point contact with the ball 110 urged by the compression coil spring 108 while being guided by the inner peripheral surface of the splay hole 106.

  In the compressor described above, the splaying hole 106 is formed at the tip of the rotating shaft 72, and the compression coil spring 108 is disposed in the staking hole 106. For this reason, it is not necessary to secure a space corresponding to the length of the compression coil spring 108 in the bearing hole 90, and the thrust bearing device can be downsized, and the compressor downsized. As a result, for example, the filter 98 having a large flow path cross-sectional area and a flow path length can be disposed in the low-pressure side communication path 40.

  In this compressor, the ball 110 is in point contact with the thrust plate 102, and the relative rotational speed between the ball 110 and the thrust plate 102 is substantially zero when viewed at the point contact portion. . Therefore, no torsional moment is applied to the compression coil spring 108, damage such as buckling of the compression coil spring 108 is prevented, and the thrust bearing device has high reliability.

  Further, when the compressor is assembled, the thrust plate 102 will not fall off if the roller plate 92 is fixed after the thrust plate 102 is disposed in the bearing hole 90. In addition, if the tip end of the rotating shaft 72 is inserted into the bearing hole 90 in a state where the coil spring 108 and the ball 110 are accommodated in the spring hole 106, the coil spring 108 and the ball 110 are easily prevented from falling off. Therefore, this compressor is mass-produced at low cost under high productivity.

On the other hand, according to this compressor, even if the thrust bearing device has the thrust plate 102, by forming the through hole 104 in the thrust plate 102, the variable capacity reciprocating fluid machine can be configured with a simple configuration. Realized.
The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the material of the thrust plate 102 and the ball 110 is preferably a metal such as steel having excellent sliding characteristics, but a lubricating film may be formed on the surface.

In one embodiment, the thrust plate 102 has high rigidity. However, as shown in FIG. 3, a thrust plate 112 that is elastically deformed may be used.
In one embodiment, the region on the inner end surface 94 side in the bearing hole 90 communicates with the crank chamber 22 through only the gap of the roller bearing 92, but the inner end surface 94 in the bearing hole 90 is inside the rotating shaft 72. You may provide the flow path which connects the area | region of the side and the crank chamber 22. FIG. That is, as shown in FIG. 4, a plurality of grooves 114 are formed in the region of the inner peripheral surface of the splaying hole 106 with which the ball 110 comes into contact, and the shaft holes that open on the bottom surface of the striating hole 106 and the outer surface of the rotating shaft 72, respectively. 116 may be formed.

  In one embodiment, although the ball 110 is in point contact with the thrust plate 102, the shape of the member that contacts the thrust plate 102 instead of the ball 110 is not limited to a spherical shape. For example, FIG. 5 shows a top-shaped contact member 118, which includes a head 120 having a hemispherical front surface, and a shaft 122 coaxially connected to the back surface of the head 120. Have. However, in order to simplify the configuration, it is preferable to use the ball 110 as the contact member.

  Finally, it goes without saying that the reciprocating fluid machine of the present invention may be of a fixed capacity type and can be similarly applied to an oscillating plate compressor.

It is a figure which shows the longitudinal cross-section of the variable capacity | capacitance type swash plate type compressor which concerns on one Embodiment. It is the figure which expanded and showed the tip vicinity of the rotating shaft in the fluid machine of FIG. It is a figure for demonstrating the thrust bearing apparatus of a modification. It is a figure for demonstrating the thrust bearing apparatus of another modification. It is a figure for demonstrating the thrust bearing apparatus of another modification.

Explanation of symbols

72 Rotating shaft 102 Thrust plate 106 Stroke hole 108 Compression coil spring 110 Ball

Claims (3)

A cylinder block having a bearing hole opened in the crank chamber and a plurality of cylinder bores concentrically formed around the bearing hole;
A piston inserted reciprocally into the cylinder bore;
A rotating shaft extending through the crank chamber and having a tip surface positioned within the bearing hole;
Conversion means for converting the rotational movement of the rotary shaft into the reciprocating movement of the piston;
A thrust plate facing the tip surface of the rotating shaft;
A striation hole having an opening end opened at a tip surface of the rotating shaft;
A compression coil spring disposed in the striation hole;
An abutting member having a hemispherical surface that is urged toward the thrust plate by the compression coil spring while being guided by the inner peripheral surface of the splay hole, and that makes point contact with the thrust plate. A reciprocating fluid machine.   The reciprocating fluid machine according to claim 1, wherein the contact member is a sphere.   3. The reciprocation according to claim 1, wherein the thrust plate is disposed in a communication path that connects the crank chamber and the inside of the cylinder head, and has a communication hole that forms a part of the communication path. Dynamic fluid machine.

Images