JP2008274879A - Thrust roller bearing for swash plate type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust roller bearing for a swash plate type compressor, which prevents local wear of an outer diameter side circumference surface in an axial direction out of the outer circumference surfaces of a roller. <P>SOLUTION: This thrust roller bearing 12 for the swash plate type compressor 1 is assembled between cylinders 2, 3 and a swash plate 8 reciprocating a piston 6 by rotation action of a rotary shaft 7. The bearing is provided with: a first raceway 70 locally butting on a seat 17 of the swash plate 8 either of an inner diameter side or an outer diameter side of an outer surface thereof; a second raceway 60 locally butting on a seat 14 of the cylinder 2 either of an inner diameter side or an outer diameter side of an outer surface thereof and having same inner and outer diameter dimensions as the first raceway 70; and a plurality of rollers put between both of the raceways 60, 70. A center position C in an axial direction of the roller 10 is set on an outer diameter side of a center position RC between an outer diameter position RO and an inner diameter position RI of both of the raceways 60, 70. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a swash plate that reciprocally moves a piston in an axial direction in a cylinder by a rotating operation of a rotating shaft, and a thrust roller bearing for a swash plate type compressor that is assembled between the cylinder.

Conventionally, as a support form of the thrust roller bearing 12 for supporting the swash plate of the swash plate type compressor, as shown in FIG. 5, the outer surface of one race 70 is outside the seat 17 of the boss portion 16 of the swash plate 8. A configuration is known in which the diameter side and the inner diameter side of the outer surface of the other race 60 are partially in contact with the receiving seat 14 of the cylinder 2.
In addition, in this kind of swash plate type compressor, it is disclosed by patent document 1, for example.
Japanese Patent No. 3604458 specification

  However, in the thrust roller bearing 12 described above, the center position C in the axial direction of the roller 10 is set to coincide with the center position RC between the inner diameter position RI and the outer diameter position RO of both the races 60 and 70. Therefore, the outer diameter side of the first race 70 is directed to the second race 60 side (arrow F1 side in FIG. 6), and the inner diameter side of the second race 60 is directed to the first race 70 side (arrow F2 side in FIG. 6). ), When a preload consisting of an axial load for the assembly place is applied to the state where the required amount is pressed, as shown in FIG. He was supposed to be in contact with one race 70. At this time, since the centrifugal force is applied to the roller 10, as a result, a problem that the peripheral surface on the outer diameter side of the 10 is locally worn occurs.

  In view of the above problems, an object of the present invention is to provide a thrust roller bearing for a swash plate compressor in which a peripheral surface on the outer diameter side in the axial direction of the outer peripheral surface of the roller can be prevented from being locally worn. It is to provide a thrust roller bearing for a machine.

The present invention is for achieving the above object, and is configured as follows.
A first aspect of the present invention is a thrust roller bearing for a swash plate type compressor that is assembled between a swash plate that reciprocally moves a piston in a cylinder in a cylinder direction by a rotating operation of a rotary shaft, and the swash plate type compressor. A first race in which either the inner diameter side or the outer diameter side of the outer surface is partially abutted against the plate seat, and the outer diameter side or inner diameter side of the outer surface with respect to the cylinder seat A first race is provided with a second race that is partially in contact with the first race and the inner and outer diameters of the first race, and a plurality of rollers that are sandwiched between the two races. Is characterized in that it is set to be on the outer diameter side from the center position between the inner diameter position and the outer diameter position of both races.
According to this configuration, when a preload is applied to the outer diameter side of the outer surface of the first race and to the inner diameter side of the outer surface of the second race, the opposing distance on the outer diameter side of both races is increased by the preload. In this case, the distance is longer (larger) than the facing distance. For this reason, the outer peripheral surface of the roller comes into contact with the first race as a whole, and the outer peripheral surface of the roller is not locally worn.

Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS.
FIG. 1 is a longitudinal sectional view of a swash plate compressor according to an embodiment of the present invention. FIG. 2 is an enlarged view of a support portion of the swash plate of FIG. FIG. 3 is an enlarged view of the thrust roller bearing of FIG. FIG. 4 shows a state when the preload is applied to the thrust roller bearing of FIG.

  As shown in FIGS. 1 and 2, reference numeral 1 denotes a swash plate compressor. 2 and 3 are two cylinders. Reference numerals 4 and 5 denote cylinder heads. Reference numeral 6 denotes a piston disposed between the two cylinders 2 and 3. Reference numeral 7 denotes a driving rotary shaft. Reference numeral 8 denotes a swash plate that is externally fitted and fixed to the rotary shaft 7 and whose outer periphery is engaged with the piston 6 via a ball 9 and a shoe 9a. Reference numeral 11 denotes a radial roller bearing for supporting the rotating shaft. Reference numeral 12 denotes a thrust roller bearing for supporting a swash plate. 13 is a side cover. On the inner diameter side of the cylindrical portions on the inner diameter side of the aforementioned two cylinders 2 and 3, annular convex portions 14 and 15 as receiving seats for the thrust roller bearing 12 are formed on the inner diameter side.

  The thrust roller bearing 12 includes first and second races 70 and 60 that are arranged to face each other in the axial direction, and a plurality of rollers 10 that are held by the cage 20 between the two races 60 and 70. . The dimensions of the inner and outer diameters of both the races 60 and 70 are the same. The races 60 and 70 and the roller 10 are subjected to a treatment such as carbonitriding or nitriding on a high-carbon material such as bearing steel so that the substrate of the surface portion becomes high carbon / high nitrogen from the inside, and the surface By forming charcoal / nitride in the part and quenching it, the wear resistance is improved and the life is extended.

  As shown in FIG. 3, the retainer 20 has an inner diameter side annular plate 40, an outer diameter side annular plate 50, and a circumferential shape of both the annular plates 40, 50 that is spanned at a predetermined interval and has a substantially M-shaped cross section. And a plurality of column portions 30 formed in a shape. Further, a pocket 31 is formed between the adjacent pillars 30, and a retaining protrusion 33 a that protrudes in an opposing manner toward the inside of the pocket 31 at the radial intermediate portion of the opposing surface 33 of the adjacent pillar 30. Are respectively protruded, and the protruding protrusions 33b that protrude in an opposing manner toward the inside of the pocket 31 are also protruded at both radial ends of the opposing surfaces 33 of the adjacent column portions 30.

  Further, the rollers 10 are rotatably held in the pockets 31 of the cage 20 while being locked by the retaining protrusions 33a and 33b. In the state where the roller 10 is held in the pocket 31, the roller 10 is prevented from slipping out from the pocket 31 in one axial direction by the retaining protrusion 33 a at the radial intermediate portion, and the roller 31 from the pocket 31 toward the other axial direction. 10 is prevented by the retaining protrusions 33b at both ends in the radial direction.

  The axial center position C of the roller 10 is set to be on the outer diameter side from the center position RC between the inner diameter position RI of both races 60 and 70 and the outer diameter position RO of both races 60 and 70. .

  The outer diameter side of the outer surface of the first race 70 of the thrust roller bearing 12 (the surface facing the end surface of the boss portion 16 of the swash plate 8) is partially brought into contact with the annular convex portion 17 of the boss portion 16. On the other hand, the inner diameter side of the outer surface of the second race 60 (the surface facing the end surface of the cylinder 2) is partially brought into contact with the annular convex portion 14 of the cylinder 2.

The thrust roller bearing 12 according to this embodiment is configured as described above.
According to this configuration, when the same preload as in the description of the prior art is given, as shown in FIG. 4, the opposing distance “L1” on the outer diameter side of both races 60 and 70 is opposite to that in the conventional case. It becomes longer (larger) than the distance “L”. That is, comparing FIG. 4 and FIG. 6, the relationship of “L1”> “L” is established. Therefore, as apparent from FIG. 4, the outer peripheral surface of the roller 10 comes into contact with the first race 70 as a whole, and the outer peripheral surface of the roller 10 is not locally worn.

The contents described above are only related to one embodiment of the present invention, and do not mean that the present invention is limited to the above contents.
In the embodiment, the outer diameter side of the outer surface of the first race 70 is partially brought into contact with the annular protrusion 17 of the boss portion 16, and the inner diameter side of the outer surface of the second race 60 is set to the annular protrusion 14 of the cylinder 2. A configuration in which a part is made to abut against has been described. However, the present invention is not limited to this, and the inner diameter side of the outer surface of the first race 70 is partially brought into contact with the annular convex portion 17 of the boss portion 16, and the outer diameter side of the outer surface of the second race 60 is It may be configured to partially abut against the annular convex portion 14 of the cylinder 2.

FIG. 1 is a longitudinal sectional view of a swash plate compressor according to an embodiment of the present invention. FIG. 2 is an enlarged view of a support portion of the swash plate of FIG. FIG. 3 is an enlarged view of the thrust roller bearing of FIG. FIG. 4 shows a state when the preload is applied to the thrust roller bearing of FIG. FIG. 5 is an enlarged view of a conventional thrust roller bearing. FIG. 6 shows a state when preload is applied to the thrust roller bearing of FIG.

Explanation of symbols

2 Cylinder 7 Rotating shaft 8 Swash plate 10 Roller 12 Thrust roller bearing 14 Receiving seat (annular convex part)
17 Receiving seat (annular protrusion)
60 Second race 70 First race

Claims (1)

A swash plate for reciprocating the piston in the axial direction in the cylinder by the rotational movement of the rotary shaft, and a thrust roller bearing for a swash plate compressor assembled between the cylinder,
A first race in which either the inner diameter side or the outer diameter side of the outer surface is partially in contact with the swash plate seat;
A second race in which either the outer diameter side or the inner diameter side of the outer surface is partially abutted against the cylinder seat, and the dimensions of the first race and the inner and outer diameters respectively match;
A plurality of rollers sandwiched between these races,
The axial center position of the roller is
A thrust roller bearing for a swash plate compressor, wherein the thrust roller bearing is set to be closer to the outer diameter side than the center position between the inner diameter position and the outer diameter position of both races.

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