JPH0121354B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shoe for a swash plate compressor.

A swash plate compressor includes a swash plate rotated by a rotating shaft within a cylinder block and a piston slidably fitted within the cylinder block. Conventionally, the rotation of the swash plate is transmitted to the piston as reciprocating motion. For this purpose, a shoe having a spherical recess formed in the swash plate was brought into sliding contact with the shoe, and a ball was interposed between the spherical recess of the shoe and the spherical recess formed in the piston. However, when a shoe and a ball are used, not only is the assembly process complicated, but also the power consumption due to friction is large due to sliding contact between the shoe and the swash plate, between the shoe and the ball, and between the ball and the piston. In addition, since it is difficult to reduce the total axial length of the shoe and the ball, the axial length of the cylinder block becomes large, which is a factor that prevents miniaturization of the swash plate type compressor.

In view of such circumstances, the present invention provides a shoe for a swash plate type compressor that improves the above-mentioned drawbacks by forming a hemispherical portion on the shoe and bringing the hemispherical portion into direct sliding contact with the spherical concave portion of the piston without using a ball. Its purpose is to:
A swash plate type compressor shuttle that is interposed between a swash plate rotated by a rotating shaft in a cylinder block and a piston slidably fitted in a cylinder bore, and that reciprocates the piston in accordance with the rotation of the swash plate. In the shoe, one surface of the shoe is formed with a hemispherical portion that fits into a spherical recess provided in the piston, and the other surface of the shoe is formed with a sliding surface that slides into contact with the end surface of the swash plate. The outer shape is configured into a block shape consisting of the hemispherical part and the cylindrical part continuous thereto, and a hole with a bottom is formed at the top of the hemispherical part of the shoe, and the inner diameter of the opening side of the hole is reduced from the bottom part. The reason is that the inside is filled with lubricant.

The present invention will be described below with reference to the illustrated embodiments.
In FIG. 1, a rotary shaft 2 is rotatably supported on the inner shaft portion of a cylinder block 1 via bearings 3 and 4, and a swash plate 5 is connected and fixed to the rotary shaft 2 by a pin 6. As shown in FIG. Further, thrust bearings 7 and 8 are provided between both ends of the shaft portion of the swash plate 5 and the cylinder block 1, respectively. Cylinder bores 9 are formed in the cylinder block 1 at regular intervals of 120 degrees, and a piston 10 is slidably fitted into each bore 9. The left end opening of the cylinder block 1 is closed by a valve plate 11 and a front cylinder head 12, and the right end opening is closed by a valve plate 13 and a rear cylinder head 14.

A concave portion 10a for receiving the outer peripheral portion of the swash plate 5 is formed in the center portion of the piston 10, and spherical concave portions 10b are formed on axially opposing surfaces of the concave portion 10a. A shoe 15 according to the present invention is interposed between each spherical concave portion 10b and the end surface 5a of the swash plate 5.

As shown in FIG.
a hemispherical portion 15a that is engaged with and comes into sliding contact with b;
It has a block-like structure consisting of a short cylindrical portion 15b continuous to the hemispherical portion and a back mold 16 provided integrally on the bottom surface of the cylindrical portion, and the bottom end surface of this back mold is in sliding contact with the end surface 5a of the swash plate 5. Further, a hole 17 with a bottom is formed in this shoe 15 and opens at the top of the hemispherical portion 15a. A filler 18 such as felt that can contain lubricating oil is filled.

When such a shoe 15 is used, assembly is easier than in the conventional shoe and ball, and the sliding portion is located between the swash plate 5 and the shoe 15, and between the shoe 15 and the piston 10. Since there are two locations, the horsepower consumption due to friction can be reduced, and the axial length of the shoe 15 can be reduced, that is, the gap between the end surface 5a of the swash plate 5 and the spherical concave portion 10b of the piston 10 can be reduced. Therefore, the axial length of the swash plate compressor can be shortened. In addition, filler 1
If the filler 8 contains lubricating oil, the sliding conditions between the shoe 15 and the piston 10 can be improved by the lubricating oil, and the filler 18 can also be used so that the inner diameter of the hole 17 becomes smaller on the opening side. This has the advantage that it is difficult to fall off. It goes without saying that instead of the filler 18, grease may be directly filled into the hole 17 as an equivalent lubricant.

In the above embodiment, the shoe 15 is made of a bimetallic material, but it goes without saying that it may be made of the same material such as an Fe-based, Cu-based, or Al-based alloy.

As described above, by using the shoe according to the present invention, assembly of a swash plate compressor is facilitated,
It has the effect of reducing horsepower consumption and shortening the overall length.In particular, since the bottomed hole is formed at the top of the hemispherical part of the shoe by reducing its opening, it is easy to apply lubricant inside this hole. By retaining it, it is possible to perform good lubrication on the sliding contact surface, and it can also be used as a pool of sliding contact debris to further reduce wear. Moreover,
The other side of the hemispherical part is formed as a sliding surface that comes into sliding contact with the end face of the swash plate, and the overall shape of the shoe has a block-like configuration consisting of the hemispherical part and a cylindrical part continuous thereto, so that the overall configuration of the shoe is The hemispherical part of the shoe that swings and slides into contact with the spherical concave part of the piston has a cohesive form with a small amount of inertia, and the above-mentioned bottomed The effect is expected to be good lubrication of the sliding contact area due to the oil supply from the hole.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a swash plate compressor using a shoe according to the present invention, and FIG. 2 is an enlarged view of the shoe shown in FIG. 1. 1... Cylinder block, 2... Rotating shaft, 5...
... Swash plate, 9 ... Cylinder bore, 10 ... Piston, 10b ... Spherical recess, 15 ... Shu, 1
5a... Hemispherical part, 15b... Cylindrical part, 16... Back metal, 17... Hole, 18... Filler.

Claims (1)

[Scope of Claims] 1 A piston is interposed between a swash plate rotated by a rotating shaft in a cylinder block and a piston slidably fitted in a cylinder bore, and the piston reciprocates in accordance with the rotation of the swash plate. In the shoe for a swash plate type compressor, one surface of the shoe is formed with a hemispherical portion that fits into a spherical recess provided in the piston, and the other surface of the shoe is provided with a sliding surface that slides into contact with an end surface of the swash plate. forming the shoe so that the outer shape of the shoe is a block consisting of the hemispherical portion and a cylindrical portion continuous thereto, and forming a hole with a bottom at the top of the hemispherical portion of the shoe, and forming a hole on the opening side of the hole. A shoe for a swash plate type compressor, characterized in that the inner diameter is reduced from the bottom and the inside is filled with lubricant. 2. The shoe for a swash plate compressor according to claim 1, wherein the shoe is a single piece made of the same material. 3. The shoe for a swash plate compressor according to claim 1, wherein the shoe is made of a bimetallic material.