JPS6410568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thrust bearing device that supports the swash plate of a swash plate type axial comprezzar, and which prevents the swash plate from wobbling in the axial direction without warping the inner and outer rings even under high-temperature operating conditions. , it is an object of the present invention to provide a thrust bearing that prevents a decrease in compression efficiency.

Before explaining the thrust bearing device of this invention,
First, the swash plate compressor will be explained. FIG. 1 is a longitudinal sectional view of a swash plate compressor. In the figure, 1 and 2 are cylindrical cylinders that are divided into two parts at the front and rear with a dividing line in the direction perpendicular to the axis.
Side covers 5 and 6 are disposed in series from the front and back with cylinder heads 3 and 4 interposed on the outer end surfaces thereof, respectively.
These are tightly fastened by the shell 7 with limited relative positional relationship. Reference numeral 8 denotes a swash plate shaft connected to the driving part of the vehicle engine, which extends through a through hole drilled in the center of the cylinders 1 and 2, and has radial bearings provided at each outer end of the cylinders 1 and 2. 9 and 10, and a swash plate 11 is wedged near the joint between the two cylinders 1 and 2. 12 is cylinder 1,
A piston fitted into the swash plate 2 engages both sides of the swash plate 11 via a pawl 13 and a slipper 14,
As the swash plate 11 rotates, it reciprocates within the cylinders 1 and 2. In the swash plate type axial compressor, the axial load due to the reciprocating motion of the piston 12 is supported by a thrust bearing 15 interposed between both ends of the boss portion of the swash plate 11 and the cylinders 1 and 2. It is a well-known fact that bearing life is greatly affected by the support method of the inner and outer rings, but in the above-mentioned swash plate type compressor, the mounting errors are eliminated using rolling bearings within a limited space. Since the method of use is to relieve overload by bending the outer ring, it is not possible to fully support the inner and outer rings a on the support b as shown in Fig. 2. Therefore, as shown in FIG. 3, a partial contact method is currently employed in which the inner and outer rings a are partially supported on supports b. In addition, in the case of swash plate compressors, preload is applied to the rolling bearing using the difference in housing width dimension, and there is a problem that the amount of preload cannot be controlled at a constant level, which is very problematic for rolling bearings used. By the way. In other words, increasing the rigidity of the bearing ring will shorten the bearing life.
Moreover, the heat generation becomes large. For this reason, each manufacturer prevents the occurrence of edge load by appropriately selecting the support points for the inner and outer rings to equalize the deflection angles of the inner and outer rings. With the materials for the inner and outer rings that are currently commonly used, even if appropriate support points and plate thicknesses are determined, the raceways have uniform hardness, and the hardness remains constant.
The disadvantage is that it has a HRC of nearly 60 and is very rigid, which causes many problems.

In view of the above-mentioned drawbacks of the conventional thrust bearing device, the thrust bearing device of the present invention improves and eliminates these drawbacks. That is,
In order to reduce the stiffness of the inner and outer rings as much as possible within the same space and extend the bearing life, heat-refinable steel is used for the raceway rings, and only the raceway surface where the rolling elements roll (in Figure 4) The rolling fatigue life of the bearing can be improved by carburizing, quenching with high frequency, etc. to give the bearing an appropriate hardness (HRC60 or higher), and also hardening the unquenched part (in the case of raceway A in Figure 4). The elasticity of the core (or the non-rolling surface side in the case of the bearing ring B) is utilized to increase the bending spring constant of the bearing ring.

Figure 5 shows the amount of deflection of the raceway ring of a thrust bearing with full support, a thrust bearing with current support dimensions, and a thrust bearing according to the present invention.The raceway ring of the thrust bearing according to the present invention has extremely high spring characteristics. Since the bearing ring easily deforms elastically with respect to the amount of preload, the preload load due to the difference in housing dimensions is small as an actual bearing load. In addition, Figure 6 shows heat generation test data under the conditions of N = 4000 rpm, P = 500 Kgf, and an oil turbine oil bath, and shows that when the thrust bearing of this invention is used, it is possible to suppress heat generation to a low level. be.

Therefore, when the thrust bearing device of the present invention is used, it is possible to improve the bearing life and the heat generation of the bearing.

As explained above, the present invention provides a swash plate for a swash plate type axial compressor in which a piston is reciprocated in the axial direction by a rotating swash plate in a cylinder divided into two parts in the axial direction to pressurize and compress a fluid. A thrust bearing device that applies a thrust load to the inner circumferential side and the outer circumferential side of the bearing raceway in the radial direction on the side opposite to the raceway surface of the bearing raceway, respectively, the surface including the raceway surface of the bearing raceway The quenched hardened layer and the non-hardened layer at least in the core provide high hardness to the raceway surface of the thrust bearing ring, while improving spring characteristics and making it possible to adjust the axial clearance by the thrust bearing. In addition, it is possible to apply an appropriate amount of preload to the thrust bearing, and also to release overload, making it possible to suppress heat generation and greatly extend the bearing life. It can exhibit excellent properties as a thrust bearing device applied to swash plates.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a swash plate type axial compressor. 2 and 3 are enlarged views of the support portion of the thrust bearing, with FIG. 2 showing full support and FIG. 3 showing partial support. FIG. 4 is an explanatory diagram showing a bearing ring of the thrust bearing device of the present invention. Fifth
The figure is a drawing showing the deflection test data of the bearing raceway. FIG. 6 is a drawing showing heat generation operation test data.

Claims (1)

[Claims] 1 Applied to the above-mentioned swash plate of a swash plate type axial compressor, in which a piston is reciprocated in the axial direction by a rotating swash plate in a cylinder divided into two in the axial direction to pressurize and compress fluid, and is applied to the swash plate of the bearing raceway. A thrust bearing device in which a thrust load is applied to the inner circumferential side and the outer circumferential side in the radial direction of the bearing on the opposite raceway surface side, respectively, wherein the surface including the raceway surface of the bearing raceway is formed as a quenched hardened layer, and at least A thrust bearing device for a swash plate type axial compressor, characterized in that the core portion is a non-hardened layer.