JPH04148082A - Bearing device for swingable swash plate type compressor - Google Patents

Abstract

PURPOSE:To prevent early abrasion of a thrust bearing by absorbing an unbalanced load exerted to the thrust bearing by a bending moment which acts upon a drive shaft, through swinging displacement of a movable seat plate along a spherical bearing surface. CONSTITUTION:A drive shaft 17 with a swingable swash plate mechanism coupled to a support shaft 18 is supported by radial bearings 5B, 5A provided in a cylinder block 1 and a front housing 2, and a thrust bearing 22 for bearing a thrust load from the drive shaft 17 is disposed between the pressure receiving part 2A of the front housing 2 and the pressure receiving part 17A of the drive shaft 17. In this arrangement, a movable seat plate 23 is interposed between the outer race 22B of the thrust bearing 22 and the pressure receiving part 2A, and the movable seat plate 23 loosely fitted on the drive shaft 17 is made into close contact with the end face of the pressure receiving part 2A by a common spherical bearing surface P. Further, this spherical bearing surface P is formed so as to have a curvature by which an unbalanced load exerted to the thrust bearing 22 by a bending moment acting upon the drive shaft 17 can be absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bearing device for a rocking swash plate compressor, and more particularly to an improvement in a bearing device that supports the thrust load of a drive shaft.

[Prior Art] As this type of oscillating swash plate compressor used for vehicle air conditioning, there is known a structure disclosed in, for example, Japanese Utility Model Application No. 61-137888. The same compressor was installed on the 6th
Generally speaking, based on the figure, 1 is a cylinder block, 2 is a front housing, and 3 is a rear housing, and the outer shell of the compressor is formed by these connections. A radial bearing 5A for supporting a drive shaft 17, which will be described later, is arranged in the center of the front housing 2, while a suction chamber 6 and a discharge chamber 7 are provided concentrically in the rear housing 3 with an annular partition 8 interposed therebetween. ing. These rain air 6.7 can communicate with a compression chamber 15 of the bore 14, which will be described later, through an inlet 9 and an outlet 10 opened in the valve plate 4, and the inlet 9 and outlet 10 are connected to the inlet valve 11 and It is opened and closed by a valve 12.

Further, a radial bearing 5B is arranged in the center of the cylinder block 1, facing the radial bearing 5A,
A piston 16 is reciprocatably fitted into a plurality of bores 4 formed in parallel around the circumference. On the other hand, the front housing 2 is provided with a crank chamber 13 that is electrically connected to each pore 4, and the crank chamber 13 includes both rod bearings 5A,
The above-mentioned drive shaft 17 is horizontally suspended over the space 5B, and the pressure receiving part 2A of the front housing 2 is formed in a boss shape with a radial bearing 5A inside, and the pressure receiving part of the drive shaft 17 is formed in a step shape. Thrust bearing 2 is installed between 17A and 17A.
2 is interposed.

A swinging swash plate mechanism 20 is connected to a support post 18 protruding from the drive shaft 17 via a guide pin 19 so as to be able to be tilted, and each piston rod 21 is connected to the swing swash plate mechanism 20. The pistons 16 are configured so that each piston 16 is reciprocated by the rocking motion of the rocking swash plate mechanism 20 based on the rotation of the drive shaft 17. Therefore, the piston stroke and the inclination angle of the rocking swash plate mechanism 20 change in response to the differential pressure between the suction pressure and the crank chamber pressure, so that the compression capacity is variably controlled.

[Problems to be Solved by the Invention] When the compressor configured as described above starts operating, a thrust force and a bending moment M act on the drive shaft 17 based on the compression reaction force of the fluid.

This bending moment M is inevitably applied to the thrust bearing 22 in the form of an unbalanced load, but in this type of compressor shown in the figure, the thrust bearing 22 is Since there is no offset support, and the contact between the rollers and the raceway surface is at a single point, the maximum load that can be applied is also large, resulting in mutual peeling phenomenon (flaking) between the rolling surface and the raceway surface, causing damage to the thrust bearing. 25 tends to wear out in a very short period of time.

A technical problem to be solved by the present invention is to absorb and correct the above-mentioned unbalanced load applied to the thrust bearing and to equalize the load.

[Means for Solving the Problems] In order to solve the above problems, the present invention includes a drive shaft co-inserted and supported by a housing and a cylinder block, and a rocking swash plate mechanism connected to the drive shaft. and a rocking swash plate compressor in which a thrust bearing is interposed between the pressure receiving parts of the housings, a movable seat plate is sandwiched adjacent to the outer ring of the thrust bearing, and the end face of the housing pressure receiving part and the movable seat plate A novel configuration is adopted in which the two are closely connected by a spherical bearing surface with a curvature capable of absorbing the uneven load applied to the thrust bearing due to the bending moment acting on the drive shaft.

As an embodiment of the present invention, the movable seat plate may be arranged to also serve as the outer ring of the thrust bearing.

In addition, it is desirable to open the outer peripheral edge of the spherical bearing surface that causes relative rocking in a wedge shape to actively introduce oil particles mixed with refrigerant gas into the bearing surface, and furthermore, one side of the bearing surface It is more preferable if oil grooves for promoting lubrication are formed in the grooves.

[Operation] Therefore, when the compressor starts operating, thrust and bending moment act on the drive shaft based on the compression reaction force of the refrigerant gas, and this causes deflection of the inner ring and is applied as an unbalanced load to the thrust bearing. However, the rollers and outer ring absorb this uneven load by following the swinging displacement of the movable seat plate along the spherical bearing surface, and as a result, the compressive load acting between the inner and outer rings across the rollers is skillfully averaged out. is applied, and flaking may occur.
effectively prevented. It should be noted that the bending moment acting on the drive shaft is borne without any problem by both radial bearings, which have an extremely high safety factor.

[Example] Hereinafter, an example of the present invention will be specifically described based on the drawings.

FIG. 1 is an enlarged view of the main parts of the compressor according to the present invention, and for ease of understanding, the same reference numerals are given to the same or similar components as in the conventional compressor. .

In the figure, reference numeral 17 denotes a drive shaft, which is supported by radial bearings 5B and 5A disposed at the center of the cylinder block 1 and the front housing 2, respectively. The thrust load of the drive shaft 17 is located between the pressure receiving portion 2A of the front housing 2, which is formed into a boss shape with the radial bearing 5A therein, and the pressure receiving portion 17A of the drive shaft 17, which is formed in a step shape. A thrust bearing 22 that supports the is interposed.

The thrust bearing 22 has an inner ring 22A that fits onto the drive shaft 17 with a required clearance, an outer ring 22B that fits onto the drive shaft 17 with a required clearance, and
It includes a ring 022C held between outer rings 22A and 22B.

A movable seat plate 2 is further provided between the outer ring 22B of the thrust bearing 22 and the pressure receiving portion 2A of the front housing 2.
The movable seat plate 23, which is fitted with the drive shaft 17 with a required clearance in the same way as the outer ring 22B, is tightly fitted with the end face of the pressure receiving part 2A facing the pressure receiving part 2A by a common spherical bearing surface P. I'm being forced to do it.

The spherical bearing surface P is formed with a curvature capable of absorbing the uneven load applied to the thrust bearing 22 due to the bending moment M (see FIG. 6) acting on the drive shaft 17 based on the compression reaction force of the refrigerant gas. . Here, the distance between the center of radial bearing 5A and the center of radial bearing 5B along the axial direction is L.
T, center of curvature Q of the spherical bearing surface P and radial bearing 5B
The distance from the center is LC1 drive shaft 17 and radial bearing 5A,
When the respective fitting clearances with 5B are ΔD1 and ΔD2, the ideal curvature center Q position can be found by the following formula, but normally ΔD1 can be considered equal to ΔD2, so LC is approximately LT /2. Note that in the illustrated embodiment, due to design constraints due to the intervention of the movable seat plate 23, the inner circumferential portion of the spherical bearing surface P is structured to freely move around even when it interferes with the radial bearing 5A. If the radial bearing 5A is allowed to shift to the right in the drawing, all of the opposing surfaces can be made into a simple spherical bearing surface P and brought into close contact with each other.

This embodiment is configured as described above, and when the compressor starts operating, the compression reaction force of the refrigerant gas is applied to the piston 16,
The bending moment M acts on the drive shaft 17 via the piston rod 21, the rocking swash plate mechanism 20, and the support post 18, and the thrust force and the bending moment M act on the i-moving shaft 17. therefore,
This bending moment M is applied as an unbalanced load to the thrust bearing 22 along with the deflection of the inner ring 22A.
The rollers 22C and the outer ring 22B follow the swinging displacement of the movable seat plate 23 along the spherical bearing surface P and absorb this uneven load, so that the rolling surface and raceway surface of the thrust bearing 22 constantly maintain a state of line contact. This ensures that the load is evened out and that flaking is completely prevented. Incidentally, the bending moment M acting on the drive shaft 17 is received without concern by both radial bearings 5A and 5B, which can maintain a linear rolling contact state due to their structure.

FIG. 2 is a roughly enlarged view of the thrust bearing 22 portion as another embodiment, and in this embodiment, the outer periphery of the spherical bearing surfaces P that are brought into close contact with each other is formed into a wedge-shaped opening S. hand,
Oil droplets mixed with refrigerant gas are actively introduced into the spherical bearing surface P to take into consideration the lubrication of the bearing surface P due to relative rocking. In addition, in the figure, the spherical bearing surface P formed on the pressure receiving part 2A side of the front housing 2 is cut and expanded, but this was replaced with the spherical bearing surface P on the movable seat plate 23 side for the sake of machinability. You can also

In roughly another embodiment shown in FIGS. 3 and 4, radial oil grooves 23A are carved in the spherical bearing surface P of the movable seat plate 23 in order to further promote lubrication of the spherical bearing surface P. The number of engraved lines etc. can be selected at will.

FIG. 5 is an enlarged view of the same part as FIG. 2 shown as another embodiment, and in this embodiment, the movable seat plate 23 itself is arranged to also serve as the outer ring 22B of the thrust bearing 22. . Therefore, not only the number of parts is limited, but also the degree of freedom in design dimensions in the longitudinal direction of the compressor is expanded.

It goes without saying that these other embodiments do not differ in basic function from the embodiment shown in FIG.

[Effects of the Invention'] As detailed above, according to the present invention, the unbalanced load that is unavoidably applied to the thrust bearing due to the bending moment acting on the drive shaft is absorbed by the movable seat plate along the spherical bearing surface. Since the thrust bearing is skillfully absorbed through the oscillating displacement of The durability of the machine can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a compressor showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main parts of a compressor showing another embodiment, and FIG.
The figure is a sectional view of the movable seat plate similarly showing another embodiment, Fig. 4 is a side view of the same, Fig. 5 is an enlarged sectional view of the main part roughly showing another embodiment, and Fig. 6 is a conventional compressor. FIG. 1...Cylinder block 2...Front housing 2A...Pressure receiving part 17.
...Drive shaft 17A...Pressure receiving part 20...
Rocking swash plate mechanism 22... Thrust bearing 22B... Outer ring 23.
・・Movable seat plate Fig. 1 Fig. 3 Fig. 4

Claims (1)

[Claims] (1) Equipped with a drive shaft co-inserted and supported by the housing and cylinder block, and a rocking swash plate mechanism connected to the drive shaft, with a thrust bearing interposed between the pressure receiving parts of the drive shaft and the housing. In the oscillating swash plate type compressor, a movable seat plate is sandwiched adjacent to the outer ring of the thrust bearing, and the end face of the housing pressure receiving part and the movable seat plate are bent by a bending moment acting on the drive shaft. 1. A bearing device for an oscillating swash plate type compressor, characterized in that the bearing device is closely fitted with a spherical bearing surface having a curvature capable of absorbing an uneven load applied to the compressor.