JP2946717B2 - Bearing device of oscillating swash plate type compressor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for an oscillating swash plate type compressor, and more particularly to an improvement in a bearing device for supporting a thrust load of a drive shaft.

2. Description of the Related Art As this type of swinging swash plate type compressor used for vehicle air conditioning and the like, one having a configuration disclosed in Japanese Utility Model Laid-Open Publication No. 61-137888, for example, is known. Referring to FIG. 6, an outline of the compressor is shown, 1 is a cylinder block, 2 is a front housing, and 3 is a rear housing, and an outer shell of the compressor is formed by combining these. A radial bearing 5A for supporting a drive shaft 17, which will be described later, is disposed at the center of the front housing 2.
, A suction chamber 6 and a discharge chamber 7 are provided concentrically via an annular partition wall 8. These two chambers 6 and 7 can communicate with a compression chamber 15 of a bore 14 to be described later through a suction port 9 and a discharge port 10 opened in the valve plate 4, and the suction port 9 and the discharge port 10 are connected to the suction valve 11 and the suction valve 11, respectively. It is opened and closed by the discharge valve 12.

A radial bearing 5B is disposed at the center of the cylinder block 1 so as to face the radial bearing 5A, and a piston 16 is reciprocally movable in a plurality of bores 4 formed in parallel around the radial bearing 5B. It is inserted in. On the other hand, the front housing 2 is provided with a crank chamber 13 that communicates with each of the bores 4. In the crank chamber 13, the drive shaft 17 described above is laid across the radial bearings 5A and 5B, and the radial bearing 5A is mounted. A pressure receiving portion 2A of the front housing 2 which is internally formed in a boss shape, and a pressure receiving portion of the drive shaft 17 which is formed in a step shape.
A thrust bearing 22 is interposed between the thrust bearing 22 and 17A.

A swinging swash plate mechanism 20 is connected to the support post 18 protruding from the drive shaft 17 via a guide pin 19 so as to be displaceable at an inclined angle, and each piston rod 21 is further connected to the swinging swash plate mechanism 20. Swash plate mechanism based on the rotation of the drive shaft 17
Each of the pistons 16 is configured to reciprocate by the oscillating motion of 20. Accordingly, the piston stroke and the tilt angle of the swash plate mechanism 20 change in response to the differential pressure between the suction pressure and the crank chamber pressure, and the compression capacity is variably controlled.

[Problem to be Solved by the Invention] When the operation of the compressor configured as described above is started, a bending moment M acts on the drive shaft 17 together with a thrust based on the compression reaction force of the fluid. This bending moment M is necessarily applied to the thrust bearing 22 in a form accompanied by an eccentric load, but this type of compressor shown in FIG. Since the bearing is not offset supported and the contact between the roller and the raceway surface becomes a point contact, the maximum load to be applied also increases, causing a mutual peeling phenomenon (flaking) between the rolling surface and the raceway surface, resulting in thrust. The bearing 25 tends to wear out in a very short time.

An object of the present invention is to correct the above-mentioned eccentric load applied to a thrust bearing and average the load by absorbing and correcting the eccentric load.

Means for Solving the Problems The present invention for solving the above problems includes a drive shaft coaxially supported by a housing and a cylinder block, and a swinging swash plate mechanism connected to the drive shaft. A swash plate type compressor in which a thrust bearing is interposed between pressure receiving portions of the housing and a movable seat plate adjacent to an outer ring of the thrust bearing, and an end surface of the housing pressure receiving portion and the movable seat plate are sandwiched. And a new configuration in which a curved bearing surface capable of absorbing an eccentric load applied to the thrust bearing by a bending moment acting on the drive shaft is adopted.

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

In addition, it is preferable that the outer peripheral edge of the spherical bearing surface that causes relative swinging is opened in a wedge shape, so that oil particles mixed with refrigerant gas are positively introduced into the bearing surface. It is more preferable to form an oil groove for promoting lubrication on the surface.

[Operation] Accordingly, when the operation of the compressor is started, a bending moment acts on the drive shaft together with the thrust based on the compression reaction force of the refrigerant gas, and this is loaded as an eccentric load on the thrust bearing with the deflection of the inner ring. As a result, the rollers and outer ring follow the swinging displacement of the movable seat plate along the spherical bearing surface and absorb this uneven load.As a result, the compressive load acting between the inner and outer rings with the roller in between is skillfully averaged. Thus, the occurrence of flaking is effectively prevented. The bending moment acting on the drive shaft can be received by the two radial bearings having a remarkably high safety factor without any problem.

[Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

FIG. 1 is an enlarged view of a main part of a compressor according to the present invention, and the same or similar components as those of a conventional compressor are denoted by the same reference numerals for easy understanding.

In the drawing, reference numeral 17 denotes a drive shaft, which is supported by radial bearings 5B and 5A provided at the center of each of the cylinder block 1 and the front housing 2. The thrust load of the drive shaft 17 is provided between the pressure receiving portion 2A of the front housing 2 formed in a boss shape with the radial bearing 5A therein and the pressure receiving portion 17A of the drive shaft 17 formed in a stepped shape. A thrust bearing 22 for supporting the bearing is interposed. Thrust bearing 22
Is an inner ring to which the drive shaft 17 is fitted with a desired interference.
22A, an outer ring 22B fitted to the drive shaft 17 with a desired clearance, and a roller 22C sandwiched between the inner and outer rings 22A and 22B.

A movable seat plate 23 is further interposed between the outer ring 22B of the thrust bearing 22 and the pressure receiving portion 2A of the front housing 2, and a required clearance is given to the drive shaft 17 like the outer ring 22B to fit. The movable seat plate 23 is closely fitted to the end face of the pressure receiving portion 2A opposed by a common spherical bearing surface P.

The spherical bearing surface P is formed with a curvature capable of absorbing the partial load applied to the thrust bearing 22 by a 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 the radial bearing 5A and the center of the radial bearing 5B along the axial direction is LT, the distance between the center of curvature Q of the spherical bearing surface P and the center of the radial bearing 5B is LC, the drive shaft 17 and the radial bearing 5A. each fitting clearance △ D ₁ and 5B, when the △ D _2, the ideal center of curvature Q position, Although it can be calculated by the following equation, since △ D ₁ can usually be regarded as being equal to △ D ₂ , LC is set to approximately LT / 2.
In the embodiment shown in the figure, the inner peripheral portion of the spherical bearing surface P is designed to avoid interference with the radial bearing 5A due to design restrictions due to the intervention of the movable seat plate 23. As a result, if the radial bearing 5A is allowed to shift to the right in the figure, all of the opposing surfaces can be tightly connected as a simple spherical bearing surface P.

This embodiment is configured as described above, when the operation of the compressor is started, the compression reaction force of the refrigerant gas is piston 16,
The bending moment M acts on the drive shaft 17 via the piston rod 21, the swinging swash plate mechanism 20, and the support post 18 together with the thrust. Therefore, the bending moment M is applied as an eccentric load to the thrust bearing 22 with the deflection of the inner ring 22A. However, the roller 22C and the outer ring 22B cause the swing displacement of the movable seat plate 23 along the spherical bearing surface P. As a result, the rolling surface of the thrust bearing 22 and the raceway surface are constantly maintained in line contact with each other, the load is reliably averaged, and the occurrence of flaking is completely prevented. . The bending moment M acting on the drive shaft 17 is
It is received without concern by the two radial bearings 5A and 5B that can maintain the rolling contact state per line on the structure.

FIG. 2 shows a further enlarged view of the thrust bearing 22 as another embodiment. In this embodiment, the outer peripheral edges of the spherical bearing surfaces P which are mutually tightly closed are formed in a wedge-shaped opening S.
The oil particles mixed with the refrigerant gas are positively introduced into the spherical bearing surface P, and lubrication of the bearing surface P due to mutual swing is taken into consideration. In the drawing, the spherical bearing surface P formed on the pressure receiving portion 2A side of the front housing 2 is cut and expanded. However, this is replaced with the spherical bearing surface P on the movable seat plate 23 side from the viewpoint of workability. You can also.

In still another embodiment shown in FIGS. 3 and 4, a radial oil groove 23A is formed in the spherical bearing surface P of the movable seat plate 23 in order to further promote the lubrication of the spherical bearing surface P. However, the number of engraved strips is arbitrarily selected.

FIG. 5 is an enlarged view of the same portion as FIG. 2 shown as still another embodiment. In this embodiment, the movable seat plate 23 itself is arranged in a form also serving as the outer ring 22B of the thrust bearing 22. Therefore, the degree of freedom in the design dimension in the longitudinal direction of the compressor is expanded, not limited to simply reducing the number of parts.

It is needless to say that these other embodiments do not differ in basic functions from the embodiment of FIG.

[Effects of the Invention] As described above, according to the present invention, the eccentric load unavoidably applied to the thrust bearing due to the bending moment acting on the drive shaft causes the movable seat plate to move along the spherical bearing surface. Since the thrust bearing is skillfully absorbed through the oscillating displacement, the thrust bearing maintains a normal rolling contact state per line, the load is averaged, and the thrust bearing is prevented from being prematurely worn due to flaking. Can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a compressor showing an embodiment of the present invention. FIG. 2 is an enlarged sectional view of a main part showing another embodiment of the present invention.
FIG. 4 is a sectional view of a movable seat plate showing another embodiment, FIG. 4 is a side view of the same, FIG. 5 is an enlarged sectional view of a main part showing still another embodiment, and FIG. It is sectional drawing which shows the whole view. 1 ... Cylinder block 2 ... Front housing, 2A ... Pressure receiving part 17 ... Drive shaft, 17A ... Pressure receiving part 20 ... Oscillating swash plate mechanism 22 ... Thrust bearing, 22B ... Outer ring 23 ... Movable seat Board

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hayato Ikeda 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (58) Field surveyed (Int. Cl. ⁶ , DB name) F04B 27 / 08

Claims (1)

(57) [Claims] A drive shaft coaxially supported by the housing and the cylinder block; and a swinging swash plate mechanism connected to the drive shaft. A thrust bearing is interposed between the drive shaft and a pressure receiving portion of the housing. In the swinging swash plate type compressor mounted, a movable seat plate is sandwiched adjacent to the outer ring of the thrust bearing, and the end face of the housing pressure receiving portion and the movable seat plate are bent by a bending moment acting on the drive shaft. A bearing device for an oscillating swash plate type compressor, wherein the bearing device has a curved bearing surface having a curvature capable of absorbing an uneven load applied to a thrust bearing.