JPH05126140A - Thrust supporter of turning member - Google Patents

Abstract

PURPOSE:To simplify the structure and to improve load capacity and lifespan of a thrust supporter for supporting a turning scroll member of a scroll compressor and the like so that the scroll member cannot be rotated by reducing the number of required rotation stopping devices, for which a ball is used. CONSTITUTION:A rotation inhibitor 21 using a ball 10, is arranged between a turning scroll member 2 and a fixed scroll member 1, and a burden of thrust load due to the rotation inhibiting ball 10, is eliminated. The rotation inhibitor 21 by the ball 10 is sufficient at one point on the circumference. The thrust load of the turning scroll member 2 due to compressed gas pressure is supported by a bearing 8 for thrust provided in an eccentric manner on a rotational driving shaft 7. For a bearing 8 for thrust, a bearing of normal rolling type, such as angular ball bearing will suffice.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust support device used in a scroll compressor or the like to support a revolving member such as a revolving scroll member so as not to rotate.

[0002]

2. Description of the Related Art A scroll compressor, as shown in FIG. 4, has an orbiting scroll member 51 and a stationary scroll member 52.
Spiral partitions 53, 54 are provided on the respective walls, and both walls 53, 54 are provided.
The compression chamber 55 formed between
The compression operation is performed by changing the volume with the eccentric rotation.

The orbiting scroll member 51 is a rotary drive shaft 5.
The eccentric shaft portion 57a of No. 7 is connected by a radial bearing 58, and is eccentrically rotated by the turning radius of the eccentric amount e by driving the rotary drive shaft 57. The rotary drive shaft 57 comprises a rotor shaft of a motor 56, and is rotatably supported by upper and lower bearings 58 and 59. The orbiting scroll member 51 needs to prevent rotation and be eccentrically rotated in a constant posture, and in order to prevent the rotation and support the thrust load, the ball 56 is interposed between the orbiting scroll member 51 and the fixed frame 60. There is.
The balls 56 are arranged in circular recesses 61, 61 provided in the orbiting scroll member 51 and the fixed frame 60 so as to restrain the moving range thereof. The diameter of the recess 61 is set such that the diameter of the circumferential orbit around which the ball 56 can freely roll is equal to the eccentric amount e.

Instead of the recess 61, there has also been proposed one in which an annular raceway groove 62 having an arc-shaped groove cross section is formed as shown in FIG. 5 (for example, JP-A-55-155916).

[0005]

In the example of FIG. 4, a large thrust load acts on the orbiting scroll member 51 in the downward direction (arrow B direction) due to the compressed gas pressure of the compression chamber 55, and this load is applied to the ball. 56 is added to the contact surface between the bottom surface of the concave portion 61. However, since this contact state is a point contact due to the relationship between the sphere and the plane, there is a problem that the contact pressure per unit area is large, and therefore the load capacity is small and the life is short.

In order to obtain a sufficient load capacity, the ball 5
It is necessary to arrange a large number of 6 and concave portions 61 on the circumference,
Moreover, there is a limit to the number of arrangements, and it is difficult to obtain a satisfactory load capacity. Further, it takes a lot of time to process the recesses 61 in which the balls 56 can freely roll, and if a large number of recesses 61 are provided as described above, the productivity is deteriorated.

In the case of the example of FIG. 5, since the inner surface of the raceway groove 62 is arcuate, the contact area of the ball 56 with the raceway surface is increased, the surface pressure is reduced, and the bearing life is greatly improved.
However, it is more difficult to process such an annular raceway groove 62 having an arcuate cross section into the orbiting scroll member 51 or the fixed frame 57, as compared with the flat surface recessed portion 61 of FIG.
Therefore, the productivity becomes even worse.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thrust support device capable of supporting the eccentric rotation by preventing the turning member from rotating, improving load capacity and life, and facilitating manufacturing.

[0009]

According to the thrust support device of the present invention, a rolling type thrust bearing eccentric from the center of rotation is attached to the end of a rotary drive shaft rotatably supported by a fixed member. A rotating member is installed in the bearing for use, and a ball for preventing rotation is arranged on the surface of the rotating member opposite to the rotary drive shaft. That is, a pair of circular recesses facing each other are provided in the outer peripheral portion of the opposite surface of the turning member and the fixing member, and balls are interposed between these recesses. The diameter of each recess is such that the diameter of the circumferential orbit around which the ball can roll in the recess is equal to the eccentric amount of the thrust bearing.

[0010]

According to the structure of the present invention, since the thrust bearing is provided eccentrically on the rotary drive shaft, the thrust load of the eccentrically rotating turning member is supported by the normal rolling type thrust bearing. The rotation of the swivel member due to the eccentric rotation is prevented by the engagement of the ball with the recess formed in the facing surface of the swivel member and the fixed member at the outer peripheral portion of the swivel member. At this time, the ball rolls freely in each of the recesses, preventing the eccentric rotation of the turning member from being hindered and preventing the rotation of the ball. Since the ball is arranged on the surface of the revolving member opposite to the rotary drive shaft, the thrust load acting from the revolving member to the rotary drive shaft does not act on the ball, only the radial load for rotation prevention acts. ..

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. This embodiment is an example applied to a scroll compressor. The fixed scroll member 1 and the orbiting scroll member 2 each have spiral partition walls 3 and 4, and a compression chamber 5 is formed between the partition walls 3 and 4. The fixed scroll member 1 is fixed to a fixed member 6 serving as a housing, and constitutes a part of the fixed member 6. A rotary drive shaft 7 that drives the orbiting scroll member 2 serves as a rotor shaft of a motor 11, and is rotatably supported by the fixed member 6 by upper and lower bearings 12 and 13. A radial bearing such as a cylindrical roller bearing is used for the upper bearing 12, and a rolling bearing capable of supporting loads in both radial and thrust directions is used for the lower bearing 13.

The orbiting scroll member 2 is supported on the upper end of the rotary drive shaft 7 by a thrust bearing 8 composed of an angular ball bearing, and is engaged with a radial bearing 9 for transmitting an eccentric rotational force. Further, between the orbiting scroll member 2 and the fixed scroll member 1, a rotation stopping device 21 by the ball 10 is interposed at one position on the outer peripheral portion.

That is, the large diameter portion 7 at the upper end of the rotary drive shaft 7
The outer ring of the thrust bearing 8 is attached to a by eccentricity a from the rotation center O, and the circular projection 14 on the lower surface of the orbiting scroll member 2 is fixed to the inner ring. Further, the large diameter portion 7a of the rotary drive shaft 7 is provided with an eccentric hole 16 concentrically with the thrust bearing 8, and a transmitted shaft 15 protruding in a stepped shaft shape from the circular protrusion 14 of the orbiting scroll member 2 is provided. , Eccentric hole 1
It is made to engage in 6 through the radial bearing 9. A needle bearing or the like is used as the radial bearing 9.

The self-rotating device 21 comprises a pair of recesses 17 and 18 provided to face the orbiting scroll member 2 and the fixed scroll member 1, and a ball 10 interposed between these recesses 17 and 18. The recesses 17 and 18 are formed in the bearing rings 19 and 20 fixed to the orbiting scroll member 2 and the fixed scroll member 1, respectively. The outer shape of the bearing rings 19 and 20 is rectangular in this embodiment as shown in FIG. 3, but may be circular. Recesses 17, 18
Has a circular planar shape, and the bottom surface is formed into a flat surface. The diameters of the recesses 17 and 18 are
The diameter b of the circular orbit around which the ball 10 can freely roll in 18
c is a diameter equal to the eccentric amount a of the eccentric hole 16 of the rotary drive shaft 7.

The operation of the above configuration will be described. Rotary drive shaft 7
When is rotated, the orbiting scroll member 2 engaged with the eccentric hole 16 by the radial bearing 9 performs eccentric rotation with an orbiting radius of the eccentricity a. With the eccentric rotation, a force that causes the orbiting scroll member 2 to rotate is applied, but since the ball 10 is engaged with the recesses 17 and 18 of the orbiting scroll member 2 and the fixed scroll member 1, Is blocked. At this time, the ball 10 has circular recesses 17, 1
It can be freely rolled in 8 and rolls in each of the recesses 17 and 18 along the outer peripheral edge thereof due to the self-rotational force acting on the orbiting scroll member 2. The diameters b and c of this rolling track are
As described above, each is equal to the radius a of the eccentric rotation of the orbiting scroll member 2, and therefore the orbiting scroll member 2 rotates eccentrically while maintaining a constant angular relationship with the fixed scroll member 1.

As described above, the eccentric rotation of the orbiting scroll member 2 does not cause rotation, so that the volume of the compression chamber 5 between the fixed scroll member 1 and the orbiting scroll member 2 changes, and the compression operation is performed. A large thrust load acts downward (in the direction of arrow A) on the orbiting scroll member 2 due to the gas pressure in the compression chamber 5, and this thrust load is transmitted to the rotary drive shaft 7 via the thrust bearing 8 and the lower bearing. It is supported by the fixing member 6 at 13.

The ball 10 for preventing rotation is arranged on the fixed scroll member 1 side contrary to the above-mentioned conventional example. Therefore, the thrust load acting on the orbiting scroll member 2 by the compressed gas pressure is not applied to the ball 10. ..

In this thrust support device, the ball 10 for preventing rotation is arranged on the surface of the orbiting scroll member 2 on the side of the fixed scroll member 1 in this manner to eliminate the load of the thrust load by the ball 10 and to rotate the rotary drive shaft 7. Since the thrust bearing 8 of FIG.
It suffices to provide one self-rotating device 21 composed of the above and the recesses 17 and 18 on the circumference. Therefore, the structure is simple. Moreover, since the orbiting scroll member 2 is supported by the thrust bearing 8 eccentrically provided on the rotary drive shaft 7, the orbiting scroll member 2 performing eccentric rotary motion.
The thrust load can be supported by the normal rolling type thrust bearing 8, so that the load capacity and the life can be easily improved.

In the above embodiment, the rotation preventing device 21 is provided at one place in the circumferential direction, but it may be provided at a plurality of places.
Further, the recesses 17 and 18 in which the balls 10 are arranged may be directly processed in the orbiting scroll member 2 and the fixed scroll member 1. The cross-sectional shape of the recesses 17 and 18 may be formed in an annular groove as in the example of FIG. The thrust bearing 8 provided on the rotary drive shaft 7 is not limited to the angular bearing, and a plane seat type thrust bearing may be used. Further, in the above-described embodiment, the eccentric rotation is transmitted from the rotary drive shaft 7 to the orbiting scroll member 2 by the radial bearing 9, but by using the angular bearing as described above, the thrust bearing 8 You can also use it together. Furthermore, the thrust support device of the present invention is not limited to the scroll compressor, but can be applied to any device that rotates eccentrically while preventing rotation.

[0020]

In the thrust support device of the present invention, the ball for rotation prevention is arranged on the surface of the revolving member on the side opposite to the rotation drive shaft to eliminate the load of the thrust load by the rotation prevention ball on the rotation drive shaft. Since the thrust bearing is eccentrically provided to support the thrust load, it is not necessary to provide a large number of rotation preventing means composed of balls and recesses on the circumference, and the structure is simplified. Moreover, since the revolving member is supported by the thrust bearing eccentrically provided on the rotary drive shaft, the thrust load of the revolving member performing the eccentric rotary motion can be supported by the normal rolling type thrust bearing. Therefore, the load capacity and life can be easily improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a scroll compressor to which a thrust support device according to an embodiment of the present invention is applied.

FIG. 2 is an enlarged cross-sectional view showing a portion where a ball and a recess are formed.

FIG. 3 is a plan view showing the relationship between balls and recesses in the orbiting scroll member.

FIG. 4 is a partial cross-sectional view of a conventional scroll compressor.

FIG. 5 is a partial cross-sectional view of another conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed scroll member, 2 ... Orbiting scroll member, 6
... Fixing member, 7 ... Rotation drive shaft, 8 ... Thrust bearing, 9
... Radial bearings, 10 ... Balls, 17,18 ... Recesses, 1
9, 20 ... Orbital ring, 21 ... Rotation stop device

Claims (1)

[Claims] 1. A rolling type thrust bearing eccentric from the center of rotation is attached to an end of a rotary drive shaft rotatably supported by a fixed member, and the swiveling member is installed on the thrust bearing. A pair of circular concave portions facing each other are provided on the outer peripheral portion of the surface opposite to the rotary drive shaft and the fixing member, balls are interposed between the concave portions, and the balls can roll freely in the respective concave portions. A thrust support device for a revolving member, wherein the diameter of the circumferential orbit is equal to the eccentric amount of the thrust bearing.