JPH0719183A - Scroll type air compressor - Google Patents

Abstract

PURPOSE:To provide an oilless scroll type air compressor of such constitution that friction generated in association with the rotation of an eccentric bush can be suppressed to a minimum without harming the sealing performance of a seal member as a shaft sealing device and that without increasing the number of part items. CONSTITUTION:A scroll type air compressor is provided with a scroll compression element 2 and a motor-driven element 3. The scroll compression element 2 is formed of a frame 5 having a bearing 4 at the center part; a fixed scroll 6 having an end plate 8 fixed to the frame 5, and a spiral lap 10 erected on the end plate 8; and an oscillating scroll 7 having an end plate 11, a spiral lap 12 erected on one face of the end plate 11, and a boss 13 erected on the other face of the end plate 11. The fixed scroll 6 and oscillating scroll 7 are assembled by engaging the laps 10, 12 with each other, and a driver 25 provided at the rotary shaft 18 of the motor-driven element 3 is fitted to the boss 13 of the oscillating scroll 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type air compressor having a drive device for transmitting the rotational force of an electric element to an orbiting scroll.

[0002]

2. Description of the Related Art A conventional scroll compressor is constructed, for example, as disclosed in Japanese Patent Laid-Open No. 62-28186. Here, in particular, the oil-free scroll-type air compressor includes a scroll compression element and an electric element,
The scroll compression element includes a frame having a bearing in the center, a fixed scroll having a mirror plate fixed to the frame and a spiral wrap standing on the mirror plate, and a mirror plate and one surface of the mirror plate. And a swing scroll having a boss that is erected on the other surface. The fixed scroll and the swing scroll are assembled by engaging the wraps with each other. In a scroll compressor in which a driving device provided on a rotating shaft of an electric element is fitted to a boss, the driving device is fitted to a step portion of the rotating shaft, and a balance weight for canceling an unbalanced force of an orbiting scroll. , An eccentric bush fitted on the balance weight and fitted to the boss portion of the orbiting scroll, and a bolt for fixing the eccentric bush to the rotating shaft. It is configured to include a bearing and seal member provided between the eccentric bush and a boss portion of the orbiting scroll.

In the scroll type air compressor of this structure,
Since it is oil-free, it is the most important thing to prevent foreign matter from entering the bearing. Therefore, generally, a seal member, which is a shaft sealing device, is mounted on the release side of the bearing.

[0004]

However, according to the above structure, since the seal member forms the seal surface by utilizing its own elastic force, a large power loss is caused by the frictional force caused by the rotation of the eccentric bush. There is a problem in that each component is adversely affected by thermal expansion and thermal deformation due to frictional heat.

The present invention solves the above problems,
An oil-free scroll-type air compressor that can minimize the friction caused by the rotation of the eccentric bush without impairing the sealing performance of the seal member as a shaft sealing device and does not increase the number of parts. The purpose is to provide.

[0006]

According to the present invention, there is provided a scroll compression element and an electric element, and the scroll compression element is provided with a frame having a bearing at its center, an end plate fixed to the frame, and an upright position on the end plate. A fixed scroll having a spiral wrap, and an orbiting scroll having a mirror plate, a spiral wrap standing on one surface of the mirror plate, and a boss standing on the other surface, In the scroll compressor, the fixed scroll and the orbiting scroll are assembled by engaging the wraps with each other, and the boss of the orbiting scroll is fitted with the drive device provided on the rotary shaft of the electric element. The device is a balance weight fitted to the step of the rotating shaft to cancel the unbalanced force of the orbiting scroll, and the balance weight is superposed on the balance weight. An eccentric bush to be fitted to the screw portion, a bolt for fixing the eccentric bush to the rotating shaft, a bearing and a seal member provided between the boss portion of the orbiting scroll and the eccentric bush, and the seal member. A step surface is formed on the outer peripheral surface of the corresponding eccentric bush.

[0007]

The present invention is constructed as described above,
While one side of the step of the eccentric bush constitutes the optimum contact surface with the bearing, the other side of the step can ensure the optimum contact dimension in the natural state of the seal member, improving the sealing performance of the seal member. It is possible to prevent foreign matter from entering the bearing, and maintain smooth sliding with the bearing to prevent power loss.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a sectional view of an oilless scroll type air compressor showing an embodiment of the present invention. FIG. 2 is a sectional view of the main part of the drive device.

Reference numeral 1 denotes a scroll type air compressor, which is composed of an upper scroll compression element 2 and a lower electric element 3. Scroll compression element 2
Is composed of a frame 5 having a main bearing 4 in the center, a fixed scroll 6 fixed to the frame, and an orbiting scroll 7 sandwiched between the fixed scroll and the frame.

The fixed scroll 6 has a disk-shaped end plate 8, an annular wall 9 projecting from the peripheral edge of one end of the end plate, and a spiral wrap 1 erected on the end plate 8 surrounded by the annular wall.
It is composed of 0 and. The fixed scroll 6 has the annular wall 9 and the wrap 10 protruding downward.

The orbiting scroll 7 has a disk-shaped end plate 11,
A spiral wrap 12 erected on one surface of this end plate
And the boss portion 13 protruding in the center of the other surface of the end plate 11.
It consists of and. The orbiting scroll 7 has the wrap 12 projecting upward.

The fixed scroll 6 and the orbiting scroll 7 are formed such that the wraps 10 and 12 face each other and engage with each other to form a plurality of compression spaces 14 therein.

The electric element 3 has a motor cover 15 fixed to the frame 5, a stator 16 fixed in the motor cover, and a rotor 17 arranged inside the stator.
And a rotary shaft 18 inserted in the center of the rotor. The motor cover 15 is provided with an auxiliary bearing 19 that supports the rotating shaft.

The main bearing 4 has an inner ring 21 fitted to the step portion 20 of the rotary shaft 18 and an outer ring 22 fixed to the frame 5.
And a ball 23 provided between the outer ring and the inner ring
A ball bearing 24 constituted by is attached.

Reference numeral 25 is a drive unit for transmitting the rotational force of the electric element 3 to the orbiting scroll 7, and this drive unit balances the unbalanced force of the orbiting scroll 7 with a balance weight 26.
And an eccentric bush 2 which is inserted into the boss hole 27 of the boss portion 13 of the orbiting scroll to revolve the orbiting scroll 7.
8, a pin 29 for positioning the eccentric bush and the balance weight, and a bolt 30 for fixing the eccentric bush 28 to the rotating shaft 18.

The fixed scroll 6 has a suction hole 31 communicating with the outer compression space 14 in the annular wall 9 and a discharge hole 32 communicating with the compression space 14 in the center of the end plate 8. A needle bearing 33 and a seal member 34 are provided between the boss portion 13 of the orbiting scroll 7 and the eccentric bush 28. Further, the cylindrical outer peripheral surface of the eccentric bush 28 has an outer peripheral surface 35 corresponding to the needle bearing 33 formed in a large diameter with the annular groove 37 interposed therebetween, while an outer peripheral surface 36 corresponding to the seal member 34 is formed. It is formed to have a small diameter, and the outer peripheral surface 36 having the small diameter serves as a step surface.

When the electric element 3 is rotated in the scroll type air compressor constructed as described above, the rotational force is transmitted to the orbiting scroll 7 through the rotary shaft 18.
That is, the orbiting scroll 7 is driven by the eccentric bush 28 of the drive device 25 attached to the rotary shaft 18 inserted into the boss hole 27 of the boss portion 13 of the scroll, and is fixed to the fixed scroll 6 by the Oldham coupling (not shown). On the other hand, it can revolve around a circular orbit so that it does not rotate. Then, the fixed scroll 6 and the orbiting scroll 7 gradually reduce the compression space 14 formed by these scrolls from the outside to the inside, and compress the air flowing in from the suction hole 31. The compressed air is discharged from the discharge hole 32 of the end plate 8 of the fixed scroll 6.

The order of assembling the drive unit 25 will be described. First, the frame 4 is fixed to the motor cover 15 in which the electric element 3 is incorporated. At this time, a ball bearing 24 is incorporated in the main bearing 4 of the frame 4. In this state, the balance weight 26 moves the inner ring 21 of the ball bearing 24.
Is inserted into the rotary shaft 18 so as to come into contact with. A pin 29 is set on the balance weight 26 inserted on the rotary shaft. Then, the eccentric bush 28 is inserted into the rotary shaft 18 so as to fit into the pin 29. Finally the bolt 30
The eccentric bush 28 is fixed to the rotary shaft 18. At this time, the boss portion 13 of the orbiting scroll 7 and the eccentric bush 28
In between, the needle bearing 33 and the seal member 34 are set. That is, the large-diameter outer peripheral surface 3 of the eccentric bush 28
5 is set at a position corresponding to the needle bearing 33, and the small-diameter outer peripheral surface 36 of the eccentric bush 28 is set at a position corresponding to the seal member 34. And
Inner ring 21 of ball bearing 24 and balance weight 2
6 is pressed and fixed to the step portion 20 of the rotary shaft 18 by the tightening force of the bolt 30 for fixing the eccentric bush 28 to the rotary shaft 18. As a result, the drive device 25 has one bolt 30
Securely fixed with.

Balance weight 26 and eccentric bush 28
By positioning with the pin 29, the unbalanced force generated by the orbiting of the orbiting scroll 7 during operation is reliably canceled by the balance weight 26.

Further, since the drive device 25 is fixed to the rotary shaft 18 with a single bolt 30, the work of attaching each component is eliminated, and the assembling process can be simplified.

According to the present invention, the drive device 25 for transmitting the rotational force of the electric element 3 to the orbiting scroll 7 is formed by the rotary shaft 18, the balance weight 26 and the eccentric bush 28 which are separate parts, and is assembled by the single bolt 30. By doing so, the assembling property and reliability of the drive device 25 can be improved.

As described above, in the scroll type air compressor of the present invention, the optimum axial dimension for the needle bearing 33 can be set to the large-diameter outer peripheral surface 35 of the eccentric bush 28.
The needle bearing 33 can be smoothly rotated and slid, and the power loss during the rocking operation of the rocking scroll 7 can be minimized.

Further, the power loss caused by mounting the seal member 34 on the lower side, which is the release side of the needle bearing 33, causes a small diameter of the eccentric bush 28, which is a diameter close to the inner diameter of the seal member 34 in the natural state. It can be reduced by the outer peripheral surface 36, and heat generation due to friction can be suppressed.

Also, the eccentric bush 28, which is an existing component, is used.
Since the large-diameter and small-diameter outer peripheral surfaces 35 and 36 are formed by using the, the number of parts does not increase, and the power loss is reduced and the heat generation is suppressed while maintaining the assembly workability of the compressor in a simple state. Can be promoted.

Further, even if the orbiting scroll 7 receives a rollover moment during the compression process, the seal member 3
Since the sliding surface of 4 and the eccentric bush 28 are in light contact with each other, the elastic force of the seal member 34 acts in a direction to suppress the overturning, and the overturning of the orbiting scroll 7 can also be suppressed.

[0027]

As described above, according to the present invention, one surface of the step of the eccentric bush constitutes the optimum contact surface with the bearing, while the other surface of the step has the optimum contact dimension in the natural state of the seal member. Therefore, it is possible to improve the sealing performance of the seal member and prevent foreign matter from entering the bearing, while maintaining smooth sliding between the bearing and power loss.

[Brief description of drawings]

FIG. 1 is a sectional view of a scroll type air compressor showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of a drive device according to the present invention.

[Explanation of symbols]

 2 Scroll compression element 3 Electric element 4 Main bearing 5 Frame 6 Fixed scroll 7 Oscillating scroll 8, 11 End plate 10, 12 Wrap 25 Drive device 26 Balance weight 28 Eccentric bush 29 Pin 30 Bolt 33 Needle bearing 34 Seal member 35 Large diameter Outer peripheral surface 36 Small diameter outer peripheral surface 37 Annular groove

Claims (1)

[Claims] 1. A scroll compression element and an electric element, the scroll compression element having a frame having a bearing in the center, an end plate fixed to the frame, and a spiral wrap standing on the end plate. A fixed scroll, an end plate and an orbiting scroll having a spiral wrap standing on one surface of the end plate and a boss standing on the other surface of the end plate. In a scroll compressor in which wraps are assembled by interlocking with each other, and a drive device provided on a rotary shaft of an electric element is fitted to a boss of the orbiting scroll,
The drive device includes a balance weight fitted to a stepped portion of a rotary shaft to cancel an unbalanced force of the orbiting scroll, an eccentric bush fitted to the balance weight and fitted to a boss portion of the orbiting scroll, and the eccentric bush. Has a bolt for fixing to the rotating shaft, a bearing and a seal member provided between the boss portion of the orbiting scroll and the eccentric bush, and a step surface is provided on the outer peripheral surface of the eccentric bush corresponding to the seal member. A scroll type air compressor characterized by being formed.