JPH0777176A - Drive bush for scroll type fluid machinery - Google Patents

Abstract

PURPOSE:To dispense with the machining mainly causing cost rise of a slide hole to reduce the manufacturing cost of a drive bush by forming the body of the drive bush of iron system sintered material to keep the slide hole of the drive bush in a sintered state, and finishing the original periphery of the drive bush through the machining after hardening. CONSTITUTION:In a scroll type hydraulic machine, a fixed scroll 4 having a lap 2 and a peripheral wall 3 which are risingly provided on an end plate 1 and a turning scroll 7 having a lap 6 risingly provided on an end plate 5 are joined together to compose a compressor section 8 to partition a closed space 9. An eccentric pin 12 to form the axial end of a rotary shaft 11 is fittedly inserted in the boss 10 of the turning scroll 7. Namely, a drive bush 15 is fittedly inserted in the boss 10, and the eccentric pin 12 is fittedly inserted in the slide hole 16 of the drive bush 15. In this case, the body 15a of the drive bush 15 is formed of iron system sintered material. The slide hole 16 is kept in a sintered state, and the outer periphery of the body 15a is finished by machining after hardening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive bush for a scroll type fluid machine used in a scroll type fluid machine constructed by combining a turning scroll and a fixed scroll.

[0002]

2. Description of the Related Art In an air conditioner, a scroll type compressor (scroll type fluid machine) has recently been adopted because of the advantage that it can perform efficient compression. As shown in FIGS. 3 and 5, the scroll type compressor includes a fixed scroll 4 having a spiral wrap 2 on an end plate 1 and a peripheral wall 3 surrounding the wrap 2, and an end plate 1. It has a scroll type compressor section 8 in which a swirl scroll 7 formed by standing a spiral wrap 6 on the plate 5 is combined.

Normally, the compressor section 8 has both scrolls 4 and 7.
The respective wraps 4 and 7 are combined so as to be engaged with each other while being displaced by a predetermined angle, to form a closed space 9 for performing a compression process between the wraps.

The volume of the closed space 9 is, for example, a cylindrical boss portion 10 provided on the rear surface of the swivel scroll 7, and an eccentric pin 12 at the tip of the rotary shaft 11 and constituting an axial end portion.
By adopting an eccentric rotation structure such as inserting and revolving, the revolving scroll 7 revolves around the axis of the fixed scroll 4 so as to gradually decrease from the peripheral side toward the center. .

That is, the scroll compressor is adapted to compress the gas by utilizing the change in the volume of the closed space 9. Although not shown, the turning scroll 7 is provided with a rotation preventing mechanism such as an Oldham ring that regulates the rotation of the turning scroll 7.

In the scroll type compressor, in order to suppress the leakage of gas from the closed space 9, a back pressure chamber 13 is provided on the back side of the fixed scroll 4, and the fixed scroll 4 is swung. -Axial force is applied to the scroll 7, or a back pressure chamber (not shown) is provided on the back side of the swivel scroll 7, and conversely the swivel scroll 7 is fixed to the fixed scroll 4. In the direction of the arrow to seal between the lap end and the inner surface of the end plate.
Is being done.

Further, in the scroll type compressor, in order to improve the performance of the compressor, the turning radius of the turning scroll 7 is made variable. That is, in the scroll type compressor, when the eccentricity r of the swivel scroll 7 is set so that the radial gap between the laps becomes 0, the shape accuracy of the fixed scroll 4 and the swivel scroll 7 is set. Depending on the situation, excessive force may be applied to the bearing portion. If such an unreasonable force is applied, there is a possibility that the bearing portion may have a problem such as seizure.

Therefore, conventionally, the eccentricity r of the turning scroll 7 is made variable by using the cylindrical drive bush 15. Specifically, the structure shown in FIGS. 3 and 4 is adopted.

That is, a flat surface portion 12a is formed on the outer periphery of the eccentric pin 12. In addition, the drive bush 15
It has an outer shape that can be inserted into the boss portion 10, and has a slide hole 16 in which a flat surface portion 16a extending in the radial direction is formed inside. The slide hole 16 is set to be slightly larger than the eccentric pin 12.

The drive bush 15 is rotatably fitted in the boss portion 10 via a swivel bearing 17. The eccentric pin 12 is fitted into the slide hole 16 of the drive bush 15 in such a manner that planes of the eccentric pin 12 and the slide hole 16 are combined with each other. In contrast, it is connected so that it can slide in the radial direction and does not rotate.

With this structure, at the time of turning scroll turning,
The revolving scroll 7 is pressed against the fixed scroll 4 by the component force F'of the synthetic force F of the generated gas load Fg and the centrifugal force Fc.

By this pressing, the gap in the radial direction between the laps is always set to 0 during operation, and problems such as a decrease in volumetric efficiency are solved. By the way, the drive bush 15 for varying the turning radius r of the turning scroll 7 has been conventionally manufactured by machining.

That is, the main body 1 of the drive bush 15
For 5a, a flat material is prepared by preparing a cylindrical material, performing hole processing so as to penetrate through the material in the axial direction, and broaching or endling the inner peripheral surface of the formed through hole. Are formed, the outer peripheral portion is finished by machining, and the inner and outer portions are subjected to surface treatment.

[0014]

However, in the drive bush 15, since the slide hole 16 is formed by a complicated broaching process or an end milling process in addition to the hole processing, the cost is considerably high. It was expensive. The present invention has been made in view of such circumstances, and an object thereof is to provide an inexpensive drive bush for a scroll type fluid machine.

[0015]

In order to achieve the above object, a drive bush for a scroll type fluid machine of the present invention is made of an iron-based sintered material, and its slide hole is kept in a sintered state. At the same time, the outer circumference was a bush that was machined after quenching.

[0016]

According to the drive bush for a scroll type fluid machine of the present invention, the shape of the slide hole, which causes the highest cost, is formed by diverting the material of the ferrous sintered material as it is. In other words, the drive bush is a machined part of which only the outer diameter is machined, so it is inexpensive.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the first embodiment shown in FIG. FIG. 1 shows the entire outer shape of the drive bush 15, which is the same as that described in the section “Prior Art” above.

The present invention is applied to this drive bush 15. That is, the main body 15a of the drive bush 15 is made of an iron-based sintered material.

The slide hole 16 of the main body 15a
The shape of (including the flat portion 16a) is formed in the sintered state. The outer peripheral shape of the main body 15a is finished by quenching an iron-based sintered material and then machining it for abrasion resistance.

The drive bush 15 is manufactured as follows. That is, the iron-based sintered material is used to form the main body 16a made of a cylindrical body having the slide hole 16 having the flat surface portion 16a. Then, the iron-based sintered material is hardened to improve wear resistance.

After that, the outer periphery of the main body 15a is machined to finish the outer periphery. That is, the shape of the slide hole 16 which is the main cause of high cost is formed by diverting the sintered state of the iron-based sintered material as it is.

That is, the drive bush 15 is a component machined only in the outer diameter portion. Therefore, the cost is considerably reduced and the drive bush 15 can be made inexpensive.

In the first embodiment, the flat surface portion 1 of one surface is
Although the present invention is applied to the drive bush 15 having the slide hole 16 in which 6a is formed, the drive bush 15 having the slide hole 16 in which two flat surfaces 16a are formed as shown in FIGS. 2 (a) and 2 (b). The present invention may be applied to the bush 15. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals and their description is omitted.

In the above-described embodiment, the drive bush used by being inserted into the boss portion of the orbiting scroll is used, but the drive bush is not limited to this, and it is fitted into a recess formed on the bearing side for receiving the orbiting scroll. It may also be applied to a drive bush used by inserting. In this case, although not shown, an eccentric pin (shaft end) is provided on the rear surface of the end plate of the swivel scroll, and the eccentric pin is slidable in the slide hole of the drive bush fitted in the recess. Is inserted into.

[0025]

As described above, according to the present invention, the drive bush is a component in which only the outer diameter portion is machined while the shape of the slide hole remains in the sintered state. That is,
Eliminates machining of slide holes, which was the main cause of high cost. Therefore, the cost is considerably reduced,
Drive bushes are cheaper.

[Brief description of drawings]

FIG. 1 is a perspective view showing an entire drive bush for a scroll type fluid machine according to a first embodiment of the present invention.

FIG. 2A is a plan view showing a drive bush for a scroll type fluid machine according to a second embodiment of the present invention together with a state in which an eccentric pin is fitted. FIG. 2B is a perspective view showing the entire drive bush for the same scroll type fluid machine.

FIG. 3 is a cross-sectional view for explaining a scroll type compressor in which a swivel radius of a swivel scroll is variable by a drive bush.

FIG. 4 is a cross-sectional view around the drive bush taken along the line AA in FIG.

FIG. 5 is a cross-sectional view showing a state in which wraps of a fixed scroll and a swivel scroll are engaged with each other.

[Explanation of symbols]

4 ... Fixed scroll 7 ... Rotating scroll
Reference numeral 10 ... Boss portion 11 ... Rotating shaft 12 ... Eccentric pin (shaft end portion) 15 ... Drive bush 15a ... Main body 16 ... Slide hole 16a ... Plane portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masumi Sekita 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Nagoya Research Laboratory

Claims (1)

[Claims] 1. A cylindrical main body having a slide hole having a flat surface portion extending in a radial direction on a part of an inner circumference, and the shaft end portion having a flat surface portion on a part of the outer circumference is flat in the slide hole. In a drive bush for a scroll-type fluid machine, in which the turning radius of the turning scroll is variable by using a slidable insertion in a radial direction so as to combine with each other, the main body is an iron-based sintered material. A drive bush for a scroll type fluid machine, characterized in that its slide hole is made in a sintered state and its outer periphery is finished by quenching and machining.