JP2002155861A - Bearing, method of manufacturing the same, and refrigerant compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in performance or deterioration in reliability by preventing a chipping in a mating part of a bush in fitting the bush into a bearing member to be finished. SOLUTION: Sliding bearings (bearings) 12b and 13b molded in a cylindrical form are cut in a specified length, chamfered properly, and then fitted into the shaft bearing member. Their surface is then removed for proper quantity by cutting work to be finished to specified size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bearing having a bush, and more particularly to a bearing for a refrigerant compressor used in a refrigerator such as an air conditioner or a refrigerator.

[0002]

2. Description of the Related Art There are various types of refrigerant compressors used for air conditioners and refrigerators. Recently, scroll compressors having low vibration noise and excellent performance have been widely used. ing.

FIG. 4 shows the structure of a general scroll compressor. In FIG. 4, reference numeral 2 denotes a fixed scroll. A substantially involute wrap 6 is formed upright on one surface of the end plate 4, and a discharge port 16 is disposed at the center. Reference numeral 3 denotes an orbiting scroll, which has a substantially involute-shaped wrap 7 formed upright on one surface of a head plate 5, and has a bearing portion 12 on the other surface of the head plate 5. The fixed scroll 2 and the orbiting scroll 3 engage with each other with the wraps 6 and 7 facing inward to form a crescent-shaped compression chamber. Orbiting scroll 3 is frame 11
Is prevented from rotating by being connected to the eccentric portion 1 of the rotary shaft 10 by the
0a via a bearing 12a.

The rotating shaft 10 is fixed to the rotor of the electric motor 14 and rotates together with the rotor.
Is eccentrically engaged with the rotating shaft 10 and is restricted from rotating, so that the fixed scroll 2 performs a revolving motion (rotating motion) without rotating.
As a result, the crescent-shaped compression chamber formed by the fixed scroll 2 and the orbiting scroll 3 moves while compressing the refrigerant by gradually reducing the volume from the outer peripheral side toward the center with the rotation of the rotating shaft 10. Has become.

The rotating shaft 10 is arranged in a vertical direction, and the sliding portions 10b and 10c are supported by slide bearings 12a and 13a. A load is applied to the eccentric portion 10a by a fluid pressure in a radial direction perpendicular to the eccentric direction. Works. On the other hand, the rotating shaft 10 is configured to be able to move by a small amount in the radial direction within a range of a gap existing between the rotating shaft 10 and the sliding bearings 12a and 13a.
When a load in the radial direction is applied by the fluid pressure in such a state, the rotating shaft 10 moves between the upper sliding bearing 12a supporting the sliding portion 10c and the lower sliding bearing 13a supporting the sliding portion 10b. And each sliding bearing 1
It rotates while being strongly pressed against the 2a and 13a in a single contact state. As a result, the sliding bearings 12a, 1
3a receives a load exceeding the oil film reaction force of the lubricating oil,
Sliding may occur in the absence of lubricating oil between the rotating shaft.

The rotating shaft 10 and the sliding bearings 12a,
If the gap size with 3a is too large, the performance is degraded due to the leakage of the compressed gas and the vibration noise is increased. If the gap size is too small, the frictional loss of the sliding portion is increased. Further, the surface condition (surface roughness, etc.) of the bearing and the rotating shaft also affects reliability and performance.

For this reason, the sliding bearings 12a and 13a have wear resistance which does not cause seizure or wear even under severe lubrication conditions.
Workability for realizing the optimum gap size is required.
In order to satisfy such requirements and to be inexpensive, many refrigerant compressors are now manufactured by combining a metal substrate (back metal) with a resin material with excellent wear resistance and self-lubricating properties. A wound bush formed into a shape is employed as a plain bearing.

[0008]

A conventional wound bush is manufactured by cutting a plate-shaped back metal having a resin material bonded thereto into a predetermined length, and joining the cut portions to form a cylindrical shape. . The rolling bearing is completed by press-fitting the wound bush into a cylindrical space provided in the bearing member and polishing and finishing the inner peripheral surface. In the case of such a process, a minute crack C as shown in FIG. 1 (b) may be formed in the resin material portion when a material obtained by bonding a resin material to a flat back metal is cut to a predetermined length. The micro-cracks C proceed due to the stress applied in the subsequent press-fitting into the bearing member and the inner peripheral surface polishing and finishing step, resulting in large cracks E as shown in FIG. F occurs. As a result, a part of the chipped resin layer becomes a foreign substance and bites into the sliding portion, impairing the function as a bearing, or flowing out during the refrigeration cycle when used as a bearing for a refrigerant compressor. Can cause clogging.

Further, since the surface accuracy is deteriorated due to the advanced cracks and chips on the inner diameter of the bush, the inner diameter changes, and the clearance with the rotating shaft changes from the set value. As a result, performance and reliability are reduced.

According to the present invention, when a bush is press-fitted into a bearing member and finished, the bush joint portion is prevented from being chipped.
An object of the present invention is to provide a bearing excellent in performance and reliability and a refrigerant compressor provided with the bearing.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, a plain bearing according to the present invention is obtained by cutting a plate-like back metal with a resin material bonded to a predetermined length, and then cutting the flat back metal into cut portions at both ends. The microcracks are completely removed by chamfering to the backing metal as shown in FIG. 1 (c), and then molded into a cylindrical shape, and the mold is again formed into a cylindrical shape with the cut portions at both ends facing each other. A pressed winding bush is formed, the winding bush is pressed into a bearing member, and then the surface thereof is removed by an appropriate amount by polishing or the like to finish it to a predetermined size.

Thus, even if a stress is applied to the butted portion when a resin material is bonded to a flat back metal to form a cylinder or press-fit a bearing member, minute cracks are completely removed. Therefore, no cracks or chips are generated, so that the clearance with the rotating shaft can be maintained at the set value, and a decrease in performance and reliability can be prevented.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is directed to cutting a composite material obtained by bonding a polyimide resin or a polyamide resin mixed with graphite as a flexible self-lubricating material to a flat back metal to a predetermined length. A bearing for finishing the surface after press-fitting a bearing bush formed into a cylindrical shape into a bearing member, and in a state before the composite is formed into a cylindrical shape, the cutting portion is made of a self-lubricating material. It is chamfered from the side to the backing metal.Since minute cracks generated during cutting of the composite are completely removed by chamfering, when forming into a cylindrical shape or pressing into a bearing member Even when a stress is applied to the joint, there is an effect that cracks or chippings in which minute cracks grow do not occur.

The present invention also relates to a method of manufacturing the above-mentioned bearing, which comprises forming a flat composite into a cylindrical shape, and then embossing the flat composite into a cylindrical shape with the cut portions joined again. By performing the shaping into a shape in two stages, the stress applied to the joint at one time can be reduced, and a bearing bush of higher quality can be manufactured.

The present invention also relates to a method of manufacturing the above bearing, in which a bearing bush is press-fitted into a bearing member, and then subjected to a heat treatment and then to a finishing process. The heat treatment removes residual stress. Therefore, it has the effect that cracking, chipping and deformation due to subsequent finishing can be more effectively prevented.

Further, the present invention provides a refrigerant compressor in which a rotary shaft is supported by using the above-mentioned bearing, and has an effect that a refrigerant compressor excellent in abrasion resistance of a sliding portion can be manufactured at a low cost. . In particular, by using this bearing in a scroll-type refrigerant compressor (scroll compressor), even if the bearing configuration supports the rotating shaft with a radial load in a one-sided state, the surface accuracy of the bushing can be improved. Is stable, which is effective in improving performance and reliability.

Further, the present invention uses an HFC refrigerant containing no chlorine as the refrigerant in the above-mentioned refrigerant compressor, and has sufficient durability even when using an HFC refrigerant which does not contain chlorine and has poor lubricity. It has the effect that a refrigerant compressor can be obtained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bearing according to an embodiment of the present invention and a refrigerant compressor provided with the bearing will be described below with reference to the drawings.

(Embodiment 1) FIG. 3 is a sectional view showing the structure of a scroll compressor having a bearing according to an embodiment of the present invention.

The fixed scroll 2 and the orbiting scroll 3 are engaged with each other with disk-shaped end plates 4 and 5 and spiral wraps 6 and 7 formed upright on the end plates 4 and 5 facing inward. A bearing portion 12 is formed on the orbiting scroll 3 below the end plate 5. The bearing portion 12 is engaged with the eccentric portion 10a of the rotating shaft 10 via a bearing 12a. The sliding portions 10b and 10c of the rotating shaft 10 are supported by an upper sliding bearing 12b and a lower sliding bearing 13b press-fitted into the bearing member 11. Due to the rotation of the rotating shaft 10, the orbiting scroll 3 is prevented from rotating by the Oldham ring 15, and orbits. In the above configuration, the gas is sucked and compressed into the fixed scroll 2 and the orbiting scroll 3 by the orbiting motion, is discharged from the discharge port 16 into the closed container 17, and is discharged from the discharge pipe 18. The lubricating oil in the oil reservoir 23 at the lower part of the closed casing 1 is supplied to the slide bearings 12b and 13b via the hole of the rotating shaft 10. The orbiting scroll 3 and the rotating shaft 10 are compressed by the action of compressing the fluid (gas) trapped by the fixed scroll 2 and the orbiting scroll 3.
The load acting on the sliding portions 10b and 10c through the eccentric portion 10a is received by the sliding bearings 12b and 13b.

Here, the sliding bearings 12b and 13b are manufactured as follows. First, as shown in FIG. 1A, a flat back metal 19 made of an iron plate (SPCC) or the like is used.
Bronze powder and the like are solidified and sintered on the surface of the
Further, a resin 21 such as polyimide or polyamide imide mixed with graphite 20 is impregnated thereon and fired (connected). After that, the part is cut to a predetermined length, and a portion from the cut portion to the back metal is chamfered along a plane D indicated by a dotted line in FIG. 1 (b), and a cylinder is formed as shown in FIG. 2 (a). Mold into a shape. FIG. 2B is an enlarged view of a main part of the joint.

Then, the slide bearings 12b and 13b are press-fitted into the bearing member 11, an appropriate amount of the inner surface is removed by cutting, and the slide bearings 12b and 13b are finished to predetermined dimensions according to the rotating shaft 10.

By performing chamfering to the back metal at the cut portion of the composite in which the back metal and the resin as the self-lubricating material are bonded as described above, minute cracks remaining in the resin 21 at the cut portion can be reliably prevented. When the plain bearings 12b and 13b are pressed into the bearing member or when the inner surface is removed by an appropriate amount, chipping due to the growth of minute cracks can be prevented, and stable performance and reliability can be secured. .

In this embodiment, the wound bush has been described. After being formed into a cylindrical shape, the bearing bush, which has been re-pressed into a cylindrical shape with the cut portions joined, is press-fitted into the bearing member and finished. Similar effects can be obtained for a formed bearing or a bearing that has been subjected to a heat treatment in advance to remove residual stress.

[0025]

As is apparent from the above description, according to the present invention, since the winding bush does not chip, a change in the surface accuracy of the bearing and the clearance with the rotating shaft can be maintained at the set values, so that a good lubricating state can be obtained. , And stable performance and reliability of the compressor can be improved.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view showing a composite before being formed into a cylindrical shape in the bearing of the present invention. (B) A of a composite cut portion before chamfering in FIG.
Part enlarged view (c) A of the composite cut part after chamfering in FIG.
Enlarged section

FIG. 2 (a) is a view showing a state in which the composite in the bearing of the present invention is formed into a cylindrical shape.

FIG. 3 is a sectional view showing a configuration of a refrigerant compressor of the present invention.

FIG. 4 is a sectional view showing a configuration of a conventional refrigerant compressor.

FIG. 5 is an enlarged view of a composite joint in a conventional bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite body which combined back metal and self-lubricating material 2 Fixed scroll 3 Orbiting scroll 10 Rotating shaft 10a Rotating shaft eccentric portion 10b Rotating shaft sliding portion 10c Rotating shaft sliding portion 11 Bearing member 12a Sliding bearing (conventional example) 13a Plain bearing (conventional example) 12b Plain bearing (example) 13b Plain bearing (example) 19 Back metal 20 Graphite 21 Synthetic resin C Micro crack

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[Procedure amendment]

[Submission date] December 5, 2000 (200.12.
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 7

[Correction method] Change

[Correction contents]

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Takuji Sasa 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Masahiro Tsubokawa 1006 Kadoma Kadoma, Kadoma City Osaka Pref. Terms (reference) 3H003 AA05 AB03 AC03 AD03 CA02 CE05 3H029 AA02 AA14 AB03 BB31 BB32 CC08 CC17 CC39 3H039 AA03 AA06 AA12 BB07 BB08 CC09 CC19 CC35 3J011 AA06 BA02 BA15 DA02 KA02 MA02

Claims (8)

[Claims] A bearing bush formed by cutting a composite body in which a self-lubricating material having flexibility is bonded to a flat back metal into a predetermined length and forming the same into a cylindrical shape is pressed into a bearing member. In the state before the composite is formed into a cylindrical shape, the cut portion is chamfered from the side of the self-lubricating material to the back metal. bearing. 2. The self-lubricating material is a polyimide resin mixed with graphite, or a polyamideimide resin mixed with graphite.
The bearing described. 3. A composite in which a flexible self-lubricating material is bonded to a plate-like backing metal is cut to a predetermined length, and the composite cutting portion extends from the side of the self-lubricating material to the backing metal. And forming the composite into a cylindrical shape to form a bearing bush, press-fitting the bearing bush into a bearing member, and finally finishing the surface. 4. The method for manufacturing a bearing according to claim 3, wherein the flat composite is formed into a cylindrical shape, and then, the flat composite is stamped into a cylindrical shape with the cut portions joined again. Bearing manufacturing method. 5. The method for producing a bearing according to claim 3, wherein after the bearing bush is press-fitted into the bearing member, heat treatment is performed, and then finishing is performed. 6. A refrigerant compressor, wherein a rotary shaft is supported by using the bearing according to claim 1. 7. A scroll-type refrigerant compressor, wherein an eccentric portion of a rotary shaft is supported by using the bearing according to claim 1. 8. The refrigerant compressor according to claim 6, wherein an HFC refrigerant containing no chlorine is used as the refrigerant.