JP2519724Y2 - Bush of scroll compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a bush for supporting a movable scroll of a scroll compressor.

[Prior Art] In a scroll type compressor, as shown in FIG. 5, a front housing 1 and a rear housing 2 are joined and fixed by sandwiching an annular fixed substrate 3, and a rotary shaft housed in the front housing 1. At the eccentric position of the end surface of the large diameter portion 4a of 4,
An eccentric shaft 5 is projectingly provided in the rear housing 2. A balance weight 6 and a bush 7 are rotatably supported on the eccentric shaft 5, and a movable scroll 8 is rotatably supported on the bush 7 via a radial bearing 12. A fixed scroll 9 is fixed in the rear housing 2 so as to face and abut the movable scroll 8.
The base end walls 8a, 9a and the spiral portions 8b, 9b form a compression chamber.

A fixed ring 10 is fixed to the fixed base plate 3 facing the movable scroll 8, and a plurality of circular revolution position restriction holes 10a are formed in the fixed ring 10 at equal intervals. The revolving position regulating hole 10 is provided on the base end wall 8a of the movable scroll 8.
A movable ring 11 having the same number of circular revolution position restricting holes 11a facing the a is fixed. Revolution position control hole 10
A shoes 11a, 13b having a smaller diameter than this are housed in a, 11a, and a ball 14 is interposed between the opposing shoes 13a, 13b, and rotation preventing holes 10a, 11a, shoes 13a, 13b, and balls 14 prevent rotation. A revolution mechanism having a function is configured, and the movable scroll 8 revolves with respect to the rotation of the rotating shaft 4 without rotating. Then, the refrigerant gas introduced into the suction chamber 1b from the inlet 1a of the front housing 1 is sucked into the suction passage 3a and both rings 1
The discharge chamber 2a in the rear housing 2 is discharged from the discharge port 9c in which the refrigerant gas compressed between the scrolls 8 and 9 enters into the compression chamber through 0 and 11 and is opened by the discharge valve 15.
Is discharged to.

The movable scroll 8 revolves around the axis of the rotary shaft 4 as the eccentric shaft 5 revolves as the rotary shaft 4 rotates, thereby contacting the spiral portion 9b of the fixed scroll 9. The force acting on the bush 7 via the movable scroll 8 is the largest force acting in parallel with the straight line connecting the center of the bush 7 and the center of the eccentric shaft 5. Now, in the state shown in FIG. 6, the compression chambers C1, C2,
A large force acts from C3 in the direction shown by the arrow. When the rotary shaft 4 rotates 180 degrees from the state shown in FIG. 6, the position of the eccentric shaft 5 also changes from the position shown in FIG. 6 as shown in FIG.
The position is rotated by 180 degrees, and in this case, the direction of the force that largely acts on the spiral portion 8b from the compression chambers C1 and C2 is also the direction toward the eccentric shaft 5. That is, the bush 7 always receives a large force from a certain direction.

[Problems to be Solved by the Invention] As described above, in the scroll compressor, the bush 7 supporting the movable scroll 8 receives a large force from a certain direction, and the radial bearing 12 rotates in that state.
The outer peripheral surface of the bush 7 is susceptible to flaking. In order to suppress flaking of the bush 7, the hardness of the outer peripheral surface of the bush 7 needs to be Vickers hardness Hv750 or more. Conventionally, the hardness of the bush 7 has been increased by quenching iron, but in quenching, the quenching conditions, that is, heating temperature and time, cooling temperature and time, have a great influence on the hardness, and the quality is kept constant. It is difficult to manufacture and mass production is difficult.

Further, it is conceivable to form the entire bush 7 with a sintered material in order to increase the hardness. When the bush 7 is made of a sintered material, stable hardness can be ensured by only controlling the sintering temperature to a predetermined temperature or higher without strict temperature control. As shown in FIG. 8, the bush 7 has a hole 7a for fitting the eccentric shaft 5 formed at an eccentric position, and the diameter of the hole 7a and the distance between the center O1 of the bush 7 and the center O2 of the hole 7a, that is, the pitch P The value greatly affects the compression efficiency of the scroll compressor. When the bush 7 is formed of a sintered material, the hole 7a is formed in advance in consideration of shrinkage after sintering, and a die-cut product having a predetermined shape is sintered and then finished. However, the shrinkage rate of the sintered material during sintering is unstable, and the pitch P may shift. After sintering
It is not so difficult to grind the outer peripheral surface of the bush 7 into a predetermined size, but when the pitch P is deviated, it is extremely difficult to accurately process the inner diameter of the hole 7a and the pitch P into a predetermined size. . Therefore, when the entire bush 7 is made of a sintered material, there is a problem that the yield is very low.

The present invention has been made in view of the above problems, and an object thereof is to secure the hardness of the outer peripheral surface, easy to process, has good dimensional accuracy, and is suitable for mass production. To provide a bush for the machine.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a fixed scroll is housed in a housing, and an eccentric shaft is planted on a rotary shaft rotatably supported by the housing.
In a scroll compressor in which a movable scroll supported non-rotatably with respect to the fixed scroll is rotatably fitted to a bush having an eccentric hole rotatably inserted in the eccentric shaft, The outer peripheral portion was formed of a ring-shaped sintered material, and the sintered material had a Vickers hardness of 750 or more.

[Operation] Since the outer peripheral portion of the bush of the present invention, which requires hardness, is made of a sintered material and has high hardness, flaking is prevented even if an unbalanced load is applied to the bush. Further, since the portion where the hole into which the eccentric shaft is inserted is formed is a normal material that is not a sintered material, it is easy to manufacture the position and diameter of the hole with high precision, which is suitable for mass production.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. The bush 7 has a hole 7a into which the eccentric shaft 5 is fitted.
It is formed of a central member 16 in which is formed and a ring 17 fitted to the outer peripheral portion thereof. SU as the material of the center material 16
High carbon chrome bearing steel such as J2 material is used, ring 17
Is made of a sintered material having a hardness of Hv900 or higher.

Next, a method of manufacturing the bush 7 will be described. A high carbon chrome bearing steel (SUJ2 material) is machined to form a disk having a predetermined diameter, and then a hole 7a having a predetermined diameter is drilled at a predetermined position to form a center material 16. Next, after putting the center material 16 in the mold and filling the outer peripheral portion with the sintered material,
Die cutting is performed and sintering is performed at a predetermined temperature. The sintering contracts the sintered material to form a ring 17 that is tightly fitted to the outer periphery of the center material 16. Although the sintered material largely contracts during sintering, the central material 16 does not contract, and the diameter of the holes 7a and the pitch P do not change. After sintering, the outer peripheral surface of the ring 17 is polished and processed into a predetermined size, and the production of the bush 7 is completed.

By using this bush 7, the eccentric shaft 5 and the movable scroll 8 are accurately assembled in a predetermined positional relationship,
There is no reduction in compression efficiency due to the displacement between the movable scroll 8 and the fixed scroll 9. Further, the outer periphery of the bush 7 has a large hardness, flaking is suppressed even if an unbalanced load is applied to the bush 7, and the durability of the bush 7 is improved and the reliability and durability of the compressor are also improved.

FIG. 3 shows the results of measuring the time until flaking occurred using the bush 7 with various hardness of the ring 17 under the following operating conditions.

Compressor operating conditions Discharge pressure 26-28 kg / mm ² Suction pressure 3-4 kg / mm ² Rotational speed 1200 rpm As a result of the bush durability test, the hardness of the ring 17, that is, the hardness of the bush outer peripheral surface is Vickers hardness Hv750 or more. If so, it was confirmed that flaking does not occur even after running for 1500 hours, which is a practically required durability time.

The present invention is not limited to the above embodiment, and for example, as shown in FIG. 4, a recess 16a is formed in a part of the outer peripheral surface of the central member 16, and the ring 17 is fitted with the recess 16a. It is also possible to provide a convex portion 17a for preventing the slip-off. Further, the hole 7a of the bush 7 may be processed after the ring 17 is sintered.

[Advantages of the Invention] As described in detail above, according to the present invention, since the outer peripheral portion of the bush is formed of a sintered material having a Vickers hardness of Hv750 or more, flaking due to an unbalanced load can be suppressed. In addition to improving the durability of the bush, the reliability and durability of the compressor are also improved. Further, since the portion where the hole into which the eccentric shaft is inserted is formed of a material that can be easily machined, it is possible to accurately form the hole diameter, pitch, etc. It is possible to reliably prevent a decrease in compression efficiency, improve product yield, and mass-produce at low cost.

[Brief description of drawings]

1 to 3 show an embodiment embodying the present invention. FIG. 1 is a front view, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. A diagram showing the relationship between surface hardness and flaking occurrence time, FIG. 4 is a cross-sectional view of a modified example,
FIG. 5 is a vertical cross-sectional view of the scroll compressor, and FIG.
FIG. 7 is a sectional view taken along the line VI-VI in FIG. 7, FIG. 7 is a view showing the relationship between the movable scroll and the fixed scroll in a state where the rotary shaft is rotated by 1/2 rotation from the state in FIG. 6, and FIG. It is a figure. Front housing 1, rear housing 2, rotary shaft 4,
Eccentric shaft 5, bush 7, hole 7a, movable scroll 8, fixed scroll roll 9, central member 16, recess 16a, ring 17, protrusion 1
7a, pitch P.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsushi Mori 2-chome, Toyota-cho, Kariya city, Aichi Inside Toyota Industries Corporation (56) References JP-A-63-45485 (JP, A) JP 58-49715 (JP, B2)

Claims (1)

(57) [Scope of utility model registration request] 1. A fixed scroll is housed in a housing,
An eccentric shaft is planted on a rotary shaft that is rotatably supported by the housing, and a bush having an eccentric hole that is rotatably inserted in the eccentric shaft is non-rotatably supported by the fixed scroll. In a scroll compressor in which a movable scroll is rotatably fitted, an outer peripheral portion of the bush is formed of a ring-shaped sintered material, and the sintered material has a Vickers hardness of 750 or more.