JP3139655B2 - Scroll compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly, to an improvement in a drive shaft and a drive bush.

[0002]

2. Description of the Related Art As a conventional scroll compressor, for example, a compressor disclosed in Japanese Utility Model Laid-Open No. 57-83291 is known. In this compressor, a fixed scroll made up of a fixed side plate and a fixed scroll is fixed in a housing, and a movable scroll made up of a movable side plate and a movable scroll is meshed with the fixed scroll by 180 ° out of phase with each other. A drive shaft is rotatably supported on the housing via a bearing, and an eccentric pin is implanted at the inner end of the large-diameter portion of the drive shaft. The eccentric pin is fitted with a drive bush that supports the orbiting scroll so that it can only revolve via a bearing in cooperation with the rotation prevention mechanism. Similarly, a counterweight is provided between the inner end of the large diameter portion and the drive bush. Are fitted.

In Japanese Patent Application Laid-Open No. 2-176179, a slide key is protruded from a drive shaft instead of the eccentric pin, and a drive bush fitted to the slide key is inclined in a direction opposite to the rotation of the drive shaft. A scroll type compressor slidable in a linear direction is disclosed. In this type of compressor, the rotation of the drive shaft is revolved by the drive bush or slide key and the anti-rotation mechanism of the movable scroll, whereby the compression chamber formed by the engagement of the fixed scroll and the movable scroll sequentially increases the volume. Since the refrigerant gas is moved toward the center while being reduced, the refrigerant gas is drawn into the compression chamber from the fluid suction port, and the refrigerant gas in the compression chamber is sequentially compressed and discharged to the discharge chamber. At this time, the counter weight is
The drive bush cancels out the eccentric moment received from the movable scroll and absorbs the dynamic imbalance of the movable scroll.

[0004] During this time, in order to secure a radial seal of the compression chamber, it is preferable that the orbiting scroll is urged in a direction to increase the orbital radius, and that the orbiting scroll is pressed against the fixed scroll of the fixed scroll. . Meanwhile, liquid compression,
It is preferable that the movable scroll be movable in the direction of reducing the orbital radius in order to avoid collision between the two spirals due to a slight difference in the relative positional relationship between the two spirals, the inclusion of foreign matter, and the like. For this reason, the present applicant has disclosed in
In No. 1, a compression in which the drive bush is always urged in the direction of increasing the orbital radius and is movable in the direction of decreasing the orbital radius by the elastic material having an urging force in the direction of increasing the orbital radius. Proposed machine. JP-A-2-1
A similar configuration is desirable in the compressor described in Japanese Patent No. 76179.

[0005]

However, even if an elastic member having a biasing force is provided in a direction to increase the orbital radius, a large amount of lubricating oil is present in the compression chamber at the time of starting or the like, and operation is performed at high speed. In such a case, the load in the direction of reducing the orbital radius temporarily becomes excessively large, and the displacement may not be enough for an elastic material that performs general elastic deformation. For this reason, in this case, both the spiral bodies are destroyed and the durability of the compressor is impaired.

SUMMARY OF THE INVENTION The present invention is intended to prevent the destruction of both spiral bodies even if the load in the direction of reducing the orbital radius becomes temporarily large while securing the radial seal of the compression chamber. Is an issue to be solved.

[0007]

[Means for Solving the Problems]

(1) In the scroll compressor of the present invention, in order to solve the above problems, a fixed scroll, a movable scroll that forms a compression chamber by meshing with the fixed scroll,
A drive shaft rotatably supported via a bearing and having an eccentric pin protruding at the inner end of the large-diameter portion, and fitted to the eccentric pin, cooperating with the rotation preventing mechanism to move the movable scroll through the bearing. A driving bush that is eccentric and supports only the revolution, and a counter weight that is disposed around the eccentric pin and absorbs a dynamic imbalance of the orbiting scroll; In a scroll type compressor that sucks gas and discharges the refrigerant by increasing the pressure of the refrigerant gas, a biasing force is provided between the drive shaft and the drive bush in a direction to increase a revolution radius, and the biasing force is reduced by the biasing force. A novel measure is taken in which an elastic material capable of elastic buckling, whose displacement is rapidly increased by a critical load to resist, is interposed.

(2) In the scroll type compressor of the present invention,
In order to solve the above problems, a fixed scroll, a movable scroll that forms a compression chamber by meshing with the fixed scroll, and a rotatable support via a bearing, and a slide key protruding from the inner end of the large diameter portion. The drive shaft is slidably fitted in the slide key in a linear direction inclined in a direction opposite to the rotational direction of the drive shaft, and the movable scroll can be eccentrically revolved through a bearing in cooperation with a rotation prevention mechanism. And a counterweight disposed around the slide key to absorb a dynamic imbalance of the movable scroll, and the orbital movement of the movable scroll causes the compression chamber to draw refrigerant gas. In a scroll type compressor that discharges by increasing the pressure of the refrigerant gas, an urging force is applied between the drive shaft and the drive bush in a direction to increase a revolution radius. It has taken a novel means of elastic buckling resilient material amount displaced by critical load against the 該付 force increases suddenly is interposed.

The elastic material capable of elastic buckling according to the present invention is described in "Strength Design Data Book (Strength Design Data Book Editing Committee, edited by Tokyo Shokabo, 380-385, 864-873)". ", An elastic material having a shape that causes jump buckling, jump buckling, or the like can be employed. Such an elastic material capable of elastic buckling is described in “Handbook of Mechanical Engineering, Revised 6th Edition (edited by the Japan Society of Mechanical Engineers, 1977, No. 4-1).
19-125), which is analyzed by the nonlinear theory.

[0010]

In the scroll compressor according to the present invention, since the elastic member interposed between the drive shaft and the drive bush has a biasing force in the direction of increasing the revolution radius, the load resisting the biasing force is less than the critical load. If so, the orbiting scroll is urged in a direction to increase the orbital radius, and the orbiting scroll is pressed against the fixed scroll of the fixed scroll.

On the other hand, when a large amount of lubricating oil is present in the compression chamber at the time of startup or the like and the engine is operated at a high speed, if the load in the direction of reducing the orbital radius becomes temporarily excessive, it resists the urging force. Since the load exceeds the critical load, the displacement of the elastic material increases rapidly. Therefore, the orbiting radius of the orbiting scroll is reduced and the orbiting scroll is separated from the fixed scroll of the fixed scroll, so that the two scrolls do not break.

[0012]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the compressor includes a fixed side plate 21, a shell 22 formed integrally with the fixed side plate 21 to form an outer shell, and a fixed spiral formed inside the fixed side plate 21 by an involute curve or the like. The fixed scroll 2 composed of the body 23 meshes with the movable scroll 4 composed of a movable side plate 41 and a movable spiral body 42 formed by an involute curve or the like inside the movable side plate 41, thereby forming a compression chamber 39. are doing.

As shown in FIG. 2, a front housing 30 connected to the shell portion 22 of the fixed scroll 2 by fastening means is provided with a shaft sealing device 31 and a main bearing 32 therebetween.
The drive shaft 33 is rotatably supported around the Os line. At the inner end 33a of the large diameter portion of the drive shaft 33, a cylindrical eccentric pin 34a having the Op line as a center line is eccentrically protruded from the Os line, and a spring seat 34b at a position away from the Op line is provided with an Op. It protrudes parallel to the line.

The counterweight 35 has an eccentric pin 34
An eccentric hole 35a into which a is fitted is provided therethrough, and an arc hole 35c into which the spring seat 34b is loosely fitted is provided therethrough. A counterbore 35b into which the large-diameter portion inner end 33a of the drive shaft 33 is loosely fitted is formed on the back surface of the counterweight 35. The drive bush 36 has an eccentric hole 36a through which the eccentric pin 34a is fitted in alignment with the eccentric hole 35a, and an arc hole 36b into which the spring seat 34b is loosely fitted in alignment with the arc hole 35c. Is pierced. The drive bush 36 is formed in a column shape centered on the Ob line, and is integrally formed with the counter weight 35 by pins (not shown).

The counterweight 35 and the drive bush 36 connect the counterbore 35 b to the inner end 3 of the large diameter portion of the drive shaft 33.
3a, the eccentric pin 34a is fitted into the eccentric hole 35a and the eccentric hole 36a, and the circlip 51 is locked to the eccentric pin 34a, thereby being moored to the drive shaft 33. Here, the counter weight 35 and the driving bush 3
6, between the arc holes 35c and 36b of the drive shaft 33 and the spring seat 34b of the drive shaft 33, as a characteristic configuration of the compressor, a spring as an elastic material having an urging force in a direction to enlarge the revolution radius is used. 34c is interposed.

The spring 34c is formed in a semi-cylindrical shell shape as shown in FIG. 5, and according to the calculation formula of the above publication, as shown in FIG. Until the critical load Fcr, the displacement δ shows a proportional relationship,
When the force F exceeds the critical load Fcr, the displacement amount is changed from δ ₁ to δ
It is set to have the characteristic of rapidly increasing (jump phenomenon) to ₂ .

The driving bush 36 cooperates with the rotation preventing mechanism 37 to support the movable scroll 4 via a bearing 38 eccentrically by a distance R so as to be able to rotate only.
As shown in FIG. 1, the front housing 30 is provided with a refrigerant suction port 8 that faces the peripheral surface of the counter weight 34 and communicates with the refrigeration circuit. The refrigerant suction port 8 communicates with a suction path 9 that penetrates through the front housing 30 and a part of the rotation preventing mechanism 37 to bypass the counterweight 35 and directly communicates with the compression chamber 39.
A discharge port 11 communicating with the compression chamber 39 at the discharge stage is formed through the center of the fixed side plate 21 of the fixed scroll 2. A rear housing 10 is fixed to the fixed scroll 2, and a discharge port 11 communicates with a discharge chamber 13 formed inside the rear housing 10 via a check valve 12.
The discharge chamber 13 communicates with a refrigeration circuit at a refrigerant discharge port (not shown).

In this compressor configured as described above,
The drive shaft 33 is rotated from the vehicle engine via an electromagnetic clutch or the like. Thereby, the eccentric pin 34a shown in FIG.
Are driven about the axis Os, and the drive bush 36 revolves the movable scroll 4 by the set eccentricity R about the axis Os in cooperation with the rotation preventing mechanism 37. A compression chamber 39 formed by the fixed side plate 21, the fixed spiral body 23, the movable side plate 41, and the movable spiral body 42 shown in FIG.
Is moved toward the center while sequentially reducing the volume, so that the refrigerant is sucked into the compression chamber 39 from the refrigerant suction port 8 through the suction path 9 from the refrigeration circuit. Thereafter, the refrigerant compressed by the movement of the compression chamber 39 pushes and opens the check valve 12 and is discharged from the discharge port 11 to the discharge chamber 13.

Here, in this compressor, the counterweight 35 and the drive bush 36 are allowed to perform a limited adjustment rotation around the eccentric pin 34a by the loose fitting gap of the counterbore 35b formed in the counterweight 35. . For this reason, as shown in FIG. 3, the counterweight 35 and the drive bush 36 are swung by a small angle θ in the direction in which the orbital radius increases around the center line Op due to the urging force F of the spring 34c that is less than the critical load Fcr. As a result, the orbiting scroll 4 revolves at an orbital radius of R, and its movable scroll 42
Is pressed against the fixed scroll 23 of the fixed scroll 2.

On the other hand, when a large amount of lubricating oil is present in the compression chamber 39 at the time of starting or the like and the engine is operated at a high speed, if the load in the direction of reducing the revolution radius becomes temporarily excessive,
Force F against the biasing force displacement of the spring 34c when it becomes critical load Fcr is sharply increased from [delta] ₁ to [delta] _2. Therefore, the movable scroll 4 revolves at the revolution radius of R-Δ, and the movable scroll 42 separates from the fixed scroll 23 of the fixed scroll 2, so that the two scrolls 23 and 42 do not break.

The force F against the urging force is equal to the critical load Fc.
When the value falls below r, the force F and the displacement δ of the spring 34c again show a proportional relationship, and the orbiting scroll 4 revolves in a state where it has returned to the orbital radius of R. Therefore, in this compressor, while ensuring the radial seal of the compression chamber 39, even if the load in the direction of reducing the orbital radius becomes temporarily excessive, the two spiral bodies 23 and 42 can be reliably destroyed. Can be avoided. In this compressor, the size of the compressor can be reduced as compared with the case where the drive bush 36 is moved by a coil spring. (Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to the drawings.

In this compressor, as shown in FIGS. 7 and 8, a slide key 61a is formed at the inner end 33a of the large-diameter portion of the drive shaft 33 by providing a two-sided width from a cylindrical projection. The slide key 6 is used for the counter weight 63.
A slide hole 63a into which the slide key 1a is fitted linearly slidably is provided, and a slide hole 62a into which the slide key 61a is fitted linearly slidably is also provided through the drive bush 62.

The counter weight 63 is provided with a columnar convex portion 63c having the center line Ob as an axis.
Also, a column-shaped concave portion 62b having a center line Ob as an axis is provided in a concave shape, and the counterweight 63 and the drive bush 62 are connected by fitting these concave and convex portions 62b and 63c. Further, the back of the counter weight 63 is provided with the first embodiment.
Similarly, a circular counterbore 63b which is loosely fitted to the large-diameter portion inner end 33a of the drive shaft 33 to allow adjustment linear sliding is formed.

Counterweight 63 and drive bush 6
2 is a slide key 61a having slide holes 62a and 63a.
The circlip 64 is fixed to the slide key 61a so that the circlip 64 can be adjusted linearly slidably. Such a counter weight 63
The direction S in which the drive bush 62 slides with the slide key 61 a is a linear direction that is inclined in the opposite direction to the rotation direction of the drive shaft 33. Here, between the slide holes 62a, 63a in the counter weight 35 and the drive bush 36 and the slide key 61a, as a characteristic configuration of the compressor, an elastic material having an urging force in a direction to enlarge the revolution radius is used. Spring 61b is interposed.

The spring 61b is also formed in a semi-cylindrical shell shape, similarly to the spring 34c of the first embodiment shown in FIG.
It has the same elastic buckling characteristic as shown in FIG.
Other configurations are the same as those of the first embodiment, and thus the same configurations are denoted by the same reference numerals and description thereof will be omitted. In this compressor, the rotation of the drive shaft 33 is revolved by the drive bush 62 and the anti-rotation mechanism 37 via the slide key 61a, so that the movable scroll 4 revolves.
9, suction, compression and discharge of the refrigerant are performed.

Here, in this compressor, the drive bush 62 is slidable in the sliding direction S by a predetermined distance in the sliding direction S by the driving force of the drive shaft 33. The counter weight 63 and the driving bush 62
, Limited linear sliding with the adjustment by the slide key 61a is allowed. For this reason, the counterweight 63 and the drive bush 62 are moved by the urging force F of the spring 61b, which is less than the critical load Fcr, by a very small length around the center line Op in a direction in which the orbital radius increases, thereby moving the movable scroll 4 Revolves at a predetermined orbital radius, and its movable spiral body 42
Is pressed against the fixed scroll 23 of the fixed scroll 2.

On the other hand, if the load in the direction of reducing the orbital radius becomes temporarily excessive, the force F against the urging force becomes the critical load F
At the time point when the pressure reaches cr, the displacement of the spring 61b is changed from δ ₁ to δ _2.
Increase rapidly. Therefore, the movable scroll 4 revolves at the reduced orbital radius, and the movable scroll 42 separates from the fixed scroll 23 of the fixed scroll 2, so that the two scrolls 23 and 42 do not break.

The force F against the urging force is equal to the critical load Fc.
When the value falls below r, the force F and the displacement δ of the spring 61b again show a proportional relationship, and the orbiting scroll 4 revolves in a state where it has returned to a predetermined orbital radius. Therefore, also in this compressor, the same effects as in the first embodiment can be obtained.

In the first and second embodiments, the spring 34c,
Although a semi-cylindrical shell is used as 61b, for example, a hemispherical shell as shown in FIG. 9 or a beam-shaped shell may be used.

[0030]

As described in detail above, in the scroll type compressor of the present invention, the elastic member interposed between the drive shaft and the drive bush has a biasing force in the direction of increasing the revolution radius. If the load against the force is less than the critical load, the radial seal of the compression chamber is secured.

In this compressor, the load in the direction of reducing the revolution radius temporarily becomes excessively large, and if the load against the urging force exceeds the critical load, the elastic material greatly increases the amount of displacement. Excellent durability can be exhibited without the spiral body being broken.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a compressor according to a first embodiment.

FIG. 2 is a sectional view of a main part of the compressor according to the first embodiment.

FIG. 3 is a cross-sectional view of the compressor according to the first embodiment, taken along the line AA in FIG. 2, when the revolution radius is at a maximum.

FIG. 4 is a cross-sectional view of the compressor according to the first embodiment taken along line AA of FIG. 2 when the revolution radius is reduced.

FIG. 5 is a perspective view of a spring according to the compressor of the first embodiment.

FIG. 6 is a graph showing characteristics of a spring according to the compressor of the first embodiment.

FIG. 7 is a sectional view of a main part of a compressor according to a second embodiment.

FIG. 8 is a cross-sectional view of the compressor according to the second embodiment, taken along the line BB in FIG. 7;

FIG. 9 is a perspective view of another spring.

[Explanation of symbols]

2 ... fixed scroll 4 ... movable scroll 39 ...
Compression chamber 32: Main bearing 34a: Eccentric pin 61a
... Slide key 33 ... Drive shaft 33a ... Large diameter part inner end 37 ...
Anti-rotation mechanism 38 ... Bearing 36 ... Drive bush 35 ...
Counter weight 34c, 61b ... spring (elastic material)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04C 18/02 311

Claims (2)

(57) [Claims] 1. A fixed scroll, a movable scroll which meshes with the fixed scroll to form a compression chamber,
A drive shaft rotatably supported via a bearing and having an eccentric pin protruding at the inner end of the large-diameter portion, and fitted to the eccentric pin, cooperating with the rotation preventing mechanism to move the movable scroll through the bearing. A driving bush that is eccentric and supports only the revolution, and a counter weight that is disposed around the eccentric pin and absorbs a dynamic imbalance of the orbiting scroll; In a scroll type compressor that sucks gas and discharges the refrigerant by increasing the pressure of the refrigerant gas, the compressor has a biasing force between the drive shaft and the drive bush in a direction of increasing a revolution radius. A scroll type compressor comprising an elastic material capable of elastic buckling whose displacement is rapidly increased by a critical load to withstand. 2. A fixed scroll, a movable scroll that meshes with the fixed scroll to form a compression chamber,
A drive shaft rotatably supported via a bearing and having a slide key protruding from the inner end of the large-diameter portion, and fitted to the slide key so as to be slidable in a linear direction inclined in a direction opposite to the rotation of the drive shaft. A drive bush for eccentrically supporting the movable scroll through a bearing in cooperation with a rotation preventing mechanism and supporting the movable scroll only for revolving; and a counter disposed around the slide key for absorbing a dynamic imbalance of the movable scroll. Including weights,
In a scroll type compressor in which the compression chamber sucks refrigerant gas by the orbital motion of the orbiting scroll and increases the pressure of the refrigerant gas to discharge the refrigerant gas, the orbital radius is increased between the drive shaft and the drive bush. A scroll compressor having an urging force in a direction in which the elastic force is applied, and an elastic material capable of elastic buckling whose displacement is rapidly increased by a critical load opposing the urging force.