JP3146751B2 - Oil-free scroll type fluid machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oilless scroll type fluid machine, and more particularly, to a technique for adjusting the orbital radius of a movable scroll and a technique for lubricating the same.

[0002]

2. Description of the Related Art Conventional oilless scroll type fluid machines,
For example, as a non-lubricating scroll compressor, an actual oil pressure type 4-
No. 54901 is known. In this compressor, a fixed scroll made up of a fixed side plate and a fixed scroll is fixed to 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 protrudes from a large-diameter portion of the drive shaft. A boss of the movable side plate is supported on the eccentric pin via a bearing,
The movable side plate is prevented from rotating by engaging with a driven crankshaft provided in the housing. In addition, a counterweight is provided in the large diameter portion to offset the eccentric moment due to the revolving motion of the orbiting scroll, and the inside of the boss is communicated with a grease cup as a lubricating device by an eccentric pin and a lubrication passage penetrating the counterweight. ing.

[0003] In this compressor, the rotation of the drive shaft is caused to revolve by a movable scroll by an eccentric pin and a driven crankshaft, whereby a compression chamber as a working chamber formed by meshing of the fixed scroll and the movable scroll is sequentially formed. Since the air is moved toward the center while reducing the volume, air is sucked into the compression chamber from the suction port, and the air in the compression chamber is sequentially compressed and discharged to the discharge port. At this time, in such an oilless compressor, since lubrication is not performed by the lubricating oil in the refrigerant as in an air conditioning compressor, grease is supplied from a grease cup into a boss via an oil supply passage. Lubrication between the eccentric pin and the bearing is performed by grease.

[0004]

However, in the above-mentioned conventional compressor, the lubricating oil such as grease supplied into the boss can flow out of the boss without any restriction. For this reason, the lubricating oil easily flows into the compression chamber due to the revolving motion of the orbiting scroll, so that replenishment of the lubricating oil is frequently required, or an undesirable situation occurs depending on the use of the compressed air.

Further, in this compressor, the eccentric pin directly supports the boss of the movable side plate via a bearing, and the relative gap between the fixed scroll of the fixed scroll and the movable scroll of the movable scroll is almost uniformly determined. Have been. For this reason, while the sealing performance of the compression chamber may not be sufficient, a collision may occur between the two spirals due to a slight difference in the relative positional relationship between the fixed spiral and the movable spiral.

As means for avoiding such a problem of sealing performance and collision, a slide key is protruded from the inner end of a large-diameter portion of a drive shaft as in a compressor described in Japanese Patent Application Laid-Open No. 2-176179. It is also conceivable that a drive bush is slidably fitted to the boss and the boss of the movable side plate is supported by the drive bush. However, the technology described in this publication relates to an air-conditioning compressor capable of lubricating with lubricating oil in a refrigerant, and cannot be directly applied to an oilless compressor. Further, if the slide key and the drive bush are made slidable in this way, the lubricating oil in the boss is more likely to flow into the compression chamber.

SUMMARY OF THE INVENTION The present invention provides an oil-free scroll-type fluid machine that effectively prevents leakage of lubricating oil from a boss while improving sealability of a working chamber and preventing collision between two spiral bodies. Issues to be solved.

[0008]

[Means for Solving the Problems]

(1) In order to solve the above-mentioned problems, an oil-free scroll type fluid machine according to the present invention includes a fixed scroll including a fixed side plate and a fixed scroll formed on an inner surface of the fixed side plate, and a movable side plate and a movable side plate. The movable scroll includes a movable scroll formed on an inner surface thereof, and includes a movable scroll that forms an operating chamber by being engaged with the fixed scroll, and a drive shaft rotatably supported by a housing via a bearing. In the oilless scroll type fluid machine in which the rotation is converted into the orbital motion of the orbiting scroll and the working chamber sucks the fluid and increases the pressure of the fluid and discharges the fluid, the inner end of the large-diameter portion of the drive shaft Is provided with a slide key having a key axis inclined in the anti-rotation direction, and a drive bush is slidably fitted on the slide key along the key axis. In cooperation with the rotation preventing mechanism, the movable scroll is supported by a boss formed on the back surface of the movable scroll via a bearing so as to be able to revolve only, and the inside of the boss is communicated with an oil supply device by an oil supply passage, A novel structure is adopted in which a seal mechanism for sealing the inside of the boss is interposed between the slide key and the drive bush and between the drive bush and the boss.

(2) The lubricating device is mounted on a drive shaft extending outside the housing, and the lubricating device is communicated with the inside of the boss through a lubricating passage provided through the drive shaft and the slide key. preferable.

[0010]

[Action]

(1) In the oil-free scroll type fluid machine of the present invention, the inside of the boss, which is communicated with the oil supply device by the oil supply passage, is sealed by the seal mechanism interposed between the drive bush and the boss. The lubricating oil such as grease supplied to the boss is hard to flow out of the boss depending on the gap between the drive bush and the boss.

In this oilless scroll type fluid machine, the relative gap between the fixed scroll of the fixed scroll and the movable scroll of the movable scroll is made variable by sliding along the key axis of the drive bush. For this reason, the drive bush slides along the key axis of the slide key in the direction of increasing the revolving radius by the drive force of the drive shaft, thereby ensuring the sealability of the working chamber. On the other hand, if there is a slight difference in the relative positional relationship between the fixed spiral body and the movable spiral body, the drive bush slides along the key axis of the slide key in a direction to reduce the revolving radius, and the two spiral bodies collide with each other. Work around.

Even if the slide key and the drive bush are slidable in this way, a seal mechanism is also interposed between the slide key and the drive bush, and the lubricating oil in the boss is removed from the slide key and the drive bush. The gap with the bush also makes it difficult to flow out of the boss. (2) When the lubrication device is mounted on a drive shaft extending outside the housing and the lubrication device is communicated with the boss through a lubrication passage formed through the drive shaft and the slide key, When refilling the lubricating oil, it is easy to replace the oil supply device.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which an oilless scroll type fluid machine of the present invention is embodied in an air compressor 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 includes a movable side plate 41 and the movable side plate 4.
A compression chamber 39 is formed by meshing with a movable scroll 4 including a movable scroll 42 formed by an involute curve or the like inside 1. The distal ends of the fixed spiral body 23 and the movable spiral body 42 are each provided with a P for smooth sliding while maintaining airtightness with the movable side plate 41 or the fixed side plate 21, respectively.
TFE chip seals 23a and 42a are mounted. A similar chip seal 41a is attached to a portion where the movable side plate 41 slides with the shell portion 22.

A drive shaft 33 is rotatably supported in a front housing 30 connected to the shell portion 22 of the fixed scroll 2 by fastening means via a shaft sealing device 31 and a main bearing 32. As shown in FIGS. 2 and 3, an eccentric slide key 5 is provided at the inner end of the large diameter portion 33a.
0 is protruding. This slide key 50 has a two-sided width 50 parallel to the key axis S inclined in the opposite direction to the rotation direction M of the drive shaft 33 from about the center of the cylindrical projection to the tip.
“a” is formed by cutting.

A slide hole 51a of a drive bush 51 is fitted into the two-sided width 50a of the slide key 50. The slide hole 51a is aligned with the two-sided width 50a of the slide key 50, and has a predetermined gap Δ in the front-rear direction orthogonal to the two-sided width 50a. Thus, the drive bush 51 is fitted slidably along the key axis S by ± Δ. The drive bush 51 is prevented from being pulled out and prevented from tilting by a circlip 52 engaged with the tip of the slide key 50, and a counter weight 39 having a center of gravity opposite to the eccentric direction is fixed to the drive bush 51. The driving bush 51 and the counterweight 39 are formed with a common circular concave portion, and a retainer 53 for holding a rubber lip 53a for sealing the cylindrical portion of the slide key 50 is press-fitted into the circular concave portion.

A revolving member 35 is integrally fixed to the movable side plate 41, and the drive bush 51 is supported by a first boss 35a formed on one surface of the revolving member 35 via a bearing 51b. A retainer 54 for holding a rubber lip 54a for sealing the drive bush 51 is press-fitted in front of the bearing 51b of the first boss 35a. Further, as shown in FIG. 1, the drive shaft 33 extending outside the front housing 30 has
A grease cup 55 is provided as a lubricating device, and the grease cup 55 is connected to the first boss 3 via a lubrication passage 56 formed through the drive shaft 33 and the slide key 50.
5a.

A revolving member 35 is provided on the front housing 30.
A boss 30a is protruded on the side, and a second boss 35b is protruded on one side of the revolving member 35 and near the boss 30a. One eccentric pin of a driven crank 38 as a rotation preventing mechanism is pivotally supported on the boss 30a via a bearing 36, and another eccentric pin of the driven crank 38 via an elastic support member 37a and a bearing 37b is supported on the second boss 35b. Is supported.
The movable side plate 41 of the movable scroll 4 is fixed to the other surface of the revolving member 35.

The rear cover 10 is connected to the shell portion 22 of the fixed scroll 2 on the other side of the front housing 30 by fastening means. The suction pipe 11 is fixed to the outer peripheral side of the fixed side plate 21 so as to communicate with the low-pressure compression chamber 39, and the discharge pipe 12 is fixed to the center of the fixed side plate 21 so as to communicate with the high-pressure compression chamber 39. . The suction pipe 11 penetrates through the rear cover 10 and communicates with the atmosphere. The discharge pipe 12 also penetrates the rear cover 10 and communicates with an external device.

Further, the fixed side plate 21 has an outer surface which is the back surface of the fixed spiral body 23 and the rear cover 10 together with the first air cooling chamber 5.
Is formed. The first air cooling chamber 5 is communicated with an air introduction device (not shown) for extracting cooling air and the atmosphere.
The first fixed side plate 21 contacts the rear cover 10 until it comes into contact with the rear cover 10.
An infinite number of cooling projections 6b protruding in a column shape are provided in the air cooling chamber 5.

The movable side plate 41 also has a second air cooling chamber 7 on the outer surface, which is the back surface of the movable spiral body 42, together with the revolving member 35. The second air cooling chamber 7 is
And a crank chamber 8 formed by the shell part 22. The crank chamber 8 is also communicated with the air introduction device for taking out cooling air and the atmosphere. Similarly to the fixed side plate 21, the movable side plate 41 is provided with a myriad of cooling projections 9b that stand in the second air cooling chamber 7 and project in a columnar shape until they come into contact with the revolving member 35.

In this compressor configured as described above,
When the drive shaft 33 shown in FIG. 1 is rotated, the slide key 50 is eccentrically driven to rotate, and the drive bush 51 revolves the revolving member 35 in cooperation with the driven crank 38. Revolve in quantity. The 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 is moved toward the center while sequentially reducing the volume.
Atmospheric air is sucked into the compression chamber 39 via the suction pipe 11. Thereafter, the air compressed by the movement of the compression chamber 39 is led to an external device via the discharge pipe 12. Further, the counterweight 39 cancels the eccentric moment received by the large diameter portion 33a from the movable scroll 4, and absorbs the dynamic imbalance of the movable scroll 4.

At this time, in this compressor, the first boss 35
g is supplied from the grease cup 55 through the oil supply passage 56 into the slide key 5a.
Lubrication is performed between the drive bush 51 and the drive bush 51 and between the drive bush 51 and the bearing 51b. The inside of the first boss 35a communicated with the grease cup 55 by the oil supply passage 56 is sealed by the rubber lip 54a held by the holder 54 as shown in FIG.
The grease supplied into the boss 35a is
Due to the gap between the first boss 35a and the first boss 35a, it is difficult to flow into the crank chamber 8.

In this compressor, as shown in FIG. 3, the relative gap between the fixed scroll 23 of the fixed scroll 2 and the movable scroll 42 of the movable scroll 4 is increased by the drive bush 51.
Is made variable by sliding along the key axis S. For this reason, the driving force of the driving shaft 33 causes the driving bush 51 to slide along the key axis S of the slide key 50 by Δ in the direction of increasing the revolving radius, thereby ensuring the sealing performance of the compression chamber 39. On the other hand, the fixed spiral 23 and the movable spiral 4
If there is a slight difference or the like that occurs in the relative positional relationship between the two spiral bodies 23, the drive bush 51 slides along the key axis S of the slide key 50 in the direction of decreasing the orbital radius.
Avoid the 42 collision. At this time, on the driven crank 38 side, the elastic support member 37a absorbs the movement of ± Δ.

Even if the slide key 50 and the drive bush 51 are slidable in this manner, as shown in FIG. 2, since the slide key 50 and the drive bush 51 are sealed by the rubber lip 53a held by the holder 53, the first The grease in the boss 35a is less likely to flow into the crank chamber 8 due to the gap between the slide key 50 and the drive bush 51. Further, in this compressor, the grease cup 55 is mounted on the drive shaft 33 extending outside the front housing 30, and the grease cup 55 is connected to the first boss 35 a via the oil supply passage 56.
The first boss 3 that is not so frequent because it is communicated with
When refilling the lubricating oil in 5a, the grease cup 55 can be easily replaced.

Therefore, in this compressor, the compression chamber 39
Of the first boss 35a can be effectively prevented at the same time while improving the sealing performance and preventing the collision between the spiral bodies 23 and 42. For this reason, this compressor exhibits excellent operation performance and durability, and also has excellent effects that replenishment of grease is not so necessary and the use is not restricted.

The second boss 3 supporting the driven crank 38 as a rotation preventing mechanism employed in the above embodiment.
It is also possible to provide a similar lubrication device, lubrication passage and seal mechanism to the 5b and the boss 30a. In addition, as a technique for adjusting the orbital radius of the orbiting scroll, an eccentric pin is protruded from the inner end of the large-diameter portion of the drive shaft, and even when the drive bush is rotatably fitted to the eccentric pin, the distance between the eccentric pin and the drive bush is reduced. It is also possible to interpose a sealing mechanism in the device.

[0027]

As described in detail above, the oil-free scroll type fluid machine of the present invention employs the structure described in the claims, so that the sealability of the working chamber is improved and both spiral bodies are improved. It is possible to effectively prevent the lubricating oil from flowing out of the boss while preventing collision.

Therefore, the fluid machine exhibits excellent running performance and durability, and also has excellent effects that the replenishment of the lubricating oil is not required so much and the application is not restricted. In addition, when the refueling device is provided on a drive shaft extending outside the housing, and the refueling device is communicated with the inside of the bore through a refueling passage penetrating the drive shaft and the slide key, it is not so frequent. The refueling device can be easily replaced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a compressor according to an embodiment.

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

FIG. 3 is a plan view of a main part of the compressor of the embodiment.

[Explanation of symbols]

2 ... fixed scroll 21 ... fixed side plate 23
... fixed spiral body 4 ... movable scroll 41 ... movable side plate 42
... Movable spiral body 39 ... Working chamber (compression chamber) 30 ... Front housing 32 ... Bearing 33 ... Drive shaft 33
a: Large diameter part 50: Slide key S: Key axis 51
... Drive bush 38... Anti-rotation mechanism (driven crank) 35 a.
Boss 51b Bearing 56 Oil supply passage 55 Grease cup 54, 53 Seal mechanism 54a, 53a Rubber lip

Claims (2)

(57) [Claims] 1. A fixed scroll comprising a fixed side plate and a fixed scroll formed on an inner surface of the fixed side plate, and a movable scroll formed on a movable side plate and an inner surface of the movable side plate, and meshing with the fixed scroll. And a drive shaft rotatably supported by a housing via a bearing. The rotation of the drive shaft is converted to the revolving motion of the movable scroll, thereby forming the working chamber. In a non-oiling scroll type fluid machine that sucks a fluid and discharges the fluid by increasing the pressure of the fluid, a slide key having a key axis inclined in a counter-rotating direction is protruded from an inner end of the large-diameter portion of the drive shaft. A drive bush is slidably fitted to the slide key along the key axis, and the drive bush can only revolve the movable scroll in cooperation with a rotation preventing mechanism. A bearing is supported by a boss formed on the back surface of the orbiting scroll through a bearing to communicate with the oil supply device through an oil supply passage, and is provided between the slide key and the drive bush and the drive bush. A seal mechanism for sealing the inside of the boss is interposed between the boss and the boss. 2. A fuel supply device is provided on a drive shaft extending outside the housing, and the fuel supply device is communicated with the inside of the boss through a fuel supply passage formed through the drive shaft and a slide key. The oil-free scroll type fluid machine according to claim 1.