JPH0526187A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To prevent the generation of a galling phenomenon between the tip side of a lap part and the tooth bottom of an end plate and heighten sealing performance so as to improve compression efficiency. CONSTITUTION:A fitting groove 23B extended along the spiral shape of a lap part 23 is formed at the tooth tip face 23A of the lap part 23, and a seal member 27 formed of thermoplastic resin material into spiral shape is fittingly inserted into the fitting groove 23B. Accordingly, when the lap part 23 is heated by compression heat or the like, the seal member 27 is softened, and the lap part 23 is thermal-expanded in the axial direction. The seal member 27 is thereby pressed to the tooth bottom 3A of an end plate 3 and deformed to seal a gap between the lap part 23 and the tooth bottom 3A. When the temperature of the lap part 23 is lowered, the lap part 23 is contracted, so that the seal member 27 is spaced from the tooth bottom 3A while being hardened as it is deformed so as to form a thrust direction gap corresponding to a temperature gradient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine suitable for use in, for example, an air compressor or a vacuum pump.

[0002]

7 to 9 show a scroll type air compressor as an example of a scroll type fluid machine according to the prior art.

In the drawings, reference numeral 1 denotes a drive shaft rotatably provided in a casing (not shown), and a tip side thereof is a crank 1A. Reference numeral 2 denotes an orbiting scroll rotatably supported by the crank 1A of the drive shaft 1. The orbiting scroll 2 has an end plate 3 formed in a disk shape, a spiral wrap portion 4 erected from the tooth bottom 3A of the end plate 3 on the center side to the winding start end and on the outer circumference side to the winding end. It is composed of a boss portion 5 provided at the center on the back side of the end plate 3, and a crank 1A of the drive shaft 1 is mounted in the boss portion 5 via a swivel bearing 6. For the reason described below, the height dimension of the wrap portion 4 is, as shown in FIG. 8, the height dimension H1 of the winding start end, the intermediate height dimension H2, and the height dimension H3 of the winding end end.

[0004]

[Formula 1] H1 <H2 <H3.

Reference numeral 7 denotes a fixed scroll which is fixed to the casing so as to face the orbiting scroll 2. The fixed scroll 7 has a disk shape arranged so that its center coincides with the axis O1 -O1 of the drive shaft 1. And the spiral wrap portion 9 which is erected from the tooth bottom 8A of the end plate 8 in the same relationship as the wrap portion 4 of the orbiting scroll 2 in the relation of the above-mentioned equation 1.
And a supporting portion 10 which is located on the outer peripheral side of the end plate 8 and is formed in a tubular shape so as to surround the wrap portion 9.

Each of the scrolls 2 and 7 thus constructed has an axis O of the orbiting scroll 2 as shown in FIG.
With the 2-O2 eccentric to the axis O1-O1 of the fixed scroll 7 by a distance .delta. Is installed in. As a result, when the orbiting scroll 2 is orbited with respect to the fixed scroll 7, a plurality of compression chambers 11, 11, ...

Reference numerals 12 and 13 denote a suction port and a discharge port formed in the fixed scroll 7, and the suction port 1
2 is provided on the outer peripheral side of the end plate 8 so as to communicate with the compression chamber 11 on the outermost peripheral side, and the discharge port 13 is provided on the outermost center side of the compression chamber 1.
1 is formed in the center of the end plate 8 so as to communicate with 1.

The scroll type air compressor according to the prior art has the above-mentioned structure, and its operation will be described below.

First, the drive shaft 1 is driven by a motor (not shown).
When the rotary drive is performed, this rotation causes the crank 1 of the drive shaft 1 to rotate.
A is transmitted from A to the orbiting scroll 2 via the orbiting bearing 6, whereby the orbiting scroll 2 is fixed to the fixed scroll 7
Around the axis O1 -O1 of, a turning radius of a distance .delta. The compression chambers 11, 11, ... Defined between the wrap portions 4, 9 are continuously contracted by this turning motion, and the air sucked from the suction port 12 is sequentially compressed in each compression chamber 11. At the same time, the compressed air is discharged from the discharge port 13 to an external air tank (not shown) or the like.

[0010]

By the way, in the above-mentioned prior art, since the compression heat at the time of the compression action is generated in each compression chamber 11 between the orbiting scroll 2 and the fixed scroll 7, this compression heat causes the compression heat. Each scroll 2, 7
Becomes hot. Moreover, since the pressure gradually increases from the compression chamber 11 on the outer peripheral side toward the compression chamber 11 on the central side, a temperature gradient is generated in each of the lap portions 4 and 9 from the central side to the outer peripheral side.

That is, the temperature of the compression chamber 11 on the center side (winding start side) becomes higher than that of the compression chamber 11 on the outer peripheral side (winding end side), and, for example, the discharge pressure reaches 0.83 MPa during the rated operation. Sometimes the center of each scroll 2, 7 is 300
Temperature rises to near ℃. As a result of this temperature increase, the respective lap portions 4, 9 are thermally expanded in the axial direction by the dimension L as shown by the chain double-dashed line in FIG. The winding start end side greatly expands thermally. Then, due to this thermal expansion, the respective wrap portions 4, 9
In addition to the gap size in the thrust direction between the tooth tip surface of each of the end plates 8 and 3 and the tooth bottoms 8A and 3A of each end plate being smaller than the gap size when it is appropriate, the tooth top surfaces of the respective wrap portions 4 and 9 are different from each other. , 3 causes contact with the tooth bottoms 8A, 3A, causing damage to the end plates 3 and 8 and the wraps 4 and 9, resulting in reliability, durability, compression efficiency, etc. of the compressor. There is a problem of a significant decrease.

Therefore, in the above-mentioned conventional technique, the height dimensions H1, H2, H of the respective lap portions 4, 9 are previously set in accordance with the thermal expansion in accordance with the temperature gradient generated from the central side to the outer peripheral side.
3 is shortened sequentially from the outer peripheral side to the center side according to the relationship of the above-mentioned numerical formula 1, and the tooth top surfaces of the respective lap portions 4, 9 and the respective end plates 8,
The gap in the thrust direction with the tooth bottoms 8A and 3A of No. 3 is gradually increased from the outer peripheral side to the central side. This allows
When the lap portions 4 and 9 thermally expand during the rated operation of the air compressor, the tooth crests of the lap portions 4 and 9 and the end plates 8 and 3 are
The thrust direction gaps with the tooth bottoms 8A and 3A are substantially constant from the center side to the outer peripheral side.

However, the steady-state temperature during the rated operation of the compressor depends on the temperature difference between day and night, winter and summer, operating time,
It is difficult to accurately set the height dimensions H1, H2, H3 of each lap 4, 9 in accordance with the thermal expansion amount during rated operation, because the load conditions are likely to change, and the thrust direction gap is There is a problem that it tends to be unstable. Also,
According to the conventional technology, it is important to prevent the occurrence of the galling phenomenon, and the tooth crests of the lap portions 4 and 9 and the tooth bottoms 8 of the end plates 8 and 3 are important.
Since the thrust direction gap with A and 3A is formed to be large with a margin, there is a problem that pressure leakage occurs through the thrust direction gap and the compression efficiency is significantly reduced.

The present invention has been made in view of the above-mentioned problems of the prior art, and prevents the galling phenomenon from occurring between the tip side of each lap portion and the tooth bottom of each end plate to improve the sealing performance. An object of the present invention is to provide a scroll type fluid machine capable of preventing pressure leakage.

[0015]

The features of the structure adopted by the present invention for solving the above-mentioned problems are that the spiral side of at least one of the orbiting scroll and the fixed scroll has a vortex of the wrap portion. This is to provide a seal member made of a thermoplastic resin material that extends along the shape and softens when reaching a predetermined temperature.

[0016]

With the above structure, when the temperature of each scroll rises due to compression heat or the like, the wrap portion of each scroll thermally expands due to this temperature rise, and the seal member softens when it reaches a predetermined temperature. As a result, the sealing member is pressed by the thermally expanded lap portions against the roots of the facing end plates to be deformed, and seals between the tip end side of the wraps and the bottoms of the end plates.

When the operation is stopped and the temperature of each scroll decreases, the wrap portion of each scroll contracts and the seal member hardens while deformed. As a result, the thrust gap between each lap portion and the tooth bottom of the facing end plate is formed according to the temperature gradient generated in each lap portion during the compression action.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the prior art shown in FIGS. 7 to 9 described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 21 denotes a fixed scroll according to the present embodiment, and the fixed scroll 21 has its center aligned with the axis O1 -O1 of the drive shaft 1 almost like the fixed scroll 7 described in the prior art. A disk-shaped end plate 22 disposed on the outer periphery of the end plate 22; And a support portion 24 formed on the outer peripheral side and the center portion of the end plate 22. However, as shown in FIG. 2, a fitting groove 23B is formed along the spiral shape of the wrap portion 23 on the tooth top surface 23A of the wrap portion 23 except for the outermost peripheral side, and the fitting groove 23B is formed in the fitting groove 23B. Is provided with a seal member 27 described later.

27 is in the range of 180 to 220 ° C., preferably polyether sulfone (PES) or polyphenylene sulfide (PP) which softens at a temperature of about 200 ° C.
S) is a sealing member formed from a thermoplastic resin material along the spiral shape of the wrap portion 23. The sealing member 27 has a proximal end side inserted into the fitting groove 23B of the wrap portion 23, The tip side projects from the fitting groove 23B so as to come into contact with the tooth bottom 3A of the end plate 3. In addition, the seal member 2
7 shows that the height of the wrap portion 23 including the seal member 27 is uniform on the line S-S from the central side to the outer peripheral side when inserted into the fitting groove 23B as shown in FIGS. From the winding start end 27A to the winding end end 27B,
The length D in the axial direction is formed to be successively shorter.

The scroll type air compressor according to this embodiment has the above-mentioned structure, and its basic operation is not different from that of the prior art.

Therefore, in this embodiment, the fitting groove 23B extending along the spiral shape of the wrap portion 23 is formed on the tooth top surface 23A of the wrap portion 23, and the seal member 27 is provided in the fitting groove 23B. It is configured to be inserted. Therefore, when the compression operation is performed, the temperature of the fixed scroll 21 rises due to the compression heat and the like during the compression action, and due to this temperature rise, the wrap portion 23
Thermally expands, and the seal member 27 that has reached a predetermined temperature is softened. As a result, the seal member 27 is deformed by being pressed against the tooth bottom 3A of the facing end plate 3 by the lap portion 23 that thermally expands as shown in FIG. 4, and between the wrap portion 23 and the bottom end 3A of the end plate 3. Seal.

The fixed scroll 21 is stopped when the operation is stopped.
When the temperature decreases, the wrap portion 23 contracts as shown in FIG. 5, and the seal member 27 is sandwiched between the wrap portion 23 and the tooth bottom 3A of the end plate 3 and hardens in a deformed state. It is separated from the tooth bottom 3A by a gap in the thrust direction corresponding to the temperature gradient during thermal expansion.

Further, when the compressor is restarted, the wrap portion 23 thermally expands due to the compression heat or the like, and the seal member 27 becomes
As shown in FIG. 4, the tooth bottom 3A is again contacted and sealed.

Thus, according to this embodiment, the seal member 27 can be deformed in accordance with the thermal expansion amount of the lap portion 23 during the rated operation, and the thrust direction gap corresponding to the temperature gradient generated in the lap portion 23 can be easily formed. Can be formed. As a result, it is possible to reliably prevent the galling phenomenon from occurring and to improve the sealing performance as much as possible.
The reliability and life can be greatly improved. Also, the adjustment work of the thrust direction gap can be simplified, and the manufacturing efficiency can be significantly improved.

In the above-described embodiment, the tip side of the seal member 27 is described as being in direct contact with the tooth bottom 3A of the end plate 3, but the present invention is not limited to this and, for example, as a modification shown in FIG. A spiral sliding contact plate 28 made of a wear resistant material may be fixed to the tip end side of the seal member 27. In this case, the seal member 27 can be prevented from wearing and the life can be further improved.

In the above embodiment, the case where the seal member 27 is provided on the fixed scroll 21 has been described as an example, but instead of this, for example, the seal member 27 is provided on the tip side of the wrap portion 4 of the orbiting scroll 2. It may be provided, or may be provided in each of the wrap portions 4 and 23.

Further, in the above embodiment, the seal member 27 is used.
Have been described as using polyether sulfone (PES) and polyphenylene sulfide (PPS) as the thermoplastic resin material, the present invention is not limited to this, and other thermoplastic resin materials such as polyether ether ketone (PEEK) are used. ), Liquid crystal polymer (LCP), polysulfone (PSF) and the like may be used.

Further, in the above embodiment, the seal member 27 has the fitting groove 23B formed in the tooth top surface 23A of the wrap portion 23.
Although it is described that the seal member 27 is inserted into and fixed to the tooth top surface 23A of the wrap portion 23, instead of this, the seal member 27 may be fixed to the tooth crest 23A of the wrap portion 23 by a fixing means such as adhesion.

On the other hand, although the scroll type air compressor has been described as an example of the scroll type fluid machine in the above embodiment, it can be widely applied to, for example, a vacuum pump, a refrigerant compressor and the like.

[0031]

As described in detail above, according to the present invention, the wrap portion of at least one of the orbiting scroll and the fixed scroll extends along the spiral shape of the wrap portion and has a predetermined temperature. Since a seal member made of a thermoplastic resin material that softens when reaching the temperature reaches the temperature of each scroll due to compression heat or the like, the seal member softens and thermally expands while facing the end plate of the facing plate. It is pressed by the tooth bottom and deforms. As a result, it is possible to seal between the tip side of the lap portion and the bottom of the end plate of the wrap portion, and prevent pressure leakage between the tip side of the wrap portion and the bottom of the end plate of the end plate to improve reliability, compression efficiency, Can be improved. Further, when the operation is stopped and the temperature of each scroll decreases, the thrust direction gap between the lap portion and the tooth bottom of the facing end plate can be appropriately formed according to the temperature gradient generated in the lap portion. It is possible to improve the manufacturing efficiency by simplifying the gap adjusting work at the time of manufacturing.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of a scroll air compressor according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state before a seal member is attached to a wrap portion.

3 is an enlarged vertical sectional view showing a wrap portion of the fixed scroll in FIG. 1. FIG.

FIG. 4 is an enlarged vertical cross-sectional view showing a deformed state of the seal member.

FIG. 5 is a view showing a state in which the seal member is separated from the end plate.
It is a longitudinal cross-sectional view similar to FIG.

FIG. 6 is an enlarged vertical sectional view of an essential part showing a modified example of the present invention.

FIG. 7 is a vertical cross-sectional view showing a main part of a scroll type air compressor according to a conventional technique.

FIG. 8 is an enlarged vertical cross-sectional view showing an orbiting scroll and a fixed scroll in FIG.

9 is a vertical cross-sectional view showing an enlarged lap portion in FIG. 7. FIG.

[Explanation of symbols]

 2 orbiting scroll 3,22 end plate 3A, 22A tooth bottom 4,23 wrap portion 11 compression chamber 21 fixed scroll 23A tooth tip surface (tip) 27 seal member

Claims (1)

Claim: What is claimed is: 1. A casing, an orbiting scroll rotatably provided in the casing, in which a spiral wrap portion is erected from a tooth bottom of an end plate, and facing the orbiting scroll. A scroll-type fluid machine comprising: a fixed scroll fixed to the casing; and a fixed scroll in which a spiral wrap portion that overlaps with a wrap portion of an orbiting scroll to form a compression chamber is erected from a tooth bottom of an end plate. Or, at least on the tip side of the wrap portion of the fixed scroll, extending along the spiral shape of the wrap portion,
A scroll-type fluid machine comprising a sealing member made of a thermoplastic resin material that softens when a predetermined temperature is reached.