JPH07119667A - Scroll type fluid machinery - Google Patents

Abstract

PURPOSE:To improve sealing ability of a sealing member and to improve the compression efficiency by forming bottomed fitting holes at required spaces in the longitudinal direction of a recessed groove at the bottom of the recessed groove, providing projecting parts fitted to the fitting holes on a seal member, and forming the projecting parts by an elastic material having a large coefficient of thermal expansion. CONSTITUTION:A seal member 22 is thermal-expanded by heat of compression at the time of compressing operation to extend projecting parts of the seal member 22 to be firmly fitted in each fitting hole 21A of a recessed groove 21, whereby the seal member 22 can be held in the state of being brought into sliding contact with the bottom land 8A of the counterpart. Accordingly, during compressing operation, the seal member 22 can continue to airtightly seal between the bottom land 8A of the counterpart and a lap part 3, so that the airtightness of each compression space can be ensured effectively. Accordingly, the air sucked in a compression space positioned on the outer peripheral side of each scroll can be effectively prevented from leaking to the outside so as to remarkably improve the compression efficiency.

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]

2. Description of the Related Art A scroll type air compressor will be described as an example of a scroll type fluid machine according to the prior art, and will be described with reference to FIGS.

In the figure, reference numeral 1 denotes a fixed scroll, and the fixed scroll 1 has an open end of a casing (not shown) formed in a generally cylindrical shape with a bottom so that the open end of the casing is covered. It is fixed to the side. The center of the fixed scroll 1 is the axis O1 of the drive shaft 13, which will be described later.
A disk-shaped end plate 2 arranged so as to coincide with O1 and a spiral wrap portion 3 erected on the tooth bottom surface 2A of the end plate 2
And a supporting portion 4 which is located on the outer peripheral side of the end plate 2 and is formed in a cylindrical shape so as to surround the wrap portion 3.

Further, the tooth top surface 3A of the wrap portion 3 has
A concave groove 5 having a U-shaped cross-section that opens toward a tooth bottom surface 8A of an end plate 8 of an orbiting scroll 7 described later is formed.
Extends spirally along the longitudinal direction of the wrap portion 3. Then, a seal member 6 described later is inserted into the groove 5.

Reference numeral 6 denotes a seal member inserted into the groove 5 of the wrap portion 3. The seal member 6 is formed in a rectangular cross section and extends spirally along the longitudinal direction of the groove 5. ing. Further, the seal member 6 is inserted into the concave groove 5 with a gap so that it can be moved up, down, left, right and the like in the concave groove 5.

During the compression operation, compressed air in the compression chamber 15, which will be described later, flows from the direction of the arrow A in FIG.
When it enters the inside, the seal member 6 floats in the groove 5 so as to be in sliding contact with the tooth bottom surface 8A of the end plate 8 of the orbiting scroll 7, and hermetically seals between the tooth bottom surface 8A of the end plate 8 and the wrap portion 3. To do.

Reference numeral 7 denotes an orbiting scroll which is provided so as to be able to orbit in the casing so as to face the fixed scroll 1, and the orbiting scroll 7 has a disk-shaped end plate 8 having a tooth bottom surface 8A on the surface side. A spiral wrap portion 9 which is erected from the tooth bottom surface 8A of the end plate 8 toward the end plate 2 of the fixed scroll 1, and is formed in the same manner as the wrap portion 3 of the fixed scroll 1, and the center of the back side of the end plate 8 Boss 1 provided on the
0, and the boss portion 10 is a drive shaft 1 described later.
It is rotatably attached to the third crank 13A.

Further, the tooth top surface 9A of the lap portion 9 has
Similar to the wrap portion 3 of the fixed scroll 1, the concave groove 1 having a U-shaped cross section that extends spirally along the longitudinal direction of the wrap portion 9.
1 is provided. A seal member 12 similar to the seal member 6 described above is movably inserted in the groove 11.

During the compression operation, the compression chamber 15
When the compressed air therein enters the concave groove 11, the seal member 12 floats so as to be in sliding contact with the tooth bottom surface 2A of the end plate 2 of the fixed scroll 1, and the gap between the tooth bottom surface 2A of the end plate 2 and the wrap portion 9 is reached. It is an airtight seal.

Reference numeral 13 denotes a drive shaft rotatably provided in the casing. The drive shaft 13 is a crank 13A having a tip end side extending into the casing. The crank 13A has its axis O2-O2 which is the axis O1-of the drive shaft 13. It is eccentric by a predetermined dimension δ with respect to O1. Then, the crank 13A of the drive shaft 13 rotatably supports the boss portion 10 of the orbiting scroll 7 via the orbiting bearing 14, and causes the orbiting scroll 7 to orbit through the rotation preventing mechanism (not shown) or the like. To give.

Here, in the fixed scroll 1 and the orbiting scroll 7, the wrap portion 9 of the orbiting scroll 7 is the wrap of the fixed scroll 1 with the axis O2-O2 eccentric with respect to the axis O1-O1 by the dimension δ. It is arranged so as to be superposed on the portion 3 while being offset by a predetermined angle in the circumferential direction.
As a result, when the orbiting scroll 7 is orbited with respect to the fixed scroll 1, a plurality of crescent-shaped compression chambers 15 and 1 are continuously reduced in volume between the wrap portions 3 and 9.
5, ... are to be defined.

Reference numerals 16 and 17 denote a suction port and a discharge port formed in the fixed scroll 1. The suction port 16 is bored on the outer peripheral side of the end plate 2 so as to communicate with the compression chamber 15 on the outermost peripheral side, and discharge is performed. The port 17 is formed in the center of the end plate 2 so as to communicate with the innermost compression chamber 15.

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

First, when the drive shaft 13 is rotationally driven by a drive source (not shown) such as a motor from the outside of the casing, this rotation is transmitted from the crank 13A of the drive shaft 13 to the orbiting scroll 7 via the orbiting bearing 14. Thus, the orbiting scroll 7 makes an orbiting motion with an orbiting radius of dimension δ about the axis O1 -O1 of the drive shaft 13.

The compression chambers 15, 15, ... Defined between the lap portions 3, 9 by this swiveling motion are continuously reduced toward the center side, and the air sucked from the suction port 16 is sequentially compressed. While compressed, this compressed air is discharged from the discharge port 17
From an external air tank (not shown) or the like.

During this compression operation, the compressed air in the compression chamber 15 on the high pressure side enters the concave grooves 5 and 11,
The pressure of the compressed air presses the seal members 6, 12 toward the tooth bottom surfaces 8A, 2A of the facing end plates 8, 2. As a result, the seal members 6 and 12 move toward the tooth bottom surfaces 8A and 2A and come into sliding contact with the tooth bottom surfaces 8A and 2A, and the wrap portion 3
Each compression chamber 15 defined between 9 is hermetically sealed.

[0017]

By the way, in the above-mentioned prior art, the seal members 6, 12 are utilized by utilizing the pressure of the compressed air in the compression chamber 15 on the high pressure side during the compression operation.
Is brought into sliding contact with the tooth bottom surfaces 8A and 2A of the end plates 8 and 2 to hermetically seal the compression chambers 15.

However, in the compression chambers 15 located on the outer peripheral side of the scrolls 1 and 7 among the compression chambers 15, a pressure difference is generated between the compression chamber 15 and the adjacent compression chambers 15 before and after. Therefore, the seal members 6 and 12 are levitated toward the tooth bottom surfaces 8A and 2A of the end plates 8 and 2, and the tooth bottom surfaces 8A and 2A are
Sufficient pressure for sliding contact with A cannot be obtained, and the sealing properties of the seal members 6 and 12 deteriorate. As a result, there is a problem in that the air once sucked into the outermost peripheral compression chamber 15 cannot always be effectively compressed, and the compression efficiency is significantly reduced.

Further, in the prior art, when the seal members 6 and 12 are in sliding contact with the tooth bottom surfaces 8A and 2A of the end plates 8 and 2 during the compression operation, the bottom surfaces of the concave grooves 5 and 11 and the seal members 6 and 6 are in contact with each other.
A gap is formed between the groove 12 and the groove 12.
Inside, the wrap portions 3 and 9 communicate with each other from the center side toward the outer peripheral side. As a result, the compressed air in each compression chamber 15 travels through this gap and is located on the outer peripheral side.
However, there is a problem in that the airtightness of each compression chamber 15 is impaired and the compression efficiency is reduced.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a scroll type fluid machine capable of improving the sealing property of a seal member and improving the compression efficiency. I am trying.

[0021]

In order to solve the above-mentioned problems, a scroll type fluid machine of the present invention is a fixed scroll in which a spiral wrap portion is erected on the tooth bottom surface of an end plate.
A revolving scroll that is provided so as to face the fixed scroll, and a spiral wrap portion is erected on the tooth bottom surface of the end plate so as to define a plurality of compression chambers with the wrap portion of the fixed scroll. At least one of the wrap portions of the fixed scroll and the orbiting scroll is provided with a groove that extends along the tooth top surface of the wrap portion, and in the groove, a mating tooth bottom surface is formed. A configuration is adopted in which a sealing member that is in sliding contact is inserted.

The features of the configuration adopted by the present invention are as follows:
A bottomed fitting hole is formed in the bottom of the groove at a required interval in the lengthwise direction of the groove, and a protrusion that fits in the fitting hole is provided in the seal member. It is formed of an elastic material having a large coefficient of thermal expansion.

[0023]

With the above structure, when the compression heat is generated in each compression chamber when, for example, the compression operation is started, the projection of the seal member is thermally expanded by the compression heat at this time. Then, due to this thermal expansion, the protrusion of the seal member expands in the fitting hole of the concave groove,
Since the seal member is tightly fitted in the fitting hole, the seal member is held in sliding contact with the tooth bottom surface of the other party, and airtightness can be ensured even in the outermost compression chamber and the like. .

[0024]

Embodiments of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the conventional technique shown in FIGS. 7 to 9 are designated by the same reference numerals and the description thereof will be omitted.

First, FIGS. 1 to 4 show a first embodiment of the present invention.

In the figure, reference numeral 21 designates a groove formed on the tooth top surface 3A of the wrap portion 3. The groove 21 is formed in a U-shaped cross section in the same manner as the groove 5 described in the prior art. The wrap portion 3 extends in a spiral shape along the length direction. But,
In the bottom surface of the concave groove 21 according to the present embodiment, a plurality of bottomed and circular fitting holes 21A are arranged at a required interval in the longitudinal direction of the concave groove 21, specifically, as shown in FIG. Wrap part 3
Is formed in two places for each turn (one for each 180 °), and the hole diameter is the same as the widthwise dimension of the concave groove 21 as shown in FIG.

Reference numeral 22 denotes a seal member inserted into the concave groove 21 of the wrap portion 3. The seal member 22 is formed in substantially the same manner as the seal member 6 described in the prior art, but the seal member is formed. 22 is integrally formed with a plurality of columnar protrusions 22A that protrude downward from the lower side surface of the seal member 22 that faces the bottom surface of the concave groove 21. And
The projections 22A of the seal member 22 are arranged with a required gap so as to correspond to the fitting holes 21A of the recessed groove 21, and are fitted in the fitting holes 21A. There is. Also, as shown in FIG. 2, the outer diameter of each protrusion 22A is formed to be the same as the width dimension of the seal member 22, and each of the fitting holes 21A is fitted with a slight gap therebetween. It is formed to be slightly smaller than the hole diameter of the hole 21A. As a result, the seal member 22 can be moved upward, downward, left, right, etc. within the concave groove 21 by the pressure during the compression operation.

Here, the seal member 22 according to the present embodiment.
Is an elastic resin material (for example, polytetrafluoroethylene (PTFE)) having a thermal expansion coefficient higher than that of the material (for example, aluminum or aluminum alloy) forming the wrap portion 3.
Fluorine-based resin) and is greatly expanded by the heat of compression during compression operation. When the sealing member 22 is thermally expanded by the compression heat, each projection 22A expands in diameter as shown by a chain double-dashed line in FIG.
The outer peripheral surface of each protrusion 22A is tightly fitted into each fitting hole 21A.

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, a plurality of fitting holes 21A are formed in the bottom surface of the recessed groove 21 at a predetermined interval in the lengthwise direction of the recessed groove 21, and the recessed groove 21 is provided with the recessed holes 21A. The seal member 22 having the projections 22A fitted therein is inserted into the fitting holes 21A of the groove 21, and the seal member 2 is formed.
Since 2 is made of a material having a coefficient of thermal expansion larger than that of the wrap portion 3, it is possible to obtain the following operational effects by utilizing the fact that the sealing member 22 is thermally expanded by the compression heat during the compression operation. You can

That is, after the compression operation is started, each compression chamber 15
When the compressed air therein enters the groove 21 in the direction of the arrow B in FIG. 2, the seal member 22 is slidably contacted with the tooth bottom surface 8A of the end plate 8 of the orbiting scroll 7 as shown in FIG. Then, the tooth bottom surface 8A and the lap portion 3 are airtightly sealed. When the compression heat generated by the compression of air is generated in each compression chamber 15, the seal member 22 is thermally expanded by this, so that each projection 22A of the seal member 22 expands as shown by a chain double-dashed line in FIG. And the outer peripheral side of each projection 22A is strongly fitted into each fitting hole 21A,
The protrusions 22A are immovably fixed in the fitting holes 21A. As a result, the seal member 22 is held in a state of sliding contact with the tooth bottom surface 8A of the other party, and fixed between the tooth bottom surface 8A and the lap portion 3 while being hermetically sealed.

Thus, according to the present embodiment, the seal member 22 is thermally expanded by the compression heat during the compression operation, and the diameter of the projection 22A of the seal member 22 is increased so that the inside of each fitting hole 21A of the concave groove 21 is expanded. The seal member 2 by strongly fitting to the
Since 2 can be held in a state of slidingly contacting the tooth bottom surface 8A of the other party, the sealing member 22 can keep airtightly sealing between the tooth bottom surface 8A of the other party and the lap portion 3 during the compression operation. The airtightness of each compression chamber 15 can be effectively ensured.

Therefore, in the compression chambers 15 located on the outer peripheral sides of the scrolls 1 and 7, the compression chambers 1 before and after the adjacent scroll chambers 1 and 7 are adjacent to each other.
Even if the pressure difference between the five is not so great, the seal member 22 can be surely brought into sliding contact with the tooth bottom surface 8A of the other side, and for example, the air sucked into each compression chamber 15 on the outermost peripheral side leaks to the outside. Can be effectively prevented, and the compression efficiency can be greatly improved.

Further, when the seal member 22 is thermally expanded by the compression heat during the compression operation, each protrusion 2 of the seal member 22 is expanded.
2A is strongly fitted in the fitting hole 21A of the concave groove 21, and is pressed against both side surfaces of the concave groove 21 in the width direction. As a result, the floating of the seal member 22 prevents the gaps S1 formed between the seal member 22 and the bottom surface of the concave groove 21 from communicating with each other in the lengthwise direction of the wrap portion 3 of the protrusion 22A. It is possible to shut off at a position, and it is possible to reliably prevent compressed air from leaking from the innermost circumferential compression chamber 15 through these gaps S1 to the outside, and more reliably compensate the airtightness of each compression chamber 15. be able to.

Next, FIGS. 5 and 6 show a second embodiment of the present invention.
The feature of this embodiment is that a plurality of protrusions having a diameter smaller than the width dimension of the seal member are formed in the length direction on the lower surface side of the seal member, and There is formed a plurality of lip portions which are located at, and which protrude from the lower surface side of the seal member and which elastically contact the bottom portion of the concave groove.

In the figure, reference numeral 31 denotes a groove formed on the tooth top surface 3A of the wrap portion 3. The groove 31 is formed in substantially the same manner as the groove 21 described in the first embodiment. A plurality of bottomed fitting holes 31A are formed on the bottom surface in the lengthwise direction of the concave groove 31 at a required interval. However, the groove 31
The fitting hole 31A of the
Corresponding to the outer diameter of A, the fitting hole 21 described in the first embodiment
The diameter is smaller than A.

Reference numeral 32 denotes a seal member inserted into the concave groove 31 of the wrap portion 3. The seal member 32 is formed in substantially the same manner as the seal member 22 described in the first embodiment.
Each of the fitting holes 3 of the concave groove 31 is formed on the lower surface of the seal member 32.
Although the protrusion 32A is integrally formed at a position corresponding to 1A, the diameter of each protrusion 22A is equal to that of the seal member 3A.
It is formed to be smaller than the width dimension of 2, and is fitted with a slight gap in the fitting hole 31A of the corresponding concave groove 31.

Further, each protrusion 32A is provided on the seal member 32.
, A plurality of lip portions 32B, 32B, ... Are arranged in a row in the length direction on the lower surface of the seal member 32, and each of the lip portions 32B is bent in a substantially V-shape to form a seal member 32. It is integrally formed on the lower surface. And each of the lip portions 3
The tip end side of 2B elastically supports the seal member 32 by abutting the bottom surface of the concave groove 31, whereby
The seal member 32 is pressed against the tooth bottom surface 8A of the other party.

Here, the seal member 32 according to the present embodiment.
Like the first embodiment, is made of a resin material having a large coefficient of thermal expansion, and is greatly expanded by the compression heat during the compression operation. When the seal member 32 expands due to the compression heat, each protrusion 32A expands in diameter as shown by a chain double-dashed line in FIG.
A is strongly fitted into each fitting hole 31A.

Thus, in the scroll type air compressor constructed as described above, substantially the same operation and effect as in the first embodiment can be obtained. In particular, in this embodiment, the seal member 32 is provided with each lip portion 32B. Are integrally formed, and the seal member 32 is pressed against the tooth bottom surface 8A of the other party, so that the seal member 32 can always be slidably contacted toward the tooth bottom surface 8A of the other party, and Airtightness can be reliably improved.

The lower surface of the seal member 32 and the concave groove 31
The lips 32B can block the gap S2 formed between the wrap portion 3 and the bottom surface of the wrap portion 3 from communicating with each other in the length direction of the lap portion 3, and the gap S2 from the compression chamber 15 on the innermost peripheral side can be prevented. It is possible to reliably prevent the compressed air from leaking to the outside, and it is possible to significantly improve the compression efficiency.

In each of the above embodiments, the groove 21 (31) is formed in the wrap portion 3 of the fixed scroll 1, and the groove 2 is formed.
Although the seal member 22 (32) is provided in the 1 (31), the present invention is not limited to this. For example, the wrap portion 9 of the orbiting scroll 7 may be formed with a concave groove having each fitting hole. Alternatively, a seal member having each protrusion or the like may be provided in the concave groove.

In each of the above embodiments, the seal member 22
Although (32) is described as being formed of a material having a large coefficient of thermal expansion together with the protrusion 22A (32A), the present invention is not limited to this, and for example, only the protrusion 22A (32A) is thermally expanded by a fluorine resin or the like. It may be formed of a material having a high rate.

Further, in each of the above embodiments, the concave groove 21 (3
Each fitting hole 21A (31A) and seal member 22 of 1)
Although it has been described that the protrusions 22A (32A) of (32) are provided in two places each time the wrap portion 3 makes one turn, the present invention is not limited to this, and one place is made each time the wrap portion 3 makes one turn. ,
Alternatively, three or more positions may be provided for each winding of the wrap portion 3. Further, the sectional shape of the protrusion 22A (32A) is not limited to a circular shape, and may be a polygonal shape.

Furthermore, in each of the above-mentioned embodiments, the scroll type air compressor has been described as an example of the scroll type fluid machine, but it can be widely applied to, for example, a vacuum pump, a refrigerant compressor and the like.

[0046]

As described in detail above, according to the present invention, bottomed fitting holes are formed in the bottom of the groove at a required interval in the lengthwise direction of the groove, and the sealing member is fitted with the fitting hole. Since the protrusion that fits into the dowel is provided and the protrusion is made of an elastic material having a large coefficient of thermal expansion, for example, when the protrusion of the seal member thermally expands due to compression heat during compression operation, the seal By tightly fitting the protrusion of the member into the fitting hole, it is possible to hold the seal member in a state of sliding contact with the tooth bottom surface of the mating member, which allows the fluid once sucked into the compression chamber on the outermost peripheral side to be retained. Leakage to the outside can be reliably prevented, and each compression chamber can be kept airtightly sealed by the seal member, so that the compression efficiency can be greatly improved.

[Brief description of drawings]

FIG. 1 is a view showing a fixed scroll, orbiting scroll, etc. of a scroll type air compressor according to a first embodiment of the present invention.
It is sectional drawing of a position similar to.

FIG. 2 is a longitudinal sectional view of an essential part showing an enlarged view of a tooth top of a lap portion, a seal member and the like in FIG.

3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view of the seal member at the same position as in FIG. 3, showing the seal member during compression operation.

FIG. 5 is a vertical cross-sectional view showing the second embodiment of the present invention at the same position as in FIG.

6 is a sectional view taken along the line VI-VI in FIG.

FIG. 7 is a vertical cross-sectional view showing a fixed scroll, an orbiting scroll, seal members, and the like of a scroll air compressor according to a conventional technique.

8 is a sectional view taken along the line VIII-VIII in FIG.

9 is a longitudinal sectional view showing an enlarged main part in FIG.

[Explanation of symbols]

 1 Fixed scroll 2,8 End plate 2A, 8A Teeth bottom surface 3,9 Lap part 7 Orbiting scroll 15 Compression chamber 21,31 Recessed groove 21A, 31A Fitting hole 22,32 Seal member 22A, 23A Projection part

Claims (1)

[Claims] 1. A fixed scroll in which a spiral wrap portion is erected on a tooth bottom surface of an end plate, and a plurality of fixed scrolls provided on the end surface of an end plate of the end plate and a wrap portion of the fixed scroll. And a revolving scroll in which a spiral wrap portion is erected so as to define a compression chamber, and at least one of the wrap portions of the fixed scroll and the revolving scroll has a wrap portion of the wrap portion. In a scroll type fluid machine in which a groove extending along a tooth crest is formed, and a seal member slidingly contacting a tooth bottom surface of a mating member is inserted into the groove, the groove is formed at the bottom of the groove. A bottomed fitting hole is formed at a required interval in the longitudinal direction of the seal member, and the sealing member is provided with a protrusion that fits in the fitting hole. The protrusion is made of an elastic material having a large coefficient of thermal expansion. Scroll type fluid machine characterized by Machinery.