JP3138112B2 - 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 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 FIGS. 4 to 7 show a scroll type air compressor as a scroll type fluid machine according to the prior art.

[0003] In the drawings, reference numeral 1 denotes a drive shaft rotatably provided on a casing (not shown), and a tip end side of which serves as 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 a disk-shaped end plate 3, a spiral wrap portion 4 erected from the tooth bottom 3 </ b> A of the end plate 3 at the center side as a winding start end and at the outer periphery side as a winding end end, A boss 5 is provided at the center of the rear side of the end plate 3. Here, as shown in FIG. 6, the wrap portion 4 has a concave groove 4B extending from the outer peripheral side to the inner peripheral side of the wrap portion 4 along the tooth tip surface 4A.
Is formed, and a seal member 7 to be described later is floatably inserted into the concave groove 4B. The crank 1 </ b> A of the drive shaft 1 is rotatably mounted in the boss portion 5 via a swing bearing 6.

[0004] Reference numeral 7 denotes a sealing member provided in the concave groove 4B of the wrap portion 4, and the sealing member 7 is formed in a string shape having a substantially square cross section as shown in FIG. Is loosely fitted with a gap over the entire circumference.

Reference numeral 8 denotes a fixed scroll fixed to the casing so as to face the orbiting scroll 2. The fixed scroll 8 is a disk disposed so that its center coincides with the axis O1-O1 of the drive shaft 1. A mirror-shaped end plate 9, a spiral wrap portion 10 erected from the tooth bottom 9A of the end plate 9 in the same manner as the wrap portion 4 of the orbiting scroll 2, and a wrap portion 10 located on the outer peripheral side of the end plate 9 And a support portion 11 formed in a cylindrical shape so as to surround the support portion.

[0006] Here, like the wrap portion 4 of the orbiting scroll 2, the wrap portion 10 has a groove 1 in the tooth tip surface 10A.
0B is formed, and the sealing member 7 is provided in the concave groove 10B.
A seal member 12 similar to that described above is loosely fitted over the entire circumference with a gap.

[0007] Each of the scrolls 2 and 8 configured as described above has an axis O of the orbiting scroll 2 as shown in FIG.
In a state where 2-O2 is eccentric with respect to the axis O1-O1 of the fixed scroll 8 by a distance δ, the wrap portion 4 of the orbiting scroll 2 is shifted by a predetermined angle with respect to the wrap portion 10 of the fixed scroll 8 so as to overlap. It is arranged in. Thus, when the orbiting scroll 2 is turned with respect to the fixed scroll 8, a plurality of compression chambers 13, 13,.

Reference numerals 14 and 15 denote a suction port and a discharge port formed in the fixed scroll 8, respectively.
4 is formed on the outer peripheral side of the end plate 9 so as to communicate with the compression chamber 13 on the outermost peripheral side, and the discharge port 15 is connected to the compression chamber 1 on the most central side.
The end plate 9 is formed so as to communicate with the center plate 3.

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

First, a drive shaft 1 is driven by a motor (not shown).
When this is driven to rotate, this rotation causes the crank 1 of the drive shaft 1 to rotate.
A through the orbit bearing 6 to the orbiting scroll 2, whereby the orbiting scroll 2 is moved to the fixed scroll 8.
About the axis O1 -O1 of FIG.

Here, the compression chambers 13, 13,... Defined between the wrap portions 4, 10 by the swirling motion are continuously reduced, and the air sucked from the suction port 14 is supplied to the inside of each compression chamber 13. By sequentially compressing, the central compression chamber 13
The higher the pressure, the more the grooves 4B, 10B
The seal members 7 and 12 provided therein are pressed against the outer peripheral surfaces of the concave grooves 4B and 10B from the inside by the pressure of the compressed air, respectively, and from the inside of the concave grooves 4B and 10B by the pressure of the air. Float as shown in FIG.
9, the tip surfaces 4A and 10A of the wrap portions 4 and 10 of the orbiting scroll 2 and the fixed scroll 8 and the tooth bottoms 3A,
Airtightly seal between 9A.

The compression chambers 13, 13,... Defined between the wrap portions 4, 10 are continuously reduced by the swirling motion, and the air sucked from the suction port 14 is supplied to the inside of each compression chamber 13. The compressed air is discharged from the discharge port 15 to an external air tank (not shown) or the like while being sequentially compressed.

[0013]

By the way, in the above-mentioned prior art, the compression heat is generated during the compression action in each of the compression chambers 13 between the orbiting scroll 2 and the fixed scroll 8, and the compression heat is generated by this compression heat. The scrolls 2, 8
Becomes hot. In addition, since the pressure gradually increases from the outer compression chamber 13 to the center compression chamber 13, the wrap portions 4 and 10 extend radially outward from the center as shown by the characteristic lines in FIG. Such a temperature gradient occurs.

That is, when the compression chamber 13 on the center side has a higher temperature than the compression chamber 13 on the outer peripheral side and the discharge pressure reaches the discharge pressure during rated operation, for example, a pressure of about 0.83 MPa, each scroll 2 The temperature on the central side of 8 rises to 200 ° C. or higher.

For this reason, in the prior art, each wrap portion 4,
The center side of 10 thermally expands, and the inner peripheral side portions of the sealing members 7 and 12 are strongly pressed against the tooth bottoms 3A and 9A of the end plates 3 and 9 without floating from the concave grooves 4B and 10B. There is a problem that the inner peripheral side portion is abraded early due to strong sliding contact with the tooth bottoms 3A and 9A, and the sealing performance may be impaired.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can effectively seal a gap between a tooth tip surface of each lap portion and a tooth bottom of a counterpart by a sealing member. An object of the present invention is to provide a scroll-type fluid machine capable of improving reliability and extending the life of a seal member.

[0017]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problem, the present invention adopts a feature that at least one of the wrap portions of the orbiting scroll and the fixed scroll has a tooth of the wrap portion. A concave groove extending from the outer peripheral side to the inner peripheral side of the wrap portion is formed along the front surface, and the concave groove is fixed to the concave groove on the inner peripheral side of the wrap portion. A spiral seal member floating in the concave groove on the outer peripheral side is provided.

[0018]

According to the above construction, even when a gap (clearance) is previously formed between the tooth tip of the lap portion and the tooth bottom of the counterpart, if the orbiting scroll starts to orbit with respect to the fixed scroll, the orbiting scroll will not move. Alternatively, on the outer peripheral side of the wrap portion of the fixed scroll, the sealing member floats from the inside of the concave groove and makes close sliding contact with the other end plate (tooth bottom), so that the fluid can be reliably contained at least in the compression chamber on the outer peripheral side,
Can be compressed to about intermediate pressure.

Since the wrap portion on the inner peripheral side thermally expands due to the heat of compression at this time, the dimension from the root to the tip of the tooth is made small in advance in consideration of the amount of thermal expansion. During operation, the gap between the inner peripheral side lap portion and the mating tooth bottom can be set to an appropriate size, and the seal member fixed to the inner peripheral side lap portion can be prevented from being worn or damaged.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the figure, 21 is a casing, 22 is a casing main body which constitutes the casing 21 together with a front casing 23 which will be described later. The casing main body 22 has a disc-shaped bottom 22A and an outer peripheral side of the bottom 22A which will be described later. Cylindrical portion 22B extending toward the fixed scroll 34 side
And a cylindrical bearing portion 22 formed on the inner peripheral side of the bottom portion 22A.
C to form a stepped cylindrical shape with a bottom.

Reference numeral 23 denotes a cylindrical portion 22 of the casing body 22.
B shows a stepped cylindrical front casing integrally formed so as to protrude inward in the radial direction from the tip end side.
The orbiting scroll 2 which is located on the inner peripheral side
7, a thrust receiving portion 23A slidingly contacting the back side of the thrust receiving member 7 to receive a load in the thrust direction, and a plurality of notches 23B located on the inner peripheral side of the thrust receiving portion 23A and formed at predetermined intervals in the circumferential direction. , 23B,... (Only two are shown).

Reference numeral 24 denotes a bearing portion 22C of the casing body 22.
2 shows a drive shaft rotatably supported via bearings 25 and 26. The tip end of the drive shaft 24 extends into the casing 21 to become a crank 24A, and the axis O3-O3 of the crank 24A is shown in FIG. As shown in FIG.
It is eccentric by a predetermined dimension d with respect to -O4. The base end of the drive shaft 24 is connected to an electric motor (not shown) outside the casing 21 and is driven to rotate by the electric motor.

Reference numeral 27 denotes a turning scroll which is located in the casing 21 and is provided on the crank 24A of the drive shaft 24 so as to be turnable. The turning scroll 27 comprises a disk-shaped mirror plate 28 and a mirror plate 28. And a spiral wrap portion 29 erected from the tooth bottom 28A, and a boss portion 30 described later.

Here, the wrap portion 29 has dimensions H1, H2, H3, H4, H from the inner peripheral side to the outer peripheral side of the height dimension H from the tooth bottom 28A to the tooth tip surface 29A.
5, H6,..., These dimensions H1 to H6 are

[0026]

.Times..times..times..times..times..times..times..times..times..times..tim- es..times..times..times..times. A groove 29B extending from the inner peripheral side to the outer peripheral side is formed along the lap portion 29 on the tooth tip surface 29A in substantially the same manner as the concave groove 4B described in the related art.

In this case, the temperature of the lap portion 29 is, for example, 120 to 130 ° C. as shown by the characteristic line in FIG.
In the range where the width of the wrap portion 29 suddenly changes, a range of about two turns from the center side of the wrap portion 29 becomes a small width portion 29B1 having a small groove width, and a large portion 29 having a larger groove width on the outer peripheral side than the small width portion 29B1.
B2.

Reference numeral 30 denotes a boss provided at the center of the rear surface 28B of the end plate 28, and a crank 24A is mounted in the boss 30 via a turning bearing 31.

Numeral 32 denotes a plurality of key grooves 32 provided on the outer peripheral side of the back surface 28B of the end plate 28.
Are formed at predetermined intervals in the circumferential direction.
An Oldham coupling 33 as a rotation preventing mechanism is disposed between the front casing 23 and each notch 23 </ b> B of the front casing 23. When the drive shaft 24 is driven to rotate, the orbiting scroll 27 is provided with a circular motion having a turning radius of dimension d by the crank 24A, and rotation is prevented by the Oldham coupling 33. It keeps turning (orbiting) around the axis.

Reference numeral 34 denotes a fixed scroll provided so as to cover the front end of the front casing 23 so as to cover the front end of the casing 21. The center of the fixed scroll 34 is the axis O4 of the drive shaft 24. A head plate 35 arranged at the center so as to coincide with -O4;
A spiral wrap portion 36 erected from A in the same manner as the wrap portion 29 of the orbiting scroll 27, and a tube formed so as to surround the outer peripheral side of the end plate 35 and abuts on the outer peripheral side of the front end surface of the front casing 23. And a unit 37. Then, the wrap portion 29 of the orbiting scroll 27 is attached to the wrap portion 36 of the fixed scroll 34 by a predetermined angle (for example, 180 degrees).
Degrees) and overlap with each other.

Here, the wrap portion 36 of the fixed scroll 34 has a height dimension from the tooth bottom 35A to the tooth tip surface 36A from the inner circumferential side to the outer circumferential side, like the wrap portion 29 of the orbiting scroll 27. It is formed so as to gradually increase. On the tooth tip surface 36A of the wrap portion 36, like the concave groove 29B provided in the wrap portion 29 of the orbiting scroll 27, a small width portion 36B1 is formed on the inner peripheral side and a large width is formed on the outer peripheral side. A concave groove 36B which is a large portion 36B2 is formed.

Reference numerals 38, 38,... Denote a plurality of compression chambers defined between the wrap portion 29 of the orbiting scroll 27 and the wrap portion 36 of the fixed scroll 34. Each of the compression chambers 38 is a wrap of the fixed scroll 34. While the orbiting scroll 27 makes an orbital movement with respect to the portion 36, the inner volume thereof is formed so as to be sequentially reduced. Each of the compression chambers 38
As the orbiting scroll 27 orbits, air is taken in from a suction port 39 to be described later, and the air is sequentially compressed.

Reference numeral 39 denotes a suction port formed in the cylindrical portion 37 of the fixed scroll 34. The suction port 39 is formed such that the wrap portion 29 is positioned between the wrap portion 29 and the wrap portion 36 of the fixed scroll 34 when the orbiting scroll 27 is turned. It communicates with the outermost compression chamber 38 to be formed.

Reference numeral 40 denotes a discharge port formed in the center of the end plate 35 of the fixed scroll 34. The discharge port 40 communicates with the compression chamber 38 on the most central side (high pressure side).

Reference numeral 41 denotes an oil scraper located in the casing body 22 and fitted and fixed to the drive shaft 24.
Is disposed so that the tip side thereof comes into contact with an oil liquid L such as lubricating oil stored in the casing 21. The oil scraper 41 supplies the oil liquid L to the bearing 25, the slewing bearing 31, the thrust receiving portion 23A of the front casing 23 and the like by scraping up the oil liquid L when the drive shaft 24 rotates.
These are cooled and lubricated. 42 is oil scraper 4
The counter weight 42 is used to balance the rotation of the drive shaft 24.

Reference numeral 43 denotes a seal member provided in the concave groove 29B of the wrap portion 29.
As shown in the figure, the inner peripheral portion 43A and the outer peripheral portion 43B are integrally connected via a connecting portion 43C in the circumferential direction, and are formed in a single spiral as a whole. It is not necessary to form the seal member 43 on the spiral in advance, and the seal member 43 may be spirally bent when the seal member 43 is mounted in the concave groove 29B.

Here, the inner peripheral portion 43A is made of a resin material in which a liquid crystal polymer or the like is blended with a carbon base material so that the inner peripheral side of the wrap portion 29 has a high temperature, so that heat resistance and abrasion resistance are enhanced. The outer peripheral portion 43B is made of a fluororesin base material so as to have high airtightness and self-lubricating property. The inner peripheral portion 43A and the outer peripheral portion 43B are connected by a connecting portion 43C made of a flexible material so as to be bendable and not to leak air in the radial direction. The inner peripheral portion 43A of the seal member 43 is fixed to the small width portion 29B1 of the concave groove 29B with a spiral of about two turns from the center side, and the outer peripheral portion 43B is floated within the large portion 29B2 of the concave groove 29B. Is mounted in a loose fit state.

A seal member 44 similar to the seal member 43 is also attached to the wrap portion 36 of the fixed scroll 34, and the inner peripheral portion 44A has a small width portion 36 of the concave groove 36B.
The outer peripheral portion 44B is fixed in the large portion 36B2 of the concave groove 36B in a loosely fit state with a gap so as to float. The inner peripheral portion 44A and the outer peripheral portion 44B are connected by a connecting portion 44C made of a flexible material so as to be bendable and not to leak air in the radial direction.

It should be noted that 45, 45 are each of the suction ports 39
, A discharge pipe for guiding compressed air discharged from the discharge port 40 to an air tank (not shown); 47, a cooling fan provided on the drive shaft 24; The pulley fixed to the base end side of the drive shaft 24 is shown.

The scroll type air compressor according to the present embodiment has the above-described structure. When the drive shaft 24 is driven to rotate by the electric motor via the pulley 48, the belt and the like, the rotation is performed from the crank 24A to the slewing bearing. The information is transmitted to the orbiting scroll 27 via 31. As a result, the orbiting scroll 27 orbits around the axis of the drive shaft 24 with a turning radius of a predetermined dimension d, and by this orbiting motion, external air is supplied from the suction port 39 to the outermost compression chamber 3.
Suck into 8. Each of the compression chambers 38 is continuously reduced, and the compressed air is sent from the discharge port 40 to the external air tank through the discharge pipe 46 while being sent to the inner compression chamber 38 for compression. Etc.

In this embodiment, however, the orbiting scroll 2
7 is formed so that the height H from the tooth bottom 28A to the tooth tip surface 29A of the end plate 28 gradually increases from the inner peripheral side to the outer peripheral side, and the concave groove 29B is formed along the tooth tip surface 29A.
On the other hand, inside the concave groove 29B, the inner peripheral portion 43A of the seal member 43 is fixed on the inner peripheral side, and the outer peripheral side of the concave groove 29B is connected to the inner peripheral portion 43A via the connecting portion 43C. The fixed outer periphery 43B is inserted and provided so as to be able to float from the concave groove 29B, and the fixed scroll 34 and the seal member 44 are also configured in the same manner.

That is, when the orbiting scroll 27 and the fixed scroll 34 are brought into contact with each other, the gap between the tooth tip surfaces 29A and 36A of the wrap portions 29 and 36 and the tooth bottoms 28A and 35A of the other end plates 28 and 35 is obtained. As shown in FIG. 2, a gap (clearance) C is formed so as to gradually increase in size from the outer peripheral side to the inner peripheral side. Then, when the orbiting scroll 27 starts the orbiting motion with respect to the fixed scroll 34, the seal members 43 and 44 are removed from the grooves 29 </ b> B and 36 </ b> B on the outer peripheral sides of the wrap portions 29 and 36 of the orbiting scroll 27 and fixed scroll 34. The outer peripheral portions 43B and 44B float and come into close sliding contact with the other end plates 28 and 35 (the tooth bottoms 28A and 35A), so that air can be reliably contained at least in the compression chamber 38 on the outer peripheral side. Can be compressed to a degree.

Since the inner peripheral side of each of the wrap portions 29 and 36 rises in temperature due to the heat of air compression and expands as shown in FIG.
Tooth surface 29A, 36A on the inner peripheral side of 36 and tooth bottom 2 of the other party
8A and 35A can be reduced to an appropriate size to maintain airtightness, and air compressed to an intermediate pressure by the outer compression chamber 38 can be further compressed to a desired high pressure in the inner compression chamber 38. Can be compressed to a level.

Here, the tooth tip surface 2 of each wrap portion 29, 36
In 9A and 36A, the height H was made smaller toward the inner circumference side in consideration of the fact that the temperature rises sharply toward the inner circumference side of each of the wrap portions 29 and 36, and the tooth tip surface expands greatly. Even if the respective tooth top surfaces 29A, 36A expand toward the other end plates 28, 35 during the rated operation, the respective tooth top surfaces 29A, 36A
The seal members 43 and 44 fixed to the end plates 28 and 35
To prevent wear and damage at an early stage, and to prevent galling between the tooth top surfaces 29A and 36A.

Therefore, according to this embodiment, each wrap portion 2
9, 36 tooth tip surfaces 29A, 36A and the mating tooth bottom 28
A and 35A can be effectively sealed by the seal members 43 and 44, the compression efficiency can be reliably increased, and the service life of the seal members 43 and 44 can be extended to improve reliability. Can be done.

In the above embodiment, the case where the present invention is used as a scroll type air compressor has been described as an example. However, the present invention is not limited to this. For example, the present invention may be applied to a vacuum pump or a compressor for a cooling device. You may.

In the above embodiment, each of the concave grooves 29B, 3
The width of 6B is small on the inner peripheral side of each wrap portion 29, 36 and large on the outer peripheral side, and the inner peripheral portions 43A, 44A of each seal member 43, 44 are formed on the inner peripheral side of each groove 29B, 36B. The outer peripheral portions 4 of the seal members 43 and 44 are fitted and fixed.
3B and 44B have been described as loosely fitted with a gap on the outer peripheral side of each of the concave grooves 29B and 36B.
For example, each of the concave grooves 29B and 36B is formed to have the same width over the entire circumference, and an inner peripheral portion of about two turns from the center side of each of the seal members 43 and 44 is formed to have a wide width, and an outer peripheral portion than this is formed. Each of the grooves 29B, 36B is formed to have a narrow width, and the inner peripheral portions of the respective seal members 43, 44 are fitted and fixed to the inner peripheral sides of the respective concave grooves 29B, 36B.
The outer peripheral portions of the seal members 43 and 44 may be loosely fitted to the outer peripheral sides of B and 36B.

Further, each of the seal members 43 and 44 includes an inner peripheral portion 43A, 44A, an outer peripheral portion 43A, 44B, and a connection portion 4.
Although the description has been made as having three parts 3C and 44C, the seal members 43 and 44 may be integrally formed of a single material instead.

[0049]

As described above in detail, according to the present invention, at least one of the wrap portions of the orbiting scroll and the fixed scroll has the outer periphery of the wrap portion along the tooth surface of the wrap portion. A concave groove extending from the side to the inner peripheral side is formed, in which is fixed to the concave groove on the inner peripheral side of the wrap portion, and floats in the concave groove on the outer peripheral side of the wrap portion. Since the spiral seal member is provided, for example, when a gap is previously formed between the tooth tip of the lap portion and the tooth bottom of the other party,
When the orbiting scroll starts orbiting relative to the fixed scroll, on the outer peripheral side of the wrap portion of the orbiting scroll or the fixed scroll, the seal member floats from within the concave groove and comes into close sliding contact with the other end plate (tooth bottom), and At least in the compression chamber on the outer peripheral side, and the compression operation can be reliably performed. Since the wrap portion on the inner peripheral side thermally expands due to the compression heat at this time, the dimension from the tooth bottom to the tooth tip is made small in advance in consideration of the amount of the thermal expansion, so that, for example, during the rated operation, The gap between the peripheral lap and the tooth bottom of the other party can be set to an appropriate size,
The seal member fixed to the inner peripheral side wrap portion can be prevented from being worn and damaged, the life of the seal member can be extended, the compression efficiency can be increased, and the reliability can be improved.

[Brief description of the drawings]

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

FIG. 2 is an enlarged view of a main part in FIG.

FIG. 3 is an enlarged front view showing a seal member.

FIG. 4 is a longitudinal sectional view showing a main part of a scroll type air compressor according to the related art.

FIG. 5 is an enlarged sectional view showing a main part in FIG. 4;

FIG. 6 is an exploded perspective view showing a wrap portion and a seal member of the orbiting scroll.

FIG. 7 is a characteristic diagram showing a relationship between a distance from a center of a wrap portion of the scroll air compressor to a radially outward direction and a temperature of the wrap portion during rated operation.

[Explanation of symbols]

 Reference Signs List 21 casing 27 orbiting scroll 28 end plate 28A tooth bottom 29 lap portion 29A tooth tip surface 29B concave groove 34 fixed scroll 35 end plate 35A tooth bottom 36 lap portion 36A tooth tip surface 36B concave groove 43, 44 sealing member 43A inner peripheral portion 43B outer peripheral portion 43C connection

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-272401 (JP, A) JP-A 62-95101 (JP, U) JP-B-6-96963 (JP, B2) (58) Investigated Field (Int. Cl. ⁷ , DB name) F04C 18/02 311

Claims (1)

(57) [Claims] A casing, a orbiting scroll provided in the casing so as to be pivotable, and having a spiral wrap portion erected from a tooth bottom of a head plate, and fixed to the casing in opposition to the orbiting scroll; A scroll-type fluid machine including a fixed scroll in which a spiral wrap portion overlapping a wrap portion of an orbiting scroll from a tooth bottom of a head plate to form a compression chamber is provided, and a wrap between the orbiting scroll and the fixed scroll is provided. At least one of the wrap portions is formed with a concave groove extending from the outer peripheral side to the inner peripheral side of the wrap portion along the tooth surface of the wrap portion, and the wrap portion is formed in the concave groove. A scroll-type fluid machine provided with a spiral seal member fixed to the groove on the inner peripheral side and floating in the concave groove on the outer peripheral side of the wrap portion.