JP2001336487A - Sealing structure in scroll fluid machine and scroll fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure capable of obtaining excellent sealing characteristics with a simple structure and always equalizing sealing characteristics at each part of circumferential direction in a scroll fluid machine. SOLUTION: A dust seal 24 composed of a slide member 25 capable of coming in contact with the end of an opposite scroll and a pressure receiving part 26 integrally formed with the slide member and aimed to retain the pressure caused with an operation of the scroll fluid machine is engaged in a circular sealing groove 21 set up at an opposite face to both fixed rotating scrolls 22 and 23 in the scroll fluid machine. The slide member 25 is sealed by pressing the end face of the opposite scroll with pressure of the fluid caused by operation of the scroll fluid machine and the pressure retaining part 26 is sealed by pressing a side of a circular seal groove 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixed scroll in which a spiral fixed wrap is provided on the surface of a fixed end plate forming a compression chamber in a housing, and a spiral orbit wrap provided on the surface of the orbiting end plate. The orbiting scroll and the orbiting scroll are fitted to each other by being shifted from each other by 180 °, and the orbiting scroll is rotated by the drive shaft with respect to the fixed scroll. The present invention relates to a scroll-type vacuum pump or a scroll fluid machine such as a compressor that prevents rotation, and more particularly, to a structure of a seal member in such a machine.

[0002]

2. Description of the Related Art A scroll fluid machine as described in the preceding paragraph is well known to those skilled in the art, but for the sake of precaution, the description in JP-A-55-64180 will be described as an example. .

[0003] In this specification, the inner and outer circumferences are defined as
The radial direction of the fixed and orbiting scrolls is referred to, and the term “inside and outside” is also referred to in the axial direction.

In FIG. 7, (1) is a fixed end plate (1a) provided with a suction hole (9) and a discharge hole (10), and is directed inward (to the right in the figure) from the end plate (1a). A fixed scroll consisting of a wrap (1b) formed in an involute curved shape that stands upright or a curved shape approximating the curved shape, and a housing (6)
It is fixed to.

[0005] (2) is a turning-side end plate (2a) and this end plate (2a)
An orbiting scroll consisting of a wrap (2b) formed in an involute curved shape orthogonal to the outer direction (leftward in the figure) or a curved shape approximating this curve, and a bearing (5) is mounted on the housing (6). Drive shaft rotatably supported via
(3) is mounted eccentrically.

(4) an Oldham ring interposed between the end plate (2a) of the orbiting scroll (2) and the housing (6);
(7) is a housing chamber formed between the end plate (2a) and the housing (6), and (8) is a wrap (1b) of the fixed scroll (1) and a wrap (2b) of the orbiting scroll (2). ), (11) is a gas working chamber, and (12) is an annular seal groove provided in the seal portion (1c) of the fixed scroll (1).

A sealing member (13) is provided in the annular seal groove (12).
Are fitted together with an elastic body (14) provided on the outside thereof.

The scroll wraps (1b) and
A tip seal groove (not shown) having a concave cross section is formed at the tip end of (2b), and a chip seal (not shown) having wear resistance and self-lubricating properties is provided in each tip seal groove.

When the orbiting scroll (2) is eccentrically rotated through the drive shaft (3), the gas sucked from the suction hole (9) is
The scrolls (1) and (2) are confined in a closed space (8) formed by the wraps (1b) and (2b) and gradually compressed to a high temperature and a high pressure, and are discharged from a discharge hole (10).

The sealing member (13) prevents gas from leaking from the housing chamber (7) to the gas working chamber (11).

By the orbiting movement of the orbiting scroll (2), the seal member on the end face of the orbiting scroll (2) (not shown) slides on the end face of the fixed scroll (1). The surface roughness is smaller than the surface roughness of the end plate on the inner surface (sliding contact surface of the chip seal) than the sliding contact surface of the seal member. In consideration of the sealing property and abrasion property of the sealing member, the end plate surface roughness of the sliding contact surface of the sealing member is 0.0.
It is desirable that the thickness be 1 to 0.5 μmRa.

[0012]

In the prior art as described above, the seal member (13) is provided with an elastic body provided outside thereof.
According to (14), since the end plate (2a) of the orbiting scroll (2) is repressed, a certain sealing property can be obtained, but the sealing member (1
It is difficult to completely shut off the gas that is going to flow from the outer circumference to the inner circumference in 3).

That is, regardless of whether the scroll fluid machine is a compressor or a vacuum pump, there is a differential pressure between the inner and outer circumferences of the seal member (13).
Depending on the sealing property of (3) and the pressing force of the orbiting scroll (2) against the end plate (2a), the pressure or the degree of vacuum of the obtained compressed gas has a great influence.

Therefore, the gas having a differential pressure between the inner and outer circumferences is
Between the seal member (13) and the inner and outer peripheral surfaces of the annular seal groove (12),
Dust seal (13) between seal member (13) and elastic body (14)
And the end plate (2a) of the orbiting scroll (2).

However, since the seal member (13) is in the form of a closed ring, the diameter of the seal member (13) must be increased or decreased while maintaining a perfect circular state by the pressure applied to the inner or outer peripheral surface thereof. However, it is inevitable that a difference occurs in the amount of deformation in the radial direction when viewed in the circumferential direction. Therefore, the pressure contact force with respect to the counterpart member is different in each part in the circumferential direction, and even if the received pressure is constant, there is a partial difference in the sealing performance, and the gas is blocked at a location where the sealing performance is small. Power drops.

Further, in order to enhance the barrier property, an elastic body (1
4) Strengthen the orbiting scroll (2) of the sealing member (13)
When the pressing force on the end plate (2a) is large, the sealing member (1
Since the wear of 3) increases and the rotational resistance of the orbiting scroll (2) also increases, the strength of the elastic body (14) has its own limit.

The present invention has been made in view of the above-mentioned problems of the prior art, and has a simple structure so that good sealing properties can be obtained and sealing properties at each part in a circumferential direction are always uniform. It is an object of the present invention to provide a scroll fluid machine provided with a sealed member.

[0018]

According to the present invention, the above-mentioned problem is solved as follows. (1) The spiral fixed wrap provided on the fixed scroll and the spiral fixed wrap provided on the orbiting scroll are fitted into each other, and the orbiting scroll is rotated with respect to the fixed scroll without rotating. In the scroll fluid machine, an annular seal groove is formed on the opposing surfaces of the two scrolls, and a sliding member capable of contacting an end surface of the counterpart scroll is formed in the annular seal groove, and is formed integrally with the sliding member. And a pressure receiving member adapted to receive the pressure of the fluid along with the operation of the scroll fluid machine, and a seal member is fitted therein.By the pressure of the fluid along with the operation of the scroll fluid machine, the sliding member is The other end face of the scroll is pressed and sealed, and the pressure receiving member suppresses one side face of the annular seal groove to seal.

(2) In the preceding paragraph, the pressure receiving member has flexibility.

(3) In the above item (1) or (2), the pressure receiving member is provided with a pressure receiving piece extending orthogonally to the sliding member on the side opposite to the side on which the fluid pressure acts on the sliding member. And

(4) In the above item (1) or (2), the pressure receiving member has a U-shaped cross section that opens toward the side of the sliding member where the fluid pressure acts.

(5) In the above item (1) or (2), the pressure receiving member has a recessed portion facing a side of the sliding member on which fluid pressure acts.

(6) In the above item (5), the pressure receiving member has recesses on both sides in the width direction of the sliding member.

(7) In the above item (6), the recessed portion on each side is provided at a staggered position.

(8) In the above item (1) or (2), the pressure receiving member has a cylindrical shape having an inclined surface on a side on which fluid pressure acts.

(9) In any one of the above items (1) to (8), a raised portion projecting toward a side surface of the annular seal groove is provided on a contact surface of the pressure receiving member with the annular seal groove.

(10) In any one of the above items (1) to (9), the sliding member and the pressure receiving member are made of different materials.

(11) In any one of the above items (1) to (9), the sliding member and the pressure receiving member are formed as a single body made of the same material.

(12) In any one of the above items (1) to (11), the surface roughness of the end plate with which the seal member slides is smaller than the surface roughness of the end plate on the inner surface of the slide contact surface of the seal member. Small.

(13) A scroll fluid machine having the seal structure according to any one of the above items (1) to (12).

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A feature of the present invention lies in the structure of a seal member fitted in an annular seal groove in various scroll fluid machines having the basic structure as described above with reference to FIG. Therefore, the following description will be made based on FIGS. 1 to 6 which show only portions directly related to the present invention in an enlarged manner.

FIGS. 1 and 2 show an example in which the first embodiment of the seal member according to the present invention is applied to a scroll vacuum pump.

The annular seal groove (21) in FIG. 1 is provided on the inner surface of the fixed scroll (22), similarly to the one shown in FIG. 7, and its opening is provided in the end plate (23) of the orbiting scroll (23).
a).

The annular seal groove (21) has a rectangular cross section, and an annular seal member (24) is fitted therein. The sealing member (24) is made of a self-lubricating material having low friction and heat and wear resistance, for example, a somewhat rigid synthetic resin such as `` Teflon '' (trademark), or a somewhat flat rectangular sliding member (2) made of metal.
On the bottom surface of 5), a lip-shaped pressure-receiving piece (26b), which is made of an elastic material having a sealing property such as fluorine rubber, and faces outward from the inner peripheral end of the support piece (26a) facing radially, is provided. Flexible pressure receiving member (26), chemical bonding means such as an adhesive,
Alternatively, they are integrally formed by heat treatment or the like.

The inner surface of the sliding member (25) is almost mirror-finished so as to minimize friction.

The radial width of the sliding member (25) is slightly smaller than the radial width of the annular seal groove (21).
For the width w1 of the annular seal groove (21), the width w2 of the sliding member (25)
Is a little small. The axial depth of the annular seal groove (21) is slightly larger than w1. Pressure receiving member (2
6) The radial width of the support piece (26a) is the width w2 of the sliding member (25).
And both are polymerized in a consistent manner.

The inner peripheral surface of the pressure receiving piece (26b) of the pressure receiving member (26)
The support piece (26a) protrudes or protrudes a little (w3 in the figure) in the inner circumferential direction from a location slightly outside the inner end.

Thus, the sliding member (25) and the pressure receiving member (2
Between the outer peripheral surface of the support piece (26a) of 6) and the outer peripheral surface of the annular seal groove (21), there is a gap w4 substantially equal to w3 or slightly smaller than w3.

A very small gap w5 in the axial direction is provided on the surface of the fixed scroll (22) facing the end plate (23a) of the orbiting scroll (23).

When the pressure on the inner peripheral side of the annular seal groove (21) decreases with the operation of the scroll vacuum pump, the atmospheric pressure becomes
End plate (23a) of fixed scroll (22) and orbiting scroll (23)
And acts on the inside of the annular seal groove (21) from the outer peripheral side through the gap in the surface facing the.

Therefore, the sliding member (25) and the pressure receiving member (2
6), the sliding member (25) is slightly displaced in the inner circumferential direction, and the sliding member (25) is moved by the support plate (26a) of the pressure receiving member (26) on which the atmospheric pressure is applied. 23a), the pressure receiving piece (26b) of the pressure receiving member (26) is
Press the inner peripheral surface of.

At this time, however, the pressure receiving piece (2) of the pressure receiving member (26)
6b) can be slightly deformed in the inner circumferential direction, so that the pressure receiving piece (26b) of the annular pressure receiving member (26) has a substantially uniform pressing force over the entire circumference with the annular seal groove. Since the inner peripheral surface of (21) is pressed, the sealing performance does not become uneven due to the pressing force at each part in the circumferential direction as in the above-described conventional one.

Further, in this embodiment, the entire inner peripheral surface of the pressure receiving piece (26b) of the pressure receiving member (26) does not abut against the inner peripheral surface of the annular seal groove (21) due to the atmospheric pressure. Only the portion of the pressure receiving piece (26a) that protrudes inward beyond the inner peripheral surface of the sliding member (25) is in contact with the inner peripheral surface of the annular seal (21). The pressing force per unit area is larger than that of the conventional one in which the entire peripheral surface is in contact with the inner peripheral surface of the annular seal groove, and higher sealing performance can be obtained.

In the embodiment shown in FIGS. 1 and 2, the sliding member (25) and the pressure receiving member (26) in the seal member (24) are made of different materials. (25) and (26) may be carried out as an integral body made of the same material.

As can be understood from the above description, the present invention provides the seal member with the pressure receiving portions in the radial direction and the axial direction. In this case, a force component in the direction is generated to obtain a good sealing property. Therefore, it is desirable that the pressure receiving portion in the axial direction has flexibility.

In the seal member (24) shown in FIGS. 1 and 2, as shown in FIG. 1, the pressure receiving piece ( 26
b) is pressed. However, there is also a case where a positive pressure (pressurized) gas such as propane gas, natural gas, or harmful gas other than air which is higher than the atmospheric pressure is sucked and compressed. In that case, since the positive pressure (pressurized) gas flows from the inner peripheral side to the outer peripheral side of the seal member, the fluid pressure in the annular seal groove (21) comes through the pressure receiving piece (26b) of the seal member (24). It is formed on the side opposite to the inner peripheral side (the upper side in FIGS. 1 and 2) to improve the sealing performance.

The cross-sectional shape of the seal member described above is
Provided that it has radial and axial pressure receiving parts,
Various modifications are possible. Next, some of them will be exemplified.

As shown in FIG. 3 (27), the pressure receiving member has a U-shaped cross section which opens toward the side where the fluid pressure acts. In this case, the U-shaped bottom piece (27b) is a pressure receiving piece.

As shown in FIG. 4 (28), the pressure receiving member is provided with an appropriate number of concave portions (28a) on the side on which the fluid pressure acts and on the opposite side, that is, on the inner or outer circumference, or any one of them. Block. In this case, one side piece (28b) of the recessed portion (28a) becomes a pressure receiving piece.

As shown in FIG. 5 (29), the pressure receiving member is provided with staggered concave portions (29a) at the side where the fluid pressure acts and at the opposite side, that is, at different positions on the inner and outer circumferences. I do. In this case, one side piece (29b) of the concave portion (29a) becomes a pressure receiving piece.

As shown in FIG. 6 (30), the pressure receiving member has a hollow cylindrical shape having an inclined surface (30a) on the side where the fluid pressure acts. In this case, the reason why the hollow cylindrical shape is used is to facilitate deformation. In addition, the pressure receiving piece (30b)
Is provided on the inner peripheral side of the pressure receiving member (30).

In any case, it is preferable to provide a pressure contact portion that partially protrudes toward the side surface of the annular seal groove on the contact surface of the pressure receiving member with the annular seal groove.

In the present invention, it goes without saying that the annular seal groove and the seal member may be provided on the orbiting scroll side.

[0054]

According to the first aspect of the present invention, the pressure of the entering fluid causes an axial seal against the opposed end faces of the fixed scroll and the orbiting scroll, and a radial seal against the pressure of the entering fluid. It is done firmly.

The invention according to claim 2: The pressure-receiving member bends easily in the radial direction when it receives pressure, so that the seal in the radial direction becomes better.

According to the third aspect of the present invention, the pressure of the entering fluid can be decomposed in the axial direction and the radial direction by the pressure receiving member having a simple shape, so that the sealing can be performed in both directions.

The pressure receiving member expands to both sides in the axial direction by the pressure of the inflowing fluid, so that the pressure receiving member presses against the end face of the counterpart scroll and the bottom surface of the annular seal groove, and presses the axial line. Good sealing performance in the direction is obtained, and the pressure receiving member effectively transmits the pressure of the fluid that has entered into the radial direction, so that good sealing performance is also obtained in the radial direction. Further, the thickness of the pressure receiving member can be reduced to facilitate its deformation, and the amount of material used can be reduced and the weight can be reduced.

According to a fifth aspect of the present invention, even when the concave portion has a small groove shape and the pressure receiving member has a sufficient rigidity, the pressure of the fluid can be effectively received and the sealing property is improved. Help.

The sixth aspect of the present invention can be used regardless of the direction in which the pressurized fluid enters in or out of the radial direction.

The invention according to claim 7: has the effects of the inventions according to claims 4, 5 and 6.

The invention according to claim 8 can be used regardless of the direction in which the pressurized fluid enters the inside or outside of the radial direction, and can reduce the weight and the amount of materials used.

According to the ninth aspect of the present invention, the pressing force per unit area of the pressure receiving member against the annular seal groove is increased with respect to the pressure of the inflowing fluid, so that better sealing performance can be obtained.

According to a tenth aspect of the present invention, the sliding member is made of, for example, a material having low friction and abrasion resistance, and the pressure receiving member is made of a material having excellent flexibility. Slidability along the scroll end surface is improved, and accordingly, the pressure receiving member is reliably pressed against the inner side surface of the annular seal groove. It is preferably pressed.

[0064] The sliding member and the pressure receiving member can be manufactured easily and inexpensively.

The twelfth aspect of the present invention: The sliding property and abrasion resistance of the sliding member of the sealing member are improved, and the sealing property is maintained for a long time.

According to the thirteenth aspect, a scroll fluid machine having a simple structure and excellent sealing properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing a first embodiment of a seal structure of the present invention.

FIG. 2 is a vertical perspective view of the seal member according to the first embodiment.

FIG. 3 is a longitudinal sectional perspective view showing a sealing member having a different configuration.

FIG. 4 is a longitudinal sectional perspective view showing a sealing member having a different form.

FIG. 5 is a longitudinal sectional perspective view showing a seal member of a different form.

FIG. 6 is a longitudinal sectional perspective view showing a different form of a sealing member.

FIG. 7 is a longitudinal sectional view schematically showing a conventional general scroll fluid machine.

[Explanation of symbols]

 (1) Fixed scroll (1a) End plate (1b) Wrap (1c) Seal (2) Orbiting scroll (2a) End plate (2b) Wrap (3) Drive shaft (4) Oldham ring (5) Bearing (6) Housing ( 7) Housing chamber (8) Sealed space (9) Suction hole (10) Discharge hole (11) Gas working chamber (12) Annular seal groove (13) Seal member (14) Elastic body (21) Annular seal groove (22) Fixed scroll (23) Orbiting scroll (23a) End plate (24) Seal member (25) Sliding member (26) Pressure receiving member (26a) Support piece (26b) Pressure receiving piece (27) (28) (29) (30) Pressure receiving Member (27b) (28b) (29b) (30b) Pressure receiving piece

Continued on the front page F term (reference) 3H029 AA02 AB01 AB06 BB16 CC04 CC19 3H039 AA02 AA12 BB15 CC02 CC03 CC08 CC31 CC35 3J043 AA17 BA08 CA02 CB14 DA05

Claims (13)

[Claims] A spiral fixed wrap provided on a fixed scroll and a spiral fixed wrap provided on a orbiting scroll are fitted into each other, and the orbiting scroll is turned with respect to the fixed scroll without rotating. In the scroll fluid machine described above, an annular seal groove is formed on the opposing surfaces of the two scrolls, and in this annular seal groove,
It comprises a sliding member capable of abutting against the end face of the counterpart scroll, and a pressure receiving member formed integrally with the sliding member and adapted to receive the pressure of fluid with the operation of the scroll fluid machine. A seal member is fitted, the sliding member presses and seals the end face of the other scroll by the pressure of the fluid accompanying the operation of the scroll fluid machine, and the pressure receiving member is one side of an annular seal groove. A seal structure in a scroll fluid machine, wherein the seal structure is pressed to seal. 2. The seal structure according to claim 1, wherein the pressure receiving member has flexibility. 3. The seal in a scroll fluid machine according to claim 1, wherein the pressure receiving member includes a pressure receiving piece extending orthogonally to the slide member on a side opposite to a side on which the fluid pressure acts on the slide member. Construction. 4. The seal structure for a scroll fluid machine according to claim 1, wherein the pressure receiving member has a U-shaped cross section that opens toward a side on which the fluid pressure acts on the sliding member. 5. The pressure receiving member has a recessed portion facing a side on which a fluid pressure acts on the sliding member.
Or a seal structure in the scroll fluid machine according to 2. 6. The seal structure for a scroll fluid machine according to claim 5, wherein the pressure receiving member has concave portions on both sides in the width direction of the sliding member. 7. The seal structure for a scroll fluid machine according to claim 6, wherein the concave portions on each side are located at staggered positions. 8. The seal structure in a scroll fluid machine according to claim 1, wherein the pressure receiving member is a cylindrical member having an inclined surface on a side on which fluid pressure acts. 9. The seal structure for a scroll fluid machine according to claim 1, wherein a raised portion protruding toward a side surface of the annular seal groove is provided on a contact surface of the pressure receiving member with the annular seal groove. . 10. The seal structure for a scroll fluid machine according to claim 1, wherein the sliding member and the pressure receiving member are made of different materials. 11. The seal structure for a scroll fluid machine according to claim 1, wherein the sliding member and the pressure receiving member are formed as a single body made of the same material. 12. The scroll according to claim 1, wherein the surface roughness of the end plate with which the seal member slides is smaller than the surface roughness of the end plate on the inner surface of the sliding surface of the seal member. Seal structure in fluid machinery. 13. A scroll fluid machine having the seal structure according to claim 1.