JPH0429112Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a seal structure in a rotary fluid device such as a scroll fluid device, and particularly relates to a tip seal.

(Prior Art) Generally, for example, a scroll fluid device is used in a compressor in a refrigerator, and this scroll fluid device is installed in a sealed casing as disclosed in Japanese Patent Application Laid-Open No. 60-73079. A fixed frame is provided to divide the chamber into an upper chamber and a lower chamber,
A fixed scroll and a revolving scroll are housed in the upper chamber, and a motor is housed in the lower chamber. Both of the above-mentioned scrolls are each made up of a wrap that is erected in a spiral shape on the front of the end plate.
Both mirror plates are made to face each other, and both laps are engaged with each other, so that the side surfaces of both laps are in contact with each other at multiple points, and a sealed chamber is formed between the contact points. Further, the above-mentioned revolving scroll is supported by connecting the crankshaft of a motor passing through the fixed frame to the back of the end plate, and the support center of the revolving scroll is provided eccentrically from the crankshaft center, and the revolution of the revolving scroll is caused by the rotation of the crankshaft. revolves around a fixed crawl without rotating, and the closed chamber is configured to contract, for example.

Therefore, the refrigerant gas that has flowed into the lower chamber of the sealed case passes through the through hole in the fixed frame, is introduced from the side of the revolving scroll into the sealed chamber between the two laps, is compressed by the revolution of the revolving scroll, and then passes through the fixed scroll. is discharged from the center of the case.

In this scroll inflow device, the closed chamber between both scrolls compresses refrigerant gas, resulting in high pressure, and a downward thrust force acts on the revolving scroll. Therefore, a back pressure chamber is formed between the back of the revolving scroll and the fixed frame, and a part of the high-pressure refrigerant gas in the sealed chamber is guided into the back pressure chamber to press the revolving scroll upward and reduce the thrust force. There is. The back pressure chamber was formed by cutting two circumferential grooves on the upper surface of the fixed frame, fitting a tip seal into the circumferential groove, and pressing the tip seal against the back surface of the end plate of the revolving scroll.

(Problems to be solved by the invention) In the scroll fluid device described above, as shown in FIG.
was formed by using a single sealing material as a closed ring. However, in this tip seal a, there is a pressure difference between the back pressure chamber and the gas chambers inside and outside the back pressure chamber, so the tip seal a outside the back pressure chamber
The expansion force P ₁ is applied to the inner tip seal a, and the contraction force is applied to the inner tip seal a.
P ₂ will act respectively. Therefore, since the tip seal a has a constant circumferential length and no degree of freedom, when tensile stress or compressive stress acts on the inside and the differential pressure increases, as shown in FIG.
There was a drawback that gas leakage occurred due to breakage (b) or deformation (c) as shown in FIG. When this gas leak occurs, the thrust force acting on the revolving scroll increases as described above, causing a problem in that gas leaks from the sealed chamber between both scrolls.

Therefore, as shown in Fig. 10, a groove d is formed in the tip seal a, or as shown in Fig. 11, a part of the tip seal a is cut and stepped portions e and f are formed at both ends. It has been proposed that the two stepped portions e and f are overlapped. Since both of these are displaced in the circumferential direction, no tensile stress or the like acts on them, but the former has the disadvantage that gas leaks from the split groove d, resulting in a decrease in efficiency. In the case of the latter, the steps e and f must be processed separately,
Both methods have the disadvantage of increased costs, making them difficult to adopt.

In view of this, the present invention has a simple structure in which a plurality of ring parts are superimposed on each other in the radial direction and at the same time is given a degree of freedom to be freely displaceable in the circumferential direction. The purpose is to reliably prevent gas leaks.

(Means for Solving the Problems) In order to achieve the above object, the means taken by the present invention are as shown in FIGS. 2 and 5. The present invention is based on a rotary fluid device that includes a rotating body 8 that rotates in close facing relation to each other, and changes fluid pressure by the rotation of the rotating body 8.

A circumferential sealing groove 32 is formed in one of the opposing end surfaces of the fixed member 22 and the rotating body 8. In addition, ring-shaped tip seals 31 and 34 are provided in the seal groove 32 to seal between the fixed member 22 and the rotating body 8. Further, the tip seals 31 and 34 have a plurality of ring portions 33,
35 are formed in a shape that overlaps each other in the radial direction, and the respective ring portions 33 and 35 are displaced in the circumferential direction due to the fluid pressure difference between the inner and outer circumferential sides of the tip seals 31 and 34, thereby changing the ring diameter. The structure is designed to be flexible.

(Function) With the above configuration, the present invention seals a back pressure chamber in a scroll fluid device, a compression chamber in a rotary piston compressor, and the like. Then, Chip Seal 3 performs this seal.
1 and 34 are formed by connecting a plurality of ring parts 33 in a spiral shape, or by forming a plurality of ring parts 35 as separate bodies having split grooves 36 and fitting each ring part 35. However, for example, when the inner peripheral sides of the tip seals 31 and 34 become high pressure and an expansion force is applied, the spiral ring portion 33 unwinds,
In the ring portion 35 having the split grooves 36, the intervals between the split grooves 36 widen to absorb the expansion force.

In addition, at this time, the outermost ring portions 33 and 35 come into pressure contact with the seal groove 32, and the ring portions 33 and
Since the rings 35 overlap in the radial direction, that is, the rings have a spiral shape or the grooves 36 have different positions, it is possible to securely seal the fluid pressure.

Therefore, since no tensile stress or compressive stress is generated in the tip seals 31, 34, breakage, deformation, etc. can be reliably prevented, and highly reliable sealing can be achieved. In addition, the above chip seal 3
1 and 34 are easy to process and can be manufactured at low cost because the ring portion 33 is spirally shaped or the ring portion 35 is fitted with a groove 36.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

As shown in FIGS. 1 and 4, a scroll fluid device 1 is a rotary fluid device, and is used as a compressor in a refrigerator to compress refrigerant gas to high pressure and discharge it.

The scroll fluid device 1 is constructed by housing a scroll mechanism 3 and a drive mechanism 4 in a sealed case 2, and a suction pipe 5 is connected to the side of the case 2, and a discharge pipe 6 is connected to the top thereof. ing. The scroll mechanism 3 is composed of a fixed scroll 7 and a revolving scroll 8 which is a rotating body, and the drive mechanism 4 is composed of an electric motor 9 and a crankshaft 10.

The fixed scroll 7 and the revolving scroll 8 have wraps 13 and 14 arranged in a spiral shape on the front surfaces of end plates 11 and 12, and both scrolls 7 and 8 are arranged vertically side by side with the front surfaces of the end plates 11 and 12 facing each other. is,
Both laps 13 and 14 are engaged. The fixed scroll 7 has a flange 11 on the outer peripheral edge of the end plate 11.
a are arranged in series and fixed to the case 2 by the flange 11a, and the inside of the case 2 is divided into a high pressure chamber 2a above the fixed scroll 7 and a low pressure chamber 2b below. Furthermore, a scroll shaft 12a is provided protruding from the center of the back surface of the end plate 12 of the revolving scroll 8. On the other hand, the crankshaft 10 is a crank main shaft 10
A support frame 15 is formed by connecting a boss 10c having a concave scroll bearing hole 10b to the upper end of a, is fixed to the case 2, and has an upper and lower opening 15a.
A crank main shaft 10a passes through the shaft, and the crankshaft 10 is supported via bearing metals 16 and 23. An electric motor 9 is attached to this crank main shaft 10a.
is installed, and the scroll bearing hole 10b has its bearing center O ₁ aligned with the axis O ₂ of the crank main shaft 10a.
The scroll bearing hole 10 is provided more eccentrically.
Scroll shaft 12a of the revolving scroll 8 is shown in b.
are fitted. A plurality of spheres 17 are provided between the outer circumferential surfaces of the mirror plates 11 and 12 of both scrolls 7 and 8 via guide circular grooves,
The revolving scroll 8 is prevented from rotating, and the fixed scroll 7 is rotated due to the eccentricity of the scroll bearing hole 10b.
The center O ₁ of this scroll bearing hole 10b (the center of the scroll shaft 12a) is the movable fulcrum of the revolving scroll 8, and the axis of the crank main shaft 10a.
O ₂ is the center of revolution.

The fixed scroll 7 and the revolving scroll 8 are provided so that both laps 13 and 14 are in multi-point contact 18 on the side surfaces, and the end surfaces of each lap 13 and 14 are in contact with the other mirror plate 12 and 11, and there is a gap between the contacts 18. A closed chamber 19 is formed. Further, the flange 11a of the fixed scroll 7 is provided with a suction port 20 extending from the inner surface to the bottom surface, and the central portion of the end plate 11 is provided with a discharge port 21. Fluid is supplied from the suction port 20 to the sealed chamber 19. It is designed so that

Further, on the back side of the end plate 12 of the revolving scroll 8, a donut-shaped fixed frame 22, which is a fixed member fixed to the case 2, is formed parallel to the end plate 12. A through hole 22a is bored in the outer circumference of the fixed frame 22, and a boss 10c of the crankshaft 10 is fitted into the center via a bearing metal 23, and the boss 10c is rotatably supported. . Further, a stepped portion 24 is formed on the inner circumferential upper surface of the fixed frame 22, and a tip seal 31, which is a feature of the present invention, is provided on the outside of the stepped portion 24 via a seal groove 32. A back pressure chamber 25 is formed between the stepped portion 24 and the end plate 12 of the revolving scroll 8. Although not shown, the back pressure chamber 25 is communicated with a high-pressure closed chamber 19, into which high-pressure refrigerant gas is introduced, and presses the revolving scroll 8 toward the fixed scroll 7. Further, on the outside of the tip seal 31, a suction passage 26 is formed between the end plate 12 of the revolving scroll 8 and the fixed frame 22, and the suction passage 26 is formed between the suction port 20 of the fixed scroll 7 and the through hole 22a of the fixed frame 22. are being communicated.

In addition, 27 in FIG. 4 is an oil reservoir for lubricating oil, and the lubricating oil is supplied to the bearing metals 16 and 23 from an oil supply passage 10d formed in the crankshaft 10a. Further, 28 is a balancer chamber formed between the support frame 15 and the fixed frame 22, and the rotation of the balancer 10e connected to the boss 10c causes mist-like lubricant oil in the refrigerant gas that has passed through the upper and lower ports 15a to collide with the side wall. The oil is then returned to the oil reservoir 27 via a passage 29.

Next, the tip seal 31, which is a feature of the present invention, will be explained. The tip seal 31 is provided in a circumferential seal groove 32, and the seal groove 32 is formed on the back surface of the end plate 12 of the revolving scroll 8, which is a rotating body, and faces the fixed frame 22, which is a fixed member. The width of the seal groove 32 is larger than the thickness of the tip seal 31.

On the other hand, the tip seal 32 is formed of two ring parts 33, 33, as shown in FIGS. has been done. One end of the inner ring part 33 is formed as a free end, and one end of the outer ring part 33 is connected to the other end, and the outer ring part 33 is connected to the inner ring part 33.
is wound so that the other end is free. Therefore, the two rings 33, 33 overlap in the radial direction, and are displaced in the circumferential direction due to the fluid pressure difference between the back pressure chamber 25 and the suction passage 26 (in this embodiment, the back pressure chamber 25 is at high pressure) and are wound. The ring diameter is freely changeable within the circumferential groove 32. The tip seal 31 presses against the bottom surface of the circumferential groove 32 and the top surface of the fixed frame 22 to seal the back pressure chamber 25.

Next, the operation of this scroll fluid device 1 will be explained.

First, the refrigerant gas flows into the case 2 from the suction pipe 5, passes through the air gap of the electric motor 9 in the low pressure chamber 2b, and passes through the upper and lower openings 15a of the support frame 15, the balancer chamber 28, and the through hole 22 of the fixed frame 22.
a) The liquid is introduced into the sealed chamber 19 from the suction port 20 of the fixed scroll 7 via the suction passage 26 in this order.

On the other hand, the revolving scroll 8 rotates eccentrically due to the rotation of the crankshaft 10 and revolves around the fixed scroll 7 without rotating on its own axis, and a sealed chamber 19 is sequentially formed between the laps 13 and 14 and contracts. Then, the refrigerant gas introduced into the sealed chamber 19 is compressed, and is passed through the discharge port 21 of the fixed scroll 7 into the high pressure chamber 2.
a and is led out of the case 2 via the discharge pipe 6.

During this compression operation, high-pressure refrigerant gas is introduced into the back pressure chamber 25 from the closed chamber 19, pressing the revolving scroll 8 against the fixed scroll 7 and reducing the thrust force of the revolving scroll 8.

The outside of this back pressure chamber 25 is sealed with a tip seal 31, and this tip seal 31 is formed in a spiral shape. The ring diameter increases as it unwinds toward tip seal 3.
It will absorb the expansion force acting on 1. Therefore, tensile stress is less generated in the tip seal 31, and breakage etc. is reliably prevented, and the outer ring portion 33 is pressed against the inner peripheral surface of the seal groove 32, and at the same time, the inner ring portion 33 is pressed against the inner circumferential surface of the seal groove 32. Since it is pressed against the outer ring portion 33, reliable sealing is achieved and the thrust force of the revolving scroll 8 is reliably reduced.

FIG. 5 shows another tip seal 34, in which instead of the tip seal 31 of the previous embodiment formed of a single sealing material, three ring portions 35, 35, 35 are formed separately. This is what I did. Each ring portion 35 is formed into a substantially C-shape with a groove 36 formed therein, and is movable in the circumferential direction. Then, the center ring section 35 is fitted into the inner ring section 35, and the outer ring section 35 is fitted into the center ring section 35 in this order, so that they are superimposed in the radial direction. Further, the grooves 36 are set at different positions, for example, on the right side of the inner ring part 34, on the lower side of the center ring part 34, and on the left side of the outer ring part 34.

Therefore, as in the previous embodiment, when the pressure in the back pressure chamber 25 becomes high, the intervals between the grooves 36 widen to absorb the expansion force. In particular, since the split groove 36 is closed by the adjacent ring portion 34, no gas leakage occurs. The rest is the same as the previous embodiment.

FIG. 6 shows an embodiment in which a rotary piston type compressor 41 is applied as the rotary fluid device.
The rotary piston type compressor 41 includes a compression pump 43 housed in a sealed case 42, and a rotary piston 45, which is a rotating body, is eccentrically provided in a cylinder 44 fixed to the case 42. At the same time, both upper and lower ends of the cylinder 44 are closed with side covers 46 and 47. Furthermore, the rotary piston 45
The cam 4 is attached to the crankshaft 48 of the electric motor (not shown).
A blade 50 is provided in the cylinder 44 so as to be able to move in and out of the cylinder 44, and a compression chamber 51 is formed in the cylinder 44. In the compression chamber 51, the refrigerant gas is compressed by rotation of the rotary piston 45.

In this compressor 41, the above-described tip seal 31 or 34 is provided between the upper side cover 46, which is a fixed member, and the rotary piston 45 via the seal groove 32, and seals the compression chamber 51. Therefore, when the pressure in the compression chamber 51 becomes high,
The tip seals 31 and 34 contract under pressure from the outside, and the spiral tip seal 3
In the tip seal 34 having split grooves 36, the intervals between the split grooves 36 become narrower, and the shrinkage force is absorbed. The rest is the same as the previous embodiment.

Although the above embodiment has been described with respect to the scroll fluid device 1 and the rotary piston type compressor 41, it goes without saying that the present invention can be applied to other rotary fluid devices, and the scroll fluid device 1 can be used not only as a compressor but also as a compressor. It may also be used as an expander.

In addition, the ring portion 3 of each tip seal 31, 34
3 and 35 are not limited to two and three, but may be four or more.

(Effects of the invention) As described above, according to the seal structure of the rotary fluid device of the invention, the chip seal for sealing between the fixed member and the rotating body is formed by overlapping a plurality of ring parts, and each Because the ring parts are displaceable in the circumferential direction due to the fluid pressure differential, and the ring diameter can be changed freely, each ring part remains circumferential even if an expansion force is applied to the tip seal from the inner circumference or a contraction force is applied from the outer circumference. Since the tip seal has the degree of freedom to be displaced in the direction, no tensile stress or compressive stress is applied to the tip seal while sealing with the tip seal, and breakage or deformation can be reliably prevented. Therefore, fluid leakage can be prevented and reliable sealing can be performed, for example, the back pressure chamber in a scroll fluid device can be reliably sealed, so that the thrust force of the revolving scroll can be reliably reduced. I can do it.

Further, since the tip seal is simply fitted by forming a ring portion into a spiral shape or by forming a groove, it is extremely easy to process and can be manufactured at low cost.

[Brief explanation of the drawing]

Figures 1 to 6 show embodiments of the present invention;
2 is a bottom view of the essential parts, FIG. 3 is a schematic diagram of a tip seal, and FIG. 4 is a sectional view of a scroll fluid device. Fifth
The figure is a plan view showing another chip seal. 6th
The figure is a sectional view of the main parts of a rotary piston compressor. Figures 7 to 11 show conventional examples, Figure 7 is a plan view of a conventional tip seal, Figure 8 is a plan view of the same showing a broken state due to tensile stress, and Figure 9 shows a deformed state due to compressive stress. The same plan view, FIG. 10, and FIG. 11 are plan views of main parts showing other chip seals. 1...Scroll fluid device, 7...Fixed scroll, 8...Revolving scroll, 9...Electric motor, 1
0... Crankshaft, 19... Sealed chamber, 22... Fixed frame, 25... Back pressure chamber, 31, 34... Chip seal, 32... Seal groove, 33, 35...
Ring part, 36... Division groove, 41... Rotary piston compressor, 43... Compression pump, 44...
Cylinder, 45...Rotary piston, 46,4
7...Side cover, 51...Compression chamber.

Claims (1)

[Claims for Utility Model Registration] (1) A rotary fluid device comprising a rotating body 8 that rotates with its end face closely facing the fixed member 22, and fluid pressure is changed by the rotation of the rotating body 8. , a ring-shaped tip seal 31 having a circumferential seal groove 32 formed in one of the opposing end surfaces of the fixing member 22 and the rotating body 8, and sealing between the fixing member 22 and the rotating body 8 in the seal groove 32; 34, the tip seals 31, 34 are formed in a shape in which a plurality of ring portions 33, 35 are superimposed in the radial direction, and each of the ring portions 33, 35 is arranged on the inner and outer circumferential sides of the tip seals 31, 34. A seal structure for a rotary fluid device, characterized in that the seal structure is formed so that the ring diameter can be freely changed by being displaced in the circumferential direction due to a fluid pressure difference between the ring and the ring. (2) The tip seal 31 is formed by winding a single sealing material in a spiral shape so that each ring portion 33 overlaps in the radial direction, and is configured to be able to be wound and unwound by a fluid pressure differential. A seal structure for a rotary fluid device according to claim (1) of the registered utility model. (3) The tip seal 34 has ring portions 35 each formed of a separate ring having a split groove 36, and the split grooves 36 are fitted and overlapped at different positions, so that the above-mentioned A seal structure for a rotary fluid device according to claim (1), wherein the interval between the grooves 36 of the ring portion 35 is configured to increase or decrease.