JP2817511B2 - 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 which is applied to a compressor, a vacuum pump or the like and has a back pressure mechanism for pressing a revolving scroll against a fixed scroll.

[0002]

2. Description of the Related Art Conventionally, a scroll type fluid machine of this type has been disclosed in Japanese Patent Application Laid-Open No. 62-182487 and shown in FIGS.

The fixed scroll F includes a fixed scroll K in which a fixed scroll L and an outer wall W continuous to the outside of the fixed scroll K are erected on the front of a fixed board K, and a front face of a revolving board M inside a casing D. Scroll O with a revolving spiral N
And a back chamber P for pressing the revolving scroll O against the fixed scroll F is provided between the back surface of the revolving board M and the housing H constituting the stationary member, and the lower surface of the outer wall W and the outer peripheral portion of the front face of the revolving board M are provided. Between them forms an annular thrust receiving portion S. In the back chamber P, oil pumped from a high-pressure oil reservoir stored at the bottom of the casing D via an oil supply hole provided in a drive shaft (not shown) fitted to the boss cylinder T of the revolving scroll O. It is open. Also, on the outer peripheral portion of the front surface of the revolving board M corresponding to the thrust receiving section S,
As shown in FIG. 4, a circular annular groove A is provided, a plurality of outer radial grooves B for opening the annular groove A to the outside of the revolving board M, and the annular groove A is formed on the outer side of each spiral body. And an inner radial groove C that communicates with a pair of suction ports X and Y located at the portion.

In this way, the oil introduced into the rear chamber P flows from the outer radial groove B to the annular groove A and the inner radial groove C,
While lubricating the thrust receiving portion S, the oil after lubricating the thrust receiving portion S is injected from each of the suction ports X and Y into the working chamber V defined between the spiral bodies. It is possible to improve the sealing properties and the like.

[0005]

However, in the above arrangement, since the circular annular groove A is provided, it can be considered at first glance that oil flows around the entire thrust receiving portion S. Since it passes through the shortest distance with little resistance connecting the chamber P and the suction ports X and Y, a large amount of oil flows in the path indicated by the arrow in FIG. 4 and the amount of oil flowing in the other paths decreases, and accordingly, However, there is a problem that the oil does not spread evenly over the entire thrust receiving portion S, and the sliding characteristics at the thrust receiving portion S cannot be sufficiently improved.

The rear chamber P has an intermediate pressure region in which the pressure of the high-pressure oil reservoir drops by an amount corresponding to the pressure loss at the oil supply hole of the drive shaft and the pressure of the low-pressure suction ports X and Y is high. On the other hand, the pressure in the rear chamber P needs to be high enough to generate a back pressure that presses the orbiting scroll O against the fixed scroll F.
And a low pressure suction port X, Y produces a large pressure difference, and it is extremely difficult to provide this pressure drop with the annular groove A and the groove portion formed by the radial grooves B and C inside and outside the annular groove A. The amount of oil supplied to each of the suction ports X and Y becomes excessive, causing a problem that oil stirring loss and the like increase.

According to the present invention, by devising the structure of the rear chamber of the orbiting scroll and the structure of the oil groove in the thrust receiving portion, the oil can be satisfactorily fed to the entire thrust receiving portion and supplied to the suction port. A main object of the present invention is to provide a scroll type fluid machine capable of preventing an excessive increase in the amount of oil.

[0008]

Therefore, in order to achieve the above-mentioned main object, first, inside the casing 9, a fixed spiral body 12 is formed on the front surface of a fixed substrate 11, and is connected to the outside of the spiral body 12. A fixed scroll 1 having an outer wall 13 erected and a revolving scroll 2 having a revolving spiral body 22 erected on the front surface of a revolving substrate 21 are pressed against the fixed scroll 1 against the back surface of the revolving substrate 21. In a scroll type fluid machine in which a back chamber 3 is provided and an annular thrust receiving portion 4 is formed between a lower surface of the outer wall 13 and an outer peripheral portion of a front surface of the revolving substrate 21, the revolving substrate 21
An annular sealing means 30 for dividing the rear chamber 3 into a central chamber 31 and an outer peripheral chamber 32 is provided between the rear surface and a stationary member facing the same, so that the central chamber 31 communicates with a high-pressure pressure area. A pair of symmetrical first arc grooves 51 and second arcs are formed by displacing the outer peripheral side chamber 32 with each other by 180 degrees on the thrust receiving portion 4 and extending almost half way along the thrust receiving portion 4. Groove 52
Through a pair of suction ports 61 and 62 located outside of the spiral bodies 12 and 22, respectively.
An oil supply passage 7 extending from a high pressure region is provided in the outer peripheral side chamber 32.
Was opened via the decompression mechanism 8.

Second, in order to easily construct the pressure reducing mechanism 8 without using a special capillary tube or the like, in the first means, the annular sealing means 30 is replaced with the revolving substrate 2.
1 and the outlet of the oil supply passage 7 is positioned at the end face of the stationary member facing the back surface of the revolving board 21 and at the inner and outer peripheral sides of the sealing means 30 with the revolving operation of the revolving scroll 2. The pressure reducing mechanism 8 is constituted by an intermittent communication mechanism 81 which is opened at alternately located portions and which opens the outlet of the oil supply passage 7 to the outer peripheral side chamber 32 intermittently with the revolving operation of the orbiting scroll 2.

Third, in each of the above means, in order to simplify the processing of the first arc groove 51 and the second arc groove 52, these arc grooves 51, 52 are provided on the lower surface of the outer wall 13 of the fixed scroll 1.

Fourth, in each of the above means, the oil supply passage 7
An Oldham ring 20 for preventing rotation of the revolving scroll 2 is provided inside the outer peripheral side chamber 32 in order to effectively use the oil reaching the suction ports 61 and 62.

[0012]

According to the above-mentioned first means, the outer peripheral side chamber 32 is annularly sealed with the center side chamber 31 in the high pressure area.
And a suction port 61, which is a low pressure region through the oil supply passage 7 having a pressure reducing mechanism 8 and a low pressure region through the first and second arc grooves 51, 52.
62 respectively. Thus, the outer peripheral side chamber 3
2, the pressure is reduced with respect to the high pressure in accordance with the reduced pressure value in the pressure reducing mechanism 8. By increasing the reduced pressure value in the pressure reducing mechanism 8, the pressure in the outer peripheral side chamber 32 is reduced to an intermediate pressure close to the low pressure. Area can be kept. In this case, the force for pressing the orbiting scroll 2 against the fixed scroll 1 and making contact with the thrust receiving portion 4 can be sufficiently obtained from the center-side chamber 31 which is a high-pressure pressure region. Then, the oil introduced from the oil supply passage 7 to the outer peripheral side chamber 32 via the pressure reducing mechanism 8 forms a pair of symmetric first and second circular arc grooves 51 and 52 provided over a half circumference along the thrust receiving portion 4. The air is supplied to each of the suction ports 61 and 62 through the corresponding port. Thus, the entire surface of the thrust receiving portion 4 can be favorably lubricated. Moreover, a relatively small pressure difference between the outer peripheral chamber 32 and the suction ports 61, 62 can be easily secured in the first and second arc grooves 51, 52. It is also possible to prevent an excessive amount of refueling.

According to the second means, the outer peripheral side chamber 32 is
While it is always in communication with the low-pressure suction ports 61 and 62 via the first and second arc grooves 51 and 52, it is only temporarily connected to the high-pressure oil supply passage 7 during one revolution operation of the orbiting scroll 2. It is. The communication time between the outer peripheral side chamber 32 and the oil supply passage 7 is set by the opening position of the outlet of the oil supply passage 7. Thus, the pressure of the outer peripheral side chamber 32 can be set according to the communication time with the oil supply passage 7, and by reducing this communication time, the pressure of the outer peripheral side chamber 32 can be maintained at an intermediate pressure close to a low pressure. . Moreover, the amount of oil released to the outer peripheral side chamber 32 can be set to an amount according to the communication time with the oil supply passage 7. Accordingly, the oil supply passage 7 has a function similar to that of opening the oil supply passage 7 to the outer peripheral side chamber 32 through the pressure reducing mechanism 8 composed of a capillary tube. On the contrary, in this case, the capillary tube is not used.
The structure can be simplified, and the clogging of the capillary tube can be prevented, and the reliability can be improved.

According to the third means, the fixed spiral body 12 does not hinder the formation of the first arc groove 51 and the second arc groove 52 and the finishing of the grooves.
Processing of 1, 52 can be simplified.

According to the fourth means, the sliding portion of the Oldham ring 20 can be lubricated with the oil introduced into the outer peripheral side chamber 32, and the oil supply mechanism can be effectively used.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The scroll type fluid machine shown in FIG. 1 is used as a compressor of a refrigerant in a refrigerating apparatus. A fixed substrate 11 is provided above a closed casing 9 via a housing 90 constituting a stationary member. Fixed spiral body 1 on front
2 and a revolving scroll 22 having a revolving spiral 22 on the front surface of a revolving substrate 21 below the fixed scroll 1 while supporting the fixed scroll 1 having an outer wall 13 continuous to the outside of the spiral 12. The scrolls 2 are arranged in opposition. A rear chamber 3 for pressing the orbiting scroll 2 against the fixed scroll 1 is provided on the back of the orbiting substrate 21,
An annular thrust receiving portion 4 is formed between the lower surface of the outer wall 13 and the outer peripheral portion of the front surface of the revolving board 21. Reference numeral 20 denotes an Oldham ring that prevents the orbiting scroll 2 from rotating.
Key 20a and housing 9 that engage with orbiting scroll 2
And a key 20b that engages with the key 20b.

A motor 91 having a stator 91a and a rotor 91b is disposed below the inside of the closed casing 9. An eccentric pin 92a provided at the upper end of a drive shaft 92 directly connected to the rotor 91b is provided with an eccentric pin 92a. It is fitted to a boss tube 23 projecting from the back. Inside the drive shaft 92, an oil supply hole 7 through which oil pumped by an oil pump of a positive displacement type, a centrifugal type or the like from an oil reservoir stored at the bottom of the closed casing 9 passes.
0 is supplied to the main bearing 93 and the pin bearing 94.

In this way, each of the spiral bodies 12,
The low-pressure gas taken into the outer part of each of the spiral bodies 12, 2
The compressed high-pressure gas is compressed inside the working chamber 6 defined between the two, and the compressed high-pressure gas is discharged into the discharge hole 1 opened at the center of the fixed scroll 1.
4 through the internal space of the casing 9 and the discharge pipe 96
From outside.

In the above construction, between the back surface of the revolving board 21 and the housing 90 facing the revolving board 21, an annular sealing means comprising a circular seal ring for dividing the back chamber 3 into a center chamber 31 and an outer chamber 32. 30 are provided. The annular sealing means 30 is fitted into an annular groove 25 provided on the back surface of the revolving board 21 and is held by the revolving board 21.

The center side chamber 31 is connected to the eccentric pin 9.
2a is communicated with the oil supply hole 70 through a cutout portion 70a cut out on the outer peripheral portion, and is communicated with the inside of the casing 9 through an oil discharge passage 90a provided in the housing 90, so that the inside is in a high pressure range. I do.

On the other hand, as clearly shown in FIG. 2, on the lower surface of the outer wall 13 of the fixed scroll 1, each of the entrance portions 51a, 5
2a is displaced by 180 degrees from each other on the thrust receiving portion 4, and a pair of symmetrical first arc grooves 51 and second arc grooves 52 are provided, each of which extends nearly half way along the thrust receiving portion 4, Exit part 5 of first arc groove 51
1b is displaced by 180 degrees with respect to the first suction port 61, and the outlet portion 52b of the second arc groove 52 is displaced by 180 degrees with respect to the first suction port 61.
The outer peripheral side chamber 32 communicates with the suction ports 61 and 62 via the first and second arc grooves 51 and 52, respectively.

As shown in FIG. 1, an oil supply passage 7 composed of an L-shaped large-diameter passage 71 extending from the bottom of the center-side chamber 31 and a small-diameter passage 72 connected thereto is formed in the outer peripheral side chamber 32 by a pressure reducing mechanism 8. Open through.

The pressure reducing mechanism 8 moves the small-diameter passage 72 serving as an outlet of the oil supply passage 7 at the end face of the housing 90 facing the back surface of the revolving substrate 21 and the sealing means 30 with the revolving operation of the revolving scroll 2. An intermittent communication mechanism in which the outlet of the oil supply passage 7 is opened intermittently to the outer peripheral side chamber 32 in accordance with the revolving operation of the orbiting scroll 2 by being opened at a portion alternately located on the inner peripheral side and the outer peripheral side. 81.

The Oldham ring 20 is disposed inside the outer peripheral side chamber 32.

With the above configuration, the outer peripheral side chamber 32 is
The center side chamber 31 in the high pressure region is partitioned via the annular sealing means 30, and at the high pressure region via the oil supply passage 7 having the pressure reducing mechanism 8, and the first and second arc grooves 51 are formed. , 52, the suction port 6 in the low pressure region
1, 62 respectively. Thus, the outer peripheral side chamber 32 is reduced in pressure with respect to the high pressure according to the reduced pressure value in the pressure reducing mechanism 8. By increasing the reduced pressure value in the pressure reducing mechanism 8, that is, By shortening the communication time between the outer peripheral chamber 32 and the oil supply passage 7 in the intermittent communication mechanism 81, the outer peripheral chamber 32
Can be maintained in the intermediate pressure range close to the low pressure. In this case, the force for pressing the orbiting scroll 2 against the fixed scroll 1 and making contact with the thrust receiving portion 4 can be sufficiently obtained from the center-side chamber 31 which is a high-pressure pressure region. The oil introduced from the oil supply passage 7 into the outer peripheral side chamber 32 via the pressure reducing mechanism 8 is supplied to the pair of symmetrical first and second circular grooves 5 provided over the semi-circumference along the thrust receiving portion 4.
The air is supplied to the respective suction ports 61 and 62 via the first and second ports 52. Thus, the entire surface of the thrust receiving portion 4 can be favorably lubricated, and the outer peripheral side chamber 32 and the suction port 61,
The relatively small pressure difference between the first and second arc grooves 5
It is possible to easily secure the oil at the portions 1 and 52, and it is possible to prevent the amount of oil supply from the outer peripheral side chamber 32 to the suction ports 61 and 62 from becoming excessive.

The pressure reducing mechanism 8 may be constituted by a capillary tube or the like. However, since the pressure reducing mechanism 8 is constituted by the intermittent communication mechanism 81 as described above, the structure can be simplified, and the clogging of the capillary tube can be prevented. It can be eliminated and reliability can be improved.

Further, a first arc groove 51 and a second arc groove 52
May be provided on the revolving scroll 2 side, but provided on the fixed scroll 1 side as described above.
The processing of 52 can also be simplified.

In addition, the Oldham ring 2 is
Since 0 is provided, the ring 20 can be lubricated, and the oil supply mechanism can be effectively used.

[0029]

According to the first aspect of the present invention, the oil can be satisfactorily supplied to the entire thrust receiving portion 4 via the first arc groove 51 and the second arc groove 52, and the fixed scroll 1 and the orbit can be revolved. The scroll 2 can be slid smoothly, and the amount of oil supplied to the suction ports 61 and 62 can be prevented from excessively increasing. Good sealing can be performed.

According to the second aspect of the present invention, since the pressure reducing mechanism 8 is constituted by the intermittent communication mechanism 81, the structure can be simplified and the reliability can be improved.

According to the third aspect of the present invention, the processing of the first arc groove 51 and the second arc groove 52 can be simplified.

According to the fourth aspect of the present invention, the Oldham ring 20 can be lubricated, and the oil supply mechanism can be effectively used.

[Brief description of the drawings]

FIG. 1 is an upper longitudinal sectional view of a scroll type fluid machine of the present invention.

FIG. 2 is a bottom view of a fixed scroll showing a groove configuration of the thrust receiving portion.

FIG. 3 is a top sectional view of a conventional scroll type fluid machine.

FIG. 4 is a top view of a revolving scroll showing a conventional groove configuration of a thrust receiving portion.

[Explanation of symbols]

Reference Signs List 1; fixed scroll, 11; fixed substrate, 12; fixed spiral, 13; outer wall, 2; revolving scroll, 20; Oldham ring, 21; revolving substrate, 22; revolving spiral, 3; Means, 31; center side chamber, 32; outer peripheral side chamber, 4; thrust receiving portion, 51; first arc groove, 52;
Second arc groove, 61, 62; suction port, 7;
8; decompression mechanism, 81; intermittent communication mechanism, 9; casing

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F04C 18/02 311 F04C 29/02 311

Claims (4)

(57) [Claims] 1. A fixed scroll 1 in which a fixed scroll 12 and an outer wall 13 continuous to the outside of the fixed scroll 12 are provided upright on a front surface of a fixed board 11 inside a casing 9;
A revolving scroll 2 having a revolving spiral body 22 erected on the front surface of the revolving scroll 2
A rear chamber 3 for pressing the orbiting scroll 2 against the fixed scroll 1 is provided on the back of the orbiting substrate 21, and an annular thrust is provided between the lower surface of the outer wall 13 and the outer peripheral portion of the front of the orbiting substrate 21. In the scroll type fluid machine in which the receiving portion 4 is formed, between the rear surface of the revolving substrate 21 and a stationary member facing the revolving substrate 21, there is provided an annular sealing means 30 for partitioning the rear chamber 3 into a central chamber 31 and an outer peripheral chamber 32. The center side chamber 31 is communicated with a high pressure area, and the outer peripheral side chamber 32 is displaced by 180 degrees with respect to the thrust receiving portion 4 at an inlet portion, and each of the outer peripheral side chambers 32 rotates halfway along the thrust receiving portion 4. A pair of suction ports 61, 62 located outside the spiral bodies 12, 22 through a pair of symmetrical first arc grooves 51 and second arc grooves 52 extending close to each other. While allowing each communicated to said outer peripheral side chamber 32, the scroll type fluid machine, characterized in that the oil supply passage 7 extending from the high pressure zone is opened through the pressure reducing mechanism 8. 2. An annular sealing means (30) is held by the revolving board (21), and an outlet of the oil supply passage (7) is connected to the revolving board (2).
1 is the end surface of the stationary member facing the back surface and the orbiting scroll 2
With the revolving operation of the seal means 30, the seal means 30 is opened at alternately located positions on the inner peripheral side and the outer peripheral side.
2. The scroll fluid machine according to claim 1, wherein an intermittent communication mechanism 81 intermittently opens an outlet portion of the oil supply passage 7 to the outer peripheral side chamber 32 in accordance with the revolving operation of the revolving scroll 2. 3. 3. The scroll type fluid machine according to claim 1, wherein the first arc groove 51 and the second arc groove 52 are provided on a lower surface of the outer wall 13 of the fixed scroll 1. 4. The scroll type fluid machine according to claim 1, wherein an Oldham ring (20) for preventing rotation of the orbiting scroll (2) is disposed inside the outer peripheral side chamber (32).