JP2002317780A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the back flow of a lubricant from a lubricant reservoir to a suction side resulting in an abrupt reduction of the lubricant at the stop of operation. SOLUTION: A radial through-hole 34 communicating with an oiling hole 25 is provided under a spindle support 22 for a driving shaft 4, a cover 30 spaced from and opposed to the through-hole 34 is fixed to the driving shaft 4 with an elastic body 31, and a deadweight 32 is connected to the cover 30 via a connector 33 where it is opposed 180 deg. to the driving shaft 4. MR<mr is established, where M is the mass of the cover 30, R is a distance from the rotational center of the driving shaft 4 to the gravity center of the cover 30, m is the mass of the deadweight 32 and r is a distance from the rotational center of the driving shaft 4 to the gravity center of the deadweight 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic scroll compressor used for refrigeration and air conditioning for business use, home use, or vehicles, or a refrigerator.

[0002]

2. Description of the Related Art A conventional scroll compressor will be described with reference to FIG. A closed casing 1 includes a compression mechanism 2, an electric motor 3 for driving the compression mechanism 2 below the compression mechanism 2, and a drive shaft 4 for transmitting the rotational force of the electric motor 3 to the compression mechanism 2. A lubricating oil reservoir 5 is provided at a lower portion in the container 1. The compression mechanism 2 combines an orbiting scroll 6 having a spiral wrap and a fixed scroll 7 so as to face each other, and holds the mirror plate of the orbiting scroll 6 between the fixed scroll 7 and the frame 8 with a gap capable of orbital movement. Configuration.

[0003] The suction refrigerant gas is sucked from a suction pipe 9 provided through the outer periphery of the end plate of the fixed scroll 7 in the radial direction, and enters the compression chamber from the outer periphery of a compression chamber 10 formed by the fixed scroll 7 and the orbiting scroll 6. Inflow. The orbiting scroll 6 is prevented from rotating by the anti-rotation mechanism 11, and the eccentric portion provided at the end of the drive shaft 4 causes the orbiting bearing 1 to rotate.
2, a swirling motion is performed, and the suction refrigerant gas is sequentially transferred to the center direction to compress the suction refrigerant gas, and is discharged from the discharge port 13 to the first discharge chamber 15 via the reed valve 14. afterwards,
The compressed high-pressure gas is supplied to the first descending passage 1 in the frame 8.
6, through a partition 17, a compression mechanism 2, and a second discharge chamber 18 surrounded by the electric motor 3, a second descending passage 1 in the electric motor 3.
Go down through 9. Further, after cooling the electric motor 3 through a first ascent passage 20 provided on the outer periphery of the electric motor 3, the electric motor 3 is pressure-fed out of the discharge pipe 21 through a second ascent passage on the outer periphery of the compression mechanism 2 (not shown). . During this time, the lubricating oil in the discharged gas is separated by repeated centrifugation and collision, and drops into the lubricating oil reservoir 5.

The drive shaft 4 is supported by a main bearing 22 and a sub bearing 23 fixed to the frame 8, and is rotated by the driving force of the electric motor 3. The back pressure chamber 24 formed between the frame 8, the orbiting scroll 6, and the fixed scroll 7 is maintained at an intermediate pressure between the suction pressure and the discharge pressure, as described later. 7
Structure.

The drive shaft 4 has an oil supply hole 25 penetrating in the axial direction.
And a minute passage 26 provided in the longitudinal direction of the shaft surface serving as a sliding surface with each bearing portion, and the oil supply hole 25 and the minute passage 26 communicate with each other through a through oil supply hole 28. A lubricating oil groove 29 is provided in the main bearing 22 at a position facing the through oil supply hole 28, and the infiltration of high-pressure gas is prevented by an oil sealing function. The lower end of the drive shaft 4 is immersed in the lubricating oil reservoir 5, and the back pressure chamber 24 and the lubricating oil reservoir 5 communicate with each other through an oil supply hole 25, a through oil supply hole 28, and a minute passage 26. Also,
Although the lubricating oil reservoir 5 is at the discharge pressure, the minute passage 26
, The back pressure chamber 24 is maintained at an intermediate pressure which is an intermediate pressure between the discharge pressure and the suction pressure.

Accordingly, the lubricating oil is supplied to the main bearing 22 and the slewing bearing 12 by the differential pressure between the lubricating oil reservoir 5 and the back pressure chamber 24 to which the discharge pressure has been applied. Supplied. The lubricating oil accumulated in the back pressure chamber 24 is guided to the compression chamber 10 via the back pressure control valve 27, and after the seal and sliding portion of the compression mechanism 2 are lubricated, is discharged together with the discharge gas. As means for maintaining the back pressure chamber 24 at an intermediate pressure, a lubricating oil groove provided on the drive shaft 4, a back pressure partition band provided on the back of the orbiting scroll 6 provided on the frame 8, and a shutoff valve provided in the orbiting scroll 6. In some cases, this is achieved in combination with

Here, when the compressor stops operating, the discharge port 13 is closed by the reed valve 14, so that the closed space 10 becomes equal to the suction pressure. On the other hand, the lubricating oil flows into the back pressure chamber 24 from the lubricating oil reservoir 5 to which the discharge pressure is applied, via the oil supply hole 25, the through oil supply hole 28, and the minute passage 26. This lubricating oil flows back to the suction side via the back pressure control valve 27, and the lubricating oil in the lubricating oil reservoir 5 rapidly decreases. When the reed valve 14 is not provided, the backflow of the lubricating oil from the lubricating oil reservoir 5 to the suction side does not occur, but it is known that the orbiting scroll 6 reversely rotates due to the differential pressure between the discharge pressure and the suction pressure. As disclosed in Japanese Patent Laying-Open No. 57-73886, a reed valve 14 is generally often mounted to prevent the orbiting scroll 6 from being reversed. On the other hand, as disclosed in Japanese Patent Publication No. 1-334312, a suction check valve using a spring and an on-off valve is mounted inside the suction pipe 9 to prevent the orbiting scroll 6 from rotating backward and preventing the lubricating oil from flowing backward. There are also things.

[0008]

However, according to the above-mentioned conventional structure, when the reed valve is used, the reverse rotation of the orbiting scroll at the time of stoppage of the operation can be prevented, but the reverse flow of the lubricating oil is generated, and the lubricating oil pool is generated. Insufficient lubrication may occur due to a decrease in lubricating oil.

When the reed valve is not used, the reverse flow of the lubricating oil can be prevented, but there is a problem that the orbiting scroll is reversed and a reverse rotation noise is generated. Further, when the efficiency during operation is taken into consideration, it is necessary to increase the number of turns of the wrap of the orbiting scroll and the fixed scroll to achieve a high compression ratio, which causes a problem that the compressor becomes larger.

On the other hand, as disclosed in Japanese Patent Publication No. 1-34312, when a suction check valve is attached to prevent backflow of lubricating oil at the time of stoppage of operation, the number of parts such as springs and on-off valves increases. Also, there is a problem that the processing accuracy of the suction pipe and the like is improved and the productivity of the assembly is deteriorated. The present invention solves such a conventional problem, and can prevent the orbiting scroll from reversing when the operation is stopped, and prevent the lubricating oil in the lubricating oil reservoir from flowing back to the suction side, and furthermore, can be simplified. An object of the present invention is to provide a hermetic scroll compressor having a structure and good workability and assembly productivity.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to an oil supply hole having an inner side and an outer side opening to an outer peripheral surface of a drive shaft below a portion of the drive shaft which slides with a main bearing. A lid is provided on the drive shaft by an elastic body so that a radial through hole is provided, which can be opened and closed with respect to the drive shaft outer peripheral surface side opening of the radial through hole, and is opened when the drive shaft is stationary. The weight is connected to the lid by a connector at a position substantially opposite to the drive shaft with respect to the drive shaft. When the mass of the lid is M, the distance between the rotation center of the drive shaft and the center of gravity of the lid is R, the mass of the weight is m, and the distance between the rotation center of the drive shaft and the center of gravity of the weight is r. , MR <mr.

When the compressor is operated with the above configuration, the lid and the weight fixed to the drive shaft rotate with the drive shaft, and the relational expression of MR <m r is established. The centrifugal force acting on the weight is larger than the centrifugal force acting on the lid, and the lid supported by the elastic body is pressed against the drive shaft by the centrifugal force of the weight, and the radial through hole communicating with the oil supply hole is You will be blocked. Therefore, during the operation of the compressor, the lubricating oil in the lubricating oil sump is supplied to the sliding portion by the differential pressure as in the case described in the related art.

On the other hand, when the compressor stops operating, the rotation of the drive shaft stops, and the rotational movement of the lid and the weight stops. At this time, since the lid is attached so as to be stationary with a gap from the radial through hole opening by the elastic body,
The radial through-hole is not closed by the lid. For this reason, the high-pressure gas applied with the discharge pressure enters the oil supply hole from the radial through hole. As a result, the pressure in the oil supply hole becomes equal to the discharge pressure, so that the lubricating oil in the lubricating oil reservoir cannot be sucked up into the oil supply hole, so that only gas flows back to the suction side. In general, since a reed valve is often attached to the discharge port, the above configuration prevents the reversal phenomenon of the orbiting scroll and prevents the lubricating oil in the lubricating oil reservoir from rapidly decreasing. Also, there is an advantage that the workability and the assembly productivity are good with a simple structure as compared with the suction check valve of the related art.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. In FIG. 1, the same reference numerals as those in FIG. 4 denote the same or equivalent parts as in the related art, and a description of the configuration and the operational relationship will be omitted. FIG. 1 is a longitudinal sectional view of a scroll compressor showing one embodiment of the present invention. FIG. 2 is a cross-sectional view of an enlarged view of a main part of the present invention, showing a state where the operation of the compressor is stopped. FIG. 3 is a cross-sectional view of an enlarged view of a main part of the present invention,
It shows the operating state of the compressor.

In FIG. 1, a radial through hole 3 is provided below the main bearing 22 of the drive shaft 4 so as to communicate the oil supply hole 25 with the outer peripheral surface of the shaft.
4 are provided. Further, a lid 30 having a mass M is fixed to the radial through hole 34 at a position facing the shaft outer peripheral surface opening by an elastic body 31 with a gap. The lid 30 is a spherical body having a diameter larger than the diameter of the radial through hole 34. The lid 30 is not limited to a spherical body,
Any shape can be used as long as the shape can close the opening. The lid 30 having a mass m is connected to the lid 30 by a rigid connecting member 33 at a position facing the drive shaft 4 by approximately 180 degrees in the circumferential direction. Here, the elastic body 31, the lid 30, the connecting body 33, and the weight 32 are arranged on substantially the same horizontal plane, but the elastic body 31 has a shape along the axial direction of the drive shaft 4. Various arrangements are possible including the case where the elastic body 31, the connecting body 33, and the weight 32 are not arranged on the same horizontal plane.

FIG. 2 shows the relationship between the lid 30 and the weight 32.
This will be further described with reference to FIG. The mass of the lid 30 is M, the distance from the rotation center of the drive shaft 4 to the center of gravity of the lid 30 is R, the mass of the weight 32 is m, and the distance from the rotation center of the drive shaft 4 to the center of gravity of the weight 32 is When r is set, the relationship MR <mr is satisfied. FIG. 2 shows a state in which the compressor is stopped.
There is a gap between them, and the oil supply hole 25 and the space of the discharge gas atmosphere communicate with each other.

A case where the compressor is operated in this configuration will be described with reference to FIG. Assuming that the drive shaft 4 is rotating at an angular velocity ω, the centrifugal force applied to the lid 30 is MR
ω ² , and the weight 32 becomes mrω ² . Comparing the centrifugal force applied to the lid 30 and the weight 32, the weight 32 is larger because the relationship MR <mr holds. As a result, the lid 30 pulled by the connecting body 33 and fixed to the elastic body 31 is pressed against the drive shaft outer peripheral opening of the radial through hole 34. At this time, R is smaller and r is larger than at the time of stop, so that the lid 30 is pressed more strongly against the opening of the outer peripheral surface of the drive shaft of the radial through hole 34.

Therefore, by appropriately selecting the elastic body 32, the cover 30 can be stably pressed against the through hole 34 from low speed operation to high speed operation. In this way, since the radial through hole 34 is closed by the lid 30 during operation, the oil supply hole 25 and the space of the discharge gas atmosphere do not communicate with each other. Is performed in the same manner as in the case of the conventional technique.

That is, the drive shaft 4 is provided with an oil supply hole 25 penetrating in the axial direction and a minute passage 26 arranged in the longitudinal direction of the surface of the sliding portion with each bearing. Through oil supply hole 28 that communicates passage 26 with oil supply hole 25
The lubricating oil groove 29 is provided at a position facing the high pressure gas, and the intrusion of the high pressure gas is prevented by the oil sealing function. Further, the lower end of the drive shaft 4 is immersed in the lubricating oil reservoir 5, and the back pressure chamber 24 and the lubricating oil reservoir 5 communicate with each other through an oil supply hole 25, a through oil supply hole 28, and a minute passage 26.

Although the lubricating oil reservoir 5 is at the discharge pressure, the pressure in the back pressure chamber 24 is reduced by the minute passage 26, and is maintained at an intermediate pressure which is an intermediate pressure between the discharge pressure and the suction pressure. Accordingly, the lubricating oil is supplied to the main bearing 22 by the pressure difference between the lubricating oil reservoir 5 to which the discharge pressure is applied and the back pressure chamber 24.
After the lubrication of each bearing, the lubricating bearing 12 is supplied to the back pressure chamber 24. The lubricating oil accumulated in the back pressure chamber 24 is guided to the compression chamber 10 via the back pressure control valve 27, and after the seal and sliding portion of the compression mechanism 2 are lubricated, is discharged together with the discharge gas.

When the compressor is stopped, the oil supply hole 25 is communicated with the discharge gas atmosphere space by the radial through hole 34 as described above. The lubricating oil tends to flow into the back pressure chamber 24 from the lubricating oil reservoir 5 to which the discharge pressure has been applied by the oil supply hole 25, the through oil supply hole 28, and the minute passage 26. However, the inflow of the lubricating oil is suppressed because the discharge gas tends to flow first through the radial through holes 34. The discharge gas filled in the back pressure chamber 24 flows to the suction side via the back pressure control valve 27. As a result, the backflow of the lubricating oil to the suction side is suppressed, and a rapid decrease of the lubricating oil in the lubricating oil reservoir 5 can be prevented. Further, since the reed valve 27 is attached, the reversing phenomenon of the orbiting scroll 6 does not occur.

According to the present embodiment, it is possible to prevent the lubricating oil in the lubricating oil pool from flowing backward to the suction side when the compressor is stopped. Further, the orbiting scroll does not reverse when the operation is stopped. Moreover, the workability and assembly productivity are good with a simple structure.

[0023]

As is apparent from the above description, the first aspect of the present invention suppresses the backflow of the lubricating oil in the lubricating oil pool to the suction side when the compressor is stopped, thereby preventing a sharp decrease in the lubricating oil. Thus, it is possible to provide a hermetic scroll compressor having a simple structure and good workability and assembly productivity.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a scroll compressor showing one embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the same embodiment when the compressor is stopped.

FIG. 3 is an enlarged cross-sectional view of a main part of the same embodiment during operation of the compressor.

FIG. 4 is a longitudinal sectional view of a conventional scroll compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Compression mechanism 3 Electric motor 4 Drive shaft 5 Lubricating oil sump 6 Swirling scroll 7 Fixed scroll 8 Frame 22 Upper main bearing 23 Lower main bearing 25 Oil supply hole 30 Cover 31 Elastic body 32 Weight body 33 Connection body 34 Through-hole

Continuing on the front page (72) Inventor Hidenobu Shintaku 1006 Kadoma Kadoma, Osaka Pref.Matsushita Electric Industrial Co., Ltd. Person Hiroyuki Kono 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Shuichi Yamamoto 1006 Kadoma Kadoma, Kadoma-shi, Osaka Pref. CC16 CC17 CC26 CC38 3H039 AA03 AA04 AA12 BB11 CC12 CC19 CC27 CC30 CC33 CC35

Claims (1)

[Claims] An orbiting scroll is formed by a fixed scroll, an orbiting scroll meshed with the fixed scroll to form a compression chamber, a bearing frame having a main bearing for supporting the orbiting scroll so as to be capable of orbiting movement, and the orbiting scroll and the bearing frame. A scroll compression mechanism comprising a back pressure chamber for bringing the orbiting scroll into close contact with the fixed scroll by being supplied with an intermediate pressure between the discharge pressure and the suction pressure, and an electric motor disposed below the compression mechanism to drive the compression mechanism And a lubricating oil reservoir provided below the motor, and one end contacting the lubricating oil reservoir, an intermediate portion coupled to the motor, and the other end slidably coupled to the orbiting scroll. A drive shaft having an oil supply hole therein for supplying lubricating oil by communicating the lubricating oil reservoir with the sliding portion of the compression mechanism and the sliding portion of the bearing; And a hermetic container housing the scroll compression mechanism, the electric motor, the lubricating oil reservoir and the drive shaft therein. The pressure of the compressed gas discharged into the hermetic container from the scroll compression mechanism causes the lubricating oil reservoir to fill the lubrication oil hole. A scroll compressor that supplies lubricating oil to each of the sliding portions via a lubricating oil, wherein an inner side opens to the lubrication hole and an outer side opens to the outer peripheral surface of the drive shaft below a portion of the drive shaft that slides with the main bearing. A lid is provided which can be opened and closed with respect to the drive shaft outer peripheral surface side opening of the radial through hole and which is opened when the drive shaft is stationary. A weight is connected to the lid by a connecting body at a position substantially opposite to the drive shaft, and the mass of the lid is M, and the distance between the rotation center of the drive shaft and the center of gravity of the lid is determined. R, mass of the weight is m, drive When the distance to the center of gravity of the rotational center frustums was r, scroll compressor, which is a MR <mr.