Rotary compressor

• US 20040247474A1
• Filed: 03/18/2004
• Published: 12/09/2004
• Est. Priority Date: 06/05/2002
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: Yamaji, Hiroyuki, Kitaura, Hiroshi, Yanagisawa, Masanori
• Granted Patent: US 7,322,809 B2
• Time in Patent Office: Days
• US Class Current: 418/55.4
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 27/009 Shaft sealings specially adapted for pumps
• CPC Class Codes: F04C 29/023 Lubricant distribution through a hollow driving shaft F04C29/025 takes precedence
• CPC Class Codes: F04C 29/028 Means for improving or restricting lubricant flow

Abstract

In a rotary compressor to perform oil supplying to bearings (32,34,45) through a main oil-supply passage (51) formed in a drive shaft (17) by making use of pressure differential between high-level pressure and low-level pressure in the casing (10), sealing portions (65) having air-tight structure is formed at the both sides in the axis direction of each of sliding faces constituted between the drive shaft (17) and the bearings (32,34,45), putting bearing-portion oil-supply passages (59,60,61) between the sealing portion (65), to improve the reliability of the bearings (32,34,45) by preventing high-pressure gas flowing into a portion between the drive shaft (17) and the bearings (32,34,45).

Claims

1. A rotary compressor comprising:

a casing including high-pressure and low-pressure spaces, a compressing mechanism and a compressor motor with a drive shaft driving the compressing mechanism the drive shaft being supported by at least one bearing that is disposed in the high-pressure space in the casing, the drive shaft having a main oil-supply passage and at least one bearing-portion oil-supply passage that are formed therein, the main oil-supply passage connecting an oil reservoir having an inside pressure that increases during its operation and the low-pressure space, one end of the bearing-portion oil-supply passage being connected with the main oil-supply passage, the and another end of the bearing-portion oil-supply passage being connected with a sliding face constituted between the drive shaft and the bearing and

a plurality of sealing portions having substantially air-tight structures, which are formed at opposite sides in an axis direction of the sliding face constituted between the drive shaft and the bearing, putting the bearing-portion oil-supply passage between the sealing portions.

2. The rotary compressor of claim 1, wherein

the compressing mechanism comprises a fixed scroll that is fixed in the casing and an orbiting scroll that revolves orbitally relative to the fixed scroll, and the orbiting scroll comprises a scroll-portion oil-supply passage that is formed so as to be connected from the main oil-supply passage of the drive shaft through a sliding surface constituted between the fixed scroll and the orbiting scroll to the low-pressure space that is located at a suction side of the compressing mechanism.

3. The rotary compressor of claim 2, wherein

at least part of the scroll-portion oil-supply passage is constituted of a restriction pathway.

4. The rotary compressor of claims 1, wherein

at least one of the drive shaft and the bearing comprises an oil supply groove, sod the oil supply groove is formed at the sliding face constituted between the drive shaft and the bearing and between the sealing portions that are disposed on opposite sides of the bearing-portion oil-supply passage in the axis direction, and the oil supply groove is connected to the bearing-portion oil-supply passage.

5. The rotary compressor of claim 4, wherein

the drive shaft is disposed so as to extend in a vertical direction in the casing, the bearing comprises a lower bearing that is close to the oil reservoir and an upper bearing that is located above the lower bearing and the oil supply groove formed at the sliding face is disposed at least at the upper bearing.

6. The rotary compressor of claim 4, wherein

a length, L of the bearing in the axis direction, a gap distance, C between an inside diameter of the bearing and an outside diameter of the drive shaft at the sliding face, and a length, b of the oil groove in the axis direction are provided such that 0.3L<

b<

L−

0.2C×

10³.

7. The rotary compressor of claim 2, wherein

at least one of the drive shaft and the bearing comprises an oil supply groove, the oil supply groove is formed at the sliding face constituted between the drive shaft and the bearing and between the sealing portions that are disposed on opposite sides of the bearing-portion oil-supply passage in the axis direction, and the oil supply groove is connected to the bearing-portion oil-supply passage.

8. The rotary compressor of claim 7, wherein

the drive shaft is disposed so as to extend in a vertical direction in the casing, the bearing comprises a lower bearing that is close to the oil reservoir and an upper bearing that is located above the lower bearing, and the oil supply groove formed at the sliding face is disposed at least at the upper bearing.

9. The rotary compressor of claim 7, wherein

a length L of the bearing in the axis direction, a gap distance C between an inside diameter of the bearing and an outside diameter of the drive shaft at the sliding face, and a length b of the oil groove in the axis direction are provided such that 0.3L<

b<

L−

0.2C×

10³.

10. The rotary compressor of claim 3, wherein

at least one of the drive shaft and the bearing comprises an oil supply groove, the oil supply groove is formed at the sliding face constituted between the drive shaft and the bearing and between the sealing portions that are disposed on opposite sides of the bearing-portion oil-supply passage in the axis direction, and the oil supply groove is connected to the bearing-portion oil-supply passage.

11. The rotary compressor of claim 10, wherein

the drive shaft is disposed so as to extend in a vertical direction in the casing, the bearing comprises a lower bearing that is close to the oil reservoir and an upper bearing that is located above the lower bearing, and the oil supply groove formed at the sliding face is disposed at least at the upper bearing.

12. The rotary compressor of claim 10, wherein

a length L of the bearing in the axis direction, a gap distance C between an inside diameter of the bearing and an outside diameter of the drive shaft at the sliding face, and a length b of the oil groove in the axis direction are provided such that 0.3L<

b<

L−

0.2C×

10³.