Scroll compressor having paired fixed and moveable scrolls

BACKGROUND OF THE INVENTION

The present invention relates to a scroll compressor.

Scroll compressors are known in the art. For example, Japanese Patent Laid-Open Publication No.59-65586 discloses a scroll compressor comprising paired fixed and movable scrolls, the fixed scroll of each pair having an end plate provided with a scroll body projecting from the end plate and the movable scroll of each pair having an end plate provided with a scroll body projecting from the end plate, wherein the movable scroll meshes with the fixed scroll to form a plurality of operation chambers between them and revolves relative to the fixed scroll to compress gas in the operation chambers, characterized in that two pairs of fixed and movable scrolls are disposed with back faces of the end plates of the fixed scrolls opposite each other, a main shaft for revolving the movable scrolls passes through the two pairs of fixed and movable scrolls to operatively engage the movable scrolls, and an outlet chamber is disposed between the end plates of the fixed scrolls.

In this known scroll compressor, the main shaft is supported at opposite ends by a housing accommodating the two pairs of fixed and movable scrolls. In the ordinary conventional scroll compressor comprising a pair of fixed and movable scrolls, and a main shaft operatively engaging the movable scroll at its one end, the main shaft is supported at its the other end by a housing accommodating the fixed scroll, the movable scroll and the main shaft. Therefore, the scroll compressor of Japanese Patent Laid-Open Publication No.59-65586 has advantages over the ordinary conventional scroll compressor, including that swirling of the main shaft is restrained, and vibration and noise due to such swirling of the main shaft are restrained.

However, the scroll compressor of Japanese Patent Laid-Open Publication No.59-65586 has following disadvantages.

1. Two movable scrolls are independent of each other. Therefore, anti-rotation mechanisms disposed between the end plates of the movable scrolls and the housing accommodating the scrolls are exposed to thrust load due to the compression of gas in the compression chambers, which causes them to wear and shorten the service life of the compressor. Downsizing of the compressor is difficult because downsizing of the ant-rotation mechanisms exposed to the thrust load is difficult

2. Also owing to the fact that two movable scrolls are independent of each other, adjustment of axial space between the fixed scroll and the movable scroll of one of the two pairs of fixed and movable scrolls must be carried out independently from the adjustment of axial space between the fixed and movable scrolls of the other of the two pairs of fixed and movable scrolls.

3. The main shaft operatively engages the movable scrolls at the central portions of the scroll bodies. Therefore, heat generated by bearings disposed at the operative engagement points is hard to disperse. As a result, the bearings are liable to heat and the service lives of the bearings are liable to become short.

4. No partition is disposed between bearings at the opposite ends of the main shaft and inlet chambers. Moreover, no partition is disposed between bearings at the operative engagement points and the inlet chambers. Therefore, gas taken into the inlet chambers is contaminated with lubricating oil in the bearings and the discharged gas is contaminated with lubricating oil. Therefore, the scroll compressor is not suitable for the compression of clean gas.

5. Also owing to the fact that no partition is disposed between bearings at the opposite ends of the main shaft and inlet chambers and no partition is disposed between bearings at the operative engagement points and the inlet chambers, gas heated by the hot bearings and increased in specific volume is taken into the operation chambers. As a result, flow rate of discharged gas from the scroll compressor is really low.

6. The bearings at the opposite ends of the main shaft and the bearings at the operative engagement points are disposed in substantially closed spaces. Therefore, heat generated by the bearings is hard to disperse, the bearings are liable to heat, and service lives of the bearings are liable to become short.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to overcome the foregoing problems by providing a scroll compressor comprising paired fixed and movable scrolls, the fixed scroll of each pair having an end plate provided with a scroll body projecting from the end plate and the movable scroll of each pair having an end plate provided with a scroll body projecting from the end plate, wherein the movable scroll meshes with the fixed scroll to form a plurality of operation chambers between them and revolves relative to the fixed scroll to compress gas in the operation chambers, characterized in that two pairs of fixed and movable scrolls are disposed with back faces of the end plates of the fixed scrolls opposite each other, a main shaft for revolving the movable scrolls passes through the two pairs of fixed and movable scrolls to operatively engage the movable scrolls, and an outlet chamber is disposed between the end plates of the fixed scrolls.

In accordance with the present invention, there is provided a scroll compressor comprising paired fixed and movable scrolls, the fixed scroll of each pair having an end plate provided with a scroll body projecting from the end plate and the movable scroll of each pair having an end plate provided with a scroll body projecting from the end plate, wherein the movable scroll meshes with the fixed scroll to form a plurality of operation chambers between them and revolves relative to the fixed scroll to compress gas in the operation chambers, characterized in that two pairs of fixed and movable scrolls are disposed with back faces of the end plates of the fixed scrolls opposite each other, the movable scrolls are integrally connected with each other, a main shaft for revolving the movable scrolls passes through the two pairs of fixed and movable scrolls to operatively engage the movable scrolls, and an outlet chamber is disposed between the end plates of the fixed scrolls.

In the present scroll compressor, the two movable scrolls integrally connected with each other bear the thrust load accompanying the compression of gas in the operation chambers. Therefore, anti-rotation mechanisms disposed between the end plates of the movable scrolls and a housing accommodating the scrolls and the main shaft do not bear the thrust load. As a result, wear of the anti-rotation mechanisms is minimized and the shortening of the service life of the compressor is minimized. Being free from the thrust load, the anti-rotation mechanisms can be downsized. As a result, the compressor can be downsized.

In the present scroll compressor, the two movable scrolls are integrally connected with each other. Therefore, axial spaces between the fixed scrolls and the movable scrolls of the two pairs of fixed and movable scrolls can be adjusted by a single operation.

According to a preferred embodiment of the present invention, the main shaft operatively engages the movable scrolls at the back faces of the end plates of the movable scrolls.

When the main shaft operatively engages the movable scrolls at the back faces of the end plates of the movable scrolls, the operative engagement points are close to the housing accommodating the two pairs of fixed and movable scrolls. Therefore, heat generated by the bearings at the operative engagement points is able to disperse to outside the compressor. As a result, heating of the bearings at the operative engagement points is suppressed and shortening of the service lives of the bearings is minimized.

According to another preferred embodiment of the present invention, the movable scrolls abut against a housing accommodating the two pairs of fixed and movable scrolls through seal members at peripheral portions of the back faces of the end plates.

Anti-rotation mechanisms and bearings of the main shaft are disposed between the back faces of the end plates of the movable scrolls and the portions of a housing opposite the back faces of the end plates. When the movable scrolls abut against the portions of the housing through seal members at peripheral portions of the back faces of the end plates, partitions are formed between the inlet paths of the compressor formed at the side of the scroll bodies of the movable scrolls and the anti-rotation mechanisms, the bearings of the main shaft and the bearings at the operative engagement points. Therefore, powder of abraded materials of the anti-rotation mechanisms and bearings, grease, etc. are prevented from entering into the operation chambers and discharged gas from the compressor is prevented from contamination by powder of abraded materials of the anti-rotation mechanisms and bearings, grease, etc. As a result, the scroll compressor in accordance with the present invention can be used for compression of clean gas.

Partitions are formed between the inlet paths of the compressor formed at the side of the scroll bodies of the movable scrolls and the anti-rotation mechanisms, the bearings of the main shaft and the bearings at the operative engagement points. Therefore, gas heated by the anti-rotation mechanisms and bearings to be increased in specific volume is prevented from entering into the operation chambers. As a result, the flow rate of discharged gas from the compressor is prevented from substantial decrease.

According to another preferred embodiment of the present invention, difference in phase angles of 180 degrees is present between scroll bodies of the fixed scrolls.

When difference in phase angles of 180 degrees is present between the scroll bodies of the fixed scrolls, difference in phase angles of 180 degrees is generated between pulsations of discharged gases from the two pairs of fixed and movable scrolls. Therefore, the pulsations of discharged gases cancel each other and generation of noise due to the pulsation of discharged gas is prevented. Moreover, difference in phase angles of 180 degrees is generated between pulsations of intake gases into the two pairs of fixed and movable scrolls. Therefore, the pulsations of intake gases cancel each other and generation of noise due to the pulsation of intake gas is prevented.

According to another preferred embodiment of the present invention, the relation r

0

>r>(r

0

−0.3 mm) is present between a revolution radius r of the movable scrolls determined by the anti-rotation mechanisms and a revolution radius r

0

of the movable scrolls determined by the scroll bodies of the fixed scrolls and the scroll bodies of the movable scrolls.

When r

0

>r, interferences between the scroll bodies of the fixed scrolls and the scroll bodies of the movable scrolls are prevented and generation of powder of abraded members due to such interferences is prevented. When r>(r

0

−0.3 mm), decrease of compression efficiency is prevented.

According to another preferred embodiment of the present invention, the housing is provided with air holes opposite the back faces of the end plates of the movable scrolls.

When the housing is provided with air holes opposite the back faces of the end plates of the movable scrolls, spaces formed between the back faces of the end plates of the movable scrolls and the housing communicate with the atmosphere through the air holes. Therefore, heat generated by the anti-rotation mechanisms, bearings, etc. disposed in the spaces disperses to the atmosphere through the air holes. As a result, decrease of compression efficiency due to thermal deformation of movable scrolls is prevented and shortening of the service lives of the anti-rotation mechanisms, bearings, etc. due to loss of grease, thermal deformation, etc. is prevented.

According to another preferred embodiment of the present invention, the end plates of the movable scrolls are provided with cooling fins at their back faces.

When the end plates of the movable scrolls are provided with cooling fins at their back faces, cooling efficiency of the movable scrolls, anti-rotation mechanisms and bearings is enhanced.

According to another preferred embodiment of the present invention, the main shaft is provided with balancing weights and axial fans connected to the balancing weights at its portions extending between the back faces of the end plates of the movable scrolls and the portions of the housing opposite the back faces of the end plates.

According to another preferred embodiment of the present invention, the main shaft is provided with balancing weights and centrifugal fans connected to the balancing weights at its portions extending between the back faces of the end plates of the movable scrolls and the portions of the housing opposite the back faces of the end plates.

When balancing weights are provided with axial fans or centrifugal fans, cooling efficiency of the movable scrolls, anti-rotation mechanisms and bearings is enhanced.

According to another preferred embodiment of the present invention, the centrifugal fans are provided with deflectors for directing the discharged air parallel to the main shaft.

When the centrifugal fans are provided with deflectors for directing the discharged air parallel to the main shaft, the flow rate of air colliding against the end plates of the movable scrolls increases and cooling efficiency of the movable scrolls is enhanced.

According to another preferred embodiment of the present invention, a cooling chamber communicating with the space outside the housing is disposed between the end plates of the fixed scrolls.

End plates of the fixed scrolls are cooled by airflow induced in the cooling chamber. As a result, thermal deformation of fixed scrolls is restrained and decrease of compression efficiency due to such thermal deformation of fixed scrolls is suppressed.

According to another preferred embodiment of the present invention, the end plates of the fixed scrolls and movable scrolls are disks with their peripheral portions partially cut off arcuately.

The end plates of fixed scrolls and movable scrolls are usually disks. Portions of the disks radially outside the scroll bodies serve no function. Partial cutting off of the functionless portions of the disks enables downsizing of the compressor.

Further objects, features and advantages of the present invention will become apparent from the Detailed Description of the Preferred Embodiment when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be more readily understood with reference to the following drawings, in which:

FIG. 1

is a side sectional view of a scroll compressor in accordance with a preferred embodiment of the present invention.

FIG. 2

is a perspective view of a half of a scroll compressor in accordance with a preferred embodiment of the present invention; and

FIG. 3

is a perspective view of a half of a scroll compressor in accordance with a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A scroll compressor in accordance with a preferred embodiment of the present invention will be described referring to

FIGS. 1

to

3

.

A scroll compressor in accordance with the present embodiment is provided with a scroll assembly

4

comprising a fixed scroll

1

having an end plate

1

a

and a scroll body

1

b

projecting from the end plate

1

a

and a movable scroll

2

having an end plate

2

a

and a scroll body

2

b

projecting from the end plate

2

a

. The movable scroll

2

meshes with the fixed scroll

1

to form a plurality of operation chambers

3

between them.

The scroll compressor is also provided with a scroll assembly

24

comprising a fixed scroll

21

having an end plate

21

a

and a scroll body

21

b

projecting from the end plate

21

a

and a movable scroll

22

having an end plate

22

a

and a scroll body

22

b

projecting from the end plate

22

a

. The movable scroll

22

meshes with the fixed scroll

21

to form a plurality of operation chambers

23

between them.

The back face of the end plate

1

a

of the fixed scroll

1

faces the back face of the end plate

21

a

of the fixed scroll

21

. The end plate

1

a

of the fixed scroll

1

is provided with a discharge hole

1

c

at its center and the end plate

21

a

of the fixed scroll

21

is provided with a discharge hole

21

c

at its center.

The end plates

1

a

,

21

a

of the fixed scrolls

1

,

21

and the end plates

2

a

,

22

a

of the movable scrolls

2

,

22

are disks with their peripheral portions radially outside the scroll bodies

1

b

,

21

b

,

2

b

and

22

b

partially cut off arcuately.

A center block

5

is disposed between the end plate

1

a

of the fixed scroll

1

and the end plate

21

a

of the fixed scroll

21

. The fixed scroll

1

, the center block

5

and the fixed scroll

21

are integrally connected with each other by a plurality of bolts

6

. Difference in phase angles of 180 degrees is present between the scroll body

1

b

of the fixed scroll

1

and the scroll body

21

b

of the fixed scroll

21

.

The center block

5

is provided with a pair of arcuate holes

5

a

. The movable scroll

2

and the movable scroll

22

are integrally connected with each other by a plurality of connecting rods

7

movably passing through the arcuate holes

5

a

and a plurality of bolts

8

passing through the connecting rods

7

. Difference in phase angles of 180 degrees is present between the scroll body

2

b

of the movable scroll

2

and the scroll body

1

b

of the fixed scroll

1

. Difference in phase angles of 180 degrees is present between the scroll body

22

b

of the movable scroll

22

and the scroll body

21

b

of the fixed scroll

21

.

A front housing

9

abuts against the center block

5

. The front housing

9

cooperates with the center block

5

to form a housing for accommodating the scroll assembly

4

.

A rear housing

29

also abuts against the center block

5

. The rear housing

29

cooperates with the center block

5

to form a housing for accommodating the scroll assembly

24

.

The front housing

9

, the center block

5

and the rear housing

29

are integrally connected with each other by a plurality of bolts

10

.

An annular seal member

11

a

is embedded in a peripheral portion

2

a

1

of the end plate

2

a

of the movable scroll

2

. The seal member

11

a

projects from the peripheral portion

2

a

1

and abuts against the front housing

9

to be able to slide.

An annular seal member

31

a

is embedded in a peripheral portion

22

a

1

of the end plate

22

a

of the movable scroll

22

. The seal member

31

a

projects from the peripheral portion

22

a

1

and abuts against the rear housing

29

to be able to slide.

The front housing

9

is provided with air holes

9

a

and

9

b

at its portion opposite the back face of the end plate

2

a

of the movable scroll

2

. The rear housing

29

is provided with air holes

29

a

and

29

b

at its portion opposite the back face of the end plate

22

a

of the movable scroll

22

.

The end plates

2

a

and

22

a

of the movable scrolls

2

and

22

are provided with a plurality of radially extending cooling fins

2

c

and

22

c

at their back faces.

A shaft

12

passes into and extends through the front housing

9

. The shaft

12

has a large diameter portion

12

a

extending in the front housing

9

. The large diameter portion

12

a

is supported to be rotatable by the front housing

9

through a bearing

13

a.

A shaft

32

passes into and extends through the rear housing

29

. The shaft

32

has a large diameter portion

32

a

extending in the rear housing

29

. The large diameter portion

32

a

is supported to be rotatable by the rear housing

29

through a bearing

33

a.

The large diameter portion

12

a

is integrally connected to the large diameter portion

32

a

by an offset shaft

14

. The offset shaft

14

passes through the fixed scrolls

1

and

21

and the movable scrolls

2

and

22

. The shaft

12

, the offset shaft

14

and the shaft

32

cooperate to form a main shaft.

A bush

15

fits on the offset shaft

14

to be able to slide around the offset shaft

14

. The bush

15

is accommodated in a boss

2

d

formed in the back face of the end plate

2

a

of the movable scroll

2

through a bearing

13

b

. The offset shaft

14

operatively engages the movable scroll

2

through the bush

15

, the bearing

13

b

and the boss

2

d.

A bush

35

fits on the offset shaft

14

to be able to slide around the offset shaft

14

. The bush

35

is accommodated in a boss

22

d

formed in the back face of the end plate

22

a

of the movable scroll

22

through a bearing

33

b

. The offset shaft

14

operatively engages the movable scroll

22

through the bush

35

, the bearing

33

b

and the boss

22

d.

An anti-rotation mechanism

16

is disposed between the movable scroll

2

and the front housing

9

opposite the movable scroll

2

. The anti-rotation mechanism

16

comprises a plurality of bearings and an auxiliary crank.

An anti-rotation mechanism

36

is disposed between the movable scroll

22

and the rear housing

29

opposite the movable scroll

22

. The anti-rotation mechanism

36

comprises a plurality of bearings and an auxiliary crank.

The anti-rotation mechanism

16

is offset circumferentially by about 90 degrees from the anti-rotation mechanism

36

The relation r

0

>r>(r

0

−0.3 mm) is present between a revolution radius r of the movable scrolls

2

and

22

determined by the anti-rotation mechanisms

16

and

36

and a revolution radius r

0

of the movable scrolls

2

and

22

determined by the scroll bodies

1

b

and

21

b

of the fixed scrolls

1

and

21

and the scroll bodies

2

b

and

22

b

of the movable scrolls

2

and

22

.

A balancing weight

17

is fixed to the large diameter portion

12

a

of the shaft

12

. The balancing weight

17

is provided with a centrifugal fan

18

. The centrifugal fan

18

is provided with a deflector

18

a

for directing discharged air parallel to the main shaft and to the end plate

2

a

of the movable scroll

2

.

A balancing weight

37

is fixed to the large diameter portion

32

a

of the shaft

32

. The balancing weight

37

is provided with a centrifugal fan

38

. The centrifugal fan

38

is provided with a deflector

38

a

for directing discharged air parallel to the main shaft and to the end plate

22

a

of the movable scroll

22

.

The end plate

1

a

of the fixed scroll

1

is provided with a boss

1

d

surrounding the offset shaft

14

. An annular seal member

11

b

is embedded in the end face of the boss

1

d

. The seal member

11

b

projects from the end face of the boss

1

d

and abuts against the end plate

2

a

of the movable scroll

2

to be able to slide.

The end plate

21

a

of the fixed scroll

21

is provided with a boss

21

d

surrounding the offset shaft

14

. An annular seal member

31

b

is embedded in the end face of the boss

21

d

. The seal member

31

b

projects from the end face of the boss

21

d

and abuts against the end plate

22

a

of the movable scroll

22

to be able to slide.

The center block

5

is provided with an inlet port

5

b

communicating with the arcuate hole

5

a

. The center block

5

is provided with a boss

5

c

surrounding the offset shaft

14

. The center block

5

is provided with a cylindrical portion

5

d

radially outside the boss

5

c

. The cylindrical portion

5

d

is made integral with the boss

5

c

and extends coaxially with the boss

5

c

. The center block

5

is provided with an outlet chamber

5

e

between the boss

5

c

and the cylindrical portion

5

d

. The outlet chamber

5

e

communicates with the discharge hole

1

c

of the fixed scroll

1

and the discharge hole

21

c

of the fixed scroll

21

. The center block

5

is provided with an outlet port

5

f

. The outlet chamber

5

e

communicates with the outlet port

5

f

through a cylindrical portion

5

g

. The center block

5

is provided with a cooling chamber

5

h

radially outside the cylindrical portion

5

d

and between the end plate

1

a

of the fixed scroll

1

and the end plate

21

a

of the fixed scroll

21

. The cooling chamber

5

h

communicates with the space outside the center block

5

through an air hole

5

i.

The abutting point between the boss

5

c

and the end plate

1

a

of the fixed scroll

1

is sealed by the seal member

11

c

and the abutting point between the boss

5

c

and the end plate

21

a

of the fixed scroll

21

is sealed by the seal member

31

c.

In operation, the shaft

12

is rotated around the central axis X by a driving means not shown in

FIGS. 1

to

3

. The offset shaft

14

rotates around the axis X accompanying the shaft

12

. Rotation of the offset shaft

14

is transmitted to the movable scrolls

2

and

22

operatively engaging the offset shaft

14

through the bushes

15

and

35

. Thus, the movable scrolls

2

and

22

integrally connected with each other revolve around the axis X. Gas is taken into the compressor through the inlet port

5

b

and then into the operation chambers

3

and

23

. The operation chambers

3

and

23

approach the center of the fixed scrolls

1

and

21

with their volume gradually decreasing. Thus, the gas in the operation chambers

3

and

23

is compressed. The compressed gas discharges into the outlet chamber

5

e

through the discharge holes

1

c

and

21

c

of the end plates

1

a

and

21

a

of the fixed scrolls

1

and

21

and discharges from the compressor through the outlet port

5

f.

The movable scrolls

2

and

22

are allowed to revolve but are prevented from rotation by the anti-rotation mechanisms

16

and

36

.

In the scroll compressor of the present embodiment, the movable scrolls

2

and

22

integrally connected with each other bear the thrust load accompanying the compression of gas in the operation chambers

3

and

23

. Therefore, the anti-rotation mechanism

16

disposed between the end plate

2

a

of the movable scroll

2

and the front housing

9

opposite the end plate

2

a

does not bear the thrust load. Similarly, the anti-rotation mechanism

36

disposed between the end plate

22

a

of the movable scroll

22

and the rear housing

29

opposite the end plate

22

a

does not bear the thrust load. As a result, wear of the anti-rotation mechanisms

16

and

36

is minimized and decrease of service life of the compressor is minimized. Being free from the thrust load, the anti-rotation mechanisms

16

and

36

can be downsized. As a result, the compressor can be downsized.

In the scroll compressor of the present embodiment, the fixed scrolls

1

and

21

are integrally connected with each other and the movable scrolls

2

and

22

are integrally connected with each other. Therefore, axial space between the fixed scroll

1

and the movable scroll

2

and the axial space between the fixed scroll

21

and the movable scroll

22

can be adjusted by a single operation of adjusting the length of the connecting rods

7

integrally connecting the movable scrolls

2

and

22

or of adjusting the thickness of shims inserted between end faces of the connecting rods

7

and the movable scrolls

2

and

22

.

In the scroll compressor of the present embodiment, the bushes

15

and

35

, the bearings

13

b

and

33

b

and the bosses

2

d

and

22

d

constituting the operative engagement points between the offset shaft

14

and the movable scrolls

2

and

22

are disposed at the back faces of the end plates

2

a

and

22

a

of the movable scrolls

2

and

22

. Thus, these members are close to the front housing

9

and the rear housing

29

. Therefore, heat generated by the bearings

13

b

and

33

b

at the operative engagement points easily disperses to the outside the compressor through the front housing

9

and the rear housing

29

. As a result, heating of the bearings

13

b

and

33

b

is minimized and decrease of the service lives of the bearings

13

b

and

33

b

is minimized.

In the scroll compressor of the preset embodiment, the end plates

2

a

and

22

a

abut against the front housing

9

and the rear housing

29

at peripheral portions

2

a

1

and

22

a

1

of their back faces through the seal members

11

a

and

31

a

. Thus, partitions are formed between the inlet paths of the compressor formed at the side of the scroll bodies

2

b

and

22

b

of the movable scrolls

2

and

22

and the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

33

a

,

13

b

and

33

b

. Therefore, powder of abraded materials of the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

33

a

,

13

b

and

33

b

, grease, etc. are prevented from entering into the operation chambers

3

and

23

and discharged gas from the compressor is prevented from contamination by the powder of abraded materials, grease, etc. As a result, the scroll compressor of the present embodiment can be used for compression of clean gas.

Partitions are formed between the inlet paths of the compressor formed at the side of the scroll bodies

2

b

and

22

b

of the movable scrolls

2

and

22

and the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

33

a

,

13

b

and

33

b

. Therefore, gas heated by the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

33

a

,

13

b

and

33

b

, to be increased in specific volume is prevented from entering into the operation chambers

3

and

23

. As a result, flow rate of discharged gas from the compressor is prevented from substantial decrease.

In the scroll compressor of the present embodiment, the bosses

1

d

and

21

d

of the fixed scrolls

1

and

21

abut against the end plates

2

a

and

22

a

of the movable scrolls

2

and

22

through the seal members

11

b

and

31

b

. Therefore, grease in the bearings

13

a

,

33

a

,

13

b

and

33

b

does not enter into the operation chambers

3

and

23

along the offset shaft

14

and contaminate the discharged gas from the compressor.

The abutting points between the boss

5

c

of the center block

5

and the end plates

1

a

and

21

a

of the fixed scrolls

1

and

21

are sealed by the seal members

11

c

and

31

c

. Therefore, grease in the bearings

13

a

,

33

a

,

13

b

and

33

b

does not enter into the outlet chamber

5

e

along the offset shaft

14

and contaminate the discharged gas from the compressor.

In the scroll compressor of the present embodiment, difference in phase angles of 180 degrees is present between the scroll bodies

1

b

and

21

b

of the fixed scrolls

1

and

21

. Thus, difference in phase angles of 180 degrees is generated between pulsation of discharged gas from the paired fixed scroll

1

and movable scroll

2

and pulsation of discharged gas from the paired fixed scroll

21

and movable scroll

22

. Therefore, the pulsations of the two discharged gases cancel each other and noise due to the pulsation of discharged gas is prevented from generation. Moreover, difference in phase angles of 180 degrees is generated between pulsation of intake gas into the paired fixed scroll

1

and movable scroll

2

and pulsation of intake gas into the paired fixed scroll

21

and movable scroll

22

. Therefore, the pulsations of the two intake gases cancel each other and noise due to the pulsation of intake gas is prevented from generation.

In the scroll compressor of the present embodiment, the relation r

0

>r is present between a revolution radius r of the movable scrolls

2

and

22

determined by the anti-rotation mechanisms

16

and

36

and a revolution radius r

0

of the movable scrolls

2

and

22

determined by the scroll bodies

1

b

and

21

b

of the fixed scrolls

1

and

21

and the scroll bodies

2

b

and

22

b

of the movable scrolls

2

and

22

. As a result, interferences between the scroll bodies

1

b

and

21

b

of the fixed scrolls

1

and

21

and the scroll bodies

2

b

and

22

b

of the movable scrolls

2

and

22

are prevented and generation of powder of abraded members due to such interferences is prevented. Moreover, the relation r>(r

0

−0.3 mm) is present between the revolution radiuses r and r

0

. As a result, decrease of compression efficiency is prevented.

In the scroll compressor of the present embodiment, spaces formed between the back faces of the end plates

2

a

and

22

a

of the movable scrolls

2

and

22

and the front and housing

9

and the rear housing

29

communicate with the atmosphere through the air holes

9

a

,

9

b

,

29

a

and

29

b

. Therefore, heat generated by the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

13

b

,

33

a

and

33

b

disperses to the atmosphere through the air holes

9

a

,

9

b

,

29

a

and

29

b

. As a result, decrease of compression efficiency due to thermal deformation of the movable scrolls

2

and

22

is prevented and shortening of service lives of the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

13

b

,

33

a

and

33

b

due to loss of grease or thermal deformation is prevented.

In the scroll compressor of the present embodiment, the end plates

2

a

and

22

a

of the movable scrolls

2

and

22

are provided with cooling fins

2

c

and

22

c

at their back faces. As a result, cooling efficiencies of the movable scrolls

2

and

22

, the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

13

b

,

33

a

and

33

b

are enhanced.

In the scroll compressor of the present embodiment, the balancing weights

17

and

37

are provided with centrifugal fans

18

and

38

. Therefore, external air is taken into the front housing

9

and the rear housing

29

through the air holes

9

a

,

9

b

,

29

a

and

29

b

. As a result, cooling efficiencies of the movable scrolls

2

and

22

, the anti-rotation mechanisms

16

and

36

, and the bearings

13

a

,

13

b

,

33

a

and

33

b

are enhanced.

In the scroll compressor of the present embodiment, discharged airs from the centrifugal fans

18

and

38

are directed to the end plates

2

a

and

22

a

of the movable scrolls

2

and

22

by the deflectors

18

a

and

38

a

. As a result, flow rates of the airs colliding against the end plates

2

a

and

22

a

of the movable scrolls

2

and

22

increase and cooling efficiencies of the movable scrolls

2

and

22

are enhanced.

The balancing weights

17

and

37

may be provided with axial fans instead of the centrifugal fans

18

and

38

.

In the scroll compressor of the present embodiment, the cooling chamber

5

h

communicating with space outside the housing of the compressor is disposed between the end plates

1

a

and

21

a

of the fixed scrolls

1

and

21

. Therefore, the end plates

1

a

and

21

a

of the fixed scrolls

1

and

21

are cooled by the airflow taken into the cooling chamber

5

h

. As a result, thermal deformations of the fixed scrolls

1

and

21

are restrained and decrease of compression efficiency due to such thermal deformations of the fixed scrolls

1

and

21

is suppressed.

In the scroll compressor of the present embodiment, functionless portions of the disk-shaped end plates

1

a

and

21

a

of the fixed scrolls

1

and

21

radially outside the scroll bodies

1

b

and

21

b

are partially cut off arcuately. In the scroll compressor of the present embodiment, functionless portions of the disk-shaped end plates

2

a

and

22

a

of the movable scrolls

2

and

22

radially outside the scroll bodies

2

b

and

22

b

are partially cut off arcuately. As a result, the scroll compressor of the present embodiment is downsized.

In the above embodiment, the difference in phase angles between the scroll bodies

1

b

and

21

b

of the fixed scrolls

1

and

21

need not be strictly 180 degrees. It may be larger or smaller than 180 degrees to some extent.

In the above embodiment, the difference in phase angles between the scroll bodies

2

b

,

22

b

of the movable scrolls

2

,

22

and the scroll bodies

1

b

,

21

b

of the fixed scrolls

1

,

21

need not be strictly 180 degrees. It may be larger or smaller than 180 degrees to some extent.

In the above embodiment, the numeral in the relation between r and r

0

need not be strictly 0.3. It may slightly deviate from 0.3.

While the present invention has been described with reference to preferred embodiments, one of ordinary skill in the art will recognize that modifications and improvements may be made while remaining within the spirit and scope of the present invention. The scope of the invention is determined solely by the appended claims.

Number	Name	Date	Kind
3802809	Vulliez	Apr 1974	A
5466134	Shaffer et al.	Nov 1995	A
5624247	Nakamura	Apr 1997	A

Number	Date	Country
5965586	Apr 1984	JP
5-141367	Jun 1993	JP

Scroll compressor having paired fixed and moveable scrolls

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

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International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (3)

Foreign Referenced Citations (2)