Scroll type fluid machine

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a scroll type fluid machine which processes coolant, air or other compressible gas, and in particular to a scroll type fluid machine characterized by the provision of a positioning means for a single unorbiting scroll member which is movable in the direction of a substantially straight line passing through a substantial center of the scroll lap of the unorbiting scroll member but unmovable in a direction substantially orthogonal to the above-mentioned substantially straight line, and which is rotatable, and an unorbiting scroll fixing member, and adapted to appropriately mesh the unorbiting scroll member with an orbiting scroll member so as to aim at ensuring a high degree of energy efficiency.

2. Related Art

Scroll type fluid machines have been widely used as compressors in refrigerators, air-conditioners, and others in various fields. In comparison with other compressors having other configurations, such fluid machines may have preferences such as a high degree of efficiency, a high degree of reliability, stillness and the like, and accordingly, they have been prosperously developed and studied.

Brief explanation will be made of one of the arrangements of these scroll type fluid machines. The basic components of the compression part thereof are a stationary scroll, an orbiting scroll and a frame, the frame being fixed to a closed container, and is also fixed to the stationary scroll with the use of vacant holes in the stationary scroll, fixing thread parts of the frame, and a fixing bolts. The basic components of the stationary scroll are a lap, a mirror plate, a lap bottom, a lap tip and a discharge port, and those of the orbiting scroll are a lap, and a mirror plate, a lap bottom and a lap tip.

The basic components of the drive part of the compressor, for driving the orbiting scroll in order to orbit the latter, are a stator and a rotor in a motor, a crank shaft, an Oldham's ring which is a main component of a mechanism for preventing the orbiting scroll from rotating around its axis, a support member of the crank shaft, for rotatably engaging the frame and the crank shaft with each other, and a support part of the orbiting scroll, for engaging the orbiting scroll and an eccentric pin part of the crankshaft with each other so as to be movable in a thrust direction which is a rotating axis direction and rotatable.

Next, referring to

FIG. 10

, brief explanation will be made of the compressing operation of the scroll type fluid machine.

FIG. 10

shows compression chambers

4

a

1

,

4

a

2

,

4

b

1

,

4

b

2

which are defined by the lap

2

a

of the stationary scroll

2

and the lap

3

a

of the orbiting scroll

3

, which are meshed with each other. The compression chambers

4

a

1

,

4

a

2

,

4

b

1

,

4

b

2

shown in this figure are those during compression stroke, and the compressing operation is carried out in such a way that the orbiting scroll carries out orbiting motion so as to reduce the volumes of the compression chambers. During compressing operation, working fluid is sucked into the compression chamber

4

by way of a suction port

5

and a suction space

15

in association with the orbiting motion of the orbiting scroll

3

. The sucked working fluid is discharged by way of a discharge space and a discharge port at the time when the compression chamber reaches a position where it is communicated with a discharge port

2

e

of the stationary scroll after the volume of the compression chamber is successively decreased as indicated by

4

a

1

,

4

a

2

,

4

b

1

and

4

b

2

. During the orbiting motion of the stationary scroll

2

and the orbiting scroll

3

which are meshed with each other, there is required sufficient gas-tightness in order to prevent occurrence of leakage of the working fluid between the suction space

15

and the compression chambers

4

a

1

,

4

b

1

, between the compression chambers

4

a

1

,

4

a

2

,

4

b

1

,

4

b

2

, and between the compression chambers

4

a

2

,

4

b

2

and the discharge port

2

e,

as far as possible.

Next, brief explanation will be made of an example of a fixing structure between the stationary scroll

2

and the frame

7

with reference to

FIG. 11

which is a schematic view illustrating an example of the stationary structure. The purpose of fixing the stationary scroll

2

and the frame

7

with each other is to isolate under pressure a space defined between the frame

7

and the stationary scroll

2

from the discharge space or the suction space in order to carry out appropriate compressing operation. In the example of the fixing structure shown in

FIG. 11

, the stationary scroll

2

and the frame

7

are fixed together by using a vacant hole

2

f

in the stationary scroll

2

, a fixing thread part

7

b

in the frame

7

and a fixing bolt

20

. In order to isolate the space from the discharge space and the suction space under pressure, as shown in

FIG. 10

, a plurality of vacant holes

2

f

in the stationary scroll arranged in a ring-like shape. Further, the diameter of the vacant holes

2

f

is dimensioned so as to allow the fixing bolts

20

to smoothly be inserted there-through in order to facilitate the assembly of the fluid machine.

An example of the positioning means for the stationary scroll, is disclosed in Japanese Laid-open patent No. H5-332267, and is shown in FIG.

12

. In this example, a stationary scroll

100

is composed of a first base plate

100

a,

a first spiral member

100

b,

and two reference holes

100

c,

100

d,

and with the use of the two reference holes

100

c,

100

d,

the stationary scroll is positioned so that the phases of the spiral bodies of the stationary scroll

100

and the orbiting scroll are precisely shifted from each other by an angle of 180 deg. In

FIG. 12

, the reference hole

100

d

is elongated. However, it is should not be limited to such an elongated hole. The elongated hole can facilitate the assembly even though there would be errors in pitch accuracy between the reference holes while the clearances between the engaging pin and the reference holes can be minimized, and the phase relationship between both scrolls can be precisely set.

The fixing structure between the stationary structure and the frame, as mentioned above offers problems in view of obtaining an appropriate engaging condition between the orbiting scroll and the stationary scroll in order to ensure a high degree of energy efficiency. As shown in

FIG. 10

, in consideration with the meshing between the orbiting scroll lap

3

a

and the stationary scroll lap

2

a,

no gaps are theoretically present between the side surfaces of the laps

2

a,

3

a

at positions where the side surfaces are made into contact with each other, and accordingly, the stationary scroll

2

and the orbiting scroll

3

can be directly meshed with each other. However, since machining tolerances are inevitably present, in fact, in machined components including the stationary scroll

2

and the orbiting scroll

3

, small gaps are, in general, defined between the side surfaces of the laps

2

a,

3

a

so as to prevent interference between the orbiting scroll lap

3

a

and the stationary scroll lap

2

a

during the assembly of the fluid machine and the orbiting motion thereof. Thus, even with scroll type fluid machines with identical specifications, deviation are inevitably caused among the gaps between the side surfaces of the laps

2

a,

3

a

within the range of machining tolerances.

Further, in the example of the fixing structure between the stationary scroll

2

and the frame

7

, shown in

FIG. 11

, it is frequent that a relatively large gap

21

is defined between the vacant hole

2

f

in the stationary scroll and the fixing bolt

20

as shown in

FIG. 11

in order to enable the fixing bolt

20

to be smoothly inserted through the vacant hole

2

f

in the stationary scroll. Accordingly, when the stationary scroll

2

is fixed to the frame

7

, there would be caused such a risk that the stationary scroll

2

is fixed, being rotated or parallelly shifted from the neutral position thereof by a degree corresponding to the gap

21

.

FIG. 13A

shows a meshing condition between the stationary scroll

2

and the orbiting scroll

3

in such a case that the stationary scroll

2

is fixed at the neutral position which is a theoretically meshing position, and

FIG. 13B

shows a meshing condition between the stationary scroll

2

and the orbiting scroll

3

in such a case that the stationary scroll

2

being fixed after being rotated and shifted from the neutral position. Although a gap of several μm or several tenth μm is actually present between the side surfaces of the stationary scroll lap

2

a

and the orbiting scroll lap

3

a,

due to machining tolerances, but it is not visible by its size. Referring

FIG. 13A

, gaps B

1

, B

2

and C

1

, C

2

defined between the stationary scroll lap

2

a

and the orbiting scroll lap

3

a

in parts where they make contact with each other, are depicted being exaggerated. The X-axis and Y-axis and the center of the stationary scroll lap

2

a

are denoted as XF, YF and OF, respectively, and the X-axis and Y-axis and the center of the orbiting scroll lap

3

a

are denoted as XM, YM and OM, respectively.

FIG. 13A

shows a meshing condition in which the orbiting scroll

3

is orbited in the positive Y-axial direction, and the Y axes of the stationary scroll lap

2

a

and the orbiting scroll lap

3

a

are coincident with each other.

FIG. 13B

shows a meshing condition in which the stationary scroll

2

is rotated counterclockwise about the center OF of the stationary scroll lap from the condition shown in FIG.

13

A. When the stationary scroll

2

is rotated and then fixed, the parts B

1

, B

2

and C

1

, C

2

shown in

FIG. 13A

are changed into parts B

3

, B

4

and C

3

and C

4

. The gaps C

3

and C

4

are decreased while the gaps B

3

and B

4

are increased. If the stationary scroll is rotated and moved counterclockwise, and is then fixed, as shown in

FIG. 13B

, the stationary scroll

2

cannot be rotated at an angle by which the gap between C

3

and C

4

becomes 0. Contrary, if it is rotated clockwise and then fixed, the stationary scroll

2

cannot be rotated at an angle by which the gap between B

3

and B

4

becomes 0.

FIGS. 14A

to

14

D show meshing conditions between the stationary scroll

2

which is fixed after the rotation and the movement shown in

FIG. 13B

, and the orbiting scroll

3

at angular intervals of 90 deg. in the order of

FIGS. 14A

to

14

D, and explanation will be made of varying situations of gaps D

1

to D

5

and E

1

to E

5

which are produced in the meshing between the stationary scroll

2

fixed after rotation and movement, and the orbiting scroll

3

. The X- and Y-axes and the center of the stationary scroll lap

2

a

are denoted by XF, YF and OF, respectively, and the X-axis and Y-axis and the center of the orbiting scroll lap

3

a

are denoted by XM, YM and OM, respectively. The gap D

1

corresponding to B

3

in

FIG. 13B

is larger than the gap which is fixed at the neutral position, and is maintained to be large always as shown by D

1

to D

5

during orbiting. Meanwhile, the gap E

1

corresponding to C

3

in

FIG. 13B

is smaller than the gap which is fixed at the neutral position, and is maintained to be always small as shown by E

1

to E

5

during orbiting. In particular, the possibility of such a tendency that the size of the gap produced through D

1

to D

5

is greater than that of the gap produced at the neutral position is high since it is defined between the laps having different curvatures caused by rotation and movement. In this case, the compression chamber in which D

1

to D

5

constitute a seal part, has a gap which becomes large always so that leakage during compression is increased, and accordingly, the energy efficiency of the scroll fluid machine is greatly lowered.

Further, in the fixing method as shown in

FIG. 11

, the stationary scroll is fixed in such a condition that it is rotated and translated within a range of processing tolerance, the size of the gap corresponding to the seal part of the compressing chamber becomes nonuniform, and as a result, the energy efficiency is largely uneven among scroll type fluid machines even having an identical specification.

Further, a stationary scroll fixing means using two reference holes shown in FIG.

12

and disclosed in the Japanese Laid-Open Patent No. H5-332267 offers several problems in view of ensuring an appropriate meshing condition between the orbiting scroll and the stationary scroll, and high energy efficiency. The positioning means using two reference holes can precisely position the stationary scroll at a preset fixing position. That is, it may be construed that the meshing condition between the stationary scroll and the orbiting scroll has been previously determined. However, since dimensional deviations within processing tolerance are inevitably present among the stationary scroll, the orbiting scroll, the Oldham's ring, the frame and the like, and it can be hardly said that the fixing position of the stationary scroll, which has been previously set, always exhibit an appropriate meshing condition between the stationary scroll and the orbiting scroll. Even though the elongated hole as shown in

FIG. 12

is used, the fixing position is still determined directly through the combination with the reference hole

100

c,

that is, the appropriate position of the fitting pin is not determined in the range of the elongated hole. Thus, although the positioning means disclosed in this well-known example can position the stationary scroll, surely at the preset fixing position of the stationary scroll, it cannot always be said that this fixing position exhibits an appropriate meshing condition between the orbiting scroll and the stationary scroll.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a scroll type fluid machine which can easily offer an appropriate meshing condition between the scroll lap of an orbiting scroll and the scroll lap of an unorbiting scroll so as to enhance the energy efficiency.

In order to solve the above-mentioned problems, according to the present invention, there is provided a scroll type fluid machine comprising a unorbiting scroll member having a spiral scroll lap and performing limited motion in a plane orthogonal to the axis thereof; an orbiting scroll having a spiral scroll lap meshed with the scroll lap of the unorbiting scroll member so as to define compression chambers and performing orbiting motion without rotation around its axis in the plane orthogonal to the axis, an unorbiting scroll fixing member for limiting the motion of the unorbiting scroll in the plane orthogonal to the axis, and a positioning means for positioning relative positions of the unorbiting scroll member and the unorbiting scroll fixing member in the plane orthogonal to the axis, the positioning means adapted to be used during the assembly of the scroll type fluid machine being constituted in the following manner: that is, the positioning means is composed of parts formed in both unorbiting scroll fixing member and unorbiting scroll member, and is adapted to engage the unorbiting scroll member with the unorbiting scroll fixing member so as to be movable in a direction along a one straight line passing through a substantial center of the unorbiting scroll member in the plane orthogonal to the axis, and to be rotatable about a straight line passing through a position where the one straight line crosses a peripheral edge of the unorbiting scroll member and in parallel with the axis.

The above-mentioned positioning means is composed of an elongated hole structure having a major axis extended in the direction of the one straight line and a pair of wall surfaces which are opposed to each other, and which extend in parallel with the one straight line, and between which the one straight line extends and a pin structure having a pin part rotatably fitted in the elongated hole so as to be movable along the pair of wall surfaces, either one of the elongated hole structure and the pin structure may be formed in the peripheral edge part of the unorbiting scroll, and the other one of them may be formed in the unorbiting scroll fixing member.

During actual positioning, the pin part of the pin structure is fitted in the elongated hole structure, then the unorbiting scroll is shifted along the major axis of the elongated hole as far as possible in the direction in which the center of the scroll lap of the unorbiting scroll member comes away from the center of the scroll lap of the orbiting scroll member in a condition in which the scroll lap of unorbiting scroll member is meshed with scroll lap of the orbiting scroll member so as to be turnable, then, after the orbiting scroll member is turned by an angle of about 180 deg. from the position, the unorbiting scroll member is similarly shifted along the major axis of the elongated hole as far as possible in the direction in which the center of the scroll lap of the unorbiting scroll member comes away from the center of the scroll lap of the orbiting scroll member, and the unorbiting scroll member may be positioned at the middle position of the above-mentioned shift.

Further, at the position set by the above-mentioned shift, the unorbiting scroll member is rotated about the pin structure as a center in a range in which the orbiting motion of the orbiting scroll can be made, and the unorbiting scroll member is desirably positioned at a middle position of the rotating angle.

With the above-mentioned positioning means according to the present invention, the gaps between the side surfaces of both scroll laps can be adjusted within an assembly error caused by the accumulation of processing tolerances of components such as the orbiting scroll member, the unorbiting scroll member, the member for fixing the unorbiting scroll member and the drive means for driving, the orbiting scroll member.

Detailed explanation will be hereinbelow made of preferred embodiments of the present invention with reference to the accompanying drawings, which are in specifically limited forms of the present invention, with reference to the accompanying drawings among which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A

is sectional view illustrating an arrangement of a stationary scroll in a first embodiment of the present invention;

FIG. 1B

is a plan view illustrating the stationary scroll shown in

FIG. 1A

;

FIG. 2A

is a plan view illustrating the arrangement of a frame in the first embodiment of the present invention;

FIG. 2B

is a sectional view illustrating the frame shown in

FIG. 2A

;

FIG. 3

is a plan view for explaining the functions of an elongated positioning hole and a positioning pin in the first embodiment;

FIGS. 4A and 4B

are plan views showing gaps between side surfaces of both stationary and orbiting laps, due to by translation of the stationary scroll;

FIGS. 5A

to

5

D are plan views showing gaps between the side surfaces of both laps, which vary through the translation of the stationary scroll;

FIG. 6A

is a sectional view illustrating the arrangement of a stationary scroll in a second embodiment of the present invention;

FIG. 6B

is a plan view illustrating the stationary scroll shown in

FIG. 6A

;

FIG. 7A

is a plan view illustrating the arrangement of a frame in a second embodiment;

FIG. 7B

is a sectional view illustrating the frame shown in

FIG. 7A

;

FIG. 8A

is a plan view illustrating an example of a positioning pin in a third embodiment of the present invention;

FIG. 8B

is a sectional view illustrating the positioning means shown in

FIG. 8A

;

FIGS. 9A

to

9

C are plan view and sectional views, respectively, illustrating an example of the shape of a positioning pin in a fourth embodiment of the present invention;

FIG. 10

is a plan view illustrating a plan view illustrating a compression chamber in a scroll compressor;

FIG. 11

is a sectional view showing an example of a method of fixing a stationary scroll and a frame in a conventional scroll type fluid machine;

FIG. 12

is a plan view showing an example of a method of positioning a stationary scroll and a frame in a conventional scroll type fluid machine;

FIGS. 13A and 13B

are explanatory views for variation of gaps between side surfaces of stationary and orbiting scroll laps due to rotation and shift of the stationary scroll in a conventional scroll-type fluid machine; and

FIGS. 14A

to

14

D are explanatory views for variation of gaps between side surfaces of stationary and orbiting scroll laps due to rotation and shift of the stationary scroll in conventional scroll type fluid machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Detailed explanation will be made of a first embodiment of the present invention with reference to

FIGS. 1A

to

5

D. First, the arrangement thereof will be explained with reference to

FIGS. 1A

to

2

B.

FIGS. 1A and 1B

show the arrangement of a stationary scroll

30

.

FIG. 1B

is a plan view illustrating the stationary scroll

30

as viewed from the lap side, and

FIG. 1A

is a sectional view along line A—A in

FIG. 1B

as viewed in the direction of the arrows. The basic structural parts of the stationary scroll

30

are a lap

30

a,

a mirror plate

30

b,

a lap bottom

30

c,

a lap tip

30

d,

a discharge port

30

e,

fixing vacant holes

30

f

and elongated positioning holes

31

.

It is noted that the XY coordinates as shown are composed of an original point which is the center

34

of the lap

30

a,

an X-axis

32

and a Y-axis

33

. In this arrangement, the parallel parts of the elongated positioning hole

31

in the stationary scroll are parallel with the X-axis

32

, but the elongated positioning hole

31

may be arranged at any position if its parallel parts in the major axis direction are substantially parallel with a straight line substantially passing through the center

34

of the lap

30

a.

However, it is preferable to extend the straight line passing through the above-mentioned center, between the parts of the elongated positioning hole

31

in the major axis direction, which are parallel with the major axis of the elongated positioning hole

31

.

FIGS. 1A and 1B

show an example in which the position and the direction of the elongated positioning hole

31

are selected so as to cause the X-axis

32

passes between the parallel parts of the elongated positioning hole

31

. In other words, the straight line passing substantially through the center

34

of the lap

30

a

is one of those including a straight line passing through a position separated from the center

34

of the lap

30

a

by a distance which is about one-half of the minor axis of the elongated positioning hole

31

.

It is noted, in the explanation hereinbelow, that the axis of the stationary scroll

30

corresponds to the one in the upright direction of the lap

30

a

at the center of the lap

30

a,

that is, the normal to the mirror plate

30

b.

The elongated positioning hole

31

is opened to a surface opposed to the frame

40

in the peripheral edge part of the stationary scroll

30

in which the fixing vacant holes

30

f

are provided, that is, in a plane perpendicular to the above-mentioned axis, and has a pair of wall surfaces which are in parallel with the above-mentioned straight line passing substantially through the center, and which are opposed to each other on both sides of the straight line.

FIGS. 2A and 2B

show the arrangement of the frame

40

which is an unorbiting scroll fixing member for fixing the stationary scroll

30

.

FIG. 2A

is a plane view illustrating the frame

40

as viewed from the stationary scroll side, and

FIG. 2B

is a sectional line along line B—B in

FIG. 2B

as viewed in the direction of arrow.

The frame

40

is provided with key grooves

40

a

in each of which one of two orthogonal key parts formed on an Oldham's ring as a main part in a rotation preventing mechanism slides, and fixing thread parts

40

b

formed at positions corresponding to the vacant holes

30

f

in the stationary scroll, and a positioning pin

41

. The frame

40

is located so as to have a predetermined positional relationship with the orbiting scroll, and regulates and inhibits the motion of the stationary scroll in a plane perpendicular to the above-mentioned axis, relative to the frame

40

.

The position where the stationary scroll is located, that is, the position where the stationary scroll lap

30

a

and the orbiting scroll lap are theoretically meshed with each other will be herein below referred to “the neutral position” for the sake of brevity in explanation. Further, the position at which the frame is located and which is determined by the positional relationship among the orbiting scroll, the Oldham's ring and the key grooves

40

a

formed in the frame when the stationary scroll

30

is located at the neutral position will be referred to “the neutral position of the frame”.

It is noted that the position where the positioning pin

41

serving as the pin part of the pin structure as one of the positioning means is arranged in the frame

40

is set on the straight line which passes substantially though the center of the stationary scroll lap

30

a

and which is used for forming the parallel parts of the elongated positioning hole

31

in the stationary scroll

30

in such a case that the frame is located at the neutral position, and in the configuration of the present embodiment, it is set on a straight line

42

on the frame, corresponding to the X-axis

32

of the stationary scroll

30

. In other words, the position where the positioning pin

41

is located on the frame

40

, is a position at which the straight line

42

crosses the surface of the frame

40

which is opposed to the surface formed therein with the above-mentioned vacant holes

30

f

in the peripheral edge part of the stationary scroll. As shown in

FIGS. 2A and 2B

, although the positioning pin

41

is formed independent from the frame

40

, they may be integrally incorporated with each other. Further, if the stationary scroll

30

and the frame

40

are arranged at the neutral positions, the positioning pin

41

is previously set on the frame

40

, and thereafter, the elongated positioning hole

31

having parts which are parallel with a straight line passing substantially through the position of the stationary scroll corresponding to the center of the pin of the positioning pin

41

and the center of the stationary scroll may be formed in the stationary scroll

30

.

FIG. 3

is a schematic view which shows an arrangement in which the elongated positioning hole

31

in the stationary scroll lap

30

shown in

FIGS. 1 and 2

, is combined with the positioning pin

41

on the frame

40

, and further detailed explanation will be made of the positioning means composed of the elongated positioning hole

31

and the positioning pin

41

. The straight line passing substantially through the center of the stationary scroll lap

30

a

corresponds to the X-axis

32

of the stationary scroll lap

30

a

in the configuration of the present embodiment. The elongated positioning hole

31

and the positioning pin

41

have such a function that the stationary scroll

30

can be translated along the parallel parts of the elongated positioning hole

31

, but cannot be moved in a direction orthogonal to the parallel parts since it is restrained by the parallel parts, and the stationary scroll

30

can be rotated around the positioning pin as a rotating center. It is noted that the radial position of the positioning pin is determined so as that the arrangement in which the positioning pin

41

is located at a substantially middle position of the elongated positioning hole

31

as shown in

FIG. 3

exhibits the neutral position of the stationary scroll

30

.

Next, referring to

FIGS. 4A

to

5

D, detailed explanation will be made of the effects exhibited by the positioning with the use of the elongated positioning hole

31

and the positioning pin

41

.

FIG. 4A

shows a meshing condition between the stationary scroll

30

and the orbiting scroll

3

in such a case that the stationary scroll is fixed at the neutral position which is the theoretical meshing position, and

FIG. 4B

shows a meshing condition between the stationary scroll

30

and the orbiting scroll

3

in such a case the stationary scroll

30

is fixed after it is translated from the neutral position. The X-axis, Y-axis and the center of the stationary scroll

30

a

are denoted by XF

1

, YF

1

and OF

1

, respectively, if the stationary scroll lap

30

a

is located at the neutral position, but are denoted by XF

2

, YM

2

, OF

2

, respectively, after the stationary scroll lap

30

a

is translated, and the X-axis, Y-axis and the center of the orbiting scroll lap

3

a

are denoted by XM, YM and OM, respectively. Further,

FIGS. 4A and 4B

show such a condition that the orbiting scroll

3

is turned in the positive direction of the Y-axis, and is then meshed, and accordingly, the Y-axes YF

1

, YF

2

of the stationary scroll lap

30

a

are coincident with the YM of the orbiting scroll lap

3

a.

In practice, although gaps in a range from several μm to several tenth μm are defined between side surfaces of the stationary scroll lap

30

a

and the orbiting scroll lap

3

a

due to processing errors of the components including the stationary scroll lap

30

a

and the orbiting scroll lap

3

a,

they have not visible sizes. In order to clearly show the situation of variation of the gap as the stationary scroll is translated and is then fixed as shown in

FIGS. 4A and 4B

, the gaps F

1

, F

2

, and G

1

, G

2

in the parts where the stationary scroll lap

30

a

and the orbiting scroll lap

30

b

theoretically make contact with each other are exaggerated in

FIG. 4

a

in order to allow the gaps to be visible.

FIG. 4B

shows a condition such that the stationary scroll

30

is translated in the negative direction of the Y-axis YF

1

from the condition shown in

FIG. 4A

, and is fixed. As explained in

FIGS. 1A

to

3

, the elongated positioning hole

31

formed in the stationary scroll

30

and the positioning pin

41

provided on the frame

40

are arranged on the Y-axes YF

1

, YF

2

and YM of the stationary scroll

30

and the orbiting scroll

3

, as shown in

FIGS. 4A and 4B

, thereby the translation of the stationary scroll

30

and the rotation thereof around the positioning pin

41

as a center can be made. If the stationary scroll

30

is translated in the negative direction of the Y-axis and is fixed, the parts F

1

, F

2

and G

1

, G

2

shown in

4

A are changed into parts F

3

, F

4

and G

3

, G

4

. The gaps in the parts F

3

, F

4

and G

3

, G

4

are decreased, different from the rotation and movement as shown in

FIGS. 13A and 13B

.

FIGS. 5A

to

5

D show meshing conditions between the stationary scroll

30

and the orbiting scroll

3

after the translation, as shown in

FIG. 4B

, at intervals of 90 deg, successively, in the order of

FIGS. 5A

to

5

D, and explanation will be made of a situation of variation of gaps H

1

to H

5

, J

1

to J

5

which are produced by meshing between the stationary scroll

30

fixed after the translation, and the orbiting scroll. The X-axis, the Y-axis and the center of the orbiting scroll

3

are denoted by XM, YM and OM, respectively, and estimation is made such that the elongated positioning hole

31

formed in the stationary scroll

30

and the positioning pin

41

located in the frame

40

are arranged in the positive direction of the Y-axis YF

2

of the stationary scroll

30

, similar to that shown in

FIGS. 4A

to

4

B, although it is not shown in

FIGS. 5A

to

5

D. The gap H

1

corresponds to F

3

in

FIG. 4B

, and is smaller than that in such a case that the scroll

30

is fixed at the neutral position, and during the orbiting motion, large and small gaps are repeatedly defined as denoted by H

1

to H

5

. Similarly, the gap J

1

corresponds to G

3

in

FIG. 4B

, and is smaller than that in such a case that the scroll

30

is fixed at the neutral position, and during orbiting motion, small gaps and large gaps are repeatedly defined as denoted by J

1

to J

5

.

Large difference is only found such that either a condition in which the gap is always small or a condition in which the gap is always large is present in a case of the fixing after the rotation and movement, but large and small gaps are repeatedly defined in a case of the fixing only after the translation. In the case of only the translation, small gap conditions inevitably occur in the compression chambers having seal parts exhibited by H

1

to H

5

and J

1

to J

5

, and accordingly, leakage during compression, which would be caused by a large gap always defined in such a case that the fixing is made after rotation and movement, does not occur, thereby it is possible to eliminate occurrence of such a risk that the energy efficiency of the scroll type fluid machine is greatly decreased.

Further, referring to

FIG. 5

a

which shows a condition in which the stationary scroll

30

is translated as far as possible in a direction from the center OM of the orbiting scroll lap

3

a

to the center OF

2

of the stationary scroll lap

30

a

in such a condition that the orbiting scroll

3

can be orbited, the gaps H

3

, J

3

as shown in

FIG. 5

c,

that is, in such a meshing condition that the orbiting motion is performed by an angle of substantially 180 deg. from the orbiting position shown in

FIG. 5

a,

may correspond to a negative component of the Y-axis YF

2

of the stationary scroll

30

due to assembly errors caused by accumulation of processing errors of components including the stationary scroll lap

30

a

and the orbiting scroll lap

3

a.

On the contrary, in a meshing condition shown in

FIG. 5C

, after the stationary scroll

30

is translated as far as possible from the center OM of the orbiting scroll lap

3

a

in a direction toward the center OF

2

of the stationary scroll

30

a

in a condition in which the orbiting scroll can orbit, the gaps H

1

, H

5

and J

1

and J

5

are similarly defined in a meshing condition as shown in

FIG. 5A

, in which turning by an angle of about 180 deg. is carried out. These gaps may correspond to the positive component of the Y-axis YF

2

of the stationary scroll caused by assembly errors exhibited by accumulation of processing errors of components including the stationary scroll lap

30

a

and the orbiting scroll lap

3

a.

Accordingly, if the stationary scroll is fixed at the center (middle point) of the range of the translation of the stationary scroll, the stationary scroll

30

can be set at a substantially neutral position with respect to the direction of the Y-axis YF

2

, and accordingly, an appropriate meshing condition can be obtained between the stationary scroll lap

30

a

and the orbiting scroll lap

3

a,

thereby it is possible to enhance the energy efficiency.

Further, as mentioned above, since the elongated positioning hole

31

provided in the stationary scroll

30

and the positioning pin

41

provided to the frame are arranged in the positive direction of the Y-axis YF

2

, similar to

FIGS. 4A and 4B

, although it is not shown in

FIG. 5

, the stationary scroll

30

can be rotated around the positioning pin

41

as a center. It is noted that, in the meshing condition shown in

FIG. 5B

, the stationary scroll can be shifted in the direction of the X-axis XF

2

by a distance which is substantially equal to the sum of the gaps H

2

, J

2

, and further, in the meshing condition shown in

FIG. 5D

, the stationary scroll

30

can be shifted in the direction of the X-axis XF

2

of the stationary scroll XF

2

by a distance which is substantially equal to the sum of the gaps H

4

, J

4

. At this time, the sum of the gaps H

2

, J

2

or the sum of the gaps H

4

, J

4

, which is equal to the distance by which the stationary scroll

30

can be shifted in the direction of the X-axis XF

2

, may be substantially equal to the component of the stationary scroll

30

in the direction of the X-axis XF

2

, which is exhibited by assembly errors caused by accumulation of processing errors of components including the stationary scroll laps

30

a

and the orbiting scroll laps

3

a.

Further, since the parallel distances from the positioning pin

41

to the parts H

2

, J

2

or to the parts H

4

, J

4

, are greater substantially than the sum of the gaps H

2

, J

2

or the sum of the gaps H

4

, J

4

, the shift of the stationary scroll

30

caused by the rotation of the positioning pin

41

exhibits such an effect that the stationary scroll

30

is substantially translated in the direction of the X-axis XF

2

. Accordingly, in the meshing condition shown in

FIG. 5B

or

FIG. 5D

, if the stationary scroll

30

is fixed at a position which is obtained substantially by one half of the shift distance of the stationary scroll from the condition in which the stationary scroll

30

is rotated and shifted as far as possible from the center OM of the orbiting scroll lap

3

a

to the center OF

2

of the stationary scroll

30

in a condition in which the orbiting scroll

3

can orbit, to the condition in which it is shifted in the reverse direction as far as possible, the stationary scroll

30

can be set at a substantially neutral position even in the direction of the X-axis XF

2

, and accordingly, it is possible to ensure high energy efficiency.

Even though the process of forcibly positioning the stationary scroll

30

at a substantially neutral position, as mentioned above, is not carried out, if the stationary scroll

30

is fixed in such a condition that the orbiting scroll

3

can orbit, the gaps between the laps can be adjusted within assembly errors caused by accumulation of processing errors of the components including the stationary scroll lap

30

a

and the orbiting scroll lap

3

a

by means of the elongated positioning hole

31

provided in the stationary scroll

30

and the positioning pin

41

provided in the frame. That is, the main feature of the present invention is such that the rotation and the shift relating to the center of the stationary scroll lap is restrained as far as possible while the stationary scroll is translated in the combination of the elongated positioning hole and the positioning pin so as to allow the gaps between the laps to be automatically adjusted within assembly errors caused by accumulation of processing errors of components. Further, another main feature of the present invention is such that the position where the stationary scroll

30

which is positioned according to the present invention is fixed, is neither a designed substantially neutral position nor the one where the gaps between the laps are adjusted within assembly errors on design, but either a substantially neutral position which can be actually determined by the components, or the one where the gaps between the laps are adjusted within assembly errors which are actually determined from the components.

Explanation will be made of the arrangement of a second embodiment of the present invention with reference to

FIGS. 6A

to

7

B. Although the arrangement of the elongated positioning hole and the positioning pin is reversed in comparison with the configuration of the first embodiment, effects similar to those obtained by the configuration of the first embodiment can be obtained.

FIGS. 6A and 6B

show the arrangement of a stationary scroll

50

.

FIG. 6B

is a plan view illustrating the stationary scroll

50

as viewed from the lap side, and

FIG. 6A

is a sectional view along line C—C in

FIG. 6B

, as viewed in the direction of arrows. The basic components of the stationary scroll

50

a lap

50

a,

a mirror plate

50

b,

a lap root

50

c,

a lap tip

50

d,

a discharge port

50

e,

fixing vacant holes

50

f

and a positioning pin

51

. It is noted that the XY coordinates are defined by an X-axis

52

and Y-axis

53

and an original point which is the center

54

of the lap

50

a.

Although the positioning pin

51

may be located at any position on the stationary scroll, it is located on the X-axis

52

of the lap

50

a.

Referring to

FIGS. 6A and 6B

, the positioning pin

51

and the stationary scroll

50

are formed, independent from each other, but they can be integrally incorporated with each other.

FIGS. 7A and 7B

show the arrangements of the frame

60

which is an unorbiting scroll fixing member for fixing the stationary scroll

50

.

FIG. 7A

is a plan view illustrating the frame

70

as viewed from the stationary scroll side, and

FIG. 7B

is a sectional view along line D—D in

FIG. 7A

, as viewed in the direction of arrows. The basic components of the frame

60

is key grooves

60

a

in each of which one of two key parts which are formed on an Oldham's ring serving a main component of a rotation preventing mechanism, orthogonal to each other, slides, fixing thread parts

60

b

corresponding to the vacant holes

50

f

in the stationary scroll, and an elongated positioning hole

61

. It is noted here that since the positioning pin

51

is set on the X-axis

52

of the lap

50

a

in the configuration of the present embodiment, the parallel parts of the elongated hole

61

in the frame

60

may be formed so that they are substantially parallel with a straight line

62

on the frame

60

corresponding to the X-axis

52

of the lap

50

a,

and the straight line passes between the parallel parts of the elongated hole

61

in such a case that the stationary scroll

50

is arranged at the neutral position.

In the configuration of the present embodiment, although the parallel parts of the elongated positioning hole

61

are formed so as to be substantially parallel with the straight line

62

on the frame

60

corresponding to the X-axis

52

, they may not always be parallel with the X-axis

52

, but they may be formed, substantially parallel with a straight line on the frame

60

corresponding to a substantially straight line substantially passing through the center of the pin part of the positioning pin

51

and the center of the lap

50

a.

However, it is desirable to set the position and the direction of the elongated positioning hole

61

so as to locate the above-mentioned straight line between the parallel parts of the elongated positioning hole

61

. Further, although the X-axis

52

of the stationary scroll lap

50

a

and the straight line passing through the center of the key groove

60

a

in the frame

60

are happenedly coincident with each other, they may not be coincident with each other.

Explanation will be made of a third embodiment of the present invention with reference to

FIGS. 8A and 8B

. Referring to

FIG. 8

, there are shown a member

73

in which an elongated positioning hole

71

is formed, and a member

74

on which a positioning pin

72

is provided.

FIGS. 8A

is a sectional plan view which shows a fitting condition between the elongated positioning hole

71

and the positioning pin

72

, and

FIG. 8B

is a sectional view which shows the shape of the positioning pin

72

and a condition in which the member provided thereon with the positioning pin

72

is arranged. In the configuration of the present embodiment, the shape of the positioning pin is different from those in the configurations of the first and second embodiments. The positioning pin

72

shown in

FIG. 8

, has a function such that it is movable in the elongated positioning hole

71

in the direction of the elongated hole but unmovable in the direction orthogonal to the direction of the elongated hole, but is rotatable around the axis of he positioning pin itself. Effects obtained by it as the positioning means are similar to those in the configuration of the first and second embodiments. The feature of the positioning pin

72

such that the part (pin part) to be fitted in the elongated positioning hole

71

, has a pair of planar surfaces which are opposed to each other, and parts interposed between these planar surfaces exhibit cylindrical surfaces (substantially cylindrical in a section orthogonal to the axis of the pin part), the cylindrical surface parts have areas sufficient for rotation of the positioning pin

72

.

It is noted here that only the cylindrical surface parts of the positioning pin

72

are those which make contact with the wall surfaces of the elongated positioning hole

71

, and which should be processed with a high degree of accuracy. Thus, according to the configuration of the present embodiment, the process can be made by specifying the parts of the positioning pin which should be processed with a high degree of accuracy, and accordingly, it is possible to aim at shortening the processing time for the positioning pin

72

. Further, since the positioning pin has the planar surface parts, different from a cylindrical positioning pin, the retentiveness of the positioning pin

72

becomes high when the positioning pin

72

is inserted in the member

74

in which it is to be set, and the positioning pin

72

can be surely inserted. Further, upon insertion, there is no such a risk that the cylindrical surface parts of the positioning pin

72

which make contact with the elongated positioning hole

72

are scratched. An insertion hole formed in the member

74

in which the positioning pin is arranged, and inserted therein with the hole part of the positioning pin

72

, has a size with which the positioning pin

72

is not rotated within the insertion hole during assembly a compressor.

Explanation will be made of the fourth embodiment of the present invention with reference to

FIGS. 9A

to

9

C. Referring to

FIGS. 9A and 9B

, there are shown a member

83

in which an elongated positioning hole

81

is formed, and a member

84

on which a positioning pin

82

is arranged. In the configuration of the present embodiment, the shape of the positioning pin is different from those in the configurations of the first to third embodiments.

FIG. 9A

is a planar sectional view which shows a fitting condition between the elongated positioning hole

81

and the positioning pin

82

,

FIG. 9B

is a sectional view which shows the shape of the positioning pin

82

and an arrangement condition of the member

84

in which the positioning pin

82

is arranged, and

FIG. 9C

is a sectional view along line D—D in

FIG. 9B

, as viewed in the direction of arrows.

The positioning pin

82

shown in

FIGS. 9A

to

9

C, has such a function that it is movable in the elongated positioning hole

81

in the direction of the elongated hole but unmovable in the direction orthogonal to the direction of the elongated hole but is rotatable. Effects obtained by it as the positioning means are similar to those in the configurations of the first to third embodiments. The feature of the positioning pin

82

is such that the center of a part (pin part) of the positioning pin

82

to be inserted in the elongated positioning hole

81

, and the center of a hole part to be inserted in the member

84

on which the positioning pin

82

is set, are eccentric from each other. The eccentric direction is substantially orthogonal to the direction of the elongated hole

81

. The shape of the pin part shown in

FIGS. 9A

to

9

C, corresponds to that in the configuration of the third embodiment, that is, the part fitted in the elongated positioning hole

81

has such a shape that it has in part a cylindrical surface, but it may has a cylindrical shape. Further, different from the arrangement shown in

FIG. 9

, with such an arrangement that the diameter of the hole part is set to be larger than the diameter of a substantially cylindrical structure part of the pin part, the shape of the pin part may have such an arrangement that it is extended inward of the member

84

on which the pin is set. With the use of the positioning pin

82

which is eccentric in a direction substantially orthogonal to the direction of the elongated positioning hole

81

, as the feature of the present invention, the degree of rotation and shift caused by unevenness in manufacturing accuracy of the stationary scroll lap and the orbiting scroll lap can be adjusted, thereby it is possible to always exhibit an appropriate meshing condition between both laps. In this case, an insertion hole for the positioning pin

82

, formed in the member

84

has such a shape that the positioning pin

82

can not be simply rotated in the insertion hole during the assembly of compressor, and care should be taken in order to prevent the eccentric direction from being deviated upon insertion of the positioning pin

82

.

In the configurations of the above-mentioned embodiments, explanation has been made of the scroll type fluid machine which is the combination of the stationary scroll fixed to the frame, and the orbiting scroll which is arranged so that its lap is meshed with the lap of the stationary scroll, not only a stationary scroll having such a structure that is literally fixed to the frame but also a stationary scroll having such a structure that allows displacement more or less in the axial direction of the drive shaft may be used. Even with such a stationary scroll, the position of the stationary scroll, relative to the frame in a plane orthogonal to the axis of the drive shaft, that is, the position relative to the orbiting scroll, should be set, similar to the configurations of the above-mentioned embodiments. If the stationary scroll which may be displaced more or less in the direction of the axis of the drive shaft, and the stationary scroll which is fixed to the frame by the fixing bolts

20

are both referred to an unorbiting scroll, the positioning pin and the elongated positioning hole can be applied in a scroll type fluid machine having an unorbiting scroll and an orbiting scroll.

ADVANTAGES OF THE INVENTION

According to the present invention, it is possible to provide a scroll type fluid machine which can practically exhibit an appropriate meshing condition between the orbiting scroll and the unorbiting scroll so as to ensure high energy efficiency.

Number	Name	Date
5188520	Nakamura et al.	Feb 1993
5458471	Ni	Oct 1995
5496160	Richardson, Jr. et al.	Mar 1996

Number	Date	Country
59-079086	May 1984	JP
61-008404	Jan 1986	JP
3-294681	Dec 1991	JP
5-018202	Jan 1993	JP
5-149263	Jun 1993	JP
5-149266	Jun 1993	JP
6-026471	Feb 1994	JP

Scroll type fluid machine

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (3)

Foreign Referenced Citations (7)