JPH11190287A - Scroll type fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an appropriate chip seal energizing force even if a turning scroll undergoes thermal expansion during the operation of a scroll type fluid machine. SOLUTION: In this scroll type fluid machine, the height of the lap 1a of a turning scroll 1 in its thrust direction when a chip seal 5 is affixed to the laps 2a, 3a of fixes scrolls 2, 3 is made lower at its center than at its outer periphery to allow for an increase in dimension caused by a rise in temperature of the lap 1a, to enable an energizing force for the outer periphery of the chip seal 5 to be held constant during operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust in a scroll type fluid machine in which a tip seal is mounted on a fixed scroll wrap and / or an orbiting scroll wrap for obtaining a proper biasing force of the tip seal during operation of the machine. It is related to the height in the direction.

[0002]

2. Description of the Related Art In a conventional scroll type fluid machine in which only the outside of a fixed scroll is cooled, a height in a thrust direction in a state in which a tip seal is attached to a fixed scroll wrap and an orbiting scroll wrap is configured to be constant. I was

[0003]

In a conventional scroll type fluid machine in which only the outside of the fixed scroll is cooled, the height in the thrust direction when the tip seal is mounted on the fixed scroll wrap and the orbiting scroll wrap is constant. In a scroll-type fluid machine, the temperature of the center of the orbiting scroll rises due to the compression of the fluid as compared with the outer peripheral part, so that the temperature of the compressed air is transmitted to the wrap of the orbiting scroll and thermally expanded. The thermal expansion is larger than that.

Here, the heat generated by the compression of the fluid is also transmitted to the wrap of the fixed scroll. However, since the fixed scroll is cooled by a fan attached to the outside thereof, the temperature rise is lower than that of the orbiting scroll. Small expansion.

As a result, since the height of the wrap of the orbiting scroll in the thrust direction becomes large (long), the urging force of the tip seal at the center of the orbiting scroll becomes large, and the tip seal is worn out early, resulting in a short life. There was a disadvantage that it was.

Therefore, for example, in order to solve this drawback, the orbiting scroll is cooled by introducing water cooling or cooling air to eliminate the temperature difference between the fixed scroll and the orbiting scroll. Means for raising the temperature of the section substantially the same can be considered, but this method has a drawback that the structure becomes complicated and the cost increases.

An object of the present invention is to provide a means which can easily absorb an increase in wrap size due to thermal expansion and can be manufactured at low cost.

[0008]

A first spiral scroll wrap erecting from the end plate of the orbiting scroll and a second spiral scroll wrap erecting from the end plate of the fixed scroll are provided. The two spiral scroll wraps are opposed to each other so as to mesh with each other, a tip seal groove is provided at the tip of the first and second spiral scroll wraps, and a tip seal is disposed in the tip seal groove, and the orbiting scroll is fixed. In a scroll type fluid machine that revolves with respect to a scroll to sequentially compress a fluid between the orbiting scroll and the fixed scroll, at least one of the first and second spiral scroll wraps includes the tip. The height in the thrust direction in a state where the seal is mounted, the central portion side is made lower than the outer peripheral portion of the orbital motion. And is done to reduce the local increase of frictional force and the wear amount of the tip seal, it is possible to achieve the life improvement of the tip seal, a result, it is possible to provide a long-life scroll type fluid machine. Further, by using a tip seal made of a fluorine-based resin material, a scroll-type fluid machine having excellent corrosion resistance can be provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view showing the entire scroll type fluid machine according to the present invention, FIG. 2 is a partial sectional view showing another structure of the scroll type fluid machine according to the present invention, and FIG. 3 is a scroll type fluid machine according to the present invention. FIG. 4 is a partial view showing a state before the operation of the scroll type fluid machine according to the present invention,
FIG. 5 is a partial view showing a state during operation of the scroll type fluid machine according to the present invention. FIG. 6 is a perspective view of the spiral scroll wrap according to the present invention, FIG. 7 is a partial view showing a first embodiment of the spiral scroll wrap according to the present invention, and FIG. FIG. 9 is a partial view of a spiral scroll wrap according to a third embodiment of the present invention, and FIG. 10 is a partial view of a tip seal groove according to a fourth embodiment of the present invention. FIG. 11 is a partial view showing a fifth embodiment of the chip seal groove according to the present invention. FIG. 12 is a partial view showing a sixth embodiment of the chip seal groove according to the present invention. FIG. 14 is a perspective view of a chip seal and an elastic body according to the present invention.
15 is a partial view showing an eighth embodiment of the tip seal according to the present invention, FIG. 16 is a partial view showing a ninth embodiment of the tip seal according to the present invention, FIG. Is a partial view showing an elastic body according to a tenth embodiment of the present invention, FIG. 18 is a partial view showing an eleventh embodiment of the elastic body according to the present invention, and FIG. 19 is a twelfth embodiment of the elastic body according to the present invention. FIG. 4 is a partial view showing an embodiment of the present invention.

FIG. 1 shows the overall structure of a scroll type fluid machine according to the present invention. In FIG. 1, spiral scroll wraps 1a are provided upright from both sides of the end plate of the orbiting scroll 1. Further, spiral scroll wraps 2a and 3a are provided upright from one side of the end plates of the fixed scrolls 2 and 3, respectively. A tip seal groove 4 is provided on the end face of the spiral scroll wraps 1a, 2a, 3a, and a tip seal 5 and an elastic body 6 are mounted in the tip seal groove 4. The orbiting scroll 1 is rotatably engaged with a crankshaft 7 via a bearing 8 so that the spiral scroll wraps 1a, 2a, 3a mesh with each other between the fixed scrolls 2, 3. The orbiting scroll 1 is supported by crank pins 9 provided at a plurality of positions so as to only revolve without rotating, and the tip seal 5 and the elastic body 6 regulate the axial position of the orbiting scroll 1. The crankshaft 7 is supported by the fixed scrolls 2 and 3 via a bearing 10, one end of which is connected to an electric motor 11 via a fan 12, and the other end of which is provided with a fan 13. Electric motor 1
As the crankshaft 7 rotates, the orbiting scroll 1 starts an eccentric orbiting motion with respect to the fixed scrolls 2 and 3, and the fluid sucked from the suction port 14 is sequentially compressed in the compression space 15, It is discharged from the discharge port 16. At the same time, the rotation of the motor 11 causes the fan 1 to rotate.
The fixed scrolls 2 and 3 are cooled by the cooling air generated by the rotation of the fixed scrolls 2 and 13. In this state, since the cooling means is not provided in the orbiting scroll 1, the temperature of the orbiting scroll 1 becomes higher than the temperature of the fixed scrolls 2 and 3, and the thermal expansion causes the scroll wrap 1a of the orbiting scroll 1 to move in the thrust direction. The dimensions increase.

In the center portion 17 and the outer peripheral portion 18 of the orbiting scroll 1, the center portion 17 has a higher fluid compressibility than the outer peripheral portion 18, so that the temperature becomes higher and the center of the scroll wrap 1a of the orbiting scroll 1 becomes larger. Since the part 17 side expands more thermally than the outer peripheral part 18 side, the dimension of the central part 17 in the thrust direction is larger than that of the outer peripheral part 18.

FIG. 2 shows another structure of the scroll type fluid machine of the present invention. A spiral scroll wrap 1a stands upright from one side of the end plate of the orbiting scroll 1. Further, the spiral scroll wrap 3 is formed from one side of the end plate of the fixed scroll 3.
a stands upright. Spiral scroll wraps 1a, 3a
A chip seal groove 4 is provided on an end face of the chip seal groove 4, and a chip seal 5 and an elastic body 6 are mounted in the chip seal groove 4. The orbiting scroll 1 is movably engaged with a crankshaft 7 via a bearing 8 so that the spiral scroll wraps 1a and 2a of the fixed scroll 3 mesh with each other. The orbiting scroll 1 is supported by a crank pin (not shown) so as to only revolve without rotating, and the axial position of the orbiting scroll 1 is regulated by the tip seal 5 and the elastic body 6. The crankshaft 7 is supported by the fixed scroll 2 via a bearing 10,
One end is connected to a motor (not shown). The fan 13
When the electric motor is operated and disposed outside the fixed scroll 2, the orbiting scroll 1 starts eccentric orbital movement with the rotation of the crankshaft 7, and the fluid sucked from the suction port 14 is sequentially compressed in the compression space 15. Is discharged from a discharge port (not shown). The fixed scroll 3 is cooled by the fan 13. In this state, since there is no cooling means for the orbiting scroll 1, the temperature of the orbiting scroll 1 becomes higher than the temperature of the fixed scroll 3, and the dimension increase in the thrust direction becomes large. In the central portion 17 and the outer peripheral portion 18 of the orbiting scroll 1, the central portion 17 is closer to the outer peripheral portion 18.
Since the compressibility of the fluid is higher and the temperature is higher, the increase in the size of the central portion 17 in the thrust direction is caused by the outer peripheral portion 18.
Be larger.

FIG. 3 is an enlarged view of a portion A in the embodiment of FIGS. A tip seal groove 4 is provided at the tip of the spiral scroll wrap 1a. A tip seal 5 and an elastic body 6 are mounted in the tip seal groove 4, and the tip seal 5 By pressing and contacting the end plate surface, it suppresses fluid leakage,
A scroll type fluid machine with good compression efficiency can be provided.

FIG. 4 schematically shows a state before operation of the scroll type fluid machine according to the present invention in the embodiment shown in FIGS. FIG. 4 is a diagram schematically showing the state of the spiral scroll wrap 1a of the orbiting scroll 1 and the spiral scroll wrap 3a of the fixed scroll 3 before the operation of the scroll fluid machine. A gap is provided between the tip seals 5 provided at the tip of the wrap 1a of the orbiting scroll 1. If the size of the gap is large, the efficiency of compressing the fluid is significantly reduced, so that it is desirable that the size be as small as possible (ie, there is no size of the gap at all (ie, the end surface of the fixed scroll 3 and the wrap 1a of the orbiting scroll 1). It is most preferable that the tip seal 5 provided at the tip is in contact with the tip seal 5). However, even in this case, it is desirable that the tip seal 5 be brought into contact with the mirror plate surface of the fixed scroll 3 by an extremely weak elastic force of the elastic body 6 in anticipation of a size increase due to thermal expansion of the wrap 1a of the orbiting scroll 1 during operation.

Next, FIG. 5 shows a state during operation of the scroll type fluid machine according to the present invention. FIG. 5 shows a state in which the operation is started from the state of FIG. 4 (a state before the operation is started), and the wrap 1a of the orbiting scroll 1 is thermally expanded in response to the temperature rise due to the compression of the fluid. The temperature rise due to the compression of the fluid is caused by the difference in the degree of the compression.
Rises. Therefore, the wrap 1a of the orbiting scroll 1 on the center portion 17 side has a larger dimension increase due to thermal expansion than the wrap 1a located on the outer peripheral portion 18 side. In the present invention, the height in the thrust direction in a state where the tip seal 5 is mounted on the wrap 1a of the orbiting scroll 1 is changed in advance in anticipation of the increase in dimension due to the thermal expansion. Specifically, the wrap 1a of the orbiting scroll 1 on the side of the center portion 17 where the dimension increase of the height in the thrust direction is larger due to thermal expansion is smaller (lower) than the wrap 1a on the outer peripheral portion 18 side. This is apparent from FIG. In the state of FIG. 5 (during operation, the state in which the wrap 1a is thermally expanded), the orbiting scroll 1 is affected by the thermal expansion.
The height of the wrap 1a in the thrust direction is substantially the same from the outer peripheral portion 18 to the entire central portion 17 (the biasing force of the tip seal 5 is substantially constant). In the state of FIG. The biasing force of the tip seal 5 is made substantially equal to the biasing force of the tip seal 5 of the fixed scroll 3. With this configuration,
An increase in the local frictional force and wear of the tip seal 5 can be reduced, the life of the tip seal 5 can be improved, and as a result, a scroll-type fluid machine with a long life can be provided.

Next, in the state shown in FIG. 5, the height of the wrap 1a of the orbiting scroll 1 in the thrust direction in the thrust direction is substantially the same from the outer peripheral portion 18 to the entire central portion 17 under the influence of thermal expansion. A detailed method will be described in detail.

Although a number of specific configurations are conceivable as described below, the following four methods can be roughly classified. (Of course, these combinations are also conceivable.) (1) A method of devising the configuration of the spiral scroll wrap 1a itself. (FIGS. 7 to 9) (2) A method of devising the configuration of the tip seal groove 4 provided at the tip of the spiral scroll wrap 1a. (FIGS. 10 to 12) (3) A method of devising the configuration of the thickness of the tip seal 5 in the thrust direction. (FIGS. 14 to 16) (4) A method of devising the configuration of the thickness of the elastic body 6 in the thrust direction. (FIGS. 17 to 19) Details will be sequentially described below.

First, FIG. 6 shows a perspective view of the spiral scroll wrap 1a of the orbiting scroll 1 during the operation of the scroll type fluid machine according to the present invention in the example shown in FIGS. 1 and 2. 7 to 9 are diagrams showing the wrap 1a shown in FIG. 6 in a straight line by unwinding the spiral. In each figure, the right side means the outer peripheral portion 18 side and the left side means the central portion 17 side.

FIG. 7 shows the first embodiment, in which the height of the spiral scroll wrap 1a increases smoothly from the center portion 17 to the outer peripheral portion 18. As shown in FIG. FIG. 8 shows a second embodiment in which the height of the outer peripheral portion 18 of the spiral scroll wrap 1a is increased by one step substantially at the center between the center portion 17 and the outer peripheral portion 18. I have. FIG. 9 shows a third embodiment in which the height of the spiral scroll wrap 1a is increased in steps from the central portion 17 to the outer peripheral portion 18 in a plurality of steps. I have. Note that the height of the spiral scroll wraps 1a, 2a, 3a is
Only the central portion 17 may be low and the outer peripheral portion 18 may be high. Alternatively, only the fixed scrolls 2 and 3 may be low at the central portion 17 and high at the outer peripheral portion 18. 3 Both may be low at the central portion 17 and high at the outer peripheral portion 18.

As described above, the height of the wrap 1a itself is increased from the center portion 17 to the outer peripheral portion 18, so that the wrap 1a of the orbiting scroll 1 is affected by the thermal expansion when the wrap 1a is thermally expanded. Can be made substantially the same in the thrust direction from the outer peripheral portion 18 to the entire region of the central portion 17, and as a result, a long-life scroll type fluid machine can be provided.

Next, a method of devising the structure of the tip seal groove 4 provided at the tip of the spiral scroll wrap 1a will be described with reference to FIGS.

FIGS. 10 to 12 show the state of the cross section after the spiral of the wrap 1a is unwound and shown in a straight line, respectively.
The configuration (depth of the groove) of the chip seal groove 4 is shown so as to be understood.

FIG. 10 shows a fourth embodiment.
A configuration is shown in which the depth of the tip seal groove 4 provided at the tip of the spiral scroll wrap 1a is gradually reduced from the center portion 17 to the outer peripheral portion 18. FIG.
5 shows a fifth embodiment, in which the spiral scroll wrap 1a is only one stage substantially at the center between the central portion 17 and the outer peripheral portion 18.
2 shows a configuration in which the depth of the outer peripheral portion 18 of the chip seal groove 4 provided at the tip end is small. FIG. 12 shows a sixth embodiment, in which a central portion 17 is moved to an outer peripheral portion 18.
2 shows a configuration in which the depth of the tip seal groove 4 provided in the spiral scroll wrap 1a in a stepwise manner in a plurality of steps gradually decreases as going to. The depth of the tip seal groove 4 of the spiral scroll wraps 1a, 2a, 3a is
Only the orbiting scroll 1 may be deep at the central portion 17 and shallow at the outer peripheral portion 18. Only the fixed scrolls 2 and 3 may be deep at the central portion 17 and shallow at the outer peripheral portion 18. Both the scrolls 2 and 3 may be deep at the center portion 17 and shallow at the outer peripheral portion 18.

As described above, the shape of the chip seal groove 4 provided in the wrap 1a is made shallower from the center portion 17 to the outer peripheral portion 18, so that the wrap 1a is swirled under the influence of thermal expansion in a state where the wrap 1a is thermally expanded. The height of the wrap 1a of the scroll 1 in the thrust direction in the thrust direction can be made substantially the same from the outer peripheral portion 18 to the entire region of the central portion 17, and as a result, a scroll-type fluid machine having a long life can be provided.

Next, a method of devising the configuration of the thickness of the tip seal 5 in the thrust direction will be described with reference to FIGS. FIG. 13 shows a perspective view of the chip seal 5 (also serves as a perspective view of an elastic body 6 described later).
FIG. 16 to FIG. 16 are diagrams showing the tip seal 5 of FIG.

FIG. 14 shows a seventh embodiment.
This shows a configuration in which the thickness of the tip seal 5 in the thrust direction increases smoothly from the center portion 17 to the outer peripheral portion 18. FIG. 15 shows an eighth embodiment,
A configuration in which the thickness of the outer peripheral portion 18 of the tip seal 5 in the thrust direction is increased by one step substantially in the middle between the central portion 17 and the outer peripheral portion 18 is shown. FIG. 16 shows a ninth embodiment, in which the thickness of the tip seal 5 in the thrust direction increases stepwise in a plurality of steps from the center portion 17 to the outer peripheral portion 18. ing. In addition, the thickness of the tip seal 5 in the thrust direction may be thin at the central portion 17 and thick at the outer peripheral portion 18 of only the orbiting scroll 1.
Only the fixed scrolls 2 and 3 are thin at the center 17 and the outer periphery 1
8, the orbiting scroll 1 and the fixed scrolls 2 and 3 may both be thin at the central portion 17 and thick at the outer peripheral portion 18.

As described above, the tip seal groove 4 of the wrap 1a
By making the shape of the tip seal 5 housed therein thicker from the central portion 17 to the outer peripheral portion 18,
In the state where the wrap 1a is thermally expanded, the height of the wrap 1a of the orbiting scroll 1 in the thrust direction is reduced by the influence of the thermal expansion.
It can be made substantially the same from 8 to the entire area of the center portion 17, and as a result, a long-life scroll type fluid machine can be provided.

Next, a method of devising the configuration of the thickness of the elastic body 6 in the thrust direction will be described with reference to FIGS. FIG. 13 is a perspective view of the elastic body 6, and FIGS. 17 to 19 are views showing the elastic body 6 of FIG.

FIG. 17 shows a tenth embodiment, which shows a configuration in which the thickness of the elastic body 6 in the thrust direction increases smoothly from the central portion 17 to the outer peripheral portion 18. FIG. 18 shows an eleventh embodiment.
The elastic body 6 is only one step substantially at the center between the center portion 17 and the outer peripheral portion 18.
The thickness of the outer peripheral portion 18 in the thrust direction increases. FIG. 19 shows a twelfth embodiment, in which the thickness of the elastic body 6 in the thrust direction increases stepwise in a plurality of steps from the center 17 to the outer periphery 18. ing. The thickness of the elastic body 6 in the thrust direction may be thin at the center portion 17 only at the orbiting scroll 1 and thick at the outer peripheral portion 18, or may be thin at the center portion 17 only at the fixed scrolls 2 and 3 and at the outer peripheral portion 18. The orbiting scroll 1 and the fixed scrolls 2 and 3 may both be thin at the central portion 17 and thick at the outer peripheral portion 18.

As described above, the tip seal groove 4 of the wrap 1a
By making the shape of the elastic body 6 accommodated therein thicker from the center portion 17 to the outer peripheral portion 18, the thrust of the wrap 1a of the orbiting scroll 1 under the influence of the thermal expansion in a state where the wrap 1a is thermally expanded. The direction height can be made substantially the same from the outer peripheral portion 18 to the entire region of the central portion 17,
As a result, a long-life scroll type fluid machine can be provided.

According to the present invention, even if the spiral scroll wrap 1a of the orbiting scroll 1 increases in the thrust direction due to a rise in temperature during operation of the scroll type fluid machine,
The pressing force of the tip seal 5 can be kept constant over the entire circumference, the urging force at the center of the tip seal 5 can be smaller than before, the increase in the amount of wear can be reduced, and as a result, the life of the tip seal 5 can be improved. Can be planned. As a result, it is to provide a scroll-type fluid machine with a long life, and even if it can be performed by one embodiment of FIGS. 4 to 12 or FIGS. It may be possible to combine nineteen embodiments. Furthermore, the use of the tip seal 4 made of a fluorine resin material and the elastic body 6 made of a polymer material having chemical resistance such as fluorine or silicon makes it possible to provide a scroll type having a long life and excellent corrosion resistance. A fluid machine can be provided.

[0032]

According to the present invention, the difference in temperature between the fixed scroll wrap and the orbiting scroll wrap during operation of the scroll type fluid machine and the difference in dimensional increase due to the difference in temperature between the center and the outer periphery of the orbiting scroll are considered. Then, the height of the fixed scroll wrap and / or the orbiting scroll wrap in the thrust direction in a state where the tip seal is attached is reduced at the center of the wrap and increased at the outer periphery of the wrap, so that the pressing force of the tip seal over the entire circumference. Can be kept constant, the increase in the local frictional force and wear of the tip seal can be reduced, and the longevity of the tip seal can be improved.
As a result, a scroll-type fluid machine having a long life can be provided.

Further, the use of a chip seal made of a fluorine-based resin material or an elastic body for biasing the chip seal made of fluorine or a polymer material having chemical resistance such as silicon makes it excellent in corrosion resistance. Scroll type fluid machine can be provided.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an entire scroll type fluid machine according to the present invention.

FIG. 2 is a partial sectional view showing another structure of the scroll type fluid machine of the present invention.

FIG. 3 is a partial sectional view of a scroll type fluid machine according to the present invention.

FIG. 4 is a partial view showing a state before the operation of the scroll type fluid machine according to the present invention.

FIG. 5 is a partial view showing a state during operation of the scroll type fluid machine according to the present invention.

FIG. 6 is a perspective view of a spiral scroll wrap according to the present invention.

FIG. 7 is a first view of a spiral scroll wrap according to the present invention.
FIG.

FIG. 8 shows a second example of the spiral scroll wrap according to the present invention.
FIG.

FIG. 9 is a third view of the spiral scroll wrap according to the present invention.
FIG.

FIG. 10 is a partial view showing a fourth embodiment of the chip seal groove according to the present invention.

FIG. 11 is a partial view showing a fifth embodiment of the chip seal groove according to the present invention.

FIG. 12 is a partial view showing a sixth embodiment of the chip seal groove according to the present invention.

FIG. 13 is a perspective view of a tip seal and an elastic body according to the present invention.

FIG. 14 is a partial view showing a seventh embodiment of the tip seal according to the present invention.

FIG. 15 is a partial view showing an eighth embodiment of the tip seal according to the present invention.

FIG. 16 is a partial view showing a ninth embodiment of the tip seal according to the present invention.

FIG. 17 is a partial view showing a tenth embodiment of the elastic body according to the present invention.

FIG. 18 is a partial view showing an eleventh embodiment of the elastic body according to the present invention.

FIG. 19 is a partial view showing a twelfth embodiment of the elastic body according to the present invention.

[Explanation of symbols]

1 is a revolving scroll, 1a is a spiral scroll wrap of a revolving scroll, 2, 3 is a fixed scroll, 2a, 3a
Is a spiral scroll wrap of a fixed scroll, 4 is a chip seal groove, 5 is a chip seal, 6 is an elastic body, 17 is a central portion, and 18 is an outer peripheral portion.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yasushi Nozaki 1060 Takeda, Hitachinaka-shi, Ibaraki Prefecture Within Hitachi Koki Engineering Co., Ltd. (72) Inventor Akio Sakazume 1060 Takeda, Hitachinaka-shi, Ibaraki Hitachi Koki

Claims (8)

[Claims] 1. A first upright standing from an end plate of an orbiting scroll.
And a second spiral scroll wrap erecting from the end plate of the fixed scroll. The first and second spiral scroll wraps are opposed to each other so as to mesh with each other. A tip seal groove is provided at the tip of the spiral scroll wrap, and a tip seal is provided in the tip seal groove. By revolving the orbiting scroll with respect to the fixed scroll, between the orbiting scroll and the fixed scroll. In the scroll type fluid machine for sequentially compressing the fluid, the height in the thrust direction in a state where the tip seal is mounted on at least one of the first and second spiral scroll wraps is determined by the outer circumference of the revolving motion. A scroll type fluid machine characterized in that a central portion side is lower than a portion. 2. A scroll-type fluid machine in which a height in a thrust direction in a state where the tip seal is mounted on the first spiral scroll wrap is lower on a center portion side than an outer peripheral portion of the revolving motion. The height of the first scroll scroll wrap located on the center side in the thrust direction is lower than the height of the second scroll scroll wrap in the thrust direction. The scroll-type fluid machine as described in the above. 3. A thrust direction height of at least one of the first and second spiral scroll wraps is smaller at a center portion side than at an outer peripheral portion of the revolving motion. Item 2. A scroll type fluid machine according to Item 1. 4. A depth of a tip seal groove provided at a tip of at least one of the first and second spiral scroll wraps is made deeper at a center portion side as compared with an outer peripheral portion of the revolving motion. The scroll type fluid machine according to claim 1, wherein: 5. The thickness of a tip seal attached to at least one of the first and second spiral scroll wraps is made thinner at a central portion thereof as compared with an outer peripheral portion of the revolving motion. The scroll type fluid machine according to claim 1, wherein 6. An elastic body is provided between the tip seal groove and the tip seal, and a thickness of the elastic body is made thinner at a central portion side as compared with an outer peripheral portion of the revolving motion. The scroll type fluid machine according to claim 1. 7. The scroll type fluid machine according to claim 1, wherein said tip seal is made of a fluorine resin material. 8. The scroll type fluid machine according to claim 6, wherein said elastic body is made of fluorine or a polymer material having chemical resistance such as silicon.