WO2016140107A1

WO2016140107A1 - Scroll fluid machine

Info

Publication number: WO2016140107A1
Application number: PCT/JP2016/055270
Authority: WO
Inventors: 貴幸萩田; 孝幸桑原; 藤田　勝博; 竹内　真実; 源太慶川; 山崎　浩; 恵太北口; 創佐藤
Original assignee: 三菱重工オートモーティブサーマルシステムズ株式会社
Priority date: 2015-03-05
Filing date: 2016-02-23
Publication date: 2016-09-09
Also published as: JP2016160912A; CN107429690B; DE112016001045T5; US20180058451A1; CN107429690A; JP6529787B2

Abstract

Provided is a scroll fluid machine comprising a fixed scroll (15) and a rotating scroll (16) which form a pair, wherein the scroll fluid machine is configured to be a one-side stepped scroll and such that one from between the fixed scroll (15) and the rotating scroll (16) is provided with a step part (16E) only at a prescribed position along the spiral direction of a tooth bottom surface (16D) of a spiral wrap (16B), and the other is provided with a step part (15E) only at a prescribed position corresponding to the step part (16E) on the tooth bottom surface (16D) side and along the spiral direction of a tooth tip surface (15C) of a spiral wrap (15B). The step part (16E) provided to the tooth bottom surface (16D) is at a position toward the spiral-direction inner circumference by only π radian of an involute angle from a winding completion position (16F) of the spiral wrap (16B) which has terminated intake, or a position toward the spiral direction outer circumference from such position.

Description

Scroll fluid machinery

The present invention relates to a scroll fluid machine that can be applied to a compressor, a pump, an expander, and the like.

The scroll fluid machine includes a pair of fixed scrolls and orbiting scrolls each having a spiral wrap standing on an end plate, and the pair of fixed scrolls and the spiral scrolls of the orbiting scrolls are opposed to each other, and the phases are shifted by 180 degrees. By engaging, a pair of compression chambers are formed between both scrolls, and fluid is supplied and discharged. In such a scroll fluid machine, for example, in a scroll compressor, the wrap heights of the spiral wraps of the fixed scroll and the orbiting scroll are made uniform over the entire circumference in the spiral direction, and the volume of the compression chamber is increased from the outer peripheral side to the inner peripheral side. A two-dimensional compression structure is generally used in which the fluid sucked into the compression chamber is compressed while being compressed and compressed in the circumferential direction of the spiral wrap.

On the other hand, in order to increase the compression volume ratio and to make the scroll compressor more efficient and smaller and lighter, each step is set at a predetermined position along the spiral direction of the tooth tip surface and the tooth bottom surface of the spiral wrap of the fixed scroll and the orbiting scroll. The height of the wrap on the outer periphery of the spiral wrap is made higher than the height of the wrap on the inner periphery, and the axial height of the compression chamber is set on the inner periphery of the spiral wrap on the outer periphery of the spiral wrap. There is provided a stepped scroll compressor having a three-dimensional compression structure in which a fluid is compressed in both the circumferential direction and the height direction of a spiral wrap by making the height higher than the height.

As such stepped scroll compressors, for example, as shown in Patent Documents 1 and 2, respectively, at a predetermined position along the spiral direction of the tooth tip surface and the tooth bottom surface of the spiral wrap of both the fixed scroll and the orbiting scroll. In addition to the scroll compressor having a stepped structure on both sides, as shown in

Patent Documents

3 and 4, one of the fixed scroll and the orbiting scroll is placed only at a predetermined position along the spiral direction of the tooth bottom surface of the spiral wrap. There is known a scroll compressor having a one-side step structure in which a scroll having a stepped portion is used and the other is a scroll having a stepped portion only at a predetermined position along the spiral direction of the tooth tip surface of the spiral wrap.

JP 2002-5053 A JP 2009-74461 A Japanese Examined Patent Publication No. 60-17756 (see Fig. 8) JP-A-4-121383

In a scroll compressor having a three-dimensional compression structure, as shown in Patent Documents 1 and 2, a pair of compression chambers are symmetrical in the case where each of the fixed and orbiting scrolls is provided with stepped portions. Therefore, even if gas is mixed by disengagement between the stepped portions and the compression chambers communicating with each other, no mixing loss occurs. However, since it is necessary to provide stepped portions on both scrolls, it takes time for processing, and there are two stepped mesh gaps contributing to gas leakage. Therefore, there is a problem that the amount of gas leakage tends to increase. Have.

On the other hand, as shown in

Patent Documents

3 and 4, with the one-side stepped structure, since the meshing by the stepped portion is one place, the amount of gas leakage can be reduced and the labor of processing is halved. be able to. However, since the pair of compression chambers becomes asymmetric depending on the presence or absence of the stepped portion and the volume becomes unbalanced, after the pair of compression chambers closes the suction and starts compression, the engagement between the stepped portions is released and both When the compression chambers communicate with each other, a differential pressure is generated between the compression chambers. This differential pressure causes a mixing loss, and there is a problem that the efficiency is reduced accordingly.

The present invention has been made in view of such circumstances, and eliminates the occurrence of mixing loss while enjoying the effects of high efficiency and small size and light weight by increasing the compression volume ratio as a stepped structure. Another object of the present invention is to provide a scroll fluid machine that can achieve higher efficiency.

In order to solve the above-described problems, the scroll fluid machine of the present invention employs the following means.
That is, a scroll fluid machine according to the present invention includes a pair of fixed scrolls and orbiting scrolls in which spiral wraps are erected on end plates and the spiral wraps are opposed to each other, and the fixed scrolls and One of the orbiting scrolls has a step portion only at a predetermined position along the spiral direction of the tooth bottom surface of the spiral wrap, and the other is in the spiral direction of the tooth tip surface of the spiral wrap corresponding to the step portion on the tooth bottom side. It is a one-side stepped scroll provided with a step portion only at a predetermined position along the position, and the position of the step portion provided on the tooth bottom surface is only π radians at an extension angle from the winding end position of the spiral wrap with suction closed It is provided at a position on the inner peripheral side in the spiral direction or at a position on the outer peripheral side of the position.

In a scroll fluid machine with a one-side stepped structure in which a step is provided only on one side of a pair of compression chambers, the internal pressure between the compression portions is disengaged because the internal pressure in both compression chambers is unbalanced. When mixing, a mixing loss occurs.
According to the present invention, the position of the stepped portion of the tooth bottom surface is set to a position on the inner circumferential side in the spiral direction by an angle of π radians from the winding end position of the spiral wrap having the suction deadline or a position on the outer circumferential side from the position. By providing, when the internal pressures of the pair of compression chambers are substantially the same before the internal pressure changes, the engagement between the step portions can be removed and both the compression chambers can be brought into a communication state.
Therefore, the mixing loss caused by the presence of the step portion only on one side of the pair of compression chambers can be eliminated, and the efficiency can be improved correspondingly.
Moreover, as a scroll fluid machine with a stepped structure on one side, it is possible to improve the efficiency by reducing the leakage of the working medium by halving the gap of the step mesh from two to one, and to work on the step processing. The cost can be reduced by halving the value.

Further, the scroll fluid machine according to the present invention includes a pair of fixed scrolls and orbiting scrolls in which spiral wraps are erected on end plates, and the spiral wraps are opposed to each other, and the fixed scrolls and The orbiting scroll is a double-sided stepped scroll having step portions at predetermined positions along the spiral direction of the tooth tip surface and the tooth bottom surface of the spiral wrap, and the height of each step portion is the fixed scroll and the orbiting scroll. And the position of the step provided on the tooth bottom surface is a position on the inner circumferential side of the spiral direction by π radians at an extension angle from the winding end position of the spiral wrap that has been closed by suction. It is provided at a position on the outer peripheral side of the position.

In a scroll fluid machine with a double-sided step structure in which a pair of compression chambers are provided with stepped portions having different heights, the internal pressure of both compression chambers is unbalanced. When mixing, a mixing loss occurs.
According to the present invention, the position of the stepped portion of the tooth bottom surface is set to a position on the inner circumferential side in the spiral direction by an angle of π radians from the winding end position of the spiral wrap having the suction deadline or a position on the outer circumferential side from the position. By providing, when the internal pressures of the pair of compression chambers are substantially the same before the internal pressure changes, the engagement between the step portions can be removed and both the compression chambers can be brought into a communication state.
Therefore, in a scroll fluid machine having a double-sided step structure in which the step portions existing in the pair of compression chambers have different heights, the mixing loss due to the difference in the step portion height can be eliminated, and the efficiency can be improved correspondingly. .

Furthermore, the scroll fluid machine according to the present invention is the scroll fluid machine according to any one of the above-described scroll fluid machines, wherein the stepped position of the tooth bottom surface is an extension angle of π / 2 radians or π radians from the winding end position of the spiral wrap. It is provided in the range of the inner circumferential side position in the spiral direction.

According to the present invention, the mixing loss that occurs when the internal pressure of the pair of compression chambers is disengaged and mixed while ensuring the effect of increasing the compression volume ratio by providing the stepped portion. It can be lost.
Therefore, the mixing loss can be eliminated and further efficiency can be improved while enjoying the high efficiency and small size and light weight effect of the scroll fluid machine due to the stepped structure.

According to the present invention, in a scroll fluid machine having a one-side stepped structure in which a step is provided only on one side of a pair of compression chambers, when the internal pressure of the pair of compression chambers is substantially the same before the internal pressure changes, Both the compression chambers can be brought into a communication state by disengaging the step portions.
For this reason, the mixing loss generated due to the presence of the step portion on only one side of the pair of compression chambers can be eliminated, and the efficiency can be improved correspondingly.
Moreover, as a scroll fluid machine with a one-sided step structure, the step mesh clearance can be reduced from two to one, thereby reducing the leakage of the working medium by half and improving the efficiency. Cost reduction can be achieved by halving.

Further, according to the present invention, in a scroll fluid machine having a double-sided step structure in which a pair of compression chambers are provided with stepped portions having different heights, when the internal pressure of the pair of compression chambers is substantially the same before the internal pressure changes. In addition, the compression chambers can be brought into communication by releasing the engagement between the step portions.
For this reason, in the scroll fluid machine having a stepped structure with the stepped portions present in the pair of compression chambers having different heights, the mixing loss due to the difference in the stepped portion height can be eliminated, and the efficiency can be improved accordingly. it can.

1 is a longitudinal sectional view of a scroll fluid machine according to a first embodiment of the present invention. It is mesh | engagement explanatory drawing (A) thru | or (D) in the turning angle position from which the fixed scroll and turning scroll of the said scroll fluid machine differ. FIG. 3 is an explanatory diagram (A) to (D) of a meshing state corresponding to FIG. 2 of a comparative example. It is a graph which shows the change of the cylinder pressure with respect to the turning angle of the scroll fluid machine which concerns on the said 1st Embodiment. It is a graph which shows the change of the cylinder pressure with respect to the turning angle of the said comparative example.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 5.
FIG. 1 is a longitudinal sectional view of the scroll fluid machine according to the first embodiment of the present invention, and FIG. 2 is an explanatory diagram of meshing states at different turning angle positions of the fixed scroll and the turning scroll. It is shown as (A) to FIG. 2 (D).
Here, as an example of the scroll fluid machine, an example in which the present invention is applied to an open scroll compressor (scroll fluid machine) 1 of a type driven by external power will be described.

The open-type scroll compressor (scroll fluid machine) 1 includes a housing 2 constituting an outer shell as shown in FIG. The housing 2 has a cylindrical shape with an opening on the front end side and a sealing on the rear end side, and a front housing 3 is fastened and fixed to the opening on the front end side with a bolt 4 to form a sealed space therein. The scroll compression mechanism 5 and the drive shaft 6 are incorporated in the sealed space.

The drive shaft 6 is rotatably supported by the front housing 3 via a main bearing 7 and a sub-bearing 8, and has a front end protruding from the front housing 3 via a lip seal (or mechanical seal) 9. A pulley 11 is rotatably connected to the outer peripheral portion of the front housing 3 via a bearing 10 via an electromagnetic clutch 12 so that power can be transmitted from the outside. A crank pin 13 that is eccentric by a predetermined dimension is integrally provided at the rear end of the drive shaft 6, and the orbiting scroll 16 of the scroll compression mechanism 5 to be described later includes a drive bush and a drive bearing whose variable orbiting radius is variable. It is connected via a known driven crank mechanism 14.

The scroll compression mechanism 5 forms a pair of compression chambers (compression chambers) 17 between the

scrolls

15 and 16 by meshing the pair of fixed scrolls 15 and the orbiting scroll 16 with a phase difference of 180 degrees. The fluid (refrigerant gas) is compressed by moving 17 from the outer peripheral position to the center position while reducing the volume. The fixed scroll 15 includes a discharge port 18 that discharges compressed gas at a central portion, and is fixedly installed on the bottom wall surface of the housing 2 via a bolt 19. The orbiting scroll 16 is connected to the crank pin 13 of the drive shaft 6 via a driven crank mechanism 14 and is supported on a thrust bearing surface of the front housing 3 via a known rotation prevention mechanism 20 so as to be capable of revolution orbiting.

An O-ring 21 is provided on the outer periphery of the end plate 15 </ b> A of the fixed scroll 15, and the O-ring 21 is brought into close contact with the inner peripheral surface of the housing 2, whereby the discharge chamber 22 and the suction chamber 23 pass through the inner space of the housing 2. It is divided into and. A discharge port 18 is opened in the discharge chamber 22 so that the compressed gas from the compression chamber 17 is discharged, and the compressed high-pressure gas is sent out to the refrigeration cycle side. Yes. A suction port 24 provided in the housing 2 is opened in the suction chamber 23 so that the low-pressure gas circulated through the refrigeration cycle is sucked into the compression chamber 17 through the suction chamber 23. It has become.

The pair of fixed scroll 15 and orbiting scroll 16 are configured such that spiral wraps 15B and 16B are erected on

end plates

15A and 16A, respectively. In the present embodiment, as shown in FIG. 2, one of the fixed scroll 15 and the orbiting scroll 16, here, the orbiting scroll 16 is provided only at a predetermined position along the spiral direction of the tooth bottom surface 16D of the spiral wrap 16B. Scroll with The other fixed scroll 15 is only at a predetermined position along the spiral direction of the tooth tip surface 15C of the spiral wrap 15B (a position corresponding to the step portion 16E provided on the tooth bottom surface 16D of the spiral wrap 16B on the orbiting scroll 16 side). The scroll is provided with a step portion 15E.

As described above, the stepped portion 16E is provided only on the tooth bottom surface 16D of the orbiting scroll 16, and the stepped portion 15E is provided only on the tooth tip surface 15C of the spiral wrap 15B of the fixed scroll 15 corresponding to the stepped portion 16E. In addition, the entire surface of the bottom surface 15D of the fixed scroll 15 in which the step portion is not provided on the bottom surface 15D is a flat surface. Furthermore, all the tooth tip surfaces 16C of the spiral wrap 16B of the orbiting scroll 16 have the same height. Thereby, the scroll compressor 1 having a one-sided stepped structure having a stepped portion only on one compression chamber 17 side is configured.

In the scroll compressor 1 having a one-sided step structure having such a configuration, one of the pair of compression chambers 17 closed by suction is a compression chamber having a stepped portion, and the other is a compression chamber having no stepped portion. As a result, the compression chambers are asymmetrical to each other, and the volume is unbalanced. For this reason, the pair of compression chambers 17 are compression chambers having different compression volume ratios, a differential pressure is generated in the compression process, and when the pair of compression chambers 17 are in communication with each other by disengagement between the step portions, Compression loss due to mixing occurs.

For example, as shown in FIG. 3, in the state of FIG. 3 (A) in which the suction is closed, the inside of the spiral direction is 1.5π radians from the winding end position 16F of the spiral wrap 16B of the orbiting scroll 16 at an extension angle. In the case where the stepped portion 16E on the tooth bottom surface 16D side is provided at the circumferential side position, the stepped

portions

16E and 15E are engaged with each other at the position shown in FIG. 3A, and the pair of compression chambers 17 are sealed. Yes. In this state, compression is started, and the stepped

portions

16E and 15E are still engaged with each other at the position of FIG. 3 (B) advanced by 90 ° in the turning angle, but from the position of FIG. 3 (B) to the position of FIG. 3 (C). When the 90 ° turning angle advances, the stepped

portions

16E and 15E are disengaged from each other, and the compression is advanced and the pair of compression chambers 17 in which the differential pressure is generated communicate with each other. It will be.

This state is as shown in the graph showing the change in the in-cylinder pressure (compression chamber internal pressure) in FIG. 5, and such a mixing loss results in a decrease in efficiency. The stepped

portions

16E and 15E mesh with each other again at the position of FIG. 3D, which has advanced 90 ° from the position of FIG. 3C, and when the angle of rotation further advances by 90 °, it turns 360 ° and turns to FIG. 3A. Return to the state. As a result, the pair of compression chambers 17 closed at the previous position in FIG. 3A are moved to the compression chamber position on the inner circumference side, and the pair of compression chambers 17 are joined by further turning. The compressed gas is discharged into the discharge chamber 22 through the discharge port 18. Note that FIG. 5 is displayed so that the turn proceeds from the larger turning angle to the smaller turning angle.

In this embodiment, the position of the

step portions

16E and 15E is specified to eliminate the mixing loss that occurs when the engagement of the

step portions

16E and 15E is released and the pair of compression chambers 17 communicate with each other. Therefore, as shown in FIG. 2, when the orbiting scroll 16 provided with the step portion 16E on the tooth bottom surface 16D is orbited to the position shown in FIG. A stepped portion 16E of the tooth bottom surface 16D is provided at a position on the inner circumferential side in the spiral direction by an angle of π radians from the winding end position 16F of 16B or a position on the outer circumferential side with respect to the displacement thereof.

Specifically, a step portion 16E of the tooth bottom surface 16D is provided in a range of the winding end position 16F of the swirl wrap 16B of the orbiting scroll 16 from the winding end position 16F to the inner circumferential side position in the spiral direction by π / 2 radians or π radians. It is configured. With this configuration, when the suction is closed at the position shown in FIG. 2A, the

step portions

16E and 15E are still engaged with each other, but the position from the position shown in FIG. 2A toward the position shown in FIG. As the turning proceeds, the

step portions

16E and 15E are immediately disengaged from each other, and the pair of compression chambers 17 communicate with each other. In this state, since the internal pressure in the pair of compression chambers 17 is substantially the suction pressure and no differential pressure is generated, even if the pair of compression chambers 17 communicate with each other, a mixing loss due to gas mixing occurs. There is no.

While turning 180 ° from the position shown in FIG. 2A to the position shown in FIG. 2C from the position shown in FIG. 2B, the stepped

portions

16E and 15E are disengaged from each other. 2C, the

step

16E and 15E are re-engaged with each other at the position shown in FIG. 2 (C), and when the turning angle further advances by 90 °, the step turns 360 ° and moves as shown in FIG. 2 (A). It will return to the state. As a result, the pair of compression chambers 17 closed at the previous position in FIG. 2A are moved to the compression chamber position on the inner circumference side, and the pair of compression chambers 17 are joined by further turning. The compressed gas is discharged into the discharge chamber 22 through the discharge port 18.

The graph in FIG. 4 shows the change in the in-cylinder pressure (compression chamber internal pressure) during this period. In contrast to the comparative example shown in FIG. 5, the comparative example has a mixing loss when the swivel angle is around 650 °, whereas that of the present embodiment (the winding of the spiral wrap 16B). It can be seen that there is no mixing loss in the case where the stepped portion 16E is provided at the position on the inner circumferential side in the spiral direction by π radians at the extension angle from the end position.

Thus, according to the present embodiment, the following operational effects are obtained.
In the scroll compressor 1, when the electromagnetic clutch 12 is turned on, power is input from the drive source to the drive shaft 6 via the pulley 11 and the electromagnetic clutch 12, and the drive shaft 6 is rotationally driven. As a result, the orbiting scroll 16 connected to the crank pin 13 of the drive shaft 6 via the driven crank mechanism 14 including the drive bush is revolved around the fixed scroll 15.

When the scroll compressor 1 is driven in this way, a low-pressure refrigerant gas is sucked into the suction chamber 23 from the refrigeration cycle side via the suction port 24, and the refrigerant gas is driven by the orbiting scroll 16 so as to rotate. Inhaled. The refrigerant gas is compressed when the orbiting scroll 16 is driven to rotate, and the compression chamber 17 is moved from the outer peripheral side to the center side while reducing the volume, and the refrigerant gas is discharged at the central portion of the fixed scroll 15. 18 is discharged into the discharge chamber 22 through 18 and sent from there to the refrigeration cycle side.

During this time, the pair of compression chambers 17 closed at the swivel angle position of FIG. 2A sequentially turn 360 ° through the positions of FIG. 2B, FIG. 2C, and FIG. 2D. Then, the position returns to the position shown in FIG. In the scroll compressor 1 with one side of the present embodiment, the step 16E provided only on the tooth bottom surface 16D of the spiral wrap 16B of the orbiting scroll 16 is positioned at the position shown in FIG. The configuration is such that π / 2 radians or π radians are provided at a position on the inner peripheral side in the spiral direction from the winding end position 16F of the spiral wrap 16B to the expansion angle from the winding end position.

For this reason, the stepped

portions

16E and 15E are engaged with each other at the position where the suction is closed in FIG. 2A, but when turning from the position of FIG. 2A toward the position of FIG. 15E are disengaged, and the pair of compression chambers 17 are in communication. However, at this time, the internal pressure in the pair of compression chambers 17 is still the suction pressure, and no differential pressure is generated, so even if the pair of compression chambers 17 communicate with each other and the gases are mixed, As a result, no mixing loss occurs.

As a result, the step 16E exists only on one side of the pair of compression chambers 17 while the scroll compressor 1 has a one-side stepped structure in which the step 16E is provided only on one side of the pair of compression chambers 17. Therefore, the mixing loss generated due to the fact can be eliminated, and the efficiency can be improved accordingly. Moreover, as the scroll compressor 1 having a stepped structure on one side, by reducing the step mesh gap from two to one, the leakage of the working medium can be reduced by half and the efficiency can be improved. Costs can be reduced by reducing labor by half.

Further, the position of the step portion 16E provided on the tooth bottom surface 16D side is provided within the range of the position in the spiral direction from the winding end position 16F of the spiral wrap 16B by π / 2 radians to π radians in the extension angle. Therefore, the mixing loss generated when the internal pressure of the pair of compression chambers 17 is disengaged and mixed while ensuring the effect of increasing the compression volume ratio by providing the stepped portion 16E. It can be lost. Therefore, the mixing loss can be eliminated and further efficiency can be improved while enjoying the effects of high efficiency and small size and light weight of the scroll compressor (scroll fluid machine) 1 due to the stepped structure.

[Other embodiments]
(1) In the first embodiment described above, the open scroll compressor 1 having a one-side stepped structure in which the stepped portion 16E is provided only on the tooth bottom surface 16D of the spiral wrap 16B on the orbiting scroll 16 side has been described. A single-sided stepped structure in which a stepped portion is provided only on the tooth bottom surface 15D of the spiral wrap 15B on the 15th side can provide the same effect as that of the first embodiment.

(2) In the first embodiment, the example applied to the scroll compressor 1 having a one-sided step structure has been described. However, even if the scroll compressor has a double-sided step structure, the fixed scroll 15 and the orbiting scroll 16 are used. In the case where the heights of the step portions provided in the two are different, a difference in pressure is generated between the pair of compression chambers 17 due to the difference in height of the step portions. When communicating, mixing loss occurs as described above.

For this reason, in the case of a scroll compressor having a stepped structure on both sides, the height of the stepped portions provided on both scrolls is different, so that the position of the stepped portion provided on the tooth bottom side is wound by a spiral wrap with the suction closed. A scroll compressor having a one-sided step structure described in the first embodiment by adopting a configuration in which the opening angle is π radians from the end position and is provided at a position on the inner peripheral side in the spiral direction or a position on the outer peripheral side than the position. As in the case of 1, effects such as elimination of mixing loss and improvement of efficiency can be obtained.

Note that the present invention is not limited to the inventions according to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the example applied to the open type scroll compressor 1 has been described, but it goes without saying that the present invention can be similarly applied to a scroll expander, a scroll pump, and the like. Of course, the present invention is not limited to the open scroll compressor 1 and may be applied to a scroll compressor having a built-in compression mechanism and motor.

1 Scroll compressor (scroll fluid machine)
15 fixed scroll 16

orbiting scroll

15A,

16A end plate

15B, 16B spiral wrap 15C, 16C

tooth tip surface

15D, 16D tooth bottom surface 15E tooth tip surface step 16E tooth bottom step 16F winding end position

Claims

A spiral wrap is erected on the end plate, and the spiral wrap is provided with a pair of fixed scroll and orbiting scroll in which the spiral wraps face each other and mesh with each other,
One of the fixed scroll and the orbiting scroll has a step portion only at a predetermined position along the spiral direction of the tooth bottom surface of the spiral wrap, and the other has a tooth tip surface of the spiral wrap corresponding to the step portion on the tooth bottom surface side. It is a one-side stepped scroll provided with a step portion only at a predetermined position along the spiral direction of
The position of the step provided on the tooth bottom surface is a position on the inner peripheral side in the spiral direction by an angle of π radians from the winding end position of the spiral wrap that has been closed by suction, or a position on the outer peripheral side than that position. A scroll fluid machine provided.
A spiral wrap is erected on the end plate, and the spiral wrap is provided with a pair of fixed scroll and orbiting scroll in which the spiral wraps face each other and mesh with each other,
The fixed scroll and the orbiting scroll are both-side stepped scrolls each provided with a step portion at a predetermined position along the spiral direction of the tooth tip surface and the tooth bottom surface of the spiral wrap,
The height of each stepped portion is different between the fixed scroll and the orbiting scroll, and the position of the stepped portion provided on the tooth bottom surface is from the winding end position of the spiral wrap that has been closed by suction. A scroll fluid machine provided at a position on the inner circumferential side of the spiral direction by an angle of spread of π radians or a position on the outer circumferential side of the position.
3. The step position of the tooth bottom surface is provided in a range of a position in the spiral direction inner circumferential side by π / 2 radians or π radians in an extension angle from a winding end position of the spiral wrap. Scroll fluid machine.