JP3146963B2 - Scroll type fluid machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a scroll type fluid machine mainly used for a refrigerant compressor of an air conditioner or a refrigerator.

[0002]

2. Description of the Related Art Conventionally, as known from Japanese Patent Publication No. 57-23793, a pair of scrolls having a symmetrical spiral with the same spiral angle are provided, and two symmetrical fluids are provided between the spiral bodies. The working chamber is defined. A back pressure mechanism communicating with the fluid working chamber in the intermediate pressure region is provided on the back side of the orbiting scroll so as to generate a reverse thrust force for pressing the orbiting scroll against the non-orbiting scroll.

[0003]

However, in the case of a symmetric spiral, as shown by imaginary lines in FIG. 4 and FIG. As shown in FIG. 6, only the first fluid working chamber A is provided so as to be in contact with the inner surface of the spiral and has a pressure equal to or higher than the minimum pressure required to secure the reverse thrust force within the range of the crank rotation angle of 360 °. It is configured to communicate. For this reason, in the latter half of the volume reduction of the fluid working chamber A of the first system, excessive pressure is introduced into the back pressure mechanism, and the reverse thrust force becomes excessively large, resulting in a large loss. In addition to the above problem, there is a problem that the fluctuation of the back pressure is large and the behavior of the scroll on the turning side becomes unstable.

That is, as shown in FIG. 11, in a symmetric spiral, the back pressure outlet hole H is opened at a position where the communication is switched between the first fluid working chamber A and the second fluid working chamber B. However, only the system changes between the chambers A1 and B1 of the same pressure (in the case of H1), and it is the same as the case of communicating with the chamber of the same system. Room B2
The communication is switched to the chamber A1 on the low pressure side, which is delayed by one rotation from the pressure A (in the case of H2), and the curve A2 and B2 in FIG.
This is because the curve shifts to the 1, B1 curve, and it becomes impossible to secure the necessary minimum pressure for generating the reverse thrust force.

As described above, the back pressure mechanism not only plays a role of generating a reverse thrust force for pressing the orbiting scroll against the non-orbiting scroll, but also serves to convert the orbiting scroll to the non-orbiting scroll. It can also play a role in moderately reducing the positive thrust force applied to the other side. However, in the conventional symmetric spiral, as shown by the imaginary line in FIGS. 7 and 8, the back pressure extraction hole H is provided so as to be in contact with, for example, the spiral outer surface of the scroll 1 on the non-orbiting side, as shown in FIG. Thus, within the range of the crank rotation angle of 360 °,
It is configured to communicate only with the fluid working chamber B of the second system which is at or below the upper limit pressure at which the positive thrust force can be secured. For this reason, as shown by the B chamber curve in FIG. 9, in the first half where the volume reduction of the fluid working chamber B of the second system is relatively shallow, the back pressure mechanism is provided with a pressure sufficient to reduce the positive thrust force. Can not be introduced, the positive thrust force becomes excessively large,
There is a problem that the loss increases. Further, similarly to the case of the reverse thrust, there is a problem that the fluctuation of the back pressure is large and the behavior of the scroll on the turning side becomes unstable.

That is, as shown in FIG. 11, in the case of a symmetric spiral, the back pressure outlet hole H will be opened at a position where the communication is switched between the first fluid working chamber A and the second fluid working chamber B. However, only the system changes between the chambers A1 and B1 of the same pressure (in the case of H1), and it is the same as the case of communicating with the chamber of the same system. Room B2
The communication is switched to the low-pressure side chamber A1 which is delayed by one rotation from (H2), and the imaginary line B is obtained from the curves B2 and A2 in FIG.
This is because the shift to the 1, A1 curve results in a smaller introduction pressure for reducing the positive thrust force.

Therefore, in the conventional symmetric spiral structure,
Regardless of the reverse thrust and the forward thrust, the pressure of the back pressure mechanism is not properly controlled, and the condition that the pressure is equal to or higher than the minimum pressure necessary to secure the reverse thrust, or that the forward thrust is reduced while Even if the condition that the pressure is lower than the upper limit pressure necessary to secure thrust is cleared, the pressure value is not appropriate and the pressure fluctuates greatly, causing a problem that the thrust loss is large and the scroll behavior becomes unstable. Was.

The main object of the present invention is to appropriately control the pressure introduced into the back pressure mechanism, reduce the thrust loss, and
An object of the present invention is to provide a scroll-type fluid machine capable of reducing the fluctuation of the back pressure and stabilizing the behavior of the scroll.

[0009]

According to the first aspect of the present invention,
In order to achieve the above-mentioned main purpose, as shown in FIG. 1 or FIG.
A scroll type fluid machine comprising a pair of scrolls 1 and 2 defining a back pressure mechanism 8 communicating with a fluid working chamber in an intermediate pressure range on the back of one scroll.
As shown in FIGS. 4 and 5 and FIGS. 7 and 8, the spiral bodies 12 and 22 of the scrolls 1 and 2 are formed into asymmetric spirals having different winding angles, and are connected to the back pressure mechanism 8. Was opened at a position where it was switched to two fluid working chambers A and B. In a scroll type compressor which is a typical example of a scroll type fluid machine, the fluid working chambers A and B constitute a compression chamber, and a refrigerant gas or the like as a compressible fluid is used as the working fluid.

According to the second aspect of the present invention, in order to achieve the desired object of the typical example of the asymmetric spiral in the first aspect of the present invention, as shown in FIGS. The scroll end angle of the scroll 1 on the revolving side
The winding angle is set to be larger than the winding end angle by about 180 °.
Increasing the winding end angle by about 180 ° means that the winding length is increased by about half a turn in terms of the number of turns.

According to a third aspect of the present invention, in the first or second aspect of the present invention, as shown in FIG. 1, in order to make the thrust force of the orbiting scroll 2 appropriate, The back pressure mechanism 8 is provided on the back.

According to a fourth aspect of the present invention, in the third aspect of the invention, in order to make the reverse thrust force appropriate, the back pressure mechanism 8 changes the orbiting scroll 2 to the non-orbiting scroll 1.
And a pressing mechanism that generates a reverse thrust force that presses against the surface.

According to a fifth aspect of the present invention, in order to optimize the reverse thrust force in the fourth aspect of the invention, FIGS.
As shown in the figure, the back pressure extraction hole 4 is connected to the first fluid working chamber A whose pressure rises first, and then the second fluid working chamber B whose pressure rises later is increased. When the back pressure mechanism 8 has reached the minimum pressure required for generating the reverse thrust force, the back pressure mechanism 8 is opened at a position where the communication is switched to the fluid working chamber B of the second system.

According to a sixth aspect of the present invention, in the third aspect of the invention, in order to make the forward thrust force appropriate, the back pressure mechanism 8 replaces the orbiting scroll 2 with the non-orbiting scroll 1.
And a positive thrust force reducing mechanism for reducing the positive thrust force pressed against the opposite side.

According to a seventh aspect of the present invention, in order to optimize the positive thrust force in the sixth aspect of the invention, FIGS.
As shown in the figure, the back pressure extracting hole 4 reduces the positive thrust force in the back pressure mechanism 8 from the state in which the back pressure extracting hole 4 communicates with the fluid working chamber A of the first system in which the pressure rises first. When the pressure reached the upper limit pressure at which the minimum required positive thrust force could be secured, the opening was opened at a position where the communication was switched to the fluid working chamber B of the second system whose pressure increased with a delay.

According to an eighth aspect of the present invention, in the first or second aspect of the present invention, as shown in FIG. 10, in order to make the back pressure on the non-orbiting scroll 1 appropriate, the non-orbiting scroll is used. 1 was provided with a back pressure mechanism 8 on the back.

According to a ninth aspect of the present invention, in order to improve the switching of the communication of the back pressure extracting hole 4, the back pressure extracting hole 4 is formed of a spiral body. The opening width was equal to the plate width.

According to a tenth aspect of the present invention, in the first aspect of the present invention, the back pressure by the back pressure mechanism 8 acts on the scroll in a well-balanced manner as shown in FIG. The pressure mechanism 8 has an annular action surface 80 surrounding the center of the scroll.

[0019]

According to the first aspect of the present invention, FIG.
As shown in 5, 7, and 8, the spiral bodies 12 and 22 of the scrolls 1 and 2 form asymmetric spirals having different winding angles.
Therefore, as shown in FIGS. 6 and 9, the pressure rise curve of the first fluid working chamber A (A room curve) and the pressure rise curve of the second system (B chamber curve) have a predetermined phase difference. Will have. For this reason, the back pressure outlet hole 4 is connected to the two fluid working chambers A,
When the reverse thrust shown in FIG. 6 is obtained by switching communication with B, the curve from the room A curve to the room B curve can be obtained within one rotation, that is, within a range of 360 °, while satisfying the condition of the minimum pressure or more that can secure the reverse thrust. Can be suppressed, and by such a shift, the introduction pressure to the back pressure mechanism 8 can be suppressed from becoming excessive in the latter half of the pressure introduction. In this manner, an excessive reverse thrust load can be reduced as compared with the conventional one which keeps the A room curve, and the loss can be reduced. On the other hand, when the positive thrust shown in FIG. 9 is reduced, the room A curve is changed from the room A curve to the moderately high pressure room B curve within one rotation, that is, within 360 °, while satisfying the condition of the upper limit pressure that can maintain the positive thrust. This shift can prevent the pressure introduced into the back pressure mechanism 8 from becoming too low in the first half of the pressure introduction. Thus, B
It is possible to obtain a proper positive thrust force reducing force as compared with the conventional one that keeps the room curve, and it is possible to suppress the positive thrust load from becoming excessive, thereby reducing the loss. In both the reverse thrust and the forward thrust, the fluctuation of the back pressure can be reduced, and the behavior of the scroll can be stabilized.

According to the second aspect of the present invention, FIGS.
As shown in FIG. 8, the winding end angle of the scroll 1 on the non-orbiting side is
Since the winding end angle of the scroll 2 on the orbiting side is larger by about 180 °, the pressure change in the fluid working chamber A of the first system is
Ahead of the fluid working chamber B of the second system by about 180 °,
As shown in FIG. 6 or FIG. 9, the A room curve and the B room curve have a phase difference of about 180 °. In this way, it is possible to ensure an accurate shift from the A-chamber curve to the B-chamber curve while satisfying the above-described pressure conditions for the reverse thrust and the positive thrust, and to achieve the intended purpose for the typical example of the asymmetric spiral.

According to the third aspect of the present invention, as shown in FIG. 1, since the back pressure mechanism 8 is provided on the back surface of the scroll 2 on the turning side, the thrust force of the scroll 2 on the turning side can be made appropriate. it can.

According to the fourth aspect of the present invention, the back pressure mechanism 8
A pressing mechanism that generates a reverse thrust force for pressing the orbiting scroll 2 against the non-orbiting scroll 1;
As shown in FIG. 6, the reverse thrust force can be made appropriate, and the reverse thrust loss can be reduced.

According to the fifth aspect of the invention, when the orbiting scroll 2 is displaced in the direction shown by the arrow in the figure from the rotation angle shown in FIG. The fluid communication chamber A of the first system indicated by the symbol is communicated. This angle is θ1 in FIG. When the rotation angle advances and reaches the rotation angle shown in FIG. 5, and when the orbiting scroll 2 is displaced in the direction shown by the arrow in the figure from this rotation angle, the back pressure extraction hole 4 is delayed and the pressure is increased in the figure. It communicates with the fluid working chamber B of the second system indicated by dots. This angle is θ2 in FIG. 6, and when this angle is θ2, the pressure of the fluid working chamber B of the second system has reached the minimum pressure necessary to generate the reverse thrust force. For this reason, while securing a necessary reverse thrust force, an excessive reverse thrust force can be eliminated as much as possible, and the reverse thrust force can be optimized.

According to the sixth aspect of the present invention, the back pressure mechanism 8 is
It comprises a positive thrust force reducing mechanism for reducing the positive thrust force for pressing the orbiting scroll 2 against the non-orbiting scroll 1 on the opposite side. As shown in FIG. 9, the positive thrust force can be properly adjusted. , The positive thrust loss can be reduced.

According to the seventh aspect of the present invention, when the orbiting scroll 2 is displaced in the direction shown by the arrow from the rotation angle shown in FIG. The fluid communication chamber A of the first system indicated by the symbol is communicated. This angle is θ1 in FIG. When the rotation angle advances and reaches the rotation angle shown in FIG. 8 and the orbiting scroll 2 is displaced in the direction shown by the arrow in the figure from this rotation angle, the back pressure outlet 4 is delayed and the pressure is increased in the figure. It communicates with the fluid working chamber B of the second system indicated by dots. This angle is θ3 in FIG. 9. Immediately before this angle θ3, the pressure of the first-system fluid working chamber A is the upper limit pressure at which the minimum required positive thrust force can be secured while reducing the positive thrust force. Has been reached. In this state, the second fluid working chamber A of the first
By switching the communication to the fluid working chamber B of the system, while properly maintaining the positive thrust, it is possible to optimally increase the introduction pressure in the range of θ1 to θ3, which is the first half of the communication of the back pressure extraction hole 4, Positive thrust force can be optimized.

According to the eighth aspect of the present invention, as shown in FIG. 10, since the back pressure mechanism 8 is provided on the back surface of the non-orbiting scroll 1, the back pressure of the non-orbiting scroll 1 can be adjusted appropriately. In addition, the bending deformation of the end plate 11 can be satisfactorily reduced.

According to the ninth aspect of the present invention, FIGS.
As shown in FIG. 8, since the back pressure outlet hole 4 has an opening width equal to the plate width of the spiral body, a short circuit between the first system fluid working chamber A and the second system fluid working chamber B can be prevented. The fluid working chambers A and B of these different systems can be satisfactorily switched to communicate with the back pressure mechanism 8.

According to the tenth aspect of the present invention, as shown in FIG. 2, the back pressure mechanism 8 has the annular working surface 80 surrounding the center of the scroll. Can act in a well-balanced manner.

[0029]

FIG. 1 shows an example of application to a refrigerant compressor. A spiral casing 12 conforming to an involute curve and an outer peripheral wall 13 connected to the spiral projecting from a lower surface of a head plate 11 are projected from a closed casing 100. Fixed scroll 1 on the non-orbiting side,
A revolving scroll 2 on the revolving side in which a spiral body 22 that also conforms to the involute curve protrudes from the upper surface of the end plate 21 and a boss tube 23 protrudes from the lower surface is provided.

The fixed scroll 1 is fixedly supported on the housing 101. The orbiting scroll 2 is pressed against a thrust receiving surface 41 provided on the lower surface of the outer peripheral wall 13 of the fixed scroll 1 by a pressing mechanism 8 provided on the back side, and the boss cylinder 23 is fitted to an eccentric pin 91 at the upper end of the drive shaft 90. The revolving scroll 2 is fitted to a slide bush 93 that slides within the range of play of the restriction pin 92, and constitutes a compliance mechanism 9 that is capable of radially displacing the revolving scroll 2 with respect to the fixed scroll 1.

As shown in FIG. 2, the pressing mechanism 8 has a large-diameter ring 81 and a small-diameter ring 82 which are in contact with the outer peripheral portion of the rear surface of the end plate 21 of the revolving scroll 2 and are concentrically arranged. An annular working surface 80 is formed between the fluid pressure chambers 82, and the working surface 80 is introduced from the back pressure outlet hole 4 which is in communication with the intermediate pressure region during compression in the first and second fluid working chambers A and B. The pressure guided through the passage 83 is applied. As shown in FIG. 3, biasing members 84 and 85 made of an elastic material such as rubber are provided on the back surfaces of the rings 81 and 82.
To ensure the initial contact force of each of the rings 81 and 82 at the beginning of the startup.

The first fluid working chamber A is formed by the spiral inner surface of the fixed scroll 1 and the spiral outer surface of the orbiting scroll 2, and the second fluid working chamber A is formed by the spiral outer surface of the fixed scroll 1 and the spiral inner surface of the orbiting scroll 2. The low-pressure gas sucked from the low-pressure port 3 outside the spiral is taken into the fluid working chambers A and B, and the compressed high-pressure gas is taken out from the high-pressure port 10 through the high-pressure chamber 102 to the discharge pipe 103. Like that.

The orbiting scroll 2 is provided on the thrust receiving surface 41.
The oil pumped from the bottom oil reservoir of the casing 100 to the oil supply passage 94 in the drive shaft 90 is supplied through the oil communication passage 40 provided in the end plate 21 of the first embodiment.

In FIG. 1, reference numeral 14 denotes a high-pressure port 10;
A reference numeral 24 denotes an Oldham ring constituting a rotation preventing mechanism of the revolving scroll 2, and 95 denotes a balancer integrated with the slide bush 93.

As shown in FIGS. 4 and 5, the winding end angle of the spiral body 12 of the fixed scroll 1 is larger than the winding end angle of the spiral body 22 of the revolving scroll 2 by 180 °. 2 constitutes an asymmetric spiral.

The first embodiment is an example in which the back pressure mechanism 8 generates a reverse thrust force for pressing the orbiting scroll 2 against the thrust receiving portion 41 of the fixed scroll 1. At the angle θ2 shown in FIG. 6, the communication is switched from the first fluid working chamber A to the second fluid working chamber B.

The second embodiment is an example in which the back pressure mechanism 8 reduces the positive thrust force for pressing the orbiting scroll 2 against the annular upper end surface of the housing 101 on the side opposite to the fixed scroll 1. The pressure extraction hole 4 has an angle θ3 shown in FIG.
, The communication is switched from the first fluid working chamber A to the second fluid working chamber B.

In the third embodiment, as shown in FIG.
A back pressure mechanism 8 is provided on the back surface of the fixed scroll 1.
0 is formed, and the inner and outer cylindrical walls 802 and 803 provided on the pressure bulkhead 801 are inserted into the concave chamber 800 so that the O-ring 80 is formed.
4,805, the back pressure is introduced into the concave chamber 800 from the back pressure extracting hole 4 to oppose the compression reaction force from the fluid working chambers A, B side.

In each of the above embodiments, the back pressure outlet 4 is provided in the end plate 11 of the fixed scroll 1.
The inner diameter is set to be the same as the width of the spiral body 22.

[Brief description of the drawings]

FIG. 1 is an upper longitudinal sectional view of a scroll type fluid machine according to the present invention.

FIG. 2 is a plan view of a back pressure mechanism.

FIG. 3 is an enlarged sectional view taken along line X, X in FIG. 2;

FIG. 4 is a cross-sectional plan view of a spiral part showing the first embodiment.

FIG. 5 is a plan sectional view showing a state where the angle has advanced from the state of FIG. 4;

FIG. 6 is a rotation angle versus pressure characteristic diagram illustrating the operation of the first embodiment.

FIG. 7 is a cross-sectional plan view of a spiral part according to a second embodiment.

FIG. 8 is a plan sectional view showing a state where the angle has advanced from the state of FIG. 7;

FIG. 9 is a graph showing a rotation angle versus pressure characteristic for explaining the operation of the second embodiment.

FIG. 10 is a longitudinal sectional view of a main part showing a third embodiment.

FIG. 11 is a cross-sectional plan view of a symmetric spiral explaining the problem of the invention.

[Explanation of symbols]

12, 22; spiral body, A, B; fluid working chamber, 1; scroll on the non-swirl side, 2; scroll on the swivel side, 4; back pressure extraction hole, 8;

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04C 18/02 311

Claims (10)

(57) [Claims] 1. A pair of scrolls (1, 1) defining two fluid working chambers (A, B) between spiral bodies (12, 22).
In the scroll type fluid machine provided with 2) and provided with a back pressure mechanism (8) communicating with the fluid working chamber in the intermediate pressure area on the back of one scroll, the scroll (12) of each scroll (1, 2) is provided. , 22) are formed into asymmetric spirals having different winding angles, and a back pressure outlet hole (4) communicating with the back pressure mechanism (8) is switched to communicate with the two fluid working chambers (A, B). A scroll-type fluid machine characterized by having an opening in a hole. 2. The winding end angle of the scroll (1) on the non-orbiting side is about 180 degrees smaller than the winding end angle of the scroll (2) on the orbiting side.
The scroll type fluid machine according to claim 1, wherein the angle is increased. 3. The scroll type fluid machine according to claim 1, wherein a back pressure mechanism is provided on a back surface of the orbiting scroll. 4. The scroll type fluid machine according to claim 3, wherein the back pressure mechanism (8) comprises a pressing mechanism for generating a reverse thrust force for pressing the orbiting scroll (2) against the non-orbiting scroll (1). . 5. The second-system fluid actuating device, wherein the back-pressure outlet hole (4) communicates with the first-system fluid actuating chamber (A), whose pressure rises first, and then the pressure rises with a delay. Room (B)
Is opened at a position where the communication is switched to the second fluid working chamber (B) when the minimum pressure required to generate a reverse thrust force in the back pressure mechanism (8) is reached.
The scroll-type fluid machine as described in the above. 6. The back pressure mechanism (8) comprises a positive thrust force reducing mechanism for reducing a positive thrust force for pressing the orbiting scroll (2) against the non-orbiting scroll (1). 3. The scroll fluid machine according to 3. 7. The state in which the back pressure outlet hole (4) is in communication with the first fluid working chamber (A), whose pressure rises first, changes the working pressure of the working chamber (A) to the back pressure mechanism (A). 8) In the position where the communication is switched to the fluid working chamber (B) of the second system, where the pressure rises with a delay when the pressure reaches the upper limit pressure at which the required minimum positive thrust force can be secured while reducing the positive thrust force. 7. The scroll type fluid machine according to claim 6, wherein said scroll type fluid machine has an opening. 8. The scroll type fluid machine according to claim 1, wherein a back pressure mechanism is provided on a back surface of the non-orbiting scroll. 9. The scroll type fluid machine according to claim 1, wherein the back pressure outlet hole has an opening width equal to a plate width of the spiral body. 10. The scroll-type fluid machine according to claim 1, wherein the back pressure mechanism has an annular working surface surrounding a central portion of the scroll.