JPH0510701U - Scroll type fluid machinery - Google Patents

Abstract

(57) [Summary] [Object] To provide a high-performance scroll-type fluid machine that prevents gas from leaking from a sealed space formed between both scrolls. [Structure] The fixed scroll 1 and the orbiting scroll 2 formed by vertically arranging spiral wraps 12 and 22 on the respective end plates 11 and 21 mesh with each other to form a closed space 24, and the fixed scroll 1 or the orbiting scroll. The scroll 2 is pressed against the fixed scroll 1 or the orbiting scroll 2 by the fluid pressure introduced from the closed space 24 through the pressure guiding hole 41 into the back pressure chamber 40 formed on the back side thereof. The scroll compressor is provided with an on-off valve 9 that opens and closes the pressure guide hole based on the pressure difference between the closed space and the back pressure chamber.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a scroll type fluid machine.

[0002]

[Prior Art]

 An example of a conventional scroll compressor will be described with reference to the vertical sectional view of FIG. 2. The interior of the hermetic housing 8 is partitioned by a discharge cover 31 into a high pressure side 44 and a low pressure side 45. Inside the low voltage side 45, a scroll type compression mechanism C 1 is arranged at an upper part thereof, and an electric motor M is arranged at a lower part thereof, which are interlockingly connected to each other via a rotary shaft 5. The electric motor M is composed of a rotor Ma and a stator Mb, the rotor Ma is fixed to the rotating shaft 5, and the stator Mb is fixed by being press-fitted into the hermetically sealed housing 8. The scroll type compression mechanism C has a fixed scroll 1 and an orbiting scroll 2. The fixed scroll 1 is provided with an end plate 11 and a spiral wrap 12 erected on its inner surface. A discharge port 13 is provided. The orbiting scroll 2 includes an end plate 21 and a spiral wrap 22 provided upright on the inner surface of the end plate 21, and a drive bush 54 is rotated via a orbiting bearing 73 in a boss 23 provided upright on the outer surface of the end plate 21. An eccentric pin 53 protruding freely from the upper end of the rotary shaft 5 is slidably fitted into a slide hole 55 formed in the drive bush 54. The fixed scroll 1 and the orbiting scroll 2 are eccentric with respect to each other by a predetermined distance, and are meshed with each other at an angle of 180 degrees to form a plurality of closed spaces 24. The orbiting scroll 2 is slidably supported on a casing 6 fixed in a hermetically sealed housing 8. The orbiting scroll 2 and the casing 6 allow the revolving orbiting motion of the orbiting scroll 2 but prevent its rotation. A rotation prevention mechanism 3 including an Oldham link or the like is provided. The fixed scroll 1 is floatably supported by a casing 6 via a support spring 32 arranged on the outer periphery of the end plate 11, and the back surface of the end plate 11 of the fixed scroll 1 is centered on the center thereof. Concentric cylindrical flanges 15 and 16 are provided so as to project upward, and a cylindrical flange 39 that is provided so as to project downward on the lower surface of the discharge cover 31 between these via a pair of inner and outer seal members 37. A back pressure chamber 40 surrounded by these is formed by fitting in a tightly sealed and slidable manner, and the back pressure chamber 40 is provided through a pressure guiding hole 41 formed in the end plate 11 during the compression of gas. It communicates with a closed space 24. Here, the pressure guiding hole 41 is located at a point in contact with the inner diameter side of the wrap 12. A high pressure chamber 42 is formed on the inner peripheral side of the back pressure chamber (also referred to as an intermediate pressure chamber) 40, and a low pressure chamber 43 is formed on the outer peripheral side thereof. The upper end of the rotary shaft 5 is supported by an upper bearing 71 provided on the casing 6, and the lower end thereof is supported by a lower bearing 72. In such a structure, the orbiting scroll 2 is driven by the orbiting drive mechanism including the rotary shaft 5, the eccentric pin 53, the drive bush 54, the boss 23, etc. by driving the electric motor M, and the orbiting scroll 2 has a rotation preventing mechanism. As a result, the rotation revolution is performed on a circular orbit whose radius is the revolution revolution radius while being prevented from rotating. Then, the gas enters the low pressure chamber 45 through the suction pipe 82, and is sucked into the closed space 24 through a path not shown. Then, as the volume of the closed space 24 decreases due to the orbiting motion of the orbiting scroll 2, the gas reaches the central portion while being compressed, and enters the high pressure side 44 from the discharge port 13 through the high pressure chamber 42. Then, the discharge pipe 83 and the reverse valve 84 built therein are pushed open to be discharged to the outside. At that time, the fixed scroll 1 is pressed against the orbiting scroll 2 by the gas pressure in the high-pressure chamber 42 and the back-pressure chamber 40, and the leakage of gas from the closed space 24 is suppressed. When the liquid is sucked into the closed space 24, the fixed scroll 1 floats and the liquid is released to prevent the scroll type compression mechanism from being damaged. Although the high pressure chamber 42, the back pressure chamber 40, and the low pressure chamber 43 are formed on the back surface side of the fixed scroll 1 in the above figure, these are formed on the back surface of the orbiting scroll 2 and these chambers 42, The orbiting scroll 2 may be pressed against the fixed scroll 1 by the back pressure load based on 40 and 43.

[0003]

In this type of scroll compressor, the compression gas in the middle of compression is introduced into the back pressure chamber 40 from the closed space 24. Since the volume in the closed space 24 is increased / decreased in accordance with the swirling motion, the internal pressure is changed. Therefore, the pressure in the back pressure chamber 40 communicating with the closed space 24 through the pressure guiding hole 41 is also fluctuated, so that a stable back pressure load cannot be applied to the fixed scroll 1, and the fixed scroll is not fixed. 1, the back pressure load applied to the compressor 1 becomes excessive and the required power of the compressor increases, and conversely, the back pressure load applied to the fixed scroll 1 becomes too small and gas leaks from the enclosed space 24. There are problems such as.

The present invention has been proposed in view of the above circumstances, and an object thereof is to provide a high-performance scroll type fluid machine capable of preventing gas from leaking from a sealed space formed between both scrolls. To do.

[0005]

[Means for Solving the Problems]

 To this end, the present invention forms a closed space by meshing a fixed scroll and an orbiting scroll, in which spiral wraps are erected on the inner surface of each end plate, with each other to form a closed space. In the scroll compressor in which the fluid pressure introduced from the enclosed space into the back pressure chamber formed on the side is pressed toward the fixed scroll or the orbiting scroll, An on-off valve that opens and closes the pressure guide hole based on a pressure difference from the back pressure chamber is provided.

[0006]

[Action]

 With this configuration, when the pressure in the closed space rises with the orbiting motion of the orbiting scroll and the pressure in the closed space is higher than the pressure in the back pressure chamber, the on-off valve opens. As a result, the pressure guiding hole is opened, and the back pressure chamber rises to the same pressure as the maximum pressure reached by the closed space. On the other hand, when the pressure in the closed space is lower than the pressure in the back pressure chamber, the on-off valve is closed and the pressure guiding hole is closed. Therefore, once the back pressure chamber rises to the maximum pressure, it is disconnected from the closed space, and thereafter, the pressure state is maintained without being affected by the pressure fluctuation in the closed space, and the pressure fluctuation in the back pressure chamber is maintained. Becomes substantially zero.

[0007]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial vertical cross-sectional view showing a main part of a scroll compressor. In the above figure, the back pressure chamber 40 is provided with an opening / closing valve including a plate valve 91 and a cover 92. That is, a disc-shaped plate valve 91 is placed on the opening surface of the pressure guiding hole 41 facing the back pressure chamber 40, and a cover 92 that covers the plate valve 91 with a gap is attached. A through hole 93 communicating with the back pressure chamber 40 is formed in the cover 92. Therefore, the plate valve 91 is moved up and down based on the pressure difference between the closed space 24 and the back pressure chamber 40 to open or close the pressure guiding hole 41. Other configurations are similar to those of the conventional one shown in FIG. 2, and corresponding members are designated by the same reference numerals. Then, as the orbiting scroll 2 revolves around the space, the sealed space 24 decreases in volume and the internal pressure rises, and becomes higher than the pressure in the back pressure chamber 40. The pressure difference causes the plate valve 91 to float and the pressure guide hole 41 to open. This causes the back pressure chamber 40 to rise to the same pressure as its maximum pressure reached by the enclosed space 24. On the other hand, in a pressure state in which the closed space 24 is lower than the back pressure chamber 40, the plate valve 91 is pressed against the opening by the pressure difference between the closed space 24 and the back pressure chamber 40, and the pressure guiding hole 41 is closed. Thus, once the back pressure chamber 40 rises to the maximum pressure, it is disconnected from the closed space 24, and thereafter, the pressure state is maintained without being affected by the pressure fluctuation in the closed space 24. The pressure fluctuation in the chamber 40 is suppressed.

According to such a structure, since the on-off valve that opens and closes the pressure guide hole based on the pressure difference between the closed space and the back pressure chamber is provided, the back pressure chamber once has the same pressure as the maximum pressure of the closed space. When the temperature rises to 0, the on-off valve automatically closes and is shut off from the closed space, so that the pressure state can be maintained without being affected by the pressure fluctuations in the closed space. As a result, the fixed scroll Alternatively, a stable back pressure load can be applied to the orbiting scroll.

In short, according to the present invention, the fixed scroll or the orbiting scroll in which spiral wraps are erected on the inner surface of each end plate is meshed with each other to form a closed space, and the fixed scroll or the orbiting scroll is formed. In a scroll-type compressor in which the fluid pressure introduced from the closed space through the pressure guide hole into the back pressure chamber formed on the back side of the cylinder is pressed toward the fixed scroll or the orbiting scroll, By providing an on-off valve that opens and closes the pressure guide hole based on the pressure difference between the closed space and the back pressure chamber, it is possible to prevent gas leakage from the closed space formed between both scrolls. The present invention is extremely advantageous industrially because a scroll type fluid machine is obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of the present invention.

FIG. 2 is an overall vertical cross-sectional view showing a conventional scroll compressor.

[Explanation of symbols]

 1 Fixed scroll 2 Orbiting scroll 9 Open / close valve 11 End plate 12 Wrap 21 End plate 22 Wrap 24 Sealed space 40 Back pressure chamber 41 Pressure guide hole 91 Plate valve 92 Cover

Claims (1)

[Claims for utility model registration] [Claim 1] A fixed scroll formed by vertically arranging spiral wraps on the inner surface of each end plate and an orbiting scroll are meshed with each other to form a closed space. Alternatively, in a scroll type fluid machine in which the orbiting scroll is pressed toward the fixed scroll or the orbiting scroll by the fluid pressure introduced from the closed space through the pressure guiding hole into the back pressure chamber formed on the back side thereof. A scroll-type fluid machine comprising an opening / closing valve for opening / closing the pressure guide hole based on a pressure difference between the closed space and the back pressure chamber.