KR20100097022A - Scroll fluid machine - Google Patents

Abstract

PURPOSE: A scroll type fluid machine is provided to ensure the airtightness of a compression chamber by controlling the capacity according to an operating condition with a simple structure. CONSTITUTION: A scroll type fluid machine comprises an operating chamber, a sucking space, a back pressure area, and a back pressure control mechanism(19). A rotating scroll(3) and a non-rotating scroll(2) are engaged to form the operating chamber. The sucking space is formed on the end plate of the non-rotating scroll. The back pressure area is formed in the non-operating chamber of at least one of the rotating scroll and the non-rotating scroll. The back pressure control mechanism controls the pressure of the back pressure back area. The capacity is controlled by the bypassing of the operating chamber and the sucking space by the back pressure control mechanism according to an operating condition.

Description

Scroll Fluid Machine {SCROLL FLUID MACHINE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to scroll fluid machines and, for example, to scroll fluid machines suitable for scroll compressors, scroll vacuum pumps, scroll blowers, etc., for handling compressed gases or liquids, such as refrigerants, in the working fluid.

As a conventional scroll fluid machine, there is one disclosed in Japanese Patent Application Laid-Open No. 2000-314382 (Patent Document 1).

This scroll fluid machine is equipped with an operating chamber formed by interlocking swing scrolls and non-swivel scrolls, each of which is provided with a spiral wrap on each base plate (end plate), an electric motor comprising a stator (stator) and a rotor (rotor), and a rotor. It has a shaft that passes through and transmits the rotational force of the rotor. The swinging scroll is pivoted about the non-orbiting scroll while being rotated by the rotation preventing mechanism. The working fluid introduced into the working chamber from the suction port formed in the non-orbiting scroll gradually reduces the volume of the operating chamber with the rotational movement of the shaft, compresses the working fluid, discharges from the discharge port formed in the non-orbiting scroll, It is sent from the discharge pipe installed in the casing to the refrigeration cycle connected with the scroll fluid machine.

In addition, during the compression operation, the force in the direction of avoiding each other acts on the swinging scroll and the non-orbiting scroll by the increased pressure in the operating chamber, thereby inhibiting the sealing of the operating chamber and increasing the leakage loss of the working fluid. Therefore, in order to maintain the sealing property of a working chamber well and to suppress the leakage of a working fluid, the back pressure which is the bearing force of the direction which mutually approaches each other is applied to at least one of a turning scroll and a non-swing scroll. The back pressure has an appropriate value according to each operating condition.If the back pressure is too low, the leakage loss is increased. If the back pressure is excessive, the friction loss generated on the sliding surface due to the pressure welding of the swing scroll and the non-orbit scroll is increased. This is a factor that deteriorates the efficiency and reliability of the scroll fluid machine.

On the other hand, the operation mode of the refrigeration cycle is diversified, and the scroll fluid machine is required to further expand the operating range. However, the scroll fluid machine has a constant set compression ratio and displacement, which are determined by the specifications of the scroll wrap regardless of the load variation such as the discharge pressure and the suction pressure of the refrigerating cycle. Thus, for example, a release valve mechanism or the like in which the operating chamber and the discharge space communicate with each other is provided in the end plate of the non-orbiting scroll, so that an extra compression operation is not performed even if the operating conditions are lower than or equal to the set compression ratio. In addition, an inverter is controlled to control the electric motor for driving the scroll fluid machine, and the rotation speed of the electric motor is varied, thereby ensuring a proper amount of circulation of the working fluid to be supplied to the refrigeration cycle even under a constant amount of pressure. In addition, by bypassing the working fluid during the compression or after the completion of the compression to the suction space, there is also a means for reducing the apparent amount of pressure suppressant and controlling the capacity.

In addition, in order to achieve high efficiency and high reliability of the scroll fluid machine, the back pressure, which is excessively large compared to that in normal operation, is reduced at the time of capacity control by bypassing the operating chamber and the suction pipe to reduce the amount of external pressure. It is necessary to prevent the increase of the loss. In Patent Document 1, as a method, the capacity control pipe 81 branched from the suction pipe 71 and the discharge pipe 72 is connected to the bypass valve 15 which communicates with an operating chamber provided in the end plate of the non-orbiting scroll. The structure is connected. At the same time, the capacity control pipe is connected to the valve body rear surface of the back pressure control valve 13. Here, the capacity control pipe is provided with a three-way valve 80 or the like for switching between normal operation and capacity control, and is electrically controlled by a control signal generated outside the compressor in accordance with the operating conditions of the refrigeration cycle. .

During normal operation, the capacity control pipe 81 connected to the bypass valve 15 or the back pressure control valve 13 communicates with the discharge pipe by the three-way valve 80 to obtain a high pressure discharge pressure and bypasses the bypass. The valve does not open and does not control the capacity. Moreover, the spring force of the back pressure control valve 13 becomes high, and a back pressure is adjusted comparatively high. On the other hand, during the capacity control, the inside of the capacity control pipe 81 connected to the bypass valve 15 and the back pressure control valve 13 communicates with the suction pipe 71 by the three-way valve 80 and the low pressure suction pressure. The bypass valve 15 is opened, and the capacity is controlled by returning the working fluid during compression into the suction pipe 71. In addition, the spring force of the back pressure control valve 13 is lowered, and the back pressure is adjusted relatively low.

As another scroll fluid machine, there is one disclosed in Japanese Patent No. 4044793 (Patent Document 2). This scroll fluid machine contributes to high efficiency by reducing dead volume of the bypass hole for volume control. In addition, vibration of the valve body is suppressed by introducing a discharge pressure passing through a narrow passage into the back of the capacity control valve.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2000-314382 [Patent Document 2] Japanese Patent No. 4044793

However, in the conventional scroll fluid machine disclosed in Patent Document 1, it is necessary to connect a suction pipe, a discharge pipe, a capacity control pipe, and a back pressure control pipe to a pipe, which leads to a complicated structure, an increase in the number of parts, and an increase in manufacturing cost. There is a task to do. In addition, since the working fluid passes through a three-way valve or the like controlled by an electric control signal from a pipe in which the branching fluid flows or from the outside of the scroll fluid machine, there is a problem that a response response of control occurs. In addition, there is a problem that pressure loss or heating occurs in the piping, which hinders high efficiency of the scroll fluid machine.

In the conventional scroll fluid machine disclosed in Patent Document 2, there is a problem that there is no description of back pressure control, and a means for performing back pressure control simultaneously with capacity control is not disclosed.

The object of the present invention is to automatically control the capacity according to the operating conditions, and to avoid the need for complicated branch piping and the like, thereby significantly reducing the manufacturing cost, and simultaneously performing the capacity control and the back pressure control with excellent responsiveness. To provide a scroll fluid machine.

The present invention for achieving the above object is an operating chamber formed by interlocking a swinging scroll and a non-orbiting scroll in which a spiral wrap is provided on each end plate, a suction space formed on the end plate of the non-orbiting scroll, In the scroll fluid machine provided with the back pressure area | region formed in the at least one semi-operation chamber side of the said rotating scroll or the non-orbiting scroll, and the back pressure control mechanism which controls the pressure of the said back pressure area | region,

The back pressure control mechanism controls the capacity by bypassing the operating chamber and the suction space in accordance with an operating condition.

Further, in the scroll fluid machine described above, the back pressure control mechanism controls the back pressure by bypassing the back pressure region and the suction space in accordance with the operating conditions, and at the same time the volume control operation of the fluid machine. And a movable valve portion for controlling the capacity by bypassing the operating chamber and the suction space.

In the scroll fluid machine described above, the movable valve portion is made of a magnetic substance, and the member which limits the movable range of the movable valve portion is made of a permanent magnet.

The present invention is also characterized in that in the scroll fluid machine, the back pressure control mechanism is controlled by an electrical signal.

In addition, the present invention is a working chamber formed by interlocking a swinging scroll and a non-orbiting scroll in which a spiral wrap is formed on each end plate, a suction space formed on an end plate of the non-orbiting scroll, and the swinging scroll or a non-orbiting. A scroll fluid machine comprising a back pressure region formed on at least one side of a reaction chamber of a scroll, and a back pressure control mechanism for controlling the pressure in the back pressure region,

And a capacity control mechanism for controlling the capacity by bypassing the operating chamber and the suction space according to the operating conditions, wherein the back pressure is controlled by the capacity control mechanism during the capacity control operation of the fluid machine.

Further, in the scroll fluid machine described above, the capacity control mechanism controls the back pressure by bypassing the back pressure region and the suction space according to the operating conditions, and at the same time the volume control operation of the fluid machine. And a movable valve portion for controlling the capacity by bypassing the operating chamber and the suction space.

In the scroll fluid machine, the present invention is characterized in that the movable valve portion is made of a magnetic material, and the member which limits the movable range of the movable valve portion is made of a permanent magnet.

The present invention is also characterized in that in the scroll fluid machine, the capacity control mechanism is controlled by an electrical signal.

In the scroll fluid machine described above, the swirl fluid wrap end angle of either the vortex scroll or the non-orbit scroll is different from the other vortex wrap end angle. It is done.

In addition, the present invention forms an operating chamber by interlocking swing scrolls and non-orbiting scrolls provided with a spiral wrap on each end plate, and a rear pressure region is provided on at least one side of the swing scrolls or non-orbit scrolls. An excitation scroll compressor, in which a compression chamber and a suction space are bypassed at the time of capacity control, and a capacity control mechanism is provided for reducing the apparent amount of pressure suppression by delaying compression start without immediately compressing the gas sucked into the compression chamber. The back pressure is simultaneously controlled by the capacity control mechanism.

According to the scroll fluid machine of the present invention, the capacity can be controlled in accordance with the operating conditions with a simple structure, and the back pressure can be provided to suppress the sliding friction loss while ensuring the tightness of the compression chamber.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the compression mechanism of the scroll compressor in 1st Embodiment of this invention.
2 is a cross-sectional view of the entire scroll compressor according to the first embodiment of the present invention.
3 is an enlarged view of a back pressure control mechanism in normal operation in the first embodiment of the present invention.
Fig. 4 is an enlarged view of the back pressure control mechanism at the time of capacity control in the first embodiment of the present invention.
5 is an enlarged view of a capacity control mechanism in normal operation in the second embodiment of the present invention.
6 is an enlarged view of a capacity control mechanism at the time of capacity control in the second embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, several embodiment of this invention is described using drawing. The same code | symbol in the drawing of each embodiment shows the same or equivalent. However, this invention is not limited to the following embodiment. In addition, it is not the meaning which limits the range of this invention only to those embodiment, unless it mentions specially limited, and is only a mere illustrative example.

(1st embodiment)

The scroll compressor 100 of the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. First, the scroll compressor 100 will be described with reference to FIGS. 1 and 2. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the compression mechanism of the scroll compressor in 1st Embodiment of this invention. 2 is a cross-sectional view of the entire scroll compressor.

The scroll compressor 100 has a structure in which a compression mechanism for performing a compression operation and a drive mechanism including an electric motor are accommodated in the sealed casing 1 and arranged.

The compression mechanism is based on the non-orbiting scroll 2, the orbiting scroll 3, and the frame 4 as basic elements. The non-orbiting scroll 2 and the orbiting scroll 3 are engaged to form the compression chamber 20.

The non-orbiting scroll 2 has the end plate 2a and the vortex wrap 2b standing up on this end plate 2a as a basic component part. The suction port 2c is formed in the outer peripheral part of this end plate 2a. The suction pipe 16 is connected to the suction port 2c. The discharge port 2d is formed in the center part of the end plate 2a. Moreover, the release valve mechanism 14 is provided in the end plate 2a, and the compression chamber 20 and the discharge space 17 communicate with each other at the time of operation | movement below a fixed predetermined compression ratio determined by the specification of a scroll wrap. .

On the other hand, the revolving scroll 3 comprises an end plate 3a, a spiral wrap 3b standing up on the end plate 3a, and a boss tube 3c standing up on the back side of the end plate 3a. It is a basic component part. The turning bearing 3d is provided in the boss cylinder 3c.

The frame 4 is fixed to the closed casing 1 by welding or the like. The non-orbiting scroll 2 is fixed to the frame 4 with a bolt or the like. The swing scroll 3 is pivotally disposed between the non-orbit scroll 2 and the frame 4. The frame 4 forms the back pressure chamber 13 which is the back pressure area 23 in the back side of the revolving scroll end plate 3a. Moreover, the back pressure control mechanism 19 is provided in the non-orbiting scroll end plate 2a, and the back pressure of the back pressure chamber 13 is adjusted between a discharge pressure and a suction pressure at the time of operation.

The swinging scroll 3 is pressed toward the non-orbiting scroll 2 side by the back pressure of the back pressure chamber 13 at the time of operation, and the sealing property of the compression chamber 20 becomes high. Here, the bypass hole 22 in which the back pressure control mechanism 19 and the compression chamber 20 communicate is formed in the non-orbiting scroll end plate 2a so that the capacity can be controlled in accordance with the operating conditions.

The drive mechanism for pivoting the swing scroll 3 includes an electric motor 21 as an example of the rotation drive means, a shaft 7, an Oldham ring 8 which is a main component of the rotation prevention mechanism of the swing scroll 3, A main bearing 9 rotatably engaging the upper portion of the shaft 7, a swivel bearing 3d movable in the rotational axis direction and rotatably engaging the eccentric portion of the shaft 7, and the shaft 7. The sub-bearing part 11 which rotatably couples the lower part of it is made into a basic element. The sliding parts of the shaft 7 correspond to parts of the main bearing 9, the swing bearing 3d, the sub bearing 11, and the like of the shaft 7.

The electric motor 21 is comprised with the induction motor etc., and consists of the annular stator 5 and the annular rotor 6. The stator 5 is fixed to the closed casing 1 by shrinkage fitting or the like. The rotor 6 is arrange | positioned rotatably in the stator 5. On the upper and lower end faces of the rotor 6, a balance weight 12 is provided which is a balanced part for canceling the imbalance force caused by the movement of the revolving scroll 3 to keep the vibration of the compressor low.

The electric motor 21 and the compression mechanism are arranged side by side in the longitudinal direction of the hermetic casing 1, and are connected by the shaft 7. The frame 4 is disposed between the electric motor 21 and the compression mechanism. The shaft 7 is provided through the rotor 6 of the electric motor 21, and is a cylindrical member which transmits the rotational force of the rotor 6 to a compression mechanism. The upper part of the shaft 7 is rotatably supported by the main bearing 9, the middle part of the shaft 7 penetrates the center of the rotor 6, and the lower part of the shaft 7 is the sub-bearing 11. It is rotatably supported on the shaft. The sub-bearing 11 is provided in order to ensure the stable rotation of the shaft 7.

The Oldham ring 8 is provided in the frame 4. One set of two orthogonal key portions formed on the Oldham ring 8 slides the key groove formed in the frame 4, and the remaining one set is configured on the back side of the turning scroll end plate 3a. Slide the groove.

The main bearing 9 is built in the center of the frame 4. The sub-bearing 11 is built in the center of the sub-bearing member 10. The sub bearing member 10 is arrange | positioned near the oil surface of the lubricating oil 15 by the side of the semi-compression mechanism of the electric motor 21, and is fixed to the airtight casing 1 by welding etc. In addition, the lubricating oil 15 is stored in the lower space in the sealed casing 1. The lower end of the shaft 7 is immersed in the lubricating oil 15.

Next, the basic operation of the scroll compressor 100 will be described. The rotational force is applied to the rotor 6 by the rotating magnetic field generated by the stator 5, and the shaft 7 fixed to the rotor 6 performs the rotation operation with the rotation of the rotor 6. The swinging scroll 3 is movable in the rotational axis direction and is rotatably coupled with the eccentric portion of the shaft 7, and the rotational movement of the shaft 7 is turned by a rotation preventing mechanism such as Oldham ring 8 or the like. It is converted into the turning movement of the scroll 3. The volume of the compression chamber 20 formed by engaging the non-orbiting scroll 2 and the revolving scroll 3 is reduced by the revolving movement of the revolving scroll 3 (compression stroke).

In the compression operation, with the swinging motion of the swinging scroll 3, a working fluid such as a refrigerant is sucked into the compression chamber 20 via the suction pipe 16 and the suction port 2c. The suctioned working fluid flows to the discharge port 2d of the non-orbiting scroll via the compression stroke in the compression chamber 20, and finally through the discharge space 17 in the hermetic casing 1, and finally the discharge pipe 18 Discharged from the outside of the compressor.

In addition, the lubricating oil 15 stored in the lower space in the hermetic casing 1 has a differential pressure between the discharge pressure in the discharge space 17 and the back pressure adjusted between the discharge pressure and the suction pressure in the back pressure chamber 13. After lubricating the turning bearing 3d and the main bearing 9 by the centrifugal force accompanying the rotational operation of the shaft 7, it is supplied to the back pressure chamber 13. Thereafter, the lubricating oil 15 in the back pressure chamber 13 is supplied to the compression chamber 20, discharged together with the working fluid from the discharge port 2d of the non-orbiting scroll, and the discharge space 17 in the sealed casing 1. In the oil is separated. The separated lubricant 15 is stored in the lower space in the hermetic casing 1.

3 and 4, the operation of the back pressure control mechanism in normal operation and in capacity control will be described in detail. 3 is an enlarged view of the back pressure control mechanism in normal operation. 4 is an enlarged view of the back pressure control mechanism at the time of capacity control.

The back pressure control mechanism 19 is provided in the non-orbiting scroll 2, and the back pressure control valve body 19a (movable valve part), the back pressure control spring 19b, the needle 19c (movable valve part), and the elastic body 19d are provided. It is configured by The lower surface of the back pressure control valve body 19a communicates with the back pressure region 23, and the upper surface of the back pressure control valve body 19a communicates with the suction space 24 formed in the non-orbiting scroll end plate 2a. have. The suction space 24 communicates with the suction port 2c. The back pressure control spring 19b is provided between the needle 19c and the back pressure control valve body 19a, and the back pressure control valve body 19a is moved downward by a certain spring force by the elastic force of the back pressure control spring 19b. I'm pressured.

In addition, the pressure of the discharge space 17 is introduced to the upper surface of the needle 19c, the elastic body 19d and the back pressure control spring 19b are compressed to press the needle 19c downward. In the non-orbiting scroll 2 on the side of the needle 19c, a bypass hole 22 communicating with the compression chamber 20 is formed. In addition, a stopper 19e (member restricting the movable range) is provided so that the needle 19c does not protrude out of the non-orbiting scroll 2, or the pressure of the discharge space 17 from the side of the needle 19c. The sealing material may be attached to the side surface of the needle 19c so as not to leak into the bypass hole 22 or the suction space 24.

Here, the back pressure control method will be described. By the back pressure control mechanism 19,

(Force due to back pressure)> (force due to suction pressure) + [elastic force of spring 19b], the back pressure control valve body 19a moves upwards to reduce the back pressure in the back pressure region 23. The back pressure is adjusted by flowing into the suction space 24. That is, at the time of normal operation, the position of the needle 19c is fixed, and the spring length of the back pressure control spring 19b becomes constant,

(Back pressure) = (suction pressure) + [constant value (alpha)] can be automatically controlled. In addition, in normal operation, the bypass hole 22 is closed at the side of the needle 19c, so that the compression chamber 20 and the suction space 24 are not bypassed.

On the other hand, in the operating conditions where capacity control is required, the pressure difference between the discharge pressure and the suction pressure is generally smaller than in normal operation. Therefore, as shown in FIG. 4, the needle 19c is pushed upward using the elastic force of the elastic body 19d and the back pressure control spring 19b at the time of dose control. When the needle 19c is pushed upward, the bypass hole 22 closed at the side of the needle 19c is opened, and the compression chamber 20 and the suction space 24 bypass. Therefore, the compression chamber 20 in which the bypass hole 22 is opened becomes the suction space 24, does not perform a compression operation, and can reduce the amount of external pressure suppression. That is, even in a state where the rotation speed of the compressor is kept constant, the circulation amount of the working fluid is reduced, and the capacity can be controlled.

At the time of capacity control, since a part of the compression chamber 20 does not perform a compression operation | movement, the back pressure required at the time of normal operation | movement will fall significantly. Here, if the back pressure is excessive, the frictional loss occurring on the sliding surfaces of the swinging scroll 3 and the non-orbiting scroll 2 is increased, which deteriorates the efficiency and reliability of the scroll compressor. However, at the time of capacity control, the needle 19c is pushed upward, and the spring length of the back pressure control spring 19b becomes longer than during normal operation, so that the elastic force becomes small, (back pressure) = (suction pressure) + [ Constant value β]. That is, the elastic force determined by the spring length of the back pressure control spring 19b is

{Elastic force at normal operation [constant value (α)]}> {elastic force at constant capacity [constant value (β)]}, and the back pressure during capacity control is considerably lower than during normal operation. Can be controlled.

In addition, by making the needle 19c in the back pressure control mechanism 19 into a magnetic substance and making the stopper 19e a permanent magnet having a constant magnetic force, the needle 19c is stopped by a magnetic force when the operating condition is normal. 19e), the needle 19c may be prevented from vibrating up and down with pulsation such as discharge pressure, and may not generate noise.

As described above, according to the present embodiment, the function of opening and closing the capacity control bypass hole is added to the back pressure control mechanism, and the back pressure is automatically controlled while the bypass hole is closed during normal operation, so that the loss of the compression chamber is lost. (While ensuring good sealability of the compression chamber), the bypass hole is opened during capacity control to reduce the amount of external pressure suppression and to automatically control the capacity, while automatically controlling the back pressure to lower the turning scroll and Friction loss occurring on the sliding surface of the non-orbiting scroll can be suppressed to improve the efficiency and reliability of the scroll compressor.

In addition, according to the present embodiment, since it is a simple structure that does not require complicated piping or the like, an increase in manufacturing cost is suppressed, control responsiveness is excellent, and pressure loss and heating during capacity control are suppressed and high efficiency is achieved. Can get a scroll compressor.

In addition, in this embodiment, although the means which controls mechanically the back pressure control and the capacity control automatically according to operation conditions was described, in order to respond to a special operation condition, an electrical control valve (not shown) is attached to a back pressure control mechanism. You may have to. In the case of this electrical control, it can respond quickly and easily at the time of a change of an operating condition.

(2nd embodiment)

A second embodiment of the present invention will be described with reference to FIGS. 5 and 6. 5 and 6 are structures in which the capacity control mechanism is separate from the back pressure control mechanism. Although the back pressure control mechanism is not shown in FIG. 5 and FIG. 6, a back pressure control mechanism having a function of adjusting the back pressure as described in the first embodiment is provided. Alternatively, the needle 19c of the back pressure control mechanism 19 is fixed by press-fitting or the like, the spring length of the back pressure control spring 19b is made constant, and the sealability of the compression chamber 20 is maintained under all operating conditions in which the flow rate is not controlled. The back pressure control mechanism is set to set (back pressure) = (suction pressure) + (constant value) to sufficiently secure the pressure. Alternatively, a hole in which the back pressure chamber 13 and the compression chamber 20 communicate is formed in the end plate 3a of the swinging scroll 3 without using the valve as described in the first embodiment, You may use the back pressure control mechanism adjusted to pressure) = (suction pressure) x (constant value).

5 is a capacity control mechanism in normal operation in the second embodiment of the present invention. The capacity control mechanism 25 is provided on the non-orbiting scroll 2 separately from the back pressure control mechanism, and the capacity control valve body 25a (the movable valve section), the capacity control spring 25b, and the needle 25c (the movable valve) A) and an elastic body 25d. The capacity control valve body 25a has a projection shape that substantially fills the bypass hole 22 communicating with the compression chamber 20 provided in the non-orbiting scroll 2. In addition, the capacity control valve body 25a has a tip shape that does not protrude into the compression chamber 20. One side of the capacity control valve body 25a is in the bypass hole 22 and communicates with the compression chamber 20, and the other side is the suction space 24 formed in the non-orbiting scroll end plate 2a. In communication with A capacity control spring 25b is provided between the needle 25c and the capacity control valve body 25a, and the capacity control valve body 25a is compressed at a certain spring force by the elastic force of the capacity control spring 25b. Stressed.

In addition, the pressure of the discharge space 17 is introduced to one surface of the needle 25c to compress the elastic body 25d and the capacity control spring 25b to press the needle 25c toward the compression chamber side. The non-orbiting scroll end plate 2a on the side of the needle 25c communicates with the back pressure region 23. In addition, a stopper 25e is provided so that the needle 25c does not protrude to the outside of the non-orbiting scroll 2, or the pressure of the discharge space 17 from the side surface of the needle 25c is reduced in the back pressure region 23 or The sealing material may be attached to the side surface of the needle 25c so as not to leak into the suction space 24.

In normal operation, the position of the needle 25c is pressed and fixed to the compression chamber side. Therefore, the capacity control spring 25b is strongly compressed, the bypass hole 22 is sealed, and capacity control is not performed. In addition, the bypass hole 22, the suction space 24, the back region 23, and the discharge space 17 are each sealed to the side surface of the capacity control valve body 25a or the needle 25c and do not communicate with each other.

On the other hand, in the operating conditions in which capacity control is required, the pressure difference between the discharge pressure and the suction pressure is generally smaller than in normal operation. Therefore, as shown in FIG. 6, the needle 25c is moved to the half compression chamber side by using the elastic force of the elastic body 25d at the time of dose control. When the needle 25c moves to the half compression chamber side, the capacity control spring 25b becomes a natural length, and the capacity control valve body 25a is separated from the bypass hole 22, so that the compression chamber 20 and the suction space. 24 bypasses. Therefore, the internal space of the compression chamber 20 in which the bypass hole 22 is opened becomes the suction space 24, does not perform a compression operation, and can reduce the amount of external pressure suppression. That is, even in the state where the rotation speed of the compressor is kept constant, the circulation amount of the working fluid is reduced, so that the capacity can be controlled.

Since a part of the compression chamber 20 does not perform a compression operation at the time of capacity control, the back pressure required at the time of normal operation is significantly reduced. Here, if the back pressure is excessive, frictional losses occurring on the sliding surfaces of the swinging scroll 3 and the non-orbiting scroll 2 are increased, thereby deteriorating the efficiency and reliability of the scroll compressor. However, at the time of dose control, the needle 25c moves to the half compression chamber side, and the back pressure region 23 and the suction space 24 communicate with each other to lower the back pressure to the suction pressure. Alternatively, a back pressure adjustment groove 25f is formed in a part of the needle 25c, and with the movement of the needle 25c (in the middle of the movement), the back pressure adjustment groove 25f intermittently moves to the back pressure region 23. By communicating, back pressure can be adjusted to a certain target value.

In addition, the needle 25c in the capacity control mechanism 25 is a magnetic material, and the stopper 25e (member limiting the movable range) is a permanent magnet having a constant magnetic force. ) May be sucked by the stopper 25e by the magnetic force, and the needle 25c may suppress the vibration by accompanying the pulsation such as the discharge pressure and may not generate noise.

As described above, according to the present embodiment, by the capacity control mechanism provided separately from the back pressure control mechanism, the back pressure is controlled by the back pressure control mechanism while the bypass hole is almost completely sealed and the invalid volume is eliminated during normal operation. Automatic control, bypassing the compression chamber and suction chamber during volume control, reducing the amount of pressure suppression on the outside, automatically controlling the capacity, and automatically controlling the back pressure low to generate on the sliding surface of the swing scroll and non-orbit scroll By suppressing frictional losses, it is possible to improve the efficiency and reliability of the scroll compressor.

Moreover, according to this embodiment, a function can be added only by adding a capacity control mechanism, the operation | work which embeds a capacity control mechanism in the existing back pressure control mechanism, etc. becomes unnecessary, and specification change is easy. In addition, according to the present embodiment, since it is a simple structure that does not require complicated piping or the like, an increase in manufacturing cost is suppressed, control responsiveness is excellent, and pressure loss and heating during capacity control are suppressed and high efficiency is achieved. Can get a scroll compressor.

In addition, in this embodiment, the means for automatically controlling the capacity control in accordance with the operating conditions has been described. However, an electric control valve (not shown) may be attached to the capacity control mechanism in order to cope with the special operating conditions. In the case of this electrical control, it can respond quickly and easily at the time of a change of an operating condition.

Moreover, in another embodiment and this embodiment, with respect to the swirl wrap shape of the swing scroll and the non-orbit scroll, the swirl wrap end angle of either the swing scroll or the non-orbit scroll is different from the other swirl wrap end angle. The present embodiment may be used in a scroll fluid machine having a different asymmetrical swirl wrap. Thereby, it can respond to the scroll fluid machine of various specifications.

1: hermetic casing
2: non-orbiting scroll
2a: end plate
2b: wrap
2c: inlet
2d: discharge port
3: turning scroll
3a: end plate
3b: wrap
3c: boss
3d: slewing bearing
4: frame
5: stator
6: rotor
7: shaft
8: Oldham Ring
9: main bearing
10: bearing member
11: buoy bearing
12: balance weight
13: back pressure chamber
14: release valve mechanism
15: lubricant
16: suction pipe
17: discharge space
18: discharge pipe
19: back pressure control mechanism
19a: Back pressure control valve body (moving valve part)
19b: spring for back pressure control
19c: needle (operating valve section)
19d: elastomer
19e: stopper (members limiting the operating range)
20: compression chamber
21: electric motor
22: bypass hole
23: back pressure area
24: suction space
25: capacity control mechanism
25a: Valve body for capacity control (moving valve part)
25b: spring for capacity control
25c: Needle (operating valve part)
25d: elastomer
25e: stopper (member limiting the operating range)
25f: Back pressure adjusting groove
100: scroll compressor

Claims (9)

At least one of the operating chamber formed by interlocking the swinging scroll and the non-orbiting scroll which are provided with the spiral wrap on each end plate, the suction space formed in the end plate of the non-orbiting scroll, and the at least one of the orbiting scroll or the non-orbiting scroll. In the scroll fluid machine provided with the back pressure area | region formed in the reaction chamber side, and the back pressure control mechanism which controls the pressure of the said back pressure area | region,
And the back pressure control mechanism bypasses the operating chamber and the suction space in accordance with an operating condition to control the capacity. The back pressure control mechanism controls the back pressure by bypassing the back pressure region and the suction space according to an operating condition, and at the same time, bypasses the operation chamber and the suction space during the volume control operation of the fluid machine. A scroll fluid machine, comprising: a movable valve portion for passing and controlling a capacity. The scroll fluid machine according to claim 2, wherein the movable valve portion is made of magnetic material, and the member limiting the movable range of the movable valve portion is made of a permanent magnet. The scroll fluid machine according to any one of claims 1 to 3, wherein the back pressure control mechanism is controlled by an electrical signal. At least one of the operating chamber formed by interlocking the swinging scroll and the non-orbiting scroll which are provided with the spiral wrap on each end plate, the suction space formed in the end plate of the non-orbiting scroll, and the at least one of the orbiting scroll or the non-orbiting scroll. In the scroll fluid machine provided with the back pressure area | region formed in the reaction chamber side, and the back pressure control mechanism which controls the pressure of the said back pressure area | region,
And a capacity control mechanism for controlling the capacity by bypassing the operating chamber and the suction space according to the operating conditions, wherein the back pressure is controlled by the capacity control mechanism during the capacity control operation of the fluid machine. Scroll fluid machine. 6. The displacement control mechanism according to claim 5, wherein the dose control mechanism bypasses the back pressure region and the suction space in accordance with an operating condition to control the back pressure, and at the same time, bypasses the operation chamber and the suction space during the volume control operation of the fluid machine. A scroll fluid machine, comprising: a movable valve portion for passing and controlling a capacity. The scroll fluid machine according to claim 6, wherein the movable valve portion is made of magnetic material, and the member limiting the movable range of the movable valve portion is made of a permanent magnet. The scroll fluid machine according to any one of claims 5 to 7, characterized in that the dose control mechanism is controlled by an electrical signal. The vortex wrap end angle of any one of Claims 1, 2, 3, 5, 6, or 7 of a swivel scroll or a non-swivel scroll, Scroll fluid machine, characterized by the use of an asymmetrical vortex wrap with a different vortex wrap end angle.

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