Variable displacement compressor and air-conditioning system

Abstract

The present application provides a variable displacement compressor and an air conditioning system. The variable displacement compressor includes a housing assembly (1) and a pump body assembly disposed within the housing assembly (1). The pump body assembly includes a cylinder, a roller, a flange, and a sliding vane. A sliding vane groove (91) is provided on the cylinder, and the sliding vane is slidably disposed within the sliding vane groove (91). A pin hole is provided on the flange, and a pin (15) is disposed within the pin hole. The pin hole communicates with the tail cavity (92) of the sliding vane groove (91) on the side of the pin (15) close to the sliding vane, and the pin hole communicates with the high-pressure side of the housing assembly (1) on the side of the pin (15) away from the sliding vane. The tail cavity (92) is connected to a switching pipeline (21), and the switching pipeline (21) can switch the refrigerant pressure within the tail cavity (92). The variable displacement compressor further includes a reset structure that can apply a force to the pin (15) away from the sliding vane. According to the variable displacement compressor of the present application, a dual-cylinder or multi-cylinder starting mode of the compressor can be achieved, and the temperature adjustment speed after the air conditioner is turned on can be increased.

Description

Technical Field

[0001] This application relates to the technical field of compressors, and particularly to a variable displacement compressor and an air-conditioning system. Background Art

[0002] In order to adjust the capacity output according to the load demand in an air-conditioning system, most of them apply variable-frequency compressors, and the compressor can adjust the capacity output by adjusting the compressor frequency. When the load of the air-conditioning system is too small, it is necessary to continuously reduce the frequency of the compressor. However, due to the limitation of the minimum operating frequency of the compressor, the minimum cooling capacity that the compressor can output is limited. Therefore, when the system load is less than the minimum capacity that can be output when the compressor operates at the lowest frequency, the compressor will frequently start and stop, resulting in high power consumption of the compressor. At the same time, when the compressor frequency is too low, the volumetric efficiency and motor efficiency of the compressor are low, resulting in low energy efficiency during low-frequency operation of the compressor.

[0003] Currently, this problem is generally solved by adopting a variable-frequency and variable-displacement method, that is, the compressor adopts a double-cylinder structure, and by adding a switching structure, the compressor can operate in two modes: single-cylinder and double-cylinder. The double-cylinder is used under large loads, and the single-cylinder is used under small loads. To achieve this function, the slide groove of the variable-displacement cylinder needs to be sealed so as to introduce high pressure or low pressure into the slide groove to control the movement of the slide.

[0004] When an existing variable displacement compressor is applied in an air-conditioning system, it can only start in the single-cylinder mode, and after the suction and discharge pressure difference is established, the discharge high pressure is introduced into the tail of the slide groove to switch to double-cylinder operation. The problem with this mode is that when the air conditioner is heating at low temperature, due to the small displacement of the single-cylinder start of the compressor, the time for the entire air-conditioning system to establish the pressure difference is long and it is difficult to push the four-way valve. This causes no warm air to appear in the indoor unit (not heating) for a long time after the air conditioner is turned on. Only after the system establishes the suction and discharge pressure difference and switches to double-cylinder operation, will the air-conditioning system quickly have warm air appear, resulting in a slow heating speed and low heating efficiency after the air conditioner is turned on. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this application is to provide a variable displacement compressor and an air-conditioning system, which can realize the double-cylinder or multi-cylinder start mode of the compressor and improve the temperature adjustment speed after the air conditioner is turned on.

[0006] To solve the above problems, the present application provides a variable displacement compressor, which includes a housing assembly and a pump body assembly disposed within the housing assembly. The pump body assembly includes a cylinder, a roller, a flange, and a sliding vane. A sliding vane groove is provided on the cylinder, and the sliding vane is slidably disposed within the sliding vane groove. A pin hole is provided on the flange, and a pin is disposed within the pin hole. The pin hole communicates with the tail cavity on the side of the pin close to the sliding vane, and the pin hole communicates with the high-pressure side of the housing assembly on the side of the pin away from the sliding vane. The tail cavity is connected with a switching pipeline, and the switching pipeline can switch the refrigerant pressure within the tail cavity. The variable displacement compressor further includes a reset structure, and the reset structure can apply a force to the pin away from the sliding vane.

[0007] Preferably, the reset structure includes a reset spring.

[0008] Preferably, the pin includes a head close to the sliding vane and a tail away from the sliding vane. An installation step is provided on the head of the pin, and a limiting step is provided at one end of the pin hole close to the sliding vane. The reset spring is disposed between the installation step and the limiting step, and applies a force to the pin away from the sliding vane.

[0009] Preferably, the pin includes a head close to the sliding vane and a tail away from the sliding vane;

[0010] An installation step is provided on the tail of the pin, and a limiting step is provided at one end of the pin hole close to the sliding vane. The reset spring is disposed between the installation step and the limiting step, and applies a force to the pin away from the sliding vane;

[0011] Or,

[0012] One end of the reset spring is fixedly connected to the tail end of the pin, and the other end is fixedly connected to the fixed structure, and applies a force to the pin away from the sliding vane.

[0013] Preferably, the reset structure includes a magnet.

[0014] Preferably, the pin includes a head close to the sliding vane and a tail away from the sliding vane. The magnet is disposed on the fixed structure at the tail of the pin, and the magnet can apply a magnetic suction force to the pin.

[0015] Preferably, the pin includes a head close to the sliding vane and a tail away from the sliding vane;

[0016] A first magnet is provided at one end of the pin hole close to the sliding vane, and a second magnet is provided on the head of the pin. The first magnet can apply a repulsive force away from the sliding vane to the second magnet;

[0017] Or,

[0018] A first magnet is provided on the fixed structure at the tail of the pin, and a second magnet is provided on the head of the pin. The first magnet can apply a suction force away from the sliding vane to the second magnet.

[0019] Preferably, one end of the pin hole away from the sliding vane communicates with the bottom oil sump of the housing assembly, and pressure oil is supplied from the bottom oil sump to the tail of the pin.

[0020] Preferably, the pre-acting force applied by the reset structure to the pin is F(x), the bottom area of the pin is S, the pressure pulsation in the tail cavity is P, and the suction and discharge pressure difference of the compressor required for the single-cylinder operation switching of the variable displacement compressor is P1, where S*P ≤ F(x) ≤ P1*S.

[0021] Preferably, the flange includes a lower flange, a lower cover plate is arranged on the lower flange, the pin hole is opened on the lower flange, and a high-pressure passage is opened on the lower cover plate corresponding to the pin hole.

[0022] According to another aspect of the present application, an air-conditioning system is provided, including a variable displacement compressor, and the variable displacement compressor is the above-mentioned variable displacement compressor.

[0023] Preferably, the variable displacement compressor further includes an evaporator, a throttle valve and a condenser. The condenser is connected to the exhaust port of the variable displacement compressor, the evaporator is connected to the suction port of the variable displacement compressor, the throttle valve is arranged between the evaporator and the condenser, and the switching pipeline can selectively communicate with the exhaust port or the suction port of the variable displacement compressor.

[0024] The variable displacement compressor provided by the present application includes a housing assembly and a pump body assembly arranged in the housing assembly. The pump body assembly includes a cylinder, a roller, a flange and a sliding vane. A sliding vane groove is arranged on the cylinder, the sliding vane can be slidably arranged in the sliding vane groove, a pin hole is arranged on the flange, a pin is arranged in the pin hole, the pin hole communicates with the tail cavity of the sliding vane groove on the side of the pin close to the sliding vane, the pin hole communicates with the high-pressure side of the housing assembly on the side of the pin away from the sliding vane, the tail cavity is connected with a switching pipeline, and the switching pipeline can switch the refrigerant pressure in the tail cavity. The variable displacement compressor further includes a reset structure, and the reset structure can apply a force to the pin away from the sliding vane. The reset structure of the variable displacement compressor can apply a force to the pin away from the sliding vane. Therefore, during the startup process of the variable displacement compressor, the tail cavity of the sliding vane only needs to provide a refrigerant pressure that can make the sliding vane stick tightly to the roller, and the loading work of the variable displacement cylinder can be realized without overcoming the force of the reset structure, so that the variable displacement compressor can realize double-cylinder or multi-cylinder startup without establishing an exhaust pressure difference, reduce the limitation of the variable displacement structure design of the variable displacement compressor, improve the temperature adjustment speed after the air conditioner is turned on, improve the temperature adjustment efficiency, and improve the user experience. Description of the Drawings

[0025] Figure 1 It is a schematic structural diagram of a variable displacement compressor according to an embodiment of the present application;

[0026] Figure 2Schematic structural diagram of a variable displacement compressor according to an embodiment of the present application when the switching pipeline is introduced with exhaust pressure;

[0027] Figure 3 is Figure 1 A-A sectional structural diagram;

[0028] Figure 4 Schematic structural diagram of a variable displacement compressor according to an embodiment of the present application when the switching pipeline is introduced with suction pressure;

[0029] Figure 5 is Figure 1 A-A sectional structural diagram;

[0030] Figure 6 Schematic diagram of the pressure pulsation in the tail cavity of the variable displacement slider of a variable displacement compressor according to an embodiment of the present application at 60 Hz;

[0031] Figure 7 Schematic structural diagram of a variable displacement compressor according to an embodiment of the present application;

[0032] Figure 8 Schematic structural diagram of a variable displacement compressor according to an embodiment of the present application when the switching pipeline is introduced with exhaust pressure;

[0033] Figure 9 is Figure 7 A-A sectional structural diagram;

[0034] Figure 10 Schematic structural diagram of a variable displacement compressor according to an embodiment of the present application when the switching pipeline is introduced with suction pressure;

[0035] Figure 11 is Figure 7 A-A sectional structural diagram.

[0036] The reference numerals are shown as:

[0037] 1. Housing assembly; 2. Motor stator; 3. Motor rotor; 4. Crankshaft; 5. Upper flange; 6. Upper cylinder; 7. Upper roller; 8. Partition; 9. Lower cylinder; 10. Lower roller; 11. Lower flange; 12. Lower cover plate; 13. Lower cover assembly; 14. Return spring; 14a. Magnet; 15. Pin; 16. Lower sliding vane; 17. Upper sliding vane; 18. High-pressure passage; 19. Lower suction pipe; 20. Upper suction pipe; 21. Switching pipeline; 22. First solenoid valve; 23. Second solenoid valve; 24. Evaporator; 25. Throttle valve; 26. Condenser; 27. Upper cover assembly; 28. Distributor assembly; 81. Pressure switching passage; 91. Sliding vane groove; 92. Tail cavity. Detailed Description of the Invention

[0038] With reference toFigures 1 to 11 As shown, according to an embodiment of the present application, a variable displacement compressor includes a housing assembly 1 and a pump body assembly disposed within the housing assembly 1. The pump body assembly includes a cylinder, a piston, a flange, and a sliding vane. A sliding vane groove 91 is provided on the cylinder, and the sliding vane is slidably disposed within the sliding vane groove 91. A pin hole is provided on the flange, and a pin 15 is disposed within the pin hole. The pin hole communicates with the tail cavity 92 of the sliding vane groove 91 on the side of the pin 15 close to the sliding vane, and the pin hole communicates with the high-pressure side of the housing assembly 1 on the side of the pin 15 away from the sliding vane. A switching pipeline 21 is connected to the tail cavity 92, and the switching pipeline 21 can switch the refrigerant pressure within the tail cavity 92. The variable displacement compressor further includes a reset structure that can apply a force to the pin 15 away from the sliding vane.

[0039] The reset structure of this variable displacement compressor can apply a force to the pin 15 away from the sliding vane. Therefore, during the startup process of the variable displacement compressor, only the refrigerant pressure that can make the sliding vane stick tightly to the roller needs to be provided in the tail cavity 92 of the sliding vane to achieve the loading operation of the variable displacement cylinder, without having to overcome the force of the reset structure. This enables the variable displacement compressor to achieve dual-cylinder or multi-cylinder startup without establishing an exhaust pressure difference, reduces the limitations of the variable displacement structure design of the variable displacement compressor, realizes a small series and large displacement design, improves the temperature adjustment speed after the air conditioner is turned on, improves the temperature adjustment efficiency, and improves the user experience.

[0040] In the related art, during the operation of a variable displacement compressor, for a structure that locks or unlocks a sliding vane through a pin, the reset mechanism of the pin generally provides a force to lock the sliding vane. Therefore, if variable displacement operation of the variable displacement compressor is to be achieved, it is necessary to wait until the exhaust pressure is established, and the pressure difference between the exhaust pressure and the suction pressure of the compressor reaches a certain level to overcome the reset force of the reset mechanism before the pin can be driven to move and unlock the sliding vane to achieve dual-cylinder operation of the compressor. This results in problems such as a long system suction and exhaust pressure difference establishment time and slow heating speed in a variable displacement air conditioning system due to the small displacement during single-cylinder startup. However, by using the variable displacement compressor of the embodiment of the present application, the above problems are well overcome, enabling dual-cylinder or multi-cylinder operation of the variable displacement compressor without waiting for the establishment of the exhaust pressure of the compressor, and achieving dual-cylinder or multi-cylinder operation at the initial startup stage of the variable displacement compressor.

[0041] In one embodiment, the reset structure includes a reset spring 14.

[0042] In one embodiment, the pin 15 includes a head portion near the sliding piece and a tail portion away from the sliding piece. The head of the pin 15 is provided with a mounting step, and a limiting step is provided at one end of the pin hole near the sliding piece. The return spring 14 is disposed between the mounting step and the limiting step and applies a force to the pin 15 away from the sliding piece. In this embodiment, by processing the structure of one end of the pin hole near the sliding piece, a limiting step is formed at one end of the pin hole near the sliding piece, which not only facilitates the installation of the return spring 14, but also can prevent the return spring 14 from contacting the sliding piece and affecting the normal operation of the sliding piece. In this embodiment, the return spring 14 is a compression spring.

[0043] In one embodiment, the tail of the pin 15 is provided with a mounting step, a limiting step is provided at one end of the pin hole near the sliding piece, and the return spring 14 is disposed between the mounting step and the limiting step and applies a force to the pin 15 away from the sliding piece. In this embodiment, one end of the return spring is fixedly connected to the mounting step at the tail of the pin 15, and the other end is fixedly connected to the limiting step on the pin hole, which can provide a pulling force to the pin 15 away from the sliding piece. In this embodiment, the return spring 14 is, for example, a tension spring.

[0044] In one embodiment, one end of the return spring 14 is fixedly connected to the tail end of the pin 15, and the other end is fixedly connected to a fixed structure and applies a force to the pin 15 away from the sliding piece. In this embodiment, the return spring 14 is, for example, a tension spring. In this embodiment, one end of the return spring 14 can be fixedly connected to the tail end of the pin 15, and the other end can be fixedly connected to the inner wall of the pin hole, that is, the fixed structure is the inner wall of the pin hole. In other embodiments, the pin hole can also be a through hole as a whole, and other structures can be provided at the end of the flange away from the sliding piece, and this other structure is the above-mentioned fixed structure.

[0045] Since the tension spring provides a tensile force to the pin 15, and no other structure is provided at the end of the pin 15 facing the sliding piece, as long as the pin 15 is pulled by the tension spring, it can be avoided that the pin 15 affects the movement of the sliding piece. Therefore, a through hole can be provided at one end of the pin hole near the sliding piece here, which will not cause any impact on the realization of the function of the pin 15.

[0046] The reset structure includes a magnet 14a.

[0047] In one embodiment, the pin 15 includes a head near the sliding vane and a tail far from the sliding vane. A magnet 14a is disposed on the fixing structure at the tail of the pin 15, and the magnet 14a can apply a magnetic suction force to the pin 15. In this embodiment, the pin 15 can be made of a magnetic material. The magnet 14a can provide a magnetic suction force to the pin 15, so that the pin 15 has a tendency to move towards the magnet 14a, and thus a pre-acting force can be applied to the pin 15 through the magnet 14a. In this embodiment, the fixing structure can be a flange or other structure disposed axially outside the flange.

[0048] In one embodiment, a first magnet is disposed at one end of the pin 15 hole near the sliding vane, and a second magnet is disposed at the head of the pin 15. The first magnet can apply a repulsive force away from the sliding vane to the second magnet. In this embodiment, the material of the pin 15 can be unrestricted. As long as a second magnet is disposed at the head of the pin 15, it can cooperate with the first magnet disposed on the flange to apply a force away from the sliding vane to the pin 15 by using the repulsive force.

[0049] In one embodiment, a first magnet is disposed on the fixing structure at the tail of the pin 15, and a second magnet is disposed at the head of the pin 15. The first magnet can apply a suction force away from the sliding vane to the second magnet. In this embodiment, the material of the pin 15 can be unrestricted. As long as a second magnet is disposed at the head of the pin 15, it can cooperate with the first magnet disposed on the flange to apply a force away from the sliding vane to the pin 15 by using the suction force.

[0050] In this embodiment, the pin hole communicates with the high-pressure side of the housing assembly 1, including at least the following two cases. The first case is that the pin hole directly communicates with the high-pressure inner cavity of the housing assembly 1, so that gaseous refrigerant can be directly introduced into the pin hole to provide a high-pressure effect on the tail of the pin 15. The second case is that the pin hole directly communicates with the oil sump, and high-pressure oil is provided to the pin hole through the oil sump, thereby realizing the provision of a high-pressure effect on the tail of the pin 15.

[0051] In one embodiment, one end of the pin hole far from the sliding vane communicates with the bottom oil sump of the housing assembly 1, and pressure oil is provided from the bottom oil sump to the tail of the pin 15.

[0052] In this embodiment, since the high-pressure oil liquid is always introduced into the pin hole, during the operation of the compressor, the high-pressure oil liquid can be used to play an oil film sealing role on the gap between the pin 15 and the pin hole, thereby reducing the leakage caused by the pressure difference between the head and the tail of the pin 15 and improving the energy efficiency of single-cylinder low-frequency operation.

[0053] In one embodiment, the pre-acting force applied by the reset structure to the pin 15 is F(x), the bottom area of the pin 15 is S, the pressure pulsation in the tail cavity 92 is P, and the suction and discharge pressure difference of the compressor required for the single-cylinder operation switching of the variable displacement compressor is P1. S*P ≤ F(x) ≤ P1*S, so as to effectively prevent the phenomenon that the pin 15 moves up and down due to pressure pulsation during the double-cylinder operation of the variable displacement compressor on the basis of ensuring the effectiveness of the single- and double-cylinder operation switching of the variable displacement compressor.

[0054] In one embodiment, the flange includes a lower flange 11, a lower cover plate 12 is arranged on the lower flange 11, a pin hole is opened on the lower flange 11, and a high-pressure channel 18 is opened on the lower cover plate 12 corresponding to the pin hole, which can conveniently introduce the high-pressure in the housing assembly 1 into the pin hole through the high-pressure channel 18 to provide high-pressure for the tail end of the pin 15.

[0055] In this embodiment, the variable displacement compressor includes a housing assembly 1, a motor stator 2, a motor rotor 3 and a pump body assembly. The housing assembly 1 includes a body in the middle, an upper cover assembly 27 at the top and a lower cover assembly 13 at the bottom. An exhaust pipe is arranged on the upper cover assembly 27. The motor stator 2 is fixed on the inner wall of the housing assembly 1. The motor rotor 3 is fixed on the crankshaft 4 of the pump body assembly and is placed in the inner hole of the motor stator 2. The pump body assembly is welded and fixed on the housing assembly 1. The pump body assembly includes an upper flange 5, a lower flange 11 and a crankshaft 4. An upper cylinder 6 and a lower cylinder 9 are arranged between the upper flange 5 and the lower flange 11. The upper cylinder 6 and the lower cylinder 9 are separated by a partition plate 8 in the middle. Upper rollers 7 and lower rollers 10 are respectively installed in the upper cylinder 6 and the lower cylinder 9. The upper rollers 7 and the lower rollers 10 are respectively sleeved on the upper and lower eccentric parts of the crankshaft 4. Upper sliding vanes 17 and lower sliding vanes 16 are installed in the sliding vane grooves in the upper cylinder 6 and the lower cylinder 9. The heads of the upper sliding vanes 17 and the lower sliding vanes 16 are respectively abutted against the outer diameters of the upper rollers 7 and the lower rollers 10, dividing the volume chambers in their respective cylinders into high-pressure chambers and low-pressure chambers to realize the compression function of the compressor. A lower cover plate 12 is installed on the lower flange 11, and a pin 15 is installed inside the lower flange 11 corresponding to the bottom of the lower sliding vane 16. A reset spring 14 is installed on the head of the pin 15. The reset spring 14 is limited between the upper end of the pin hole and the head of the pin 15. A liquid separator assembly 28 is arranged outside the housing assembly 1. The liquid separator assembly 28 is respectively connected to the suction ports of the upper cylinder 6 and the lower cylinder 9 through an upper suction pipe 20 and a lower suction pipe 19. A lower cover assembly 13 is installed at the bottom of the housing assembly 1, and an upper cover assembly 27 is installed at the upper part, thus forming a sealed cavity.

[0056] In one embodiment, the lower cylinder 9 is a variable displacement cylinder, with a lower roller 10 installed at its inner circle, and a lower sliding vane 16 installed in the sliding vane groove 91 of the lower cylinder 9. To enable the variable displacement compressor to start in a double-cylinder mode with both cylinders, a pin hole is provided at the position of the lower flange 11 corresponding to the lower sliding vane 16. The upper end of the pin hole is a stepped round hole for limiting the return spring 14. This pin hole communicates with the sliding vane groove 91 of the lower cylinder and is used to accommodate the pin 15. Under the combined action of gas force and spring force, the pin 15 can move up and down to achieve the function of locking or unlocking the sliding vane. To achieve this function, it is necessary to seal the sliding vane groove 91 of the lower cylinder and its sliding vane tail cavity 92.

[0057] To enable the up and down movement of the pin 15 to achieve the function of locking or unlocking the lower sliding vane 16, a low pressure or high pressure needs to be introduced into the sliding vane tail cavity 92. Therefore, in this application, a pressure switching channel 81 is provided on the pump body assembly for communicating the sliding vane tail cavity 92 and the external switching pipeline 21.

[0058] According to an embodiment of the present application, the air conditioning system includes a variable displacement compressor, and this variable displacement compressor is the above-mentioned variable displacement compressor.

[0059] In one embodiment, the variable displacement compressor further includes an evaporator 24, a throttle valve 25, and a condenser 26. The condenser 26 is connected to the exhaust port of the variable displacement compressor, the evaporator 24 is connected to the suction port of the variable displacement compressor, the throttle valve 25 is provided between the evaporator 24 and the condenser 26, and the switching pipeline 21 can selectively communicate with the exhaust port or the suction port of the variable displacement compressor.

[0060] When the compressor is running, the upper and lower cylinders suck refrigerant from the liquid distributor assembly 28. The refrigerant enters the cylinder for compression. The compressed high-pressure refrigerant enters the shell cavity and then enters the upper cavity of the motor through the through-hole between the motor stator 2 and the motor rotor 3 and the rotor through-hole. Finally, the refrigerant is discharged from the exhaust pipe of the upper cover assembly 27 out of the compressor and enters the condenser 26 of the air conditioning system. After passing through the throttle valve 25, the refrigerant enters the evaporator 24, and the refrigerant in the evaporator 24 enters the liquid distributor assembly 28 again, thus completing a cycle.

[0061] When the variable displacement compressor starts in a double-cylinder mode or operates in a double-cylinder mode, the upper cylinder 6 of the variable displacement compressor is a continuously compressed cylinder, and the lower cylinder 9 can be divided into two states: unloading or compression. The high-pressure channel 18 at the tail of the pin 15 needs to continuously introduce high-pressure oil. The switching pipeline 21 can be connected to the low-pressure suction through the first solenoid valve 22 or to the high-pressure exhaust through the second solenoid valve 23. To achieve starting in a double-cylinder mode and maintaining the double-cylinder operation of the compressor, that is, the lower cylinder 9 needs to be in a compressed state, the pin 15 inside the pump body needs to be disengaged from the lower sliding vane 16, the second solenoid valve 23 is opened, and the first solenoid valve 22 is closed, as Figure 2 and Figure 3As shown, the exhaust high pressure is introduced into the tail cavity 92 of the sliding vane through the switching pipeline 21. The tail of the pin 15 is always under the exhaust high-pressure oil. The gas pressure at the head of the pin 15 is basically equal to the oil pressure at the tail. At this time, under the action of the elastic force of the return spring 14 and the gravity of the pin 15 itself, the pin 15 is completely pressed into the pin hole and will not contact the lower sliding vane 16. The lower sliding vane 16 fits with the lower roller 10 under the action of the exhaust high-pressure in the tail cavity 92 of the sliding vane, so that the compression of the lower cylinder 9 can be realized, and the compressor can be started in the double-cylinder mode or maintain the double-cylinder operation. Therefore, the double-cylinder starting mode solves the problem of slow heating speed caused by the long time for establishing the suction and exhaust pressure difference in the existing variable-capacity series air-conditioning system due to the small displacement at single-cylinder start-up.

[0062] When the compressor operates in single-cylinder mode, the lower cylinder 9 needs to be in the unloaded state, that is, the pin 15 inside the pump body needs to move upward, and the lower end face of the lower sliding vane 16 is pressed tightly by its head. The upper end face of the lower sliding vane 16 is pressed against the partition plate 8 to generate frictional force to lock the lower sliding vane 16. At this time, the second solenoid valve 23 is closed and the first solenoid valve 22 is opened. As Figure 4 and Figure 5 shown, the low-pressure suction is introduced into the tail cavity 92 of the sliding vane through the switching pipeline 21. The tail of the pin 15 is always under the exhaust high-pressure oil. When the tail cavity 92 is at low pressure, under the action of the high-pressure oil at the tail of the pin 15, the elastic force of the return spring 14 is overcome, and the pin 15 moves upward. Its head presses tightly against the lower end face of the lower sliding vane 16 to lock the lower sliding vane 16. The lower sliding vane 16 is separated from the lower roller 10, and the stable unloaded operation of the lower cylinder 9 can be realized. When the compressor operates in single-cylinder mode, the low-pressure suction is introduced into the tail cavity 92 of the sliding vane through the switching pipeline 21. The tail of the pin 15 is always under the exhaust high-pressure oil. The high-pressure oil can play a role in oil film sealing for the gap between the pin 15 and the pin hole, reducing the leakage caused by the pressure difference between the head and the tail of the pin 15, and improving the energy efficiency of the single-cylinder low-frequency operation.

[0063] According to the experimental monitoring, there is always pressure pulsation in the tail cavity 92 of the variable-capacity compressor whether it operates in single-cylinder mode or double-cylinder mode. Especially when operating in double-cylinder mode, the pressure pulsation in the tail cavity 92 of the sliding vane is relatively large, which is related to the intermittent suction and exhaust characteristics of the rotary compressor. Therefore, the pressure pulsation will cause certain pressure pulsation of the high-pressure gas and high-pressure oil at the head and tail of the pin 15 when the compressor operates in double-cylinder mode. As Figure 6As shown, to ensure that the pin 15 can still stay stably in the pin hole under the interference of pressure pulsation during the operation of the two cylinders, and to prevent the pin 15 from moving up and down due to pressure pulsation during the operation of the variable displacement compressor with two cylinders, so that the pin 15 does not contact the sliding vane 16, it is necessary to design a return spring 14 with a specific elastic force at the head of the pin 15 to overcome the pressure pulsation at the head and tail of the pin 15. Suppose there is a pressure pulsation P in the tail cavity 92 of the sliding vane during the operation of the two cylinders, the installation pre-tightening force of the return spring 14 is F(x), and the lower end area of the pin 15 is S. It is necessary to satisfy: S*P ≤ F(x); if the elastic force F(x) of the spring is too large, it will lead to too large a suction and exhaust pressure difference required when the compressor switches to a single cylinder. To ensure that the variable displacement compressor can smoothly switch from two cylinders to a single cylinder and operate stably when the suction and exhaust pressure difference is greater than P1, it is necessary to satisfy: F(x) ≤ P1*S; therefore, to ensure the smooth switching and stable operation of the compressor between single and two cylinders, it is necessary to satisfy: S*P ≤ F(x) ≤ P1*S. When the pin 15 is cylindrical, if the radius of the pin 15 at the tail end is R, then S = πR 2 。In one embodiment, P1 = 50 bar. At the same time, to ensure the reliability of the single and two-cylinder switching of the variable displacement compressor, during the operation of the compressor with two cylinders, it is only necessary to ensure that the tail end of the sliding vane 16 is always on the side away from the roller of the head of the pin 15, which can ensure that the head of the pin 15 can always top against the lower end surface of the sliding vane 16 when the compressor switches to a single cylinder, reducing the limitations of the variable displacement structure design.

[0064] When the reset structure uses a magnet 14a, except for the different force application methods, its working principle and working mode are basically the same as those of the previous embodiment, and will not be elaborated here.

[0065] This embodiment is not only applicable to the twin-rotor variable displacement compressor, but also applicable to the multi-rotor variable displacement compressor.

[0066] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned advantageous ways can be freely combined and superimposed.

[0067] The above are only the preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art in the technical field of the present application, without departing from the technical principle of the present application, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A variable displacement compressor, characterized in that, it includes a housing assembly (1) and a pump body assembly arranged in the housing assembly (1). The pump body assembly includes a cylinder, a roller, a flange and a sliding vane. A sliding vane groove (91) is provided on the cylinder, and the sliding vane is slidably arranged in the sliding vane groove (91). A pin hole is provided on the flange, and a pin (15) is arranged in the pin hole. The pin hole communicates with the tail cavity (92) of the sliding vane groove (91) on the side of the pin (15) close to the sliding vane, and the pin hole communicates with the high-pressure side of the housing assembly (1) on the side of the pin (15) far from the sliding vane. The tail cavity (92) is connected with a switching pipeline (21), and the switching pipeline (21) can switch the refrigerant pressure in the tail cavity (92). The variable displacement compressor further includes a reset structure, and the reset structure can apply a force to the pin (15) to move away from the sliding vane.

2. The variable displacement compressor according to claim 1, characterized in that, the reset structure includes a reset spring (14).

3. The variable displacement compressor according to claim 2, characterized in that, the pin (15) includes a head close to the sliding vane and a tail far from the sliding vane. An installation step is provided on the head of the pin (15), and a limiting step is provided at one end of the pin hole close to the sliding vane. The reset spring (14) is arranged between the installation step and the limiting step, and applies a force to the pin (15) to move away from the sliding vane.

4. The variable displacement compressor according to claim 2, characterized in that, the pin (15) includes a head close to the sliding vane and a tail far from the sliding vane; an installation step is provided on the tail of the pin (15), and a limiting step is provided at one end of the pin hole close to the sliding vane. The reset spring (14) is arranged between the installation step and the limiting step, and applies a force to the pin (15) to move away from the sliding vane; or, one end of the reset spring (14) is fixedly connected to the tail end of the pin (15), and the other end is fixedly connected to a fixed structure, and applies a force to the pin (15) to move away from the sliding vane.

5. The variable displacement compressor according to claim 1, characterized in that, the reset structure includes a magnet (14a).

6. The variable displacement compressor according to claim 5, characterized in that, the pin (15) includes a head close to the sliding vane and a tail far from the sliding vane. The magnet (14a) is arranged on the fixed structure at the tail of the pin (15), and the magnet (14a) can apply a magnetic suction force to the pin (15).

7. The variable displacement compressor according to claim 5, characterized in that, the pin (15) includes a head close to the sliding vane and a tail far from the sliding vane; a first magnet is provided at one end of the pin (15) hole close to the sliding vane, and a second magnet is provided on the head of the pin (15). The first magnet can apply a repulsive force away from the sliding vane to the second magnet; or, A first magnet is provided on the fixing structure at the tail of the pin (15), a second magnet is provided at the head of the pin (15), and the first magnet can apply a suction force away from the sliding vane to the second magnet.

8. The variable displacement compressor according to any one of claims 1 to 7, characterized in that One end of the pin hole away from the sliding vane communicates with the bottom oil sump of the housing assembly (1), and pressure oil is supplied from the bottom oil sump to the tail of the pin (15).

9. The variable displacement compressor according to any one of claims 1 to 7, characterized in that The pre-acting force applied by the reset structure to the pin (15) is F(x), the bottom area of the pin (15) is S, the pressure pulsation of the tail cavity (92) is P, and the suction and exhaust pressure difference of the compressor required for single-cylinder operation switching of the variable displacement compressor is P1, and S*P ≤ F(x) ≤ P1*S.

10. The variable displacement compressor according to claim 1, characterized in that The flange includes a lower flange (11), a lower cover plate (12) is provided on the lower flange (11), the pin hole is opened on the lower flange (11), and a high-pressure passage (18) is opened on the lower cover plate (12) corresponding to the pin hole.

11. An air conditioning system includes a variable displacement compressor, characterized in that The variable displacement compressor is the variable displacement compressor according to any one of claims 1 to 10.

12. The air conditioning system according to claim 11, characterized in that The variable displacement compressor further includes an evaporator (24), a throttle valve (25) and a condenser (26), the condenser (26) is connected to the exhaust port of the variable displacement compressor, the evaporator (24) is connected to the suction port of the variable displacement compressor, the throttle valve (25) is provided between the evaporator (24) and the condenser (26), and the switching pipeline (21) can be selectively communicated with the exhaust port or the suction port of the variable displacement compressor.

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