Pump body assembly and rotary compressor having the same

Abstract

The present invention discloses a pump body assembly and a rotary compressor having the same, wherein the pump body assembly comprises: a crankshaft, wherein the crankshaft is provided with an eccentric portion; a cylinder, wherein a first chamber and a second chamber are defined in the cylinder, wherein the second chamber is provided with a secondary exhaust port and a secondary air intake port; a first piston, wherein the first piston is sleeved on the eccentric portion and is rotatably arranged in the first chamber; a sliding vane, wherein the first piston and the sliding vane cooperate to separate the first chamber into an air intake chamber and an air discharge chamber, wherein a connecting hole communicating with the second chamber is provided on the peripheral wall of the air intake chamber; and a second piston, wherein the second piston is reciprocatably arranged in the second chamber, wherein the piston rod of the second piston passes through the connecting hole to stop against the first piston so as to be driven to reciprocate by the first piston, and the second piston reciprocates so that the volume of the second chamber changes and the secondary exhaust port and the secondary air intake port are switched and opened. The pump body assembly of the present invention can realize multi-stage compression or multi-cylinder compression, and the pump body assembly has a strong compression capacity for refrigerant and high working efficiency.

Description

Technical Field

[0001] The present invention relates to the field of compressors, and in particular to a pump body assembly and a rotary compressor having the same. Background Art

[0002] In the related technology, the application of rotary compressors is becoming more and more common, and the related technicians have higher and higher requirements for the pump body assemblies used in rotary compressors. However, most pump body assemblies have a single compression type, and the compression capacity of the pump body assemblies for the refrigerant and the working efficiency of the pump body assemblies need to be improved. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a pump assembly for a rotary compressor, which can realize multi-stage compression or multi-cylinder compression, and the pump assembly has a strong compression capacity for refrigerant and high working efficiency.

[0004] The present invention also provides a rotary compressor, comprising the above-mentioned pump body assembly.

[0005] A pump body assembly for a rotary compressor according to an embodiment of the present invention comprises: a crankshaft, the crankshaft is provided with an eccentric portion; a cylinder, a first chamber and a second chamber are defined in the cylinder and are arranged at intervals, a vane groove is provided on the cylinder, and the second chamber is provided with a secondary exhaust port and a secondary suction port; a first piston, the first piston sleeve is on the eccentric portion and is rotatably arranged in the first chamber; a vane, the vane is reciprocatingly arranged in the vane groove, the tip end of the vane stops on the outer peripheral wall of the first piston, the first piston and the vane cooperate to divide the first chamber into an intake chamber and an exhaust chamber, and a connecting hole communicating with the second chamber is provided on the peripheral wall of the intake chamber; a second piston, the second piston is reciprocatingly arranged in the second chamber, the piston rod of the second piston passes through the connecting hole to stop on the first piston so as to be driven to reciprocate by the first piston, and the second piston reciprocates to change the volume of the second chamber and the secondary exhaust port and the secondary suction port are switched open.

[0006] According to the pump body assembly for a rotary compressor according to an embodiment of the present invention, a second chamber is set on the cylinder, a second piston is set in the second chamber, and the second piston passes through the connecting hole to stop on the first piston so as to be driven to reciprocate by the first piston, so that the pump body assembly can realize multi-stage compression or multi-cylinder compression and realize the application of various compression types. The compression capacity of the pump body assembly for the refrigerant can be improved to a certain extent, the application scope of the pump body assembly can be expanded, the flexibility of the use of the pump body assembly can be improved, and the working efficiency of the pump body assembly can be improved.

[0007] According to some embodiments of the present invention, the piston rod is clearance-fitted with the connecting hole.

[0008] In some embodiments of the present invention, an oil groove is provided on the peripheral wall of the second piston that cooperates with the inner wall of the second chamber, and the second piston is provided with oil holes that are respectively connected to the connecting hole and the oil groove.

[0009] Specifically, the oil groove is formed in a closed ring shape.

[0010] According to some embodiments of the present invention, a portion of the second piston that is slidably matched with the inner wall of the second chamber is provided with a weight-reducing groove.

[0011] In some embodiments of the present invention, the weight reduction groove is provided on a side wall of the second piston facing the center of the cylinder.

[0012] Further, the weight-reducing groove is formed as an annular groove extending around the piston rod.

[0013] According to some embodiments of the present invention, the outer wall of the cylinder is provided with a cutout communicating with the second chamber, a valve plate assembly is provided at the cutout, and the auxiliary exhaust port and the auxiliary intake port are respectively provided on the valve plate assembly.

[0014] According to some embodiments of the present invention, the angle between the central axis of the second chamber and the central axis of the sliding sheet is α, and α satisfies: 15°≤α≤45°.

[0015] The rotary compressor according to an embodiment of the present invention comprises: a pump body assembly, which is the pump body assembly for the rotary compressor according to the above embodiment of the present invention; and a motor assembly, wherein the crankshaft is connected to the motor assembly to be driven to rotate by the motor assembly.

[0016] The rotary compressor according to the embodiment of the present invention can realize multi-stage compression or multi-cylinder compression and the application of various compression types by setting the pump body assembly according to the above-mentioned embodiment of the present invention, which can improve the compression capacity of the rotary compressor for the refrigerant to a certain extent, expand the application scope of the rotary compressor, and improve the flexibility of the use of the rotary compressor, thereby improving the working efficiency of the rotary compressor.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1is a schematic diagram of a pump assembly according to an embodiment of the present invention;

[0020] Figure 2 is a cross-sectional view of a pump assembly according to an embodiment of the present invention, wherein the pump assembly compresses a refrigerant;

[0021] Figure 3 is a cross-sectional view of a pump assembly according to an embodiment of the present invention, wherein the pump assembly draws refrigerant.

[0022] Reference numerals:

[0023] Pump body assembly 100;

[0024] Crankshaft 1; eccentric portion 11;

[0025] Cylinder 2; first chamber 21; suction chamber 21a; exhaust chamber 21b; connecting hole 21c; second chamber 22;

[0026] Slide slot 23; cutout 24;

[0027] First piston 3;

[0028] Slide 4;

[0029] Second piston 5; piston rod 51; oil groove 52; oil hole 53; weight-reducing groove 54;

[0030] Valve plate assembly 6; suction and exhaust valve plate 61; suction and exhaust cavity plate 62; cavity 62a;

[0031] Main bearing 7;

[0032] Auxiliary bearing 8. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "length", "thickness", "upper", "lower", "inner", "outer", "axial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Reference below Figure 1-Figure 3 A pump body assembly 100 for a rotary compressor (not shown) according to an embodiment of the present invention is described.

[0037] like Figure 1-Figure 3 As shown, a pump body assembly 100 for a rotary compressor according to an embodiment of the present invention includes: a crankshaft 1, a cylinder 2, a first piston 3, a sliding vane 4 and a second piston 5.

[0038] Specifically, the crankshaft 1 is provided with an eccentric portion 11. A first chamber 21 and a second chamber 22 are defined in the cylinder 2, and a sliding vane groove 23 is provided on the cylinder 2. The second chamber 22 is provided with an auxiliary exhaust port (not shown) and an auxiliary intake port (not shown). The first piston 3 is mounted on the eccentric portion 11 and is rotatably disposed in the first chamber 21. In other words, the first piston 3 is driven to rotate by the eccentric portion 11.

[0039] The slide 4 is reciprocatingly arranged in the slide groove 23, and the front end of the slide 4 stops on the outer peripheral wall of the first piston 3. The first piston 3 and the slide 4 cooperate to separate the first chamber 21 into the suction chamber 21a and the exhaust chamber 21b. The peripheral wall of the suction chamber 21a is provided with a connecting hole 21c connected to the second chamber 22. In other words, one end of the slide 4 cooperates with the first piston 3 to divide the first chamber 21 into the suction chamber 21a and the exhaust chamber 21b. It can be understood that as the first piston 3 rotates in the first chamber 21 driven by the eccentric part 11, the volume of the suction chamber 21a and the exhaust chamber 21b is constantly changing.

[0040] Specifically, the first chamber 21 is provided with a main air intake port (not shown) and a main air exhaust port (not shown), wherein the air intake chamber 21a has the main air intake port, and the air exhaust chamber 21b has the main air exhaust port. Thus, when the refrigerant gas enters the air intake chamber 21a through the main air intake port, as the first piston 3 rotates in the first chamber 21, the refrigerant gas in the air intake chamber 21a gradually enters the air exhaust chamber 21b, and under the rotation of the first piston 3, the volume of the air exhaust chamber 21b gradually changes to achieve a gradual compression of the refrigerant, thereby achieving the compression of the refrigerant by the pump body assembly 100, and the compressed high-pressure refrigerant can be discharged from the first chamber 21 through the main air exhaust port, thereby ensuring the normal operation of the pump body assembly 100.

[0041] It is known that the pump body assembly 100 also includes a main bearing 7 and a secondary bearing 8. The main bearing 7 and the secondary bearing 8 are located on the upper and lower sides of the cylinder 2. Among them, the air intake channel connected to the main air intake port can be arranged on the cylinder 2, the main bearing 7 or the secondary bearing 8, and the exhaust channel connected to the main exhaust port can be arranged on the cylinder 2, the main bearing 7 or the secondary bearing 8. For example, the air intake channel connected to the main air intake port is arranged on the secondary bearing 8, and the exhaust channel connected to the main exhaust port is arranged on the main bearing 7. This is conducive to increasing the volume of the first chamber 21 and the second chamber 22 in the cylinder 2, and then improving the ability of the pump body assembly 100 to compress the refrigerant. At the same time, the reliability of the overall operation of the pump body assembly 100 can be guaranteed.

[0042] The second piston 5 is reciprocatably disposed in the second chamber 22. The piston rod 51 of the second piston 5 passes through the connecting hole 21c to stop on the first piston 3 so as to be driven to reciprocate by the first piston 3. The second piston 5 reciprocates so that the volume of the second chamber 22 changes and the auxiliary exhaust port and the auxiliary intake port are switched open.

[0043] Thus, since the suction chamber 21a is connected to the second chamber 22 through the connecting hole 21c, when the first chamber 21 inhales, the second piston 5 gradually moves toward the suction chamber 21a as the first piston 3 rotates, thereby increasing the volume of the second chamber 22, so that the pressure in the second chamber 22 is less than the pressure outside the second chamber 22, and under the action of the pressure difference, the auxiliary suction port is opened. It can be seen that the first chamber 21 and the second chamber 22 inhale and compress the gas at the same time. Therefore, when the first piston 3 rotates one circle, that is, when the eccentric part 11 of the crankshaft 1 rotates one circle, the second piston 5 can make a reciprocating movement in the second chamber 22, thereby making the stroke of the second piston 5 twice the eccentricity of the crankshaft 1.

[0044] When the auxiliary air inlet is opened, the refrigerant enters the second chamber 22 through the auxiliary air inlet. Under the reciprocating movement of the second piston 5, the volume of the second chamber 22 gradually changes, so that the refrigerant in the second chamber 22 can be gradually compressed, thereby realizing the compression of the refrigerant by the pump body assembly 100. When the refrigerant in the second chamber 22 is compressed so that the pressure in the second chamber 22 is greater than the pressure outside the second chamber 22, the auxiliary exhaust port is opened under the action of the pressure difference, thereby discharging the high-pressure refrigerant from the second chamber 22. Thus, the reliability of switching the auxiliary exhaust port and the auxiliary air inlet to open can be ensured, thereby ensuring the normal operation of the pump body assembly 100.

[0045] It can be seen that in the pump body assembly 100 of the embodiment of the present invention, when the main exhaust port is connected to the auxiliary air intake port, or the auxiliary exhaust port is connected to the main air intake port, the pump body assembly 100 can achieve two-stage compression of the refrigerant. When the air intake and exhaust of the first chamber 21 and the second chamber 22 are independent of each other, the pump body assembly 100 can achieve two-cylinder independent compression of the refrigerant. In this way, the pump body assembly 100 can achieve multi-stage compression or multi-cylinder compression, which can improve the compression capacity of the pump body assembly 100 for the refrigerant to a certain extent, realize the application of various compression types, expand the application scope of the pump body assembly 100, improve the flexibility of the use of the pump body assembly 100, and thus improve the working efficiency of the pump body assembly 100. It should be noted here that "multi-stage" means two or more stages, and "multi-cylinder" means two or more cylinders.

[0046] It can be understood that the rotary compressor also includes a motor assembly (not shown in the figure). The pump body assembly 100 of the embodiment of the present invention can be connected to the motor assembly through the crankshaft 1 so that the crankshaft 1 is driven to rotate by the motor assembly, so that the rotary compressor using the pump body assembly of the embodiment of the present invention can be powered by only one motor, thereby reducing the number of parts of the rotary compressor to a certain extent, reducing the volume and weight of the rotary compressor, making the structure of the rotary compressor compact, which is conducive to the miniaturization and lightweight of the rotary compressor, and can also reduce the manufacturing cost of the rotary compressor to a certain extent.

[0047] It should also be noted that, if it is to be ensured that the piston rod 51 of the second piston 5 always stops against the first piston 3 so as to be driven to move back and forth by the first piston 3, this can be achieved by ensuring that the pressure generated by the refrigerant in the second chamber 22 on the second piston 5 is greater than the pressure generated by the first chamber 21 on the second piston 5. Thus, under the action of the pressure difference, the piston rod 51 of the second piston 5 can be ensured to always stop against the first piston 3 so as to be driven to move back and forth by the first piston 3.

[0048] According to the pump body assembly 100 for a rotary compressor according to an embodiment of the present invention, by setting a second chamber 22 on the cylinder 2, setting a second piston 5 in the second chamber 22, and allowing the second piston 5 to pass through the connecting hole 21c to stop on the first piston 3 so as to be driven by the first piston 3 to reciprocate, the pump body assembly 100 can achieve multi-stage compression or multi-cylinder compression and realize the application of various compression types, which can improve the compression capacity of the pump body assembly 100 for the refrigerant to a certain extent, expand the application scope of the pump body assembly 100, improve the flexibility of the use of the pump body assembly 100, and thus improve the working efficiency of the pump body assembly 100.

[0049] According to some embodiments of the present invention, the piston rod 51 and the connecting hole 21c are clearance-matched, thereby ensuring the reliability and flexibility of the reciprocating movement of the second piston 5 in the connecting hole 21c, and facilitating the lubricating oil to enter the second chamber 22 through the clearance between the piston rod 51 and the connecting hole 21c, thereby ensuring the reliability of the pump assembly 100 in compressing the refrigerant and improving the reliability of the operation of the pump assembly 100.

[0050] In some embodiments of the present invention, an oil groove 52 is provided on the peripheral wall of the second piston 5 that cooperates with the inner wall of the second chamber 22, and an oil hole 53 that is respectively connected to the connecting hole 21c and the oil groove 52 is provided on the second piston 5. Thus, the lubricating oil can enter the second chamber 22 through the second piston 5, which is conducive to ensuring the reliability and flexibility of the cooperation between the second piston 5 and the connecting hole 21c, reducing the friction between the second piston 5 and the inner wall of the second chamber 22, and then ensuring the reliability of the pump body assembly 100 in compressing the refrigerant, improving the reliability of the pump body assembly 100, and extending the service life of the pump body assembly 100 to a certain extent.

[0051] Specifically, the oil groove 52 is formed in a closed ring shape, thereby ensuring reliable sliding fit between the second piston 5 and the inner wall of the second chamber 22, effectively reducing the friction between the second piston 5 and the inner wall of the second chamber 22, thereby facilitating the service life of the pump body assembly 100 and improving the reliability of the pump body assembly 100. At the same time, the production and processing of the oil groove 52 is facilitated, which is conducive to improving the manufacturing efficiency of the pump body assembly 100.

[0052] According to some embodiments of the present invention, a portion of the second piston 5 that slides with the inner wall of the second chamber 22 is provided with a weight-reducing groove 54. This can reduce the production material of the second piston 5 to a certain extent, reduce the production cost of the pump body assembly 100, and is also conducive to the lightweight of the pump body assembly 100, improve the portability and flexibility of the second piston 5 in the second chamber 22, and reduce the labor of the operator when installing the pump body assembly 100 to a certain extent.

[0053] In some embodiments of the present invention, the weight-reducing groove 54 is disposed on the side wall of the second piston 5 facing the center of the cylinder 2. That is, the opening of the weight-reducing groove 54 faces the cylinder 2, thereby reducing the weight of the second piston 5 and, to a certain extent, preventing the second piston 5 from affecting the uniformity of the refrigerant compression of the second chamber 22 due to the setting of the weight-reducing groove 54.

[0054] Furthermore, the weight-reducing groove 54 is formed as an annular groove extending around the piston rod 51 , so that the structure of the second piston 5 is evenly distributed, the processing and manufacturing of the weight-reducing groove 54 are convenient, and the reliability of the reciprocating movement of the second piston 5 in the second chamber 22 is ensured.

[0055] According to some embodiments of the present invention, the outer peripheral wall of the cylinder 2 is provided with a cutout 24 communicating with the second chamber 22, a valve plate assembly 6 is provided at the cutout 24, and the auxiliary exhaust port and the auxiliary air intake port are respectively provided on the valve plate assembly 6. Thus, the reliability of the refrigerant compression in the second chamber 22 can be ensured, the structure of the pump body assembly 100 is made more reliable, and at the same time, it is beneficial to reduce the occupied space of the pump body assembly 100 and improve the utilization rate of the pump body assembly 100 itself.

[0056] Specifically, the valve plate assembly 6 includes an intake and exhaust valve plate 61 and an intake and exhaust cavity plate 62 located at the outer end of the second chamber 22. The intake and exhaust cavity plate 62 is located on the inner side of the intake and exhaust valve plate 61. The intake and exhaust cavity plate 62 is provided with a plurality of cavities 62a that penetrate it in the thickness direction. The plurality of cavities 62a are arranged at intervals, and a sealing gasket (not shown) is provided at one end of the intake and exhaust cavity plate 62 close to the intake and exhaust valve plate 61. The intake and exhaust valve plate 61 is provided with an intake valve (not shown) and an exhaust valve (not shown) to control the inlet and outlet of the refrigerant in the second chamber 22. Thus, the reliability of the valve plate assembly 6 can be ensured, so that the refrigerant entering the second chamber 22 through the auxiliary air inlet must pass through the cavities 62a on the intake and exhaust cavity plate 62 before entering the second chamber 22. The provision of the sealing gasket can ensure the sealing of the second chamber 22 to a certain extent.

[0057] According to some embodiments of the present invention, the angle between the central axis of the second chamber 22 and the central axis of the vane 4 is α. When α satisfies: 15°≤α≤45°, the reliability and consistency of the refrigerant compression in the first chamber 21 and the second chamber 22 of the pump body assembly 100 can be ensured, thereby ensuring the reliability of the operation of the pump body assembly 100, which is beneficial to improving the working efficiency of the pump body assembly 100.

[0058] In some embodiments of the present invention, the second piston 5 stops at one end of the first piston 3 and is formed as an arc surface. Thus, the second piston 5 forms a line contact with the first piston 3, which can improve the flexibility of the contact and cooperation between the second piston 5 and the first piston 3 to a certain extent, and ensure the reliability of the second piston 5 driven by the first piston 3 to reciprocate.

[0059] Specifically, the central axis of the first chamber 21 intersects the central axis of the second chamber 22. In other words, the straight line of the reciprocating path of the second piston 5 passes through the center of the cylinder 2. This ensures the reliability of the piston rod 51 of the second piston 5 abutting against the first piston 3 to be driven to reciprocate by the first piston 3. This ensures the reliability of the operation of the pump assembly 100.

[0060] The rotary compressor according to the embodiment of the present invention includes a pump body assembly 100 and a motor assembly.

[0061] Specifically, the pump body assembly 100 is a pump body assembly 100 for a rotary compressor according to the above embodiment of the present invention. Thus, the rotary compressor can realize multi-stage compression or multi-cylinder compression, realize the application of various compression types, improve the compression capacity of the rotary compressor for the refrigerant to a certain extent, expand the application range of the rotary compressor, improve the flexibility of the use of the rotary compressor, and thus improve the working efficiency of the rotary compressor.

[0062] The crankshaft 1 is connected to the motor assembly to be driven to rotate by the motor assembly. As a result, the rotary compressor of the embodiment of the present invention can provide a power source for the first piston 3 and the second piston 5 through only one motor, thereby reducing the number of parts of the rotary compressor to a certain extent, reducing the volume and weight of the rotary compressor, making the structure of the rotary compressor compact, facilitating the miniaturization and lightness of the rotary compressor, and reducing the manufacturing cost of the rotary compressor to a certain extent.

[0063] It is understandable that the rotary compressor of the embodiment of the present invention can be used as a single-cylinder compressor or a double-cylinder compressor. If there are multiple pump body assemblies 100, it can also be used as a multi-cylinder compressor (here, "multiple" means more than two). At the same time, the rotary compressor of the embodiment of the present invention can be formed as a fixed-frequency rotary compressor or a variable-frequency rotary compressor. Therefore, the rotary compressor has a wide range of applications.

[0064] The rotary compressor according to the embodiment of the present invention can realize multi-stage compression or multi-cylinder compression and the application of various compression types by setting the pump body assembly 100 according to the above-mentioned embodiment of the present invention, which can improve the compression capacity of the rotary compressor for the refrigerant to a certain extent, expand the application scope of the rotary compressor, and improve the flexibility of the use of the rotary compressor, thereby improving the working efficiency of the rotary compressor.

[0065] Other structures and operations of the rotary compressor according to the embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0067] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A pump assembly for a rotary compressor, characterized in that: include: A crankshaft, wherein the crankshaft is provided with an eccentric portion; A cylinder, wherein a first chamber and a second chamber are defined in the cylinder and are spaced apart from each other, a sliding vane groove is provided on the cylinder, and the second chamber is provided with a secondary exhaust port and a secondary intake port; a first piston, the first piston sleeve is disposed on the eccentric portion and is rotatably disposed in the first chamber; a sliding plate, the sliding plate being reciprocatably arranged in the sliding plate groove, the front end of the sliding plate being abutted against the outer peripheral wall of the first piston, the first piston and the sliding plate cooperating to separate the first chamber into an air suction chamber and an air discharge chamber, and a connecting hole communicating with the second chamber being arranged on the peripheral wall of the air suction chamber; A second piston, the second piston is reciprocatably disposed in the second chamber, a piston rod of the second piston passes through the connecting hole to stop on the first piston so as to be driven by the first piston to reciprocate, the second piston reciprocates to change the volume of the second chamber and the auxiliary exhaust port and the auxiliary intake port are switched open.

2. The pump assembly for a rotary compressor according to claim 1, characterized in that: The piston rod is clearance-matched with the connecting hole.

3. The pump assembly for a rotary compressor according to claim 2, characterized in that: An oil groove is arranged on the peripheral wall of the second piston that matches the inner wall of the second chamber, and an oil hole that is respectively connected to the connecting hole and the oil groove is arranged on the second piston.

4. The pump assembly for a rotary compressor according to claim 3, characterized in that: The oil groove is formed in a closed ring shape.

5. The pump assembly for a rotary compressor according to claim 1, characterized in that: A weight-reducing groove is provided on a portion of the second piston that is slidably matched with the inner wall of the second chamber.

6. The pump assembly for a rotary compressor according to claim 5, characterized in that: The weight-reducing groove is provided on a side wall of the second piston facing the center of the cylinder.

7. The pump assembly for a rotary compressor according to claim 6, characterized in that: The lightening groove is formed as an annular groove extending around the piston rod.

8. The pump assembly for a rotary compressor according to claim 1, characterized in that: The outer peripheral wall of the cylinder is provided with a cutout communicated with the second chamber, a valve plate assembly is provided at the cutout, and the auxiliary exhaust port and the auxiliary air intake port are respectively provided on the valve plate assembly.

9. The pump assembly for a rotary compressor according to any one of claims 1 to 8, characterized in that: An included angle between a central axis of the second chamber and a central axis of the sliding sheet is α, and α satisfies: 15°≤α≤45°.

10. A rotary compressor, characterized in that: include: A pump body assembly, wherein the pump body assembly is a pump body assembly for a rotary compressor according to any one of claims 1 to 9; The crankshaft is connected to the motor assembly so as to be driven to rotate by the motor assembly.

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