Piston assembly and compressor

Abstract

The application discloses a piston assembly and a compressor. The piston assembly comprises a cylinder base, a first piston, a second piston and a power element. The cylinder base is provided with a cylinder hole. The first piston and the second piston are arranged in the cylinder hole in the axial direction of the cylinder hole to separate the cylinder hole into a low-pressure cavity and a high-pressure cavity. The low-pressure cavity is formed between the first piston and the second piston, and the high-pressure cavity is formed on the side of the first piston away from the second piston. The power element is connected with the second piston and is used for driving the second piston to reciprocate in the axial direction of the cylinder hole. The first piston and the second piston are elastically connected, and the gas in the low-pressure cavity is compressed and discharged into the high-pressure cavity under the elastic force. The application reduces the compression ratio of the compressor and effectively improves the refrigerating capacity of the compressor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a piston assembly and a compressor. BACKGROUND

[0002] With the continuous progress of science and technology, the application of compressors in the field of refrigeration technology is also more and more widely. Especially in the field of air conditioners and refrigerators, the market demand for high-efficiency refrigerator compressors shows a rapid upward trend, and the development of high-efficiency compressors needs to improve the refrigerating capacity of the compressor to a certain extent. In addition to optimizing the design of the valve group of the compressor, the structure of the moving parts of the compressor should also be designed to improve the suction efficiency and increase the refrigerating capacity. Among them, the piston is the main moving part that affects the refrigerating capacity of the compressor. The movement mode of the piston of the traditional compressor is that the rotation of the crankshaft drives the piston and the connecting rod to reciprocate. The disadvantage of this movement mode is that the compression ratio of the compressor is large, the refrigeration efficiency is low, and the refrigerating capacity of the refrigerator is difficult to meet the demand. SUMMARY

[0003] Embodiments of the present application provide a piston assembly and a compressor, aiming to solve the problem of low refrigeration efficiency caused by the large compression ratio of the existing compressor.

[0004] The present application provides a piston assembly, comprising: a cylinder seat, a first piston, a second piston and a power piece, the cylinder seat is provided with a cylinder hole; the first piston and the second piston are arranged in the cylinder hole along the axial direction of the cylinder hole to separate the cylinder hole into a low-pressure cavity and a high-pressure cavity, the low-pressure cavity is formed between the first piston and the second piston, and the high-pressure cavity is formed on the side of the first piston away from the second piston; the power piece is connected with the second piston, and the power piece is used to drive the second piston to reciprocate along the axial direction of the cylinder hole; wherein the first piston and the second piston are elastically connected, and the gas in the low-pressure cavity is compressed and discharged into the high-pressure cavity under the action of the elastic force.

[0005] In the piston assembly provided by the present application, the maximum stroke of the first piston moving along the axial direction of the cylinder hole is greater than the maximum stroke of the second piston moving along the axial direction of the cylinder hole.

[0006] In the piston assembly provided by the present application, the maximum stroke of the first piston moving along the axial direction of the cylinder hole is twice the maximum stroke of the second piston moving along the axial direction of the cylinder hole.

[0007] In the piston assembly provided by the present application, a groove is formed in the inner wall of the cylinder hole along the axial direction thereof, and the groove extends away from the second piston; a limiting convex strip is arranged on the outer wall of the first piston along the axial direction thereof, and the limiting convex strip is arranged in the groove to move along the groove.

[0008] In the piston assembly provided by the application, the groove is close to the lower stop end of the second piston, and the groove is away from the upper stop end of the second piston; when the second piston moves to the maximum stroke, the first piston moves between the upper stop end and the lower stop end, and continues to move towards the upper stop end or the lower stop end.

[0009] In the piston assembly provided by the application, when the first piston continues to move towards the lower stop end, the first piston is compressed towards the low-pressure cavity, and the gas in the low-pressure cavity is discharged into the high-pressure cavity.

[0010] In the piston assembly provided by the application, the first piston is provided with a first gas valve for sucking the gas from the low-pressure cavity into the high-pressure cavity; and / or the second piston is provided with a second gas valve for sucking the gas into the low-pressure cavity.

[0011] In the piston assembly provided by the application, the first gas valve comprises a first gas suction port and a first gas suction valve plate for opening and closing the first gas suction port, the first piston is provided with a first mounting groove on the side away from the second piston, the first gas suction port is opened on the first mounting groove, and the first gas suction valve plate is mounted in the first mounting groove; and / or the second gas valve comprises a second gas suction port and a second gas suction valve plate for opening and closing the second gas suction port, the second piston is provided with a second mounting groove on the side close to the first piston, the second gas suction port is opened on the second mounting groove, and the second gas suction valve plate is mounted in the second mounting groove.

[0012] In the piston assembly provided by the application, the power member comprises a connecting rod and a crankshaft, one end of the connecting rod is connected with the second piston, the other end of the connecting rod is connected with the crankshaft, and the crankshaft rotates to drive the second piston to make reciprocating motion along the axial direction of the cylinder bore through the connecting rod; and / or the piston assembly further comprises an elastic connecting member, and two ends of the elastic connecting member are connected with the first piston and the second piston, respectively.

[0013] The application further provides a compressor comprising the piston assembly.

[0014] The application provides a piston assembly and a compressor, the piston assembly comprising a cylinder base, a first piston, a second piston and a power element, the first piston and the second piston are arranged in the cylinder hole of the cylinder base at intervals, a low-pressure cavity is formed between the first piston and the second piston in the cylinder hole, a high-pressure cavity is formed on the side of the first piston away from the second piston, the first piston and the second piston are elastically connected, the power element drives the second piston to make reciprocating motion and in turn drives the first piston to make reciprocating motion, in the process of reciprocating motion, the low-pressure cavity can inhale gas, and the low-pressure cavity is compressed under the action of the elastic force, the gas in the low-pressure cavity is discharged into the high-pressure cavity, thereby, the cylinder hole is divided into the high-pressure cavity and the low-pressure cavity by the two pistons, the gas is inhaled by the increased low-pressure cavity to realize air supplement, the displacement of the compressor is increased, the gas in the low-pressure cavity is discharged into the high-pressure cavity after compression to realize secondary compression, the two-stage compression can reduce the compression ratio of the compressor, effectively improve the refrigerating capacity of the compressor and the refrigeration efficiency, and the system energy efficiency ratio is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0016] Figure 1 It is a sectional structure schematic view of the piston assembly of the embodiment of the application.

[0017] Figure 2 It is a sectional structure schematic view of the piston assembly of the embodiment of the application. Figure 1 It is an enlarged view schematic view of A part of the piston assembly of the embodiment of the application.

[0018] Figure 3 It is a structure schematic view of the piston assembly of the embodiment of the application.

[0019] Figure 4 It is a structure schematic view of the cylinder base of the piston assembly of the embodiment of the application.

[0020] Figure 5 It is a schematic view of the first piston of the piston assembly of the embodiment of the application.

[0021] Figure 6 It is a schematic view of the second piston of the piston assembly of the embodiment of the application.

[0022] Figure 7 It is an assembly schematic view of the first piston and the second piston of the piston assembly of the embodiment of the application. BRIEF DESCRIPTION OF DRAWINGS:

[0024] 1, first piston; 11, first suction port; 12, first suction valve; 13, first mounting groove; 14, limiting convex strip; 2, second piston; 21, second suction port; 22, second suction valve; 23, mounting hole; 3, cylinder seat; 31, cylinder hole; 311, low-pressure cavity; 312, high-pressure cavity; 32, groove; 321, upper stop end; 322, lower stop end; 4, power piece; 41, connecting rod; 42, crankshaft; 43, piston pin; 44, elastic positioning pin; 5, elastic connecting piece. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0026] The direction terms mentioned in the present application, such as "up", "down", "front", "back", "left", "right", "inner", "outer", "side", etc., are only the directions of the attached drawings. Therefore, the direction terms used are used to illustrate and understand the present application, rather than to limit the present application. In addition, in the drawings, structures similar or identical to each other are denoted by the same reference numerals.

[0027] Please refer to Figures 1 to 7 , Figure 1 A structure schematic diagram of a piston assembly according to an embodiment of the present application is provided. The piston assembly comprises a cylinder seat 3, a first piston 1, a second piston 2 and a power piece 4. The cylinder seat 3 is provided with a cylinder hole 31. The first piston 1 and the second piston 2 are arranged in the cylinder hole 31 along the axial direction of the cylinder hole 31 to separate the cylinder hole 31 into a low-pressure cavity 311 and a high-pressure cavity 312. The low-pressure cavity 311 is formed between the first piston 1 and the second piston 2, and the high-pressure cavity 312 is formed on the side of the first piston 1 away from the second piston 2. The power piece 4 is connected with the second piston 2, and is used to drive the second piston 2 to make reciprocating motion along the axial direction of the cylinder hole 31. The first piston 1 and the second piston 2 are elastically connected, and the gas in the low-pressure cavity 311 is compressed and discharged into the high-pressure cavity 312 under the action of elastic force.

[0028] Specifically, the cylinder seat 3 is mounted in the shell of a compressor. The cylinder seat 3 is provided with a through cylinder hole 31 at both ends. The cylinder hole 31 has a certain length and can accommodate two pistons to make reciprocating motion in the cylinder hole 31. The side wall of the cylinder seat 3 is provided with an air inlet hole, which provides air for the low-pressure cavity and the high-pressure cavity.

[0029] Referring to Figure 2 and Figure 3 , the first piston 1 and the second piston 2 are both hollow cylinders, one side of the cylinder has an end face, and the other side is open. The axial direction of the first piston 1 and the second piston 2 is consistent with the axial direction of the cylinder bore 31, and the end face of the first piston 1 and the second piston 2 is directed to the same end of the cylinder bore 31. The first piston 1 and the second piston 2 are arranged in the cylinder bore 31 at intervals, and the open side of the first piston 1 and the side of the end face of the second piston 2 are enclosed with the inner wall of the cylinder bore 31 to define a low-pressure cavity 311, and the side of the end face of the first piston 1 is enclosed with the inner wall of the cylinder bore 31 to define a high-pressure cavity 312. The first gas valve is arranged on the end face of the first piston 1, and the second gas valve is arranged on the end face of the second piston 2. The gas in the low-pressure cavity 311 is mainly sucked from the inside of the compressor housing through the second gas valve on the second piston 2, and the gas in the high-pressure cavity 312 is mainly from the normal suction of the valve group and the intermediate pressure gas sucked from the low-pressure cavity 311 through the opening of the first gas valve of the first piston 1. In addition, in order to avoid the mass of the cylinder seat 3 being too large and save space, the height of the first piston 1 is half the height of the second piston 2.

[0030] Continuing to refer to Figure 2 and Figure 3 , the piston assembly further comprises an elastic connecting piece 5, two ends of the elastic connecting piece 5 are connected to the two sides of the first piston 1 and the second piston 2 respectively. In this embodiment, the elastic connecting piece 5 can be a spring, and can also be other elastic components, which are not limited here. The second piston 2 is provided with a mounting hole 23 on the end face, one end of the spring is fixed to the mounting hole 23, and the other end is fixed to the inner wall platform on the open side of the first piston 1.

[0031] Continuing to refer to Figure 2 and Figure 3The power element 4 comprises a connecting rod 41 and a crankshaft 42, one end of the connecting rod 41 is connected with the second piston 2, the other end of the connecting rod 41 is connected with the crankshaft 42, and the second piston 2 is driven to move reciprocally along the axial direction of the cylinder bore 31 by the connecting rod 41 when the crankshaft 42 rotates. Specifically, the power element 4 further comprises a piston pin 43 and an elastic positioning pin 44, the second piston 2 is provided with a pin hole in the radial direction, one end of the connecting rod 41 is also provided with a pin hole, the one end of the connecting rod 41 extends into the cavity of the second piston 2 from the side of the second piston 2, the pin hole on the one end of the connecting rod 41 is aligned with the pin hole on the second piston 2, the piston pin 43 is inserted into the two pin holes, and the elastic positioning pin 44 is inserted into the piston pin 43 along the axial direction of the second piston 2, so that the connecting rod 41 is fixedly connected with the second piston 2. The crankshaft 42 is provided with an eccentric shaft portion, the other end of the connecting rod 41 is fixed with the shaft portion, and the connecting rod 41 is driven to move reciprocally by the eccentric shaft portion when the crankshaft 42 rotates, so that the second piston 2 moves reciprocally along the axial direction of the cylinder bore 31, and since the second piston 2 is elastically connected with the first piston 1, the first piston 1 is also driven to move reciprocally along the axial direction of the cylinder bore 31.

[0032] In the process that the gas in the low-pressure cavity 311 is discharged into the high-pressure cavity 312, the first piston 1 moves reciprocally under the driving of the second piston 2, and since the first piston 1 and the second piston 2 are elastically connected, the relative movement between the first piston 1 and the second piston 2 exists under the elastic force, the volume of the low-pressure cavity 311 is changed, the low-pressure cavity 311 between the first piston 1 and the second piston 2 is compressed, the gas in the low-pressure cavity 311 is compressed and discharged into the high-pressure cavity 312, and the process that the gas in the low-pressure cavity 311 is discharged into the high-pressure cavity 312 realizes intermediate gas supplement, and the gas supplemented into the high-pressure cavity 312 is compressed by the first piston 1 again to realize two-stage compression.

[0033] By implementing the embodiment, the crankshaft 42 drives the connecting rod 41 and the two pistons to move together, the structure that the two pistons move together divides the cylinder bore 31 into the high-pressure cavity 312 and the low-pressure cavity 311, the second piston 2 of the low-pressure cavity 311 is provided with the second gas valve and mainly sucks the gas from the compressor shell, and the high-pressure cavity 312 mainly sucks the gas through the valve group; the second piston 2 of the low-pressure cavity 311 sucks and compresses the gas to reach an intermediate pressure and then discharges the gas into the high-pressure cavity 312, and the gas in the high-pressure cavity 312 is compressed and discharged after the pressure of the gas in the low-pressure cavity 311 is mixed, the gas is compressed by two stages, the compression ratio of the compressor is reduced, the refrigerating capacity of the compressor is improved, and the system energy efficiency ratio is effectively improved.

[0034] During the reciprocating movement of the first piston 1 and the second piston 2, including the process of air intake and compression of exhaust gas. For the air intake process, the connecting rod 41 is driven by the crankshaft 42 to move away from the cylinder bore 31, and the first piston 1 and the second piston 2 move to the lower side of the cylinder bore 31, that is, the left-to-right movement in Figure 1 For the compression process, the connecting rod 41 is driven by the crankshaft 42 to move close to the cylinder bore 31, and the first piston 1 and the second piston 2 move to the upper side of the cylinder bore 31, that is, the right-to-left movement in Figure 1 For the compression process, the connecting rod 41 is driven by the crankshaft 42 to move close to the cylinder bore 31, and the first piston 1 and the second piston 2 move to the upper side of the cylinder bore 31, that is, the right-to-left movement in

[0035] Referring to Figure 2 In an embodiment, the maximum stroke of the axial movement of the first piston 1 along the cylinder bore 31 is greater than the maximum stroke of the axial movement of the second piston 2 along the cylinder bore 31. More specifically, the maximum stroke of the axial movement of the first piston 1 along the cylinder bore 31 is twice the maximum stroke of the axial movement of the second piston 2 along the cylinder bore 31. Of course, it can be understood that in other embodiments, the maximum stroke of the first piston 1 can also be other multiples of the maximum stroke of the second piston 2, which can be an integer multiple or a non-integer multiple, and is set according to actual needs. Specifically, the second piston 2 drives the first piston 1 to reciprocate axially along the cylinder bore 31, and because the maximum stroke of the second piston 2 is shorter and the maximum stroke of the first piston 1 is longer, the second piston 2 stops moving when it reaches the maximum stroke, that is, it stops for a short time, waiting for the first piston 1 to continue moving to the maximum stroke. For example, for the air intake process, when the second piston 2 moves to the maximum stroke, the first piston 1 has only run half the stroke, at this time, the second piston 2 stops moving and waits for the first piston 1 to continue moving to the right to its maximum stroke, and finally, the first piston 1 and the second piston 2 run from right to left at the same time to compress the exhaust gas. The purpose of such design is to provide the stroke for the first piston 1 to continue moving to the right when the second piston 2 moves to the maximum stroke to complete the air intake, so that the first piston 1 moves towards the second piston 2 to compress the low-pressure cavity 311, at this time, the pressure in the low-pressure cavity 311 is greater than the pressure in the high-pressure cavity 312, the first gas valve is opened, and the high-pressure cavity 312 intakes air from the low-pressure cavity 311, thereby discharging the gas in the low-pressure cavity 311 into the high-pressure cavity 312. For the compression process, the first piston 1 and the second piston 2 run from right to left at the same time to compress, and because the maximum stroke of the second piston 2 is shorter and part of the gas in the low-pressure cavity 311 has been discharged into the high-pressure cavity 312 during the air intake process, the remaining gas can be compressed and discharged into the high-pressure cavity 312 during the movement of the second piston 2 to the maximum stroke, and the gas in the low-pressure cavity 311 mixes with the gas in the high-pressure cavity 312. Finally, the first piston 1 continues to run to the maximum stroke to compress and discharge the mixed gas in the high-pressure cavity 312, achieving two-stage compression.

[0036] Referring to Figure 4In the embodiment, a groove 32 is formed in the inner wall of the cylinder hole 31 along the axial direction of the cylinder hole 31, and the groove 32 extends away from the second piston 2; a limiting protrusion 14 is arranged on the outer wall of the first piston 1 along the axial direction of the first piston 1, and the limiting protrusion 14 is arranged in the groove 32 to move along the groove 32. Specifically, the groove 32 is a linear groove body formed in the axial direction of the cylinder hole 31, and two linear grooves are symmetrically formed in the inner wall of the cylinder hole 31. Similarly, two linear limiting protrusions 14 are symmetrically arranged on the outer wall of the first piston 1. The length of the linear groove body is greater than the length of the limiting protrusion 14, and the limiting protrusion 14 is embedded in the groove 32. When the first piston 1 reciprocates, the first piston 1 is limited by the limiting protrusion 14 and the groove 32, which limits the running range of the first piston 1 and enables the first piston 1 to reciprocate stably in the axial direction of the cylinder hole 31. The length of the groove 32 is 3 / 5 of the length of the cylinder hole 31. The groove 32 can store oil to ensure the lubrication of the reciprocating first piston 1. It should be noted that in other embodiments, the groove 32 can be formed on the first piston 1, and the limiting protrusion 14 can be arranged on the inner wall of the cylinder hole 31, which can be selected according to actual conditions.

[0037] With reference to Figure 2 and Figure 4 In the embodiment, one end of the groove 32 close to the second piston 2 is a lower stop end 322, and the other end of the groove 32 away from the second piston 2 is an upper stop end 321; when the second piston 2 moves to the maximum stroke, the first piston 1 moves to between the upper stop end 321 and the lower stop end 322, and continues to move towards the upper stop end 321 or the lower stop end 322. Specifically, as shown in FIG. 2, when the second piston 2 moves to the maximum stroke, the first piston 1 moves to between the upper stop end 321 and the lower stop end 322, and continues to move towards the upper stop end 321 or the lower stop end 322. Figure 4As shown, the upper stop end 321 is the leftmost end of the groove 32, and the lower stop end 322 is the rightmost end of the groove 32. The first piston 1 moves towards the lower stop end 322 in the process of suction, and the first piston 1 reaches the maximum stroke in the process of suction when it moves to the lower stop end 322, and the suction ends when the first piston 1 moves to the lower stop end 322. In the process of suction, when the second piston 2 moves to the maximum stroke, the first piston 1 is located in the region of the groove 32 which is not at both ends, i.e. between the upper stop end 321 and the lower stop end 322, and specifically, it can be in the middle of the upper stop end 321 and the lower stop end 322. The remaining running distance of the first piston 1 in the groove 32 between the limiting protrusion 14 of the first piston 1 and the lower stop end 322 provides the first piston 1 with a remaining running stroke, so that the first piston 1 can continue to move towards the lower stop end 322. The first piston 1 moves towards the upper stop end 321 in the process of compression and exhaust, and the first piston 1 reaches the maximum stroke in the process of compression and exhaust when it moves to the upper stop end 321, and the exhaust ends when the first piston 1 moves to the upper stop end 321. In the process of exhaust, when the second piston 2 moves to the maximum stroke, the first piston 1 is located in the region of the groove 32 which is not at both ends, i.e. between the upper stop end 321 and the lower stop end 322, and specifically, it can be in the middle of the upper stop end 321 and the lower stop end 322. The remaining running distance of the first piston 1 in the groove 32 between the limiting protrusion 14 of the first piston 1 and the upper stop end 321 provides the first piston 1 with a remaining running stroke, so that the first piston 1 can continue to move towards the upper stop end 321.

[0038] Further, in a specific implementation, when the first piston 1 continues to move towards the lower stop end 322, the first piston 1 compresses towards the low-pressure cavity 311, and the gas in the low-pressure cavity 311 is discharged into the high-pressure cavity 312 through the first gas valve. Specifically, in the process of suction, when the second piston 2 moves to the maximum stroke, the second piston 2 completes the suction, and the low-pressure cavity 311 has sucked the gas from the shell of the compressor. At this time, the second piston 2 stops moving and waits for the first piston 1 to continue to move towards the lower stop end 322, and the first piston 1 compresses the low-pressure cavity 311. The gas in the low-pressure cavity 311 is compressed and has a higher pressure than the gas in the high-pressure cavity 312, and the first gas valve on the first piston 1 opens, and the high-pressure cavity 312 starts to suck the gas from the low-pressure cavity 311 until the end of suction.

[0039] Referring to Figure 5 and Figure 7In an embodiment, the first gas valve comprises a first air inlet 11 and a first air valve plate 12 for opening and closing the first air inlet 11, and the first piston 1 is provided with a first mounting groove 13 on the side away from the second piston 2, the first air inlet 11 is opened on the first mounting groove 13, and the first air valve plate 12 is mounted in the first mounting groove 13. Specifically, the first piston 1 is a hollow cylinder with one end having an end face and the other end being open. The first mounting groove 13 is opened on the end face, and the shape of the first mounting groove 13 is the same as that of the first air valve plate 12. The first air valve plate 12 is arranged in the first mounting groove 13, and the upper surface of the first air valve plate 12 is not higher than the end face of the first piston 1, so as to avoid colliding with the valve plate of the valve group part. The first air valve plate 12 is preferentially fixed by spot welding, but is not limited to the method of metal glue fixing. The first air inlet 11 is opened on the first mounting groove 13, and the first air valve plate 12 can open or close the first air inlet 11 under the action of air pressure, and the first air inlet 11 is connected with the low-pressure cavity 311 and the high-pressure cavity 312. When inhaling, the first gas valve is opened, and the high-pressure cavity 312 inhales gas from the low-pressure cavity 311. In this embodiment, the first valve plate is mounted on the first piston 1, the mass of the valve plate is reduced, and thus the cost is reduced. The conventional air valve plate structure covers the piston, and the mass of the valve plate mounted on the piston is relatively large.

[0040] Referring to Figure 6 and Figure 7 In this embodiment, the second gas valve comprises a second air inlet 21 and a second air valve plate 22 for opening and closing the second air inlet 21, and the second piston 2 is provided with a second mounting groove on the side close to the first piston 1, the second air inlet 21 is opened on the second mounting groove, and the second air valve plate 22 is mounted in the second mounting groove. Specifically, the second piston 2 is also a hollow cylinder with one end having an end face and the other end being open. The second mounting groove (not shown in the figure) is opened on the end face, and the shape of the second mounting groove is the same as that of the second air valve plate 22. The second air valve plate 22 is arranged in the second mounting groove, and the second air valve plate 22 is preferentially fixed by spot welding, but is not limited to the method of metal glue fixing. The second air inlet 21 is opened on the second mounting groove, and the second air valve plate 22 can open or close the second air inlet 21 under the action of air pressure, and the second air inlet 21 is connected with the low-pressure cavity 311 and the compressor housing. When inhaling, the second gas valve is opened, and the low-pressure cavity 311 inhales gas from the compressor housing. In this embodiment, the second valve plate is mounted on the second piston 2, the mass of the valve plate is reduced, and thus the cost is reduced. The conventional air valve plate structure covers the piston, and the mass of the valve plate mounted on the piston is relatively large.

[0041] The embodiment of the present application also provides a compressor, which comprises a shell and a piston assembly installed in the shell, and the piston assembly is the piston assembly in the above embodiment. Specifically, the piston assembly has been described in detail in the above embodiment, and is not described here again for the sake of brevity of the description.

[0042] The working process of the compressor of the embodiment for suction and compression of exhaust gas is as follows:

[0043] The suction process: the stroke distance of the first piston 1 is twice that of the second piston 2, and since the stroke distance of the second piston 2 is short, when the first piston 1 is half way through the suction process, the second piston 2 has already completed the suction process, and the first piston 1 is compressed downward under the action of the spring force, the gas in the low-pressure cavity 311 is compressed to a pressure higher than that of the gas in the high-pressure cavity 312, the suction valve of the first piston 1 is opened, and the suction process is started from the low-pressure cavity 311 until the end of the suction process.

[0044] The compression process of the exhaust gas: from the start of the compression, the first piston 1 and the second piston 2 start to compress at the same time, and since the stroke of the second piston 2 is short and part of the gas has been discharged into the high-pressure cavity 312 in the suction process, the remaining gas is compressed and discharged into the high-pressure cavity 312, and the gas in the low-pressure cavity 311 is mixed with the gas in the high-pressure cavity 312 and then compressed and discharged in the high-pressure cavity 312, the first piston 1 is driven by the second piston 2 and the elastic connecting member 5 to rotate with the crankshaft 42, and the first piston 1 can complete the whole process of suction, compression and discharge when the crankshaft 42 rotates 360°. After the gas in the low-pressure cavity 311 is discharged into the high-pressure cavity 312, the pressure in the high-pressure cavity 312 is the intermediate pressure after mixing, and the compressor can reduce the power consumption and improve the refrigerating capacity through two-stage compression.

[0045] Through the embodiment of the present application, the compressor can be divided into two cylinders by changing the structure of the cylinder seat 3 without changing the eccentricity of the crankshaft 42, the piston intercept distance and the center distance between the two holes of the connecting rod 41, thereby increasing the displacement of the compressor and reducing the compression ratio of the compressor, and effectively improving the refrigerating capacity of the compressor.

[0046] The above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A piston assembly, characterized in that, include: Cylinder housing, with cylinder bore; A first piston and a second piston are disposed axially in the cylinder bore to divide the cylinder bore into a low-pressure chamber and a high-pressure chamber. The low-pressure chamber is formed between the first piston and the second piston, and the high-pressure chamber is formed on the side of the first piston away from the second piston. An elastic connector, the two ends of which are respectively connected to the first piston and the second piston; A power component is connected to the second piston. The power component is used to drive the second piston to reciprocate along the axial direction of the cylinder bore. The first piston reciprocates under the drive of the second piston. Wherein, the maximum stroke of the first piston along the axial direction of the cylinder bore is greater than the maximum stroke of the second piston along the axial direction of the cylinder bore. Under the elastic force provided by the elastic connector, the first piston and the second piston move relative to each other to compress the low-pressure chamber, so that the gas in the low-pressure chamber is compressed and discharged into the high-pressure chamber.

2. The piston assembly according to claim 1, characterized in that, The maximum stroke of the first piston along the axial direction of the cylinder bore is twice the maximum stroke of the second piston along the axial direction of the cylinder bore.

3. The piston assembly according to claim 1, characterized in that, The inner wall of the cylinder bore is provided with a groove along its axial direction, and the groove extends away from the second piston; the outer wall of the first piston is provided with a limiting protrusion along its axial direction, and the limiting protrusion is provided in the groove to move along the groove.

4. The piston assembly according to claim 3, characterized in that, The end of the groove closest to the second piston is the lower stop end, and the end of the groove furthest from the second piston is the upper stop end. When the second piston moves to its maximum stroke, the first piston moves between the upper stop end and the lower stop end, and continues to move toward the upper stop end or the lower stop end.

5. The piston assembly according to claim 4, characterized in that, As the first piston continues to move toward the lower stop end, the first piston compresses toward the low-pressure chamber, and the gas in the low-pressure chamber is discharged into the high-pressure chamber.

6. The piston assembly according to any one of claims 1-5, characterized in that, The first piston is provided with a first gas valve that draws gas from the low-pressure chamber into the high-pressure chamber; and / or the second piston is provided with a second gas valve that draws gas into the low-pressure chamber.

7. The piston assembly according to claim 6, characterized in that, The first air valve includes a first air intake port and a first air intake valve plate for opening and closing the first air intake port. A first mounting groove is provided on the side of the first piston away from the second piston. The first air intake port is located in the first mounting groove, and the first air intake valve plate is mounted in the first mounting groove; and / or The second air valve includes a second air intake port and a second air intake valve plate for opening and closing the second air intake port. The second piston is provided with a second mounting groove on the side near the first piston. The second air intake port is opened on the second mounting groove, and the second air intake valve plate is installed in the second mounting groove.

8. The piston assembly according to claim 1, characterized in that, The power component includes a connecting rod and a crankshaft. One end of the connecting rod is connected to the second piston, and the other end of the connecting rod is connected to the crankshaft. When the crankshaft rotates, it drives the second piston to reciprocate along the axial direction of the cylinder bore through the connecting rod.

9. A compressor, characterized in that, Includes the piston assembly as described in any one of claims 1-8.

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