Pump body structure of rotary cylinder piston compressor and rotary cylinder piston compressor

Abstract

The present invention provides a pump body structure of a rotary cylinder piston compressor and a rotary cylinder piston compressor. The pump body structure includes a rotating shaft, a piston and a cylinder. The piston is sleeved on the rotating shaft, and the cylinder is sleeved on the piston. The rotating shaft and the cylinder can be rotatably arranged around their own axes respectively, and the axis of the rotating shaft is eccentrically arranged relative to the axis of the cylinder. When the pump body structure is in operation, the rotating shaft drives the piston to rotate, and the piston drives the cylinder to rotate. The piston reciprocates relative to the cylinder to achieve suction, compression and exhaust. The distance between the outer wall surface of the end of the piston and the inner wall surface of the inner circle of the cylinder is the sealing distance, and the minimum value of the sealing distance is S, and S>1mm. In the rotary cylinder piston compressor, the minimum value S of the sealing distance has a certain influence on leakage and power consumption. By limiting the value range of the minimum sealing distance S and the range of the minimum gap value c, the comprehensive efficiency of the rotary cylinder piston compressor can be improved while ensuring good sealing and smooth assembly, so as to achieve energy saving and emission reduction.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a pump body structure of a rotary cylinder piston compressor and a rotary cylinder piston compressor. Background Art

[0002] The rotary piston compressor is a new type of positive displacement compressor. Its cylinder and shaft rotate around their respective centers, and the piston reciprocates relative to the cylinder and shaft at the same time. The reciprocating motion of the piston relative to the cylinder realizes the periodic expansion and contraction of the volume chamber; the circular motion of the cylinder relative to the cylinder sleeve realizes the connection of the volume chamber with the suction channel and the exhaust channel respectively; the above two composite motions realize the suction, compression and exhaust process of the compressor.

[0003] With the progress of society, the requirements for high efficiency and energy saving of compressors are getting higher and higher. Therefore, it is necessary to optimize the design of rotary cylinder compressors to further improve the efficiency of compressors and achieve energy saving and emission reduction. Summary of the invention

[0004] The present invention provides a pump body structure of a rotary cylinder piston compressor and a rotary cylinder piston compressor, so as to improve the efficiency of the rotary cylinder piston compressor in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, the present invention provides a pump body structure of a rotary cylinder piston compressor, including a rotating shaft, a piston and a cylinder, the piston is sleeved on the rotating shaft, the cylinder is sleeved on the piston, the rotating shaft and the cylinder are respectively rotatable around their own axes, and the axis of the rotating shaft is eccentrically arranged relative to the axis of the cylinder; when the pump body structure is in operation, the rotating shaft drives the piston to rotate, the piston drives the cylinder to rotate, and the piston reciprocates relative to the cylinder; the distance between the outer wall surface of the end of the piston and the inner wall surface of the inner circle of the cylinder is the sealing distance, and the minimum value of the sealing distance is S, S>1mm.

[0006] Furthermore, 2mm≤S≤5mm.

[0007] Furthermore, the cylinder has an axial hole arranged along its axial direction and a radial hole arranged along its radial direction, and the radial hole is connected to the axial hole, wherein the axial hole is used to penetrate the rotating shaft, the radial hole is used to penetrate the piston, and the axial hole is the inner circle of the cylinder.

[0008] Furthermore, the pump body structure has a preset cross-section, the axis of the cylinder is located on the preset cross-section, the inner wall surface of the inner circle of the cylinder and the outer wall surface of the end of the piston are both perpendicular to the preset cross-section, the intersection line of the inner wall surface of the inner circle of the cylinder and the preset cross-section is the first intersection line, the intersection line of the outer wall surface of the end of the piston and the preset cross-section is the second intersection line, the first intersection line and the second intersection line are both parallel to the axis of the cylinder, and the distance between the first intersection line and the second intersection line is the sealing distance.

[0009] Furthermore, there is a gap between the inner wall surface of the inner circle of the cylinder and the surface of the rotating shaft, and the minimum value of the gap is c, which is greater than the sum of the maximum machining deviation of the inner diameter of the cylinder and the maximum machining deviation of the outer diameter of the rotating shaft.

[0010] Furthermore, 0.05mm≤c≤0.3mm.

[0011] Furthermore, the eccentricity between the axis of the rotating shaft and the axis of the cylinder is e, the radius of the rotating shaft is r1, the stroke of the piston is L, the radius of the inner circle of the cylinder is r, and the radius of the outer circle of the cylinder is R, wherein r=r1+e+c, R=r+s+L.

[0012] Furthermore, the outer wall surfaces of the two ends of the piston are both arc-shaped surfaces, and the distance between any one of the two arc-shaped surfaces and the inner wall surface of the inner circle of the cylinder is a sealing distance; the piston has a limiting hole, the limiting hole is located between the two arc-shaped surfaces, the side wall of the rotating shaft is provided with a limiting surface, the rotating shaft is passed through the limiting hole, the limiting surface and the side wall of the limiting hole are limitedly matched to prevent the rotating shaft and the piston from rotating relative to each other, and the maximum size of the radial cross-section of the limiting hole is larger than the size of the diameter of the rotating shaft, so that the piston can move relative to the rotating shaft along the radial direction of the rotating shaft.

[0013] Furthermore, the pump body structure also includes a cylinder liner, in which the cylinder is rotatably arranged, and the inner wall of the cylinder liner, the outer wall surface of the end of the piston and the inner wall of the cylinder form a volume chamber. When the pump body structure is in operation, the position and volume of the volume chamber change to achieve suction, compression and exhaust.

[0014] According to another aspect of the present invention, a rotary piston compressor is provided. The rotary piston compressor comprises the pump body structure provided above.

[0015] By applying the technical solution of the present invention, a pump body structure of a rotary piston compressor is provided. The pump body structure includes a rotating shaft, a piston and a cylinder. The piston is sleeved on the rotating shaft, and the cylinder is sleeved on the piston. The rotating shaft and the cylinder can be rotatably arranged around their own axes respectively, and the axis of the rotating shaft is eccentrically arranged relative to the axis of the cylinder. When the pump body structure is in operation, the rotating shaft drives the piston to rotate, and the piston drives the cylinder to rotate. The piston reciprocates relative to the cylinder to achieve suction, compression and exhaust. The distance between the outer wall surface of the end of the piston and the inner wall surface of the inner circle of the cylinder is the sealing distance, and the minimum value of the sealing distance is S, S>1mm. In the rotary piston compressor, the minimum value S of the sealing distance has a certain influence on leakage and power consumption. Taking into account the volumetric efficiency and mechanical efficiency of the rotary piston compressor, and setting S to the above range through experiments and calculations, the comprehensive efficiency of the compressor can be improved to achieve energy saving and emission reduction.

[0016] Furthermore, by limiting the value range of the minimum sealing distance S and the range of the minimum clearance value c, the overall efficiency of the compressor can be improved while ensuring good sealing and smooth assembly, so as to achieve energy conservation and emission reduction. That is, while ensuring assembly, by controlling the clearance between the inner circle of the cylinder and the rotating shaft, the outer diameter of the cylinder is reduced, the power consumption of the compressor is reduced, and the performance is improved; while ensuring volumetric efficiency, by controlling the minimum sealing distance S between the cylinder and the piston, the outer diameter of the cylinder is reduced, the friction power consumption is reduced, and the mechanical efficiency of the compressor is improved, thereby improving the performance of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 An exploded view of a pump body structure provided by an embodiment of the present invention is shown;

[0019] Figure 2 Shows Figure 1 A cross-sectional view of the pump structure in FIG.

[0020] Figure 3 Shows Figure 1 A cross-sectional view of the cylinder in FIG.

[0021] Figure 4 Shows Figure 3 A top view of the cylinder in FIG.

[0022] Figure 5 Shows Figure 1 A three-dimensional diagram of the rotating shaft in;

[0023] Figure 6 Shows Figure 5 A front view of the rotating shaft in FIG.

[0024] Figure 7 Shows Figure 6 A side view of the rotating shaft in FIG.

[0025] Figure 8 Shows Figure 2 A top view of the pump structure at the end of the suction process;

[0026] Fig. 9 Shows Figure 8 A cross-sectional view of the pump body structure along a preset cross section;

[0027] Fig.10 Shows Figure 2 Another top view of the pump structure at the position just after the suction process ends;

[0028] Fig.11 Shows Fig.10 A cross-sectional view of the pump body structure along a preset cross section;

[0029] Fig.12 A schematic diagram showing the relationship between the efficiency and the minimum sealing distance S of the rotary cylinder piston compressor provided by the present invention is shown;

[0030] Fig.13 Another schematic diagram showing the relationship between the efficiency and the minimum sealing distance S of the rotary cylinder piston compressor provided by the present invention is shown.

[0031] The above drawings include the following reference numerals:

[0032] 10. Rotating shaft; 11. Limiting surface; 12. First shaft section; 13. Second shaft section; 14. Third shaft section; 20. Piston; 21. Outer wall surface; 22. Limiting hole; 30. Cylinder; 31. Inner wall surface; 32. Axial hole; 33. Radial hole; 34. Cylinder body; 35. Upper support ring; 36. Lower support ring; 40. Cylinder liner; 51. Preset cross section; 52. Volume chamber; 61. Upper limiting plate; 62. Lower limiting plate; 70. Upper flange; 80. Lower flange; 81. Flange; 82. Boss. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] As shown in the accompanying drawings, an embodiment of the present invention provides a pump body structure of a rotary cylinder piston compressor, including a rotating shaft 10, a piston 20 and a cylinder 30, wherein the piston 20 is sleeved on the rotating shaft 10, and the cylinder 30 is sleeved on the piston 20, and the rotating shaft 10 and the cylinder 30 are respectively rotatable around their own axes, and the axis of the rotating shaft 10 is eccentrically arranged relative to the axis of the cylinder 30; when the pump body structure is in operation, the rotating shaft 10 drives the piston 20 to rotate, and the piston 20 drives the cylinder 30 to rotate, and the piston 20 reciprocates relative to the cylinder 30; the distance between the outer wall surface 21 of the end of the piston 20 and the inner wall surface 31 of the inner circle of the cylinder 30 is the sealing distance, and the minimum value of the sealing distance is S, and S>1mm.

[0035] When the pump structure is in operation, the size of the seal distance changes with the operation of the pump structure, such as Figure 8 and Fig. 9As shown, when the pump body structure just finishes the suction process, at the position where the piston 20 and the cylinder 30 are located, the distance between the outer wall surface 21 of the end of the piston 20 and the inner wall surface 31 of the inner circle of the cylinder 30 is the smallest, that is, the sealing distance is the minimum value.

[0036] The technical solution of the present invention is applied to provide a pump body structure of a rotary piston compressor, the pump body structure includes a rotating shaft 10, a piston 20 and a cylinder 30, the piston 20 is sleeved on the rotating shaft 10, the cylinder 30 is sleeved on the piston 20, the rotating shaft 10 and the cylinder 30 are respectively rotatable around their own axes, and the axis of the rotating shaft 10 is eccentrically arranged relative to the axis of the cylinder 30; when the pump body structure is in operation, the rotating shaft 10 drives the piston 20 to rotate, the piston 20 drives the cylinder 30 to rotate, and the piston 20 reciprocates relative to the cylinder 30 to achieve suction, compression and exhaust; the distance between the outer wall surface 21 of the end of the piston 20 and the inner wall surface 31 of the inner circle of the cylinder 30 is the sealing distance, and the minimum value of the sealing distance is S, S>1mm. In the rotary piston compressor, the minimum value S of the sealing distance has a certain influence on leakage and power consumption. Taking into account the volumetric efficiency and mechanical efficiency of the rotary piston compressor, and setting S to the above range through experiments and calculations, the comprehensive efficiency of the compressor can be improved to achieve energy saving and emission reduction.

[0037] The minimum seal distance S has a certain influence on the leakage and power consumption of the rotary cylinder piston compressor. The larger the minimum seal distance S, the smaller the leakage and the higher the volumetric efficiency; however, the larger the minimum seal distance S, the larger the outer diameter of the cylinder 30, the greater the friction power consumption, and the lower the mechanical efficiency of the compressor. If the minimum seal distance S is too small, it will lead to poor sealing ability and leakage, affecting the efficiency of the compressor. Therefore, the design of this parameter needs to comprehensively consider the volumetric efficiency and mechanical efficiency to optimize the overall efficiency of the compressor. Fig.12 and Fig.13 The figure shows the relationship curves between the volumetric efficiency, mechanical efficiency and comprehensive efficiency and the minimum sealing distance S obtained through experiments and calculations. It can be seen from the curve that setting the minimum sealing distance S within 2 to 5 mm can make the rotary piston compressor have a higher comprehensive efficiency, so as to achieve energy saving and emission reduction.

[0038] In this embodiment, the cylinder 30 has an axial hole 32 arranged along its axial direction and a radial hole 33 arranged along its radial direction, and the radial hole 33 is connected to the axial hole 32, wherein the axial hole 32 is used to penetrate the rotating shaft 10, and the radial hole 33 is used to penetrate the piston 20, and the axial hole 32 is the inner circle of the cylinder 30. The axis of the axial hole 32 of the cylinder 30 is eccentrically arranged relative to the axis of the rotating shaft 10. When the pump body structure is in operation, the rotating piston 20 drives the cylinder 30 to rotate by cooperating with the radial hole 33, and the piston 20 reciprocates relative to the cylinder 30 in the radial hole 33 of the cylinder 30 to achieve suction, compression and exhaust.

[0039] like Figures 8 to 11 As shown, the pump body structure has a preset cross-section 51, the axis of the cylinder 30 is located on the preset cross-section 51, the inner wall surface 31 of the inner circle of the cylinder 30 and the outer wall surface 21 of the end of the piston 20 are both perpendicular to the preset cross-section 51, the intersection line of the inner wall surface 31 of the inner circle of the cylinder 30 and the preset cross-section 51 is the first intersection line, the intersection line of the outer wall surface 21 of the end of the piston 20 and the preset cross-section 51 is the second intersection line, the first intersection line and the second intersection line are both parallel to the axis of the cylinder 30, and the distance between the first intersection line and the second intersection line is the sealing distance. The inner wall surface 31 of the inner circle of the cylinder 30 is separated from the outer wall surface 21 of the end of the piston 20, that is, by setting the sealing distance, leakage can be avoided as much as possible to ensure the compression effect. For those skilled in the art, the meaning of the sealing distance and its position in the pump body structure are clear and known. The expression here is to further explain the position and definition of the sealing distance from a mathematical perspective so that readers can know the position and definition of the sealing distance more clearly. And, Figure 8 The position shown in is the position where the sealing distance has the minimum value.

[0040] like Fig.10 and Fig.11 As shown, there is a gap between the inner wall surface 31 of the inner circle of the cylinder 30 and the surface of the rotating shaft 10, and the minimum value of the gap is c, which is greater than the sum of the maximum machining deviation of the inner diameter of the cylinder 30 and the maximum machining deviation of the outer diameter of the rotating shaft 10. Since the cylinder 30 is eccentrically arranged, the value of the gap between the inner wall surface 31 of the inner circle of the cylinder 30 and the surface of the rotating shaft 10 is different in the radial direction of the rotating shaft 10 in different directions.

[0041] The friction power consumption between the cylinder 30 and the cylinder sleeve 40 of the rotary piston compressor is proportional to the cube of the outer diameter of the cylinder 30. The larger the outer diameter of the cylinder 30, the greater the power consumption of the whole machine. In order to ensure the assembly of the compressor, a certain gap is set between the inner wall surface 31 of the inner circle of the cylinder 30 and the surface of the rotating shaft 10. If the gap is too large, the size of the cylinder 30 will become larger and the friction power consumption will increase. If the gap is too small, the pump body structure cannot be assembled normally. Therefore, setting the minimum gap value c to be greater than the sum of the maximum machining deviation of the inner diameter of the cylinder 30 and the maximum machining deviation of the outer diameter of the rotating shaft 10 can ensure the normal assembly of the pump body structure. In order to reduce power consumption, it is necessary to minimize the value of c while ensuring normal assembly. In this application, according to the actual processing accuracy and test conditions, the numerical range of c is set to 0.05mm≤c≤0.3mm, which can not only ensure normal assembly, but also reduce power consumption, thereby improving the efficiency of the pump body structure and the compressor.

[0042] In this embodiment, the eccentricity between the axis of the rotating shaft 10 and the axis of the cylinder 30 is e, the radius of the rotating shaft 10 is r1, the stroke of the piston 20 is L, the radius of the inner circle of the cylinder 30 is r, and the radius of the outer circle of the cylinder 30 is R, wherein r=r1+e+c, R=r+s+L. By defining the above parameters, the processing and assembly accuracy of different components of the pump body structure can be guaranteed, and good operation can be achieved. Further, the stroke of the piston 20 is L=2e, the inner diameter of the cylinder 30 is d, and the outer diameter of the cylinder 30 is D.

[0043] In this embodiment, the outer wall surfaces 21 of the two ends of the piston 20 are both arc-shaped surfaces, and the distance between any one of the two arc-shaped surfaces and the inner wall surface 31 of the inner circle of the cylinder 30 is a sealing distance; the piston 20 has a limiting hole 22, and the limiting hole 22 is located between the two arc-shaped surfaces. The side wall of the rotating shaft 10 has a limiting surface 11, and the rotating shaft 10 is inserted into the limiting hole 22. The limiting surface 11 cooperates with the side wall of the limiting hole 22 to prevent the rotating shaft 10 and the piston 20 from rotating relative to each other. The maximum size of the radial cross section of the limiting hole 22 is greater than the size of the diameter of the rotating shaft 10, so that the piston 20 can move relative to the rotating shaft 10 along the radial direction of the rotating shaft 10. Through the cooperation between the limiting surface 11 of the rotating shaft 10 and the side wall of the limiting hole 22 of the piston 20, circumferential limiting can be achieved, so that the rotating shaft 10 drives the piston 20 to rotate when rotating. Since the maximum dimension of the radial cross section of the limiting hole 22 is larger than the diameter of the shaft 10 and the cylinder 30 is eccentrically arranged with respect to the shaft 10, the piston 20 will reciprocate radially relative to the shaft 10 when rotating to achieve suction, compression and exhaust.

[0044] In this embodiment, the pump body structure further includes a cylinder sleeve 40, and the cylinder 30 is rotatably disposed in the cylinder sleeve 40. The inner wall of the cylinder sleeve 40, the outer wall surface 21 of the end of the piston 20, and the inner wall of the cylinder 30 surround and form a volume chamber 52. When the pump body structure is in operation, the position and volume of the volume chamber 52 change to achieve suction, compression, and exhaust. The cylinder sleeve 40 has a suction hole for suction and an exhaust hole for exhaust. When the pump body structure is in operation, the rotating volume chamber 52 can be alternately connected with the suction hole and the exhaust hole to achieve suction and exhaust. There are two volume chambers 52, which are located on both sides of the piston 20. During operation, one volume chamber sucks air, and the other volume chamber 52 compresses and exhausts air.

[0045] Alternatively, if Figure 1 and Figure 2As shown, the pump body structure also includes an upper limit plate 61 and a lower limit plate 62, which are respectively matched with the two end faces of the cylinder sleeve 40, and the cylinder 30 includes a cylinder body 34 and an upper support ring 35 and a lower support ring 36 respectively arranged at both ends of the cylinder body 34, and the upper support ring 35 and the lower support ring 36 are respectively located at both ends of the cylinder body 34, and the piston 20 is arranged in the cylinder body 34, and the rotating shaft 10 passes through the upper support ring 35, the cylinder body 34 and the lower support ring 36 in sequence, and the upper support ring 35 is arranged in the hole of the upper limit plate 61, and the lower support ring 36 is arranged in the hole of the lower limit plate 62, and the upper limit plate 61 and the upper limit plate 61 have a clearance match, and the lower limit plate 62 and the lower limit plate 62 have a clearance match. Through the above arrangement, the reliable assembly and limiting of the cylinder 30 and other components can be achieved, and the smooth rotation of the cylinder 30 can be ensured.

[0046] Optionally, the pump body structure further includes an upper flange 70 and a lower flange 80, wherein the upper flange 70 is connected to the upper limit plate 61, and the lower flange 80 is connected to the lower limit plate 62, and there is a gap between the upper support ring 35 and the upper flange 70, and there is a gap between the lower support ring 36 and the lower flange 80. In this way, reliable connection of the components can be further achieved, and resistance and wear of the cylinder 30 during rotation can be reduced.

[0047] Optionally, the rotating shaft 10 includes a first shaft section 12, a second shaft section 13 and a third shaft section 14 connected in sequence, the second shaft section 13 has a limiting surface 11, the first shaft section 12 is inserted into the upper flange 70 and the upper limit plate 61, the piston 20 is sleeved on the second shaft section 13, the diameter of the first shaft section 12 is equal to the diameter of the second shaft section 13, the diameter of the third shaft section 14 is smaller than the diameter of the second shaft section 13, and the third shaft section 14 is inserted into the lower flange 80. Through the above arrangement, the rotating shaft 10 can be matched with related components and the axial direction of the rotating shaft 10 can be limited.

[0048] Optionally, the lower flange 80 includes a flange 81 and a boss 82 disposed on the flange 81, the boss 82 is inserted into the second support ring, the third shaft section 14 is inserted into the boss 82, and the end surface of the second shaft section 13 abuts against the end surface of the boss 82. The boss 82 is columnar. In this way, the boss 82 can limit and guide the rotation of the cylinder 30, and the boss 82 can limit the axial direction of the rotating shaft 10.

[0049] Another embodiment of the present invention further provides a rotary cylinder piston compressor, which includes the pump body structure provided above. The rotary cylinder piston compressor is a positive displacement compressor, in which the cylinder 30 and the rotating shaft 10 rotate around their respective centers, and the piston 20 reciprocates simultaneously relative to the cylinder 30 and the rotating shaft 10. The reciprocating motion of the piston 20 relative to the cylinder 30 realizes the periodic enlargement and reduction of the volume chamber; the circular motion of the cylinder 30 relative to the cylinder sleeve realizes the communication between the volume chamber and the intake channel and the exhaust channel respectively; the above two composite motions realize the intake, compression, and exhaust processes of the compressor.

[0050] The rotary piston compressor is essentially a compressor that adopts the principle of the cross slider structure and combines the main structure of the piston compressor with the main structure of the rotor compressor. The rotary piston compressor includes a rotating shaft 10, a piston 20 sleeved outside the rotating shaft 10, and a cylinder 30 sleeved outside the piston 20. The rotating shaft 10 and the cylinder 30 are eccentrically assembled. The rotating shaft 10 drives the cylinder 30 to rotate through the piston 20. Due to the eccentric relationship between the rotating shaft 10 and the cylinder 30, during operation, the rotating shaft 10 and the cylinder 30 rotate around their respective axes respectively, and the piston 20 reciprocates relative to the cylinder 30 to achieve gas compression.

[0051] In this embodiment, by limiting the value range of the minimum sealing distance S and the range of the minimum clearance value c, the overall efficiency of the compressor can be improved while ensuring good sealing and smooth assembly, so as to achieve energy conservation and emission reduction. That is, while ensuring assembly, by controlling the clearance between the inner circle of the cylinder 30 and the rotating shaft 10, the outer diameter of the cylinder 30 is reduced, the power consumption of the compressor is reduced, and the performance is improved; while ensuring volumetric efficiency, by controlling the minimum sealing distance S between the cylinder 30 and the piston 20, the outer diameter of the cylinder 30 is reduced, the friction power consumption is reduced, and the mechanical efficiency of the compressor is improved, thereby improving the performance of the compressor.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pump body structure of a rotary cylinder piston compressor, characterized in that: The invention comprises a rotating shaft (10), a piston (20) and a cylinder (30), wherein the piston (20) is sleeved on the rotating shaft (10), and the cylinder (30) is sleeved on the piston (20); the rotating shaft (10) and the cylinder (30) are respectively rotatable around their own axes, and the axis of the rotating shaft (10) is eccentrically arranged relative to the axis of the cylinder (30); When the pump body structure is in operation, the rotating shaft (10) drives the piston (20) to rotate, the piston (20) drives the cylinder (30) to rotate, and the piston (20) performs reciprocating motion relative to the cylinder (30); The distance between the outer wall surface (21) of the end of the piston (20) and the inner wall surface (31) of the inner circle of the cylinder (30) is a sealing distance, and the minimum value of the sealing distance is S, 2mm≤S≤5mm; The cylinder (30) has an axial hole (32) arranged along its axial direction and a radial hole (33) arranged along its radial direction, the radial hole (33) being in communication with the axial hole (32), wherein the axial hole (32) is used to penetrate the rotating shaft (10), the radial hole (33) is used to penetrate the piston (20), and the axial hole (32) is the inner circle of the cylinder (30); The pump body structure further comprises a cylinder sleeve (40), the cylinder (30) being rotatably arranged in the cylinder sleeve (40), the inner wall of the cylinder sleeve (40), the outer wall surface (21) of the end of the piston (20) and the inner wall of the cylinder (30) surroundingly forming a volume chamber (52), and when the pump body structure is in operation, the position and volume of the volume chamber (52) change to achieve suction, compression and exhaust.

2. The pump structure according to claim 1, characterized in that: The pump body structure has a preset cross section (51), the axis of the cylinder (30) is located on the preset cross section (51), the inner wall surface (31) of the inner circle of the cylinder (30) and the outer wall surface (21) of the end of the piston (20) are both perpendicular to the preset cross section (51), the intersection line of the inner wall surface (31) of the inner circle of the cylinder (30) and the preset cross section (51) is a first intersection line, the intersection line of the outer wall surface (21) of the end of the piston (20) and the preset cross section (51) is a second intersection line, the first intersection line and the second intersection line are both parallel to the axis of the cylinder (30), and the distance between the first intersection line and the second intersection line is the sealing distance.

3. The pump body structure according to any one of claims 1 to 2, characterized in that: There is a gap between the inner wall surface (31) of the inner circle of the cylinder (30) and the surface of the rotating shaft (10), and the minimum value of the gap is c, which is greater than the sum of the maximum machining deviation of the inner diameter of the cylinder (30) and the maximum machining deviation of the outer diameter of the rotating shaft (10).

4. The pump structure according to claim 3, characterized in that: 0.05mm≤c≤0.3mm.

5. The pump structure according to claim 3, characterized in that: The eccentricity between the axis of the rotating shaft (10) and the axis of the cylinder (30) is e, the radius of the rotating shaft (10) is r1, the stroke of the piston (20) is L, the radius of the inner circle of the cylinder (30) is r, and the radius of the outer circle of the cylinder (30) is R, wherein: r= r1+e+c, R=r+S+L.

6. The pump structure according to claim 1, characterized in that: The outer wall surfaces (21) of the two ends of the piston (20) are both arc-shaped surfaces, and the distance between any one of the two arc-shaped surfaces and the inner wall surface (31) of the inner circle of the cylinder (30) is the sealing distance; The piston (20) has a limiting hole (22), and the limiting hole (22) is located between the two arc-shaped surfaces. The side wall of the rotating shaft (10) has a limiting surface (11), and the rotating shaft (10) is inserted into the limiting hole (22). The limiting surface (11) and the side wall of the limiting hole (22) are limitedly matched to prevent the rotating shaft (10) and the piston (20) from rotating relative to each other. The maximum size of the radial cross section of the limiting hole (22) is greater than the diameter of the rotating shaft (10), so that the piston (20) can move relative to the rotating shaft (10) along the radial direction of the rotating shaft (10).

7. A rotary piston compressor, characterized in that: The rotary piston compressor comprises the pump body structure according to any one of claims 1 to 6.

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