Single-machine two-stage compressor with screw and piston connected in series and compression method of single-machine two-stage compressor

Abstract

The invention relates to a single-machine two-stage compressor with a screw and a piston connected in series and a compression method of the single-machine two-stage compressor. The motor comprises a motor body and a rotor body, a motor stator and a motor rotor which are matched with each other are arranged in the motor body, one end of the rotor body is connected with one end of the motor body, and a male rotor and a female rotor which are meshed with each other are arranged in the rotor body. One end of the connecting machine body is connected with the other end of the rotor machine body, a worm gear and worm shell is fixed to the inner wall of a sealing plate of the connecting machine body, a worm gear and a worm which are matched with each other are arranged in the worm gear and worm shell, a driven bevel gear is arranged at one end of the worm, and a driving bevel gear is arranged at the rear end of the male rotor. One end of the connecting pipe is connected with a sealing plate of the connecting machine body, and the other end of the connecting pipe is connected with one end of the air cylinder machine body. The device is reasonable in structural design, reliable in performance and low in noise.

Description

Technical Field

[0001] The invention relates to a single-machine two-stage compressor in which a screw rod and a piston are connected in series and a compression method thereof, belonging to the technical field of compressors. Background Art

[0002] The adaptability of a twin-screw single-unit two-stage compressor is poor. In applications with lower evaporation temperatures, the performance of a twin-screw single-unit two-stage compressor will be greatly limited and cannot meet the working requirements under large pressure difference conditions of low evaporation or high condensation.

[0003] In order to improve the adaptability of single-machine two-stage compressors, there are currently single-machine two-stage compressors with screws and pistons in series. However, the existing single-machine two-stage compressors with screws and pistons in series have poor safety and produce relatively loud noise during operation. This is because the structural design of the existing single-machine two-stage compressors with screws and pistons in series is unreasonable. The screw machine and the piston machine are generally connected by a reduction gear, and the piston machine has low-frequency pulsation, which can easily affect the rotation of the screw machine, reduce the life of the screw bearing, and have an adverse effect on the screw machine, affecting safety and causing relatively loud noise.

[0004] Currently, there is no single-unit two-stage compressor and compression method thereof in which the screw and the piston are connected in series and which has a reasonable structural design, reliable safety performance and low noise. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a single-unit two-stage compressor with a screw and a piston connected in series, which has a reasonable structural design, reliable safety performance and low noise, and a compression method thereof.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: the single-machine two-stage compressor with a screw and a piston connected in series comprises a motor body, a terminal block and a rotor body, the motor body is provided with a motor stator and a motor rotor that cooperate with each other, the motor body is provided with an air inlet, and the terminal block is installed on the motor body; one end of the rotor body is connected to one end of the motor body through a flange, and a male rotor and a female rotor that mesh with each other are provided in the rotor body, and the front end of the male rotor is fixed to the motor rotor in the motor body; its structural characteristics are: it also includes a connecting body, a connecting pipe and a cylinder body, one end of the connecting body is connected to the other end of the rotor body through a flange, and the other end of the connecting body is provided with a sealing plate for sealing, the connecting body is provided with an air supply port, and an exhaust end body is installed inside the connecting body, and the rear of the male rotor and the rear of the female rotor are both installed on the exhaust end body; the inner wall of the sealing plate of the connecting body is fixed with a worm gear and a worm gear. The worm gear housing is provided with a worm gear and a worm gear which cooperate with each other, a driven bevel gear is provided at one end of the worm gear, and a driving bevel gear is provided at the rear end of the male rotor, and the driving bevel gear and the driven bevel gear are meshed; the cylinder body is fixed to the outer wall of the sealing plate of the connecting body, a crankshaft is installed in the cylinder body, one end of the crankshaft extends into the connecting body and is coaxially fixed with the worm gear, a plurality of piston chambers are provided in the cylinder body, a piston suction port and a piston exhaust port are provided at the top of each piston chamber, and an suction valve plate and an exhaust valve plate are respectively provided on the piston suction port and the piston exhaust port, a piston is installed in each piston chamber, and each piston is connected to the crankshaft by a connecting rod; one end of the connecting pipe is connected to the sealing plate of the connecting body, and the connecting pipe is connected to the interior of the connecting body, the other end of the connecting pipe is connected to one end of the cylinder body, and the connecting pipe is connected to the interior of the cylinder body, and the other end of the cylinder body is provided with an outlet.

[0007] Preferably, the connecting body of the present invention is a gradually expanding cylindrical structure.

[0008] Preferably, the rear part of the male rotor and the rear part of the female rotor of the present invention are both mounted on the exhaust end body via bearings.

[0009] Preferably, the air intake valve plate of the present invention is located on a side of the piston air intake port close to the piston.

[0010] Preferably, the exhaust valve plate of the present invention is located on a side of the piston exhaust port away from the piston.

[0011] Preferably, the motor body of the present invention has a cylindrical structure in appearance.

[0012] Preferably, the rotor body of the present invention has a cylindrical structure in appearance.

[0013] Preferably, the piston air intake port of the present invention is a cylindrical through-hole structure, and the piston exhaust port is a cylindrical through-hole structure.

[0014] Preferably, the number of piston chambers in the cylinder body of the present invention is 2 to 12.

[0015] Preferably, the cylinder body of the present invention has a rectangular parallelepiped structure in appearance.

[0016] A compression method of a single-unit two-stage compressor in which a screw and a piston are connected in series, wherein the compression method comprises the following steps: a. When the power supply is turned on, the motor rotor starts to rotate, driving the positive rotor to rotate. The negative rotor meshes with the positive rotor, and the positive rotor drives the negative rotor to rotate. b. As the male rotor rotates, the driving bevel gear on the male rotor rotates with the male rotor, the driving bevel gear meshes with the driven bevel gear, and the driving bevel gear drives the driven bevel gear to rotate; c. The worm and the driven bevel gear rotate synchronously, the worm drives the worm wheel to rotate, the worm wheel drives the crankshaft to rotate, the crankshaft drives the connecting rod to make periodic motion, and the connecting rod drives the piston to make reciprocating motion; d. The working fluid to be compressed enters the compressor from the air inlet, passes through the interior of the motor body, and reaches the air intake of the yin and yang rotors in the rotor body. As the yang and yin rotors rotate, the working fluid is continuously compressed and moves toward the direction of the exhaust end body. The compressed working fluid is discharged from the exhaust port of the exhaust end body and then reaches the interior of the connecting body; e. While the working fluid flows inside the connecting body, the connecting body exchanges heat with the outside to reduce the temperature of the internal working fluid. In addition, low-temperature gas is added to the gas supply port, and the added low-temperature gas is mixed with the working fluid in the connecting body to reduce the temperature of the working fluid inside the connecting body, thereby achieving the effect of interstage cooling, and the temperature of the working fluid will be significantly reduced; f. The working fluid inside the connecting body enters the cylinder body through the connecting pipe, and the connecting pipe is exposed to the outside. After the working fluid flows through the connecting pipe, the temperature is also reduced. When the outside temperature is low, the cooling effect here is better; g. After the cooled working medium enters the cylinder body, the piston reciprocates under the action of the crankshaft. When the piston is in the process of moving away from the piston suction port, the suction valve plate opens, the exhaust valve plate closes, and the working medium enters the piston cavity from the piston suction port; when the piston is in the process of approaching the piston suction port, the suction valve plate closes, the exhaust valve plate opens, and the working medium in the piston cavity is discharged from the piston exhaust port, thereby leaving the piston cavity; h. The working fluid leaving the piston chamber is eventually discharged through the outlet and leaves the compressor, thus completing the compression of the working fluid.

[0017] Compared with the prior art, the present invention has the following advantages and effects: (1) Compared with the existing twin-screw two-stage compressor, the advantages of the present invention are as follows: ① Better compression efficiency and refrigeration capacity On the one hand, the screw-piston two-stage compressor uses two-stage continuous compression and intercooling technology. The high-temperature gas after the first stage of compression is cooled by the intercooler before entering the second stage of compression. This can significantly reduce the temperature of the gas and improve the efficiency of the next stage of compression. This design makes the gas closer to isothermal compression during the compression process and also reduces power consumption. Therefore, it can show higher compression efficiency and refrigeration capacity under conditions requiring large cooling output or low temperature operation. On the other hand, the high-pressure stage adopts piston compression, which is essentially a contact seal, easier to implement, and has less internal leakage and higher performance than the screw compression form.

[0018] ② Wider scope of application On the one hand, in the middle of the two-stage compression, cooling is performed through an intercooler, which can significantly reduce the temperature of the gas. This design makes the gas closer to isothermal compression during the compression process, reduces power consumption, and helps to obtain a lower evaporation temperature; On the other hand, the piston compression method as the second-stage compression can adapt to situations where there is a large difference between the suction and exhaust pressures, such as continuing to compress the gas under low temperature and low pressure or high temperature and high pressure conditions, thereby meeting lower evaporation temperature or higher condensation temperature requirements. Therefore, in applications where a large difference in suction and exhaust pressure is required, the screw plus piston two-stage compressor can ensure stable operation of the system while meeting this requirement, thus having a wider range of applications.

[0019] (2) Compared with the existing screw plus piston single-unit two-stage compressor, the advantages of the present invention are as follows: ①Higher reliability In the existing single-machine two-stage compressor with screw and piston connected in series, the screw machine and the piston machine are generally connected by a reduction gear, and the piston machine has low-frequency pulsation, which is transmitted to the screw, and it is easy to affect the rotation of the screw machine, causing adverse effects on the screw machine. The present invention is designed with a worm gear and a worm with a reducer function. The piston and the crankshaft have low-frequency pulsation, and the worm gear and the worm have a self-locking function, that is, the worm gear cannot drive the worm, blocking the transmission of low-frequency pulsation. Therefore, the self-locking function of the worm gear and the worm is used to achieve "one-way transmission", eliminating the possibility that the pulsation of the piston and the crankshaft affects the screw in reverse, so the reliability is higher.

[0020] ②Smooth transmission and low noise On the one hand, the kinematic pair of the worm gear transmission is a spiral pair, so the transmission is smooth and not easy to generate vibration and noise. This stable transmission method allows the worm gear connection to maintain a low noise level at high speed, improving the overall performance of the equipment; On the other hand, the transmission ratio of the worm gear transmission can be between 8-100. Compared with the gear transmission, its transmission ratio is larger and can achieve a larger reduction ratio, which means that the speed of the crankshaft of the piston part can be further reduced, which helps to reduce noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention and / or the technical solutions in the prior art, the drawings required for use in the embodiments and / or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of a single-unit two-stage compressor in which a screw and a piston are connected in series in an embodiment of the present invention.

[0023] Figure 2 It is a three-dimensional structural schematic diagram from another perspective of a single-unit two-stage compressor in which a screw and a piston are connected in series in an embodiment of the present invention.

[0024] Figure 3 It is a three-dimensional structural schematic diagram from another perspective of a single-unit two-stage compressor in which a screw and a piston are connected in series in an embodiment of the present invention.

[0025] Figure 4 It is a schematic diagram of the main structure of a single-unit two-stage compressor in which a screw and a piston are connected in series in an embodiment of the present invention.

[0026] Figure 5 It is a schematic diagram of the structure of a single-unit two-stage compressor in which a screw and a piston are connected in series in an embodiment of the present invention, viewed from above.

[0027] Figure 6 yes Figure 4 The cross-sectional structure diagram of the AA plane is shown in the figure, and the working medium flow direction is indicated in the figure.

[0028] Figure 7 yes Figure 5 Schematic diagram of the cross-sectional structure of the BB surface.

[0029] Figure 8 yes Figure 5 Schematic diagram of the enlarged cross-sectional structure of the middle CC surface.

[0030] Fig. 9 yes Figure 4Schematic diagram of the enlarged cross-sectional structure of the middle DD surface.

[0031] Fig.10 yes Figure 5 The cross-sectional enlarged structural diagram of the EE surface in the middle shows the flow direction of the working medium.

[0032] Fig.11 yes Figure 5 Schematic diagram of the enlarged cross-sectional structure of the middle FF surface.

[0033] In the figure: 1-air inlet; 2-motor body; 3-terminal board; 4-rotor body; 5-connecting body; 6-connecting pipe; 7-cylinder body; 8-air supply port; 9-air outlet; 10-motor stator; 11-motor rotor; 12-male rotor; 13-female rotor; 14-exhaust end body; 15-driving bevel gear; 16-driven bevel gear; 17-worm; 18-worm wheel; 19-worm gear housing; 20-crankshaft; 21-connecting rod; 22-piston; 23-piston suction port; 24-piston exhaust port; 25-intake valve plate; 26-exhaust valve plate; 27-piston chamber; 28-sealing plate. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0035] Example

[0036] See also Figures 1 to 11 The single-unit two-stage compressor with a screw and a piston connected in series in this embodiment includes a motor body 2, a terminal board 3, a rotor body 4, a connecting body 5, a connecting pipe 6 and a cylinder body 7.

[0037] In the present embodiment, a motor body 2 is provided with a motor stator 10 and a motor rotor 11 that cooperate with each other, an air inlet 1 is provided on the motor body 2, and a terminal block 3 is installed on the motor body 2. When the terminal block 3 is powered on, the motor rotor 11 can rotate under the action of the motor stator 10.

[0038] One end of the rotor body 4 in this embodiment is connected to one end of the motor body 2 through a flange, and a male rotor 12 and a female rotor 13 that mesh with each other are arranged in the rotor body 4. The front end of the male rotor 12 is fixed to the motor rotor 11 in the motor body 2. After the motor rotor 11 rotates, it can drive the male rotor 12 to rotate, and drive the female rotor 13 to rotate through the male rotor 12, thereby realizing the function of the male rotor 12 and the female rotor 13 to compress the working fluid.

[0039] In this embodiment, one end of the connecting body 5 is connected to the other end of the rotor body 4 through a flange, and the other end of the connecting body 5 is provided with a sealing plate 28 for sealing. The connecting body 5 is provided with an air supply port 8, and the working medium can enter the compressor from the air supply port 8. An exhaust end body 14 is installed inside the connecting body 5, and the rear part of the male rotor 12 and the rear part of the female rotor 13 are both installed on the exhaust end body 14, that is, the rear part of the male rotor 12 is rotatably installed on one exhaust end body 14, and the rear part of the female rotor 13 is rotatably installed on the other exhaust end body 14. The working medium in the rotor body 4 can enter the connecting body 5 through the exhaust end body 14. Normally, the rear part of the male rotor 12 and the rear part of the female rotor 13 are both installed on the exhaust end body 14 through bearings.

[0040] In this embodiment, a worm gear housing 19 is fixed to the inner wall of the sealing plate 28 of the connecting body 5, and a worm gear 18 and a worm 17 are arranged in the worm gear housing 19. A driven bevel gear 16 is arranged at one end of the worm 17, and a driving bevel gear 15 is arranged at the rear end of the male rotor 12, and the driving bevel gear 15 and the driven bevel gear 16 are meshed. The driving bevel gear 15 can be driven to rotate by the rotation of the male rotor 12, and the driven bevel gear 16 can be driven to rotate by the driving bevel gear 15, and the worm 17 can be driven to rotate by the driven bevel gear 16, and then the worm 17 can be driven to rotate by the rotation of the worm 17.

[0041] The cylinder body 7 in this embodiment is fixed to the outer wall of the sealing plate 28 of the connecting body 5. A crankshaft 20 is installed in the cylinder body 7. One end of the crankshaft 20 extends into the connecting body 5 and is coaxially fixed with the worm gear 18. The rotation of the worm gear 18 can drive the crankshaft 20 to rotate. Four piston chambers 27 are arranged in the cylinder body 7. The number of piston chambers 27 can be determined according to actual conditions. Under normal circumstances, the number of piston chambers 27 in the cylinder body 7 is 2 to 12. The top of each piston chamber 27 is provided with a piston suction port 23 and a piston exhaust port 24. The piston suction port 23 is provided with an intake valve plate 25. The intake valve plate 25 is located on the side of the piston suction port 23 close to the piston 22. The intake valve plate 25 can be opened and closed as the force of the working medium changes. The piston exhaust port 24 is provided with an exhaust valve plate 26. The exhaust valve plate 26 is located on the side of the piston exhaust port 24 away from the piston 22. The exhaust valve plate 26 can be opened and closed as the force of the gas changes. A piston 22 is installed in each piston chamber 27, and each piston 22 is connected to the crankshaft 20 via a connecting rod 21, that is, one end of the connecting rod 21 is connected to the piston 22, and the other end of the connecting rod 21 is connected to the crankshaft 20. Through the rotation of the crankshaft 20 and under the action of the connecting rod 21, the piston 22 can make reciprocating motion in the piston chamber 27.

[0042] In this embodiment, one end of the connecting pipe 6 is connected to the sealing plate 28 of the connecting body 5, and the connecting pipe 6 is connected to the inside of the connecting body 5, and the other end of the connecting pipe 6 is connected to one end of the cylinder body 7, and the connecting pipe 6 is connected to the inside of the cylinder body 7, and the working medium inside the connecting body 5 can enter the cylinder body 7 through the connecting pipe 6. An outlet 9 is provided at the other end of the cylinder body 7, and the compressed working medium is discharged from the compressor through the outlet 9.

[0043] The connecting body 5 in this embodiment is a gradually expanding cylindrical structure, that is, along the flow direction of the working medium, the connecting body 5 gradually expands. The outer shape of the motor body 2 is a cylindrical structure, and the outer shape of the rotor body 4 is also a cylindrical structure. The piston air intake port 23 is a cylindrical through-hole structure, and the piston exhaust port 24 is also a cylindrical through-hole structure. The outer shape of the cylinder body 7 is a rectangular parallelepiped structure.

[0044] The steps of the compression method of the single-unit two-stage compressor in which the screw and the piston are connected in series in this embodiment are as follows: a. When the power supply is turned on to the terminal block 3, the motor rotor 11 starts to rotate, and drives the positive rotor 12 to rotate, the negative rotor 13 meshes with the positive rotor 12, and the positive rotor 12 drives the negative rotor 13 to rotate; b. Under the rotation of the positive rotor 12, the driving bevel gear 15 on the positive rotor 12 rotates with the positive rotor 12, the driving bevel gear 15 and the driven bevel gear 16 mesh, and the driving bevel gear 15 drives the driven bevel gear 16 to rotate; c. The worm 17 rotates synchronously with the driven bevel gear 16, the worm 17 drives the worm wheel 18 to rotate, the worm wheel 18 drives the crankshaft 20 to rotate, the crankshaft 20 drives the connecting rod 21 to perform periodic motion, and the connecting rod 21 drives the piston 22 to reciprocate; d. The working medium to be compressed enters the compressor from the air inlet 1, passes through the interior of the motor body 2, and reaches the air intake ports of the yin and yang rotors in the rotor body 4. As the yang rotor 12 and the yin rotor 13 rotate, the working medium is continuously compressed and moves in the direction of the exhaust end body 14. The compressed working medium is discharged from the exhaust port of the exhaust end body 14 and then reaches the interior of the connecting body 5; e. While the working fluid flows inside the connecting body 5, the connecting body 5 exchanges heat with the outside to reduce the temperature of the working fluid inside. In addition, low-temperature gas is added to the gas inlet 8, and the added low-temperature gas is mixed with the working fluid in the connecting body 5 to reduce the temperature of the working fluid inside the connecting body 5, thereby achieving the effect of interstage cooling, and the temperature of the working fluid will be significantly reduced; the operation of achieving a significant cooling effect on the working fluid is mainly achieved by adding low-temperature gas to the gas inlet 8. The low-temperature gas added to the gas inlet 8 is usually low-temperature gas fluorine. Of course, the heat exchange between the connecting body 5 and the outside also achieves the effect of reducing the temperature of the working fluid inside the connecting body 5; f. The working fluid located inside the connecting body 5 enters the cylinder body 7 through the connecting pipe 6, and the connecting pipe 6 is exposed to the outside. After the working fluid flows through the connecting pipe 6, the cooling effect is also achieved; when the outside temperature is low, the cooling effect here is better; g. After the cooled working medium enters the cylinder body 7, the piston 22 reciprocates under the action of the crankshaft 20. When the piston 22 is in the process of moving away from the piston air intake port 23, the air intake valve plate 25 opens, the exhaust valve plate 26 closes, and the working medium enters the piston cavity 27 from the piston air intake port 23; when the piston 22 is in the process of approaching the piston air intake port 23, the air intake valve plate 25 closes, the exhaust valve plate 26 opens, and the working medium in the piston cavity 27 is discharged from the piston exhaust port 24, thereby leaving the piston cavity 27; h. The working fluid leaving the piston chamber 27 is finally discharged through the gas outlet 9 and leaves the compressor, thereby completing the compression of the working fluid.

[0045] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A single-unit two-stage compressor with a screw and a piston connected in series, comprising a motor body (2), a terminal block (3) and a rotor body (4), wherein the motor body (2) is provided with a motor stator (10) and a motor rotor (11) that cooperate with each other, the motor body (2) is provided with an air inlet (1), and the terminal block (3) is mounted on the motor body (2); one end of the rotor body (4) is connected to one end of the motor body (2) through a flange, and the rotor body (4) is provided with a male rotor (12) and a female rotor (13) that mesh with each other, and the front end of the male rotor (12) is fixed to the motor rotor (11) in the motor body (2); characterized in that: It also comprises a connecting body (5), a connecting pipe (6) and a cylinder body (7), one end of the connecting body (5) being connected to the other end of the rotor body (4) via a flange, the other end of the connecting body (5) being provided with a sealing plate (28) for sealing, the connecting body (5) being provided with an air supply port (8), an exhaust end body (14) being installed inside the connecting body (5), the rear part of the male rotor (12) and the rear part of the female rotor (13) being both installed on the exhaust end body (14); A worm gear housing (19) is fixed to the inner wall of the sealing plate (28) of the connecting body (5), and a worm gear (18) and a worm (17) are arranged in the worm gear housing (19) and cooperate with each other. A driven bevel gear (16) is arranged at one end of the worm (17), and a driving bevel gear (15) is arranged at the rear end of the male rotor (12), and the driving bevel gear (15) and the driven bevel gear (16) are meshed; the cylinder body (7) is fixed to the sealing plate (28) of the connecting body (5). The outer wall of the cylinder body (7) is provided with a crankshaft (20), one end of the crankshaft (20) extends into the connecting body (5) and is coaxially fixed with the worm gear (18), a plurality of piston chambers (27) are provided in the cylinder body (7), a piston air intake port (23) and a piston air exhaust port (24) are provided at the top of each piston chamber (27), an air intake valve plate (25) and an air exhaust valve plate (26) are provided on the piston air intake port (23) and the piston air exhaust port (24), respectively, and each piston chamber (27) is provided with a plurality of piston chambers (27), each piston chamber (27) is provided with a plurality of piston chambers (27), and a plurality of piston chambers (27) are provided with a plurality of piston chambers (27) at the top of each piston chamber (27). A piston (22) is installed in each of the plug chambers (27), and each piston (22) is connected to the crankshaft (20) via a connecting rod (21). One end of the connecting pipe (6) is connected to a sealing plate (28) of the connecting body (5), and the connecting pipe (6) and the interior of the connecting body (5) are in communication. The other end of the connecting pipe (6) is connected to one end of the cylinder body (7), and the connecting pipe (6) and the interior of the cylinder body (7) are in communication. The other end of the cylinder body (7) is provided with an air outlet (9).

2. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1 is characterized in that: The connecting body (5) is a gradually expanding cylindrical structure.

3. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1, characterized in that: The rear part of the male rotor (12) and the rear part of the female rotor (13) are both mounted on the exhaust end body (14) via bearings.

4. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1, characterized in that: The air intake valve plate (25) is located on a side of the piston air intake port (23) close to the piston (22).

5. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1, characterized in that: The exhaust valve plate (26) is located on a side of the piston exhaust port (24) away from the piston (22).

6. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1, characterized in that: The motor body (2) has a cylindrical structure in appearance.

7. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1, characterized in that: The rotor body (4) has a cylindrical structure in appearance.

8. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1, characterized in that: The piston air intake port (23) is a cylindrical through-hole structure, and the piston air exhaust port (24) is a cylindrical through-hole structure.

9. The single-unit two-stage compressor with a screw and a piston connected in series according to claim 1, characterized in that: The number of piston chambers (27) in the cylinder body (7) is 2 to 12.

10. A compression method for a single-unit two-stage compressor in which a screw and a piston are connected in series, characterized in that: Using a single-unit two-stage compressor in which a screw and a piston are connected in series as claimed in any one of claims 1 to 9, the steps of the compression method are as follows: a. When the power supply is turned on at the terminal block (3), the motor rotor (11) starts to rotate and drives the male rotor (12) to rotate. The female rotor (13) meshes with the male rotor (12), and the male rotor (12) drives the female rotor (13) to rotate. b. As the male rotor (12) rotates, the driving bevel gear (15) on the male rotor (12) rotates together with the male rotor (12), the driving bevel gear (15) and the driven bevel gear (16) mesh, and the driving bevel gear (15) drives the driven bevel gear (16) to rotate; c. The worm (17) and the driven bevel gear (16) rotate synchronously, the worm (17) drives the worm wheel (18) to rotate, the worm wheel (18) drives the crankshaft (20) to rotate, the crankshaft (20) drives the connecting rod (21) to perform periodic motion, and the connecting rod (21) drives the piston (22) to perform reciprocating motion; d. The working medium to be compressed enters the compressor from the air inlet (1), passes through the interior of the motor body (2), and reaches the air intake ports of the male and female rotors in the rotor body (4). As the male rotor (12) and the female rotor (13) rotate, the working medium is continuously compressed and moves in the direction of the exhaust end body (14). The compressed working medium is discharged from the exhaust port of the exhaust end body (14) and then reaches the interior of the connecting body (5); e. While the working fluid flows inside the connecting body (5), the connecting body (5) exchanges heat with the outside to reduce the temperature of the working fluid inside. In addition, low-temperature gas is added to the gas supply port (8), and the added low-temperature gas is mixed with the working fluid in the connecting body (5) to reduce the temperature of the working fluid inside the connecting body (5), thereby achieving an inter-stage cooling effect, and the temperature of the working fluid is significantly reduced; f. The working fluid located inside the connecting body (5) enters the cylinder body (7) through the connecting pipe (6), and the connecting pipe (6) is exposed to the outside. After the working fluid flows through the connecting pipe (6), the temperature is also reduced; g. After the cooled working medium enters the cylinder body (7), the piston (22) performs reciprocating motion under the action of the crankshaft (20). When the piston (22) is in the process of moving away from the piston suction port (23), the suction valve plate (25) is opened, the exhaust valve plate (26) is closed, and the working medium enters the piston cavity (27) from the piston suction port (23); when the piston (22) is in the process of moving close to the piston suction port (23), the suction valve plate (25) is closed, the exhaust valve plate (26) is opened, and the working medium in the piston cavity (27) is discharged from the piston exhaust port (24), thereby leaving the piston cavity (27); h. The working fluid leaving the piston chamber (27) is finally discharged through the gas outlet (9) and leaves the compressor, thereby completing the compression of the working fluid.

Images