Refrigeration three-stage compressor

Abstract

The invention discloses a refrigeration three-stage compressor, and relates to the technical field of refrigeration compressors, the refrigeration three-stage compressor comprises a first shell casting and a motor body, the motor body is arranged in the first shell casting, and a first male screw rotor and a first female screw rotor are rotatably arranged in a second shell casting; one end of the first male screw rotor extends into a rotor body of the motor body and then is connected with the rotor body, one end of the impeller shaft is connected with the first male screw rotor, a centrifugal impeller is installed on the impeller shaft, and a second male screw rotor and a second female screw rotor are rotationally arranged in the third shell casting. The rotor body, the impeller shaft, the first male screw rotor and the second male screw rotor form a coaxial structure and are all driven by the motor body, the characteristic that a centrifugal impeller is suitable for low-pressure-ratio and large-displacement can be exerted, and the characteristic that the screw rotors are suitable for high-pressure-ratio working condition application can also be exerted; and in the field of high-pressure-ratio refrigeration, the refrigeration and energy-saving effects are remarkable.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration compressors, and in particular to a three-stage refrigeration compressor. Background Art

[0002] A single-stage screw compressor is a positive displacement compressor, which consists of a cylindrical screw and two symmetrically arranged planar star wheels forming a meshing pair, installed in the casing. The air enters the air compressor through the air inlet and is directly compressed once by the screw rotor, directly increasing from the suction pressure to the exhaust pressure. In the single-stage compression process, a closed compression chamber is formed between the screw rotor and the casing. As the screw rotates, the volume of the compression chamber gradually decreases, thereby achieving gas compression. A two-stage screw compressor is a screw compressor that uses two-stage compression. Its working principle is that through the rotation of a pair of intermeshing screw rotors in the casing, the gas between the rotor teeth produces a periodic volume change, thereby achieving gas suction, compression and discharge. In the first stage of compression, the gas is initially compressed; in the second stage of compression, the gas after initial compression is further compressed to reach the required pressure.

[0003] The working principle of a centrifugal compressor is to convert mechanical energy into gas pressure energy through the impeller of the centrifugal compressor. When the gas flows through the impeller of the centrifugal compressor, the high-speed rotating impeller exerts centrifugal force on the gas, which increases the gas pressure and speed. Subsequently, when the gas flows through the diffuser channel, the flow channel cross-section gradually increases, the gas flow rate decreases, the flow rate of the gas molecules in front decreases, and the gas molecules behind continue to flow forward, so that most of the kinetic energy of the gas is converted into static pressure energy, which plays a role in further pressurization.

[0004] However, the pressure ratio of the single-stage compressor and the two-stage compressor in the prior art still cannot meet the use needs of the ultra-low temperature and high pressure ratio refrigeration field. Combining the centrifugal compressor with the two-stage compressor can improve the pressure ratio. Therefore, the present invention proposes a refrigeration three-stage compressor to solve the shortcomings of the prior art. Summary of the invention

[0005] In view of the above problems, the object of the present invention is to provide a three-stage refrigeration compressor, by extending one end of the first positive screw rotor to the inside of the rotor body of the motor body and then connecting it to the rotor body, by connecting one end of the impeller shaft to the first positive screw rotor, by connecting one end of the second positive screw rotor to the first positive screw rotor, the rotor body, the impeller shaft, the first positive screw rotor and the second positive screw rotor form a coaxial structure, and are all driven by the motor body. The three-stage compressor formed has a simple structure, which can give full play to the characteristics of the centrifugal impeller that is suitable for low pressure ratio and large displacement, and can also give full play to the characteristics of the screw rotor that is suitable for high pressure ratio working conditions.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A refrigeration three-stage compressor comprises a first housing casting and a motor body, wherein the motor body is arranged inside the first housing casting, an air intake cover casting is arranged on one side of the first housing casting, a second housing casting is arranged on the other side of the first housing casting, a first male screw rotor and a first female screw rotor are rotatably arranged inside the second housing casting, one end of the first male screw rotor extends to the inside of the rotor body of the motor body and is connected to the rotor body, an impeller shaft is rotatably arranged inside the air intake cover casting, one end of the impeller shaft is connected to the first male screw rotor, a centrifugal impeller is mounted on the impeller shaft, and a first shaft is arranged on one side of the second housing casting A bearing seat casting, an exhaust end casting is provided on one side of the first bearing seat casting, a third shell casting is provided on one side of the exhaust end casting, a second bearing seat casting is provided on one side of the third shell casting, a second male screw rotor and a second female screw rotor are rotatably provided inside the third shell casting, one end of the second male screw rotor is connected to the first male screw rotor, the rotor body, the impeller shaft, the first male screw rotor and the second male screw rotor form a coaxial structure, an air intake is provided at one end of the air intake cover casting, a centrifugal compression volute exhaust port is provided inside the air intake cover casting at the centrifugal impeller position, and an air inlet is provided on the first shell casting.

[0008] A further improvement is that an air intake passage is formed between the air inlet and the exhaust port of the centrifugal compression volute, and an air outlet is provided on the second bearing seat casting.

[0009] A further improvement is that the first male screw rotor and the first female screw rotor are arranged vertically and side by side inside the second shell casting, and the first male screw rotor and the first female screw rotor are adapted to each other.

[0010] A further improvement is that the second male screw rotor and the second female screw rotor are arranged vertically and parallelly inside the third shell casting, and the second male screw rotor and the second female screw rotor are adapted to each other.

[0011] Further improvements are: a first bearing body and a second bearing body are provided inside the first bearing seat casting, one end of the first male screw rotor extends into the first bearing seat casting and is rotatably installed inside the first bearing seat casting through the first bearing body, and one end of the first female screw rotor extends into the first bearing seat casting and is rotatably installed inside the first bearing seat casting through the second bearing body.

[0012] Further improvements are: a third bearing body and a fourth bearing body are provided inside the second bearing seat casting, one end of the second male screw rotor extends into the second bearing seat casting and is rotatably installed inside the second bearing seat casting through the third bearing body, and one end of the second female screw rotor extends into the second bearing seat casting and is rotatably installed inside the second bearing seat casting through the fourth bearing body.

[0013] A further improvement is that an opening is provided on the top of the second shell casting, and a sealing plate is installed above the opening by bolts.

[0014] A further improvement is that a support casting is provided at the connection between the first casing casting and the air intake cover casting, a support bearing is provided inside the support casting, and the impeller shaft is connected to the support casting through the support bearing inside the support casting.

[0015] A further improvement is that a clamping nut is provided on the outer side of the connection position between the first male screw rotor and the impeller shaft, and the first male screw rotor is connected to the rotor body through the clamping nut.

[0016] The beneficial effects of the present invention are as follows: the present invention extends one end of the first positive screw rotor to the inside of the rotor body of the motor body and then connects it to the rotor body, by connecting one end of the impeller shaft to the first positive screw rotor, by connecting one end of the second positive screw rotor to the first positive screw rotor, the rotor body, the impeller shaft, the first positive screw rotor and the second positive screw rotor form a coaxial structure, and are all driven by the motor body, so that the formed three-stage compressor has a simple structure, which can not only give play to the characteristics of the centrifugal impeller being suitable for low pressure ratio and large displacement, but also give play to the characteristics of the screw rotor being suitable for high pressure ratio working conditions. The three-stage compressor of the present invention can increase the pressure ratio by 2-3 times. In the field of refrigeration with high pressure ratio, the refrigeration and energy-saving effects are remarkable. When the three-stage compressor of the present invention is used in a refrigeration system as an integral structure, the operating principle is as convenient and simple as that of a single-stage compressor, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0018] Figure 2 It is a schematic front view of the internal structure of the air intake cover casting of the present invention.

[0019] Among them: 1. first housing casting; 2. motor body; 3. air intake cover casting; 4. second housing casting; 5. first male screw rotor; 6. first female screw rotor; 7. rotor body; 8. impeller shaft; 9. centrifugal impeller; 10. first bearing seat casting; 11. exhaust end casting; 12. third housing casting; 13. second bearing seat casting; 14. second male screw rotor; 15. second female screw rotor; 16. air intake; 17. centrifugal compression volute exhaust port; 18. air inlet; 19. air outlet; 20. first bearing body; 21. second bearing body; 22. third bearing body; 23. fourth bearing body; 24. opening; 25. sealing plate; 26. support casting; 27. support bearing; 28. clamping nut. DETAILED DESCRIPTION

[0020] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0021] according to Figure 1-2 As shown, this embodiment proposes a refrigeration three-stage compressor, including a first shell casting 1 and a motor body 2, wherein the motor body 2 is arranged inside the first shell casting 1, an air intake cover casting 3 is arranged on one side of the first shell casting 1, and a second shell casting 4 is arranged on the other side of the first shell casting 1, and a first male screw rotor 5 and a first female screw rotor 6 are rotatably arranged inside the second shell casting 4, one end of the first male screw rotor 5 extends to the inside of the rotor body 7 of the motor body 2 and is connected to the rotor body 7, an impeller shaft 8 is rotatably arranged inside the air intake cover casting 3, one end of the impeller shaft 8 is connected to the first male screw rotor 5, and a centrifugal impeller 9 is installed on the impeller shaft 8, and a first bearing seat casting is arranged on one side of the second shell casting 4 10, an exhaust end casting 11 is provided on one side of the first bearing seat casting 10, a third housing casting 12 is provided on one side of the exhaust end casting 11, a second bearing seat casting 13 is provided on one side of the third housing casting 12, a second male screw rotor 14 and a second female screw rotor 15 are rotatably provided inside the third housing casting 12, one end of the second male screw rotor 14 is connected to the first male screw rotor 5, the rotor body 7, the impeller shaft 8, the first male screw rotor 5 and the second male screw rotor 14 form a coaxial structure, an air intake port 16 is provided at one end of the air intake cover casting 3, a centrifugal compression volute exhaust port 17 is provided inside the air intake cover casting 3 at the position of the centrifugal impeller 9, and an air inlet 18 is provided on the first housing casting 1.

[0022] When the three-stage refrigeration compressor of the present invention is in operation, gas is sucked in from the air intake port 16, and the first-stage compression is realized through the centrifugal impeller 9. The compressed first-stage compressed gas is discharged from the centrifugal compression volute exhaust port 17 into the air inlet 18. The first-stage compressed gas sucked into the air inlet 18 cools the motor body 2, and then the first-stage compressed gas continues to be compressed through the rotor body 7 and the first male screw rotor 5. The first-stage compressed gas is compressed into second-stage compressed gas. When the second-stage compressed gas enters the third shell casting 12, it is compressed through the second male screw rotor 14 and the second female screw rotor 15 to complete the three-stage compression. The third compressed gas obtained after the three-stage compression goes out from the air outlet 19. The three-stage compression can realize the acquisition of high-pressure ratio gas, thereby significantly improving the energy-saving effect of the three-stage compressor in ultra-low temperature and high-pressure ratio applications.

[0023] An air intake passage is formed between the air inlet 18 and the centrifugal compression volute exhaust port 17 , and an air outlet 19 is provided on the second bearing seat casting 13 .

[0024] The first male screw rotor 5 and the first female screw rotor 6 are arranged vertically and side by side inside the second housing casting 4 , and the first male screw rotor 5 and the first female screw rotor 6 are adapted to each other.

[0025] The second male screw rotor 14 and the second female screw rotor 15 are arranged vertically and side by side inside the third casing casting 12 , and the second male screw rotor 14 and the second female screw rotor 15 are adapted to each other.

[0026] A first bearing body 20 and a second bearing body 21 are provided inside the first bearing seat casting 10. One end of the first male screw rotor 5 extends into the first bearing seat casting 10 and is rotatably installed inside the first bearing seat casting 10 through the first bearing body 20. One end of the first female screw rotor 6 extends into the first bearing seat casting 10 and is rotatably installed inside the first bearing seat casting 10 through the second bearing body 21.

[0027] A third bearing body 22 and a fourth bearing body 23 are provided inside the second bearing seat casting 13. One end of the second male screw rotor 14 extends into the second bearing seat casting 13 and is rotatably installed inside the second bearing seat casting 13 through the third bearing body 22. One end of the second female screw rotor 15 extends into the second bearing seat casting 13 and is rotatably installed inside the second bearing seat casting 13 through the fourth bearing body 23.

[0028] An opening 24 is provided on the top of the second housing casting 4 , and a sealing plate 25 is installed above the opening 24 by means of bolts.

[0029] A support casting 26 is provided at the connection between the first housing casting 1 and the air intake cover casting 3, a support bearing 27 is provided inside the support casting 26, and the impeller shaft 8 is connected to the support casting 26 through the support bearing 27 inside the support casting 26. The support casting 26 can improve the stability of the impeller shaft 8, the rotor body 7, the first male screw rotor 5 and the second male screw rotor 14 when they are coaxial.

[0030] A clamping nut 28 is provided on the outer side of the connection position between the first male screw rotor 5 and the impeller shaft 8, and the first male screw rotor 5 is connected to the rotor body 7 through the clamping nut 28. The clamping nut 28 can improve the coaxial connection stability between the first male screw rotor 5 and the rotor body 7.

[0031] The present invention extends one end of the first male screw rotor 5 to the inside of the rotor body 7 of the motor body 2 and then connects it to the rotor body 7. By connecting one end of the impeller shaft 8 to the first male screw rotor 5, and by connecting one end of the second male screw rotor 14 to the first male screw rotor 5, the rotor body 7, the impeller shaft 8, the first male screw rotor 5 and the second male screw rotor 14 form a coaxial structure, and are all driven by the motor body 2. The formed three-stage compressor has a simple structure, which can not only give play to the characteristics of the centrifugal impeller being suitable for low pressure ratio and large displacement, but also give play to the characteristics of the screw rotor being suitable for high pressure ratio working conditions. The three-stage compressor of the present invention can increase the pressure ratio by 2-3 times. In the field of refrigeration with high pressure ratio, the refrigeration and energy-saving effects are remarkable. When the three-stage compressor of the present invention is used in a refrigeration system as an integral structure, the operating principle is as convenient and simple as that of a single-stage compressor, and has broad application prospects.

[0032] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A three-stage refrigeration compressor, characterized in that: The invention comprises a first housing casting (1) and a motor body (2), wherein the motor body (2) is arranged inside the first housing casting (1), an air intake cover casting (3) is arranged on one side of the first housing casting (1), and a second housing casting (4) is arranged on the other side of the first housing casting (1), and a first male screw rotor (5) and a first female screw rotor (6) are rotatably arranged inside the second housing casting (4), one end of the first male screw rotor (5) extends into the rotor body (7) of the motor body (2) and is then connected to the rotor body (7), an impeller shaft (8) is rotatably arranged inside the air intake cover casting (3), one end of the impeller shaft (8) is connected to the first male screw rotor (5), and a centrifugal impeller (9) is mounted on the impeller shaft (8), a first bearing seat casting (10) is arranged on one side of the second housing casting (4), and the first shaft An exhaust end casting (11) is provided on one side of the bearing casting (10), a third housing casting (12) is provided on one side of the exhaust end casting (11), a second bearing seat casting (13) is provided on one side of the third housing casting (12), a second male screw rotor (14) and a second female screw rotor (15) are rotatably provided inside the third housing casting (12), one end of the second male screw rotor (14) is connected to the first male screw rotor (5), the rotor body (7), the impeller shaft (8), the first male screw rotor (5) and the second male screw rotor (14) form a coaxial structure, an air intake port (16) is provided on one end of the air intake cover casting (3), a centrifugal compression volute exhaust port (17) is provided inside the air intake cover casting (3) at the position of the centrifugal impeller (9), and an air inlet port (18) is provided on the first housing casting (1).

2. A three-stage refrigeration compressor according to claim 1, characterized in that: An air intake passage is formed between the air inlet (18) and the centrifugal compression volute exhaust port (17), and an air outlet (19) is provided on the second bearing seat casting (13).

3. A three-stage refrigeration compressor according to claim 1, characterized in that: The first male screw rotor (5) and the first female screw rotor (6) are arranged vertically and side by side inside the second casing casting (4), and the first male screw rotor (5) and the first female screw rotor (6) are adapted to each other.

4. A three-stage refrigeration compressor according to claim 1, characterized in that: The second male screw rotor (14) and the second female screw rotor (15) are arranged vertically and side by side inside the third casing casting (12), and the second male screw rotor (14) and the second female screw rotor (15) are adapted to each other.

5. A three-stage refrigeration compressor according to claim 3, characterized in that: A first bearing body (20) and a second bearing body (21) are provided inside the first bearing seat casting (10); one end of the first male screw rotor (5) extends into the first bearing seat casting (10) and is rotatably mounted inside the first bearing seat casting (10) through the first bearing body (20); one end of the first female screw rotor (6) extends into the first bearing seat casting (10) and is rotatably mounted inside the first bearing seat casting (10) through the second bearing body (21).

6. A three-stage refrigeration compressor according to claim 4, characterized in that: A third bearing body (22) and a fourth bearing body (23) are provided inside the second bearing seat casting (13); one end of the second male screw rotor (14) extends into the second bearing seat casting (13) and is rotatably mounted inside the second bearing seat casting (13) through the third bearing body (22); one end of the second female screw rotor (15) extends into the second bearing seat casting (13) and is rotatably mounted inside the second bearing seat casting (13) through the fourth bearing body (23).

7. A three-stage refrigeration compressor according to claim 1, characterized in that: The top of the second shell casting (4) is provided with an opening (24), and a sealing plate (25) is installed above the opening (24) by means of bolts.

8. A three-stage refrigeration compressor according to claim 1, characterized in that: A support casting (26) is provided at the connection between the first casing casting (1) and the air intake cover casting (3), a support bearing (27) is provided inside the support casting (26), and the impeller shaft (8) is connected to the support casting (26) through the support bearing (27) inside the support casting (26).

9. A three-stage refrigeration compressor according to claim 1, characterized in that: A clamping nut (28) is provided on the outer side of the connection position between the first male screw rotor (5) and the impeller shaft (8), and the first male screw rotor (5) is connected to the rotor body (7) via the clamping nut (28).

Images