Totally enclosed single stage centrifugal compressor

Abstract

This utility model relates to the field of compressor technology and discloses a fully enclosed single-stage centrifugal compressor, including a lower casing, an upper casing, an impeller, a rotating main shaft, and a motor stator. An impeller and a thrust disc are provided on one side of the rotating main shaft. The main body of the rotating main shaft is rotatably connected to the upper and lower casings via radial bearings on both sides, and the main body of the rotating main shaft is rotatably mounted in the motor stator, which is mounted on the lower casing's internal fixed seat. The upper and lower casings are connected by welding. A refrigerant inlet is provided on the side of the lower casing, and a refrigerant outlet is provided on the volute. This utility model uses refrigerant as the compressor's compression medium. The refrigerant enters through the lower casing inlet, passes through the lower and upper casings, is compressed by the impeller, and flows out through the outlet. Simultaneously, the refrigerant cools the motor stator, reducing the number of compressor parts and improving heat dissipation efficiency. Furthermore, the bearings used in this utility model are air-suspended or magnetic-suspended bearings, eliminating the need for lubrication and increasing energy efficiency.

Description

Technical Field

[0001] This utility model relates to the field of compressor technology, and more particularly to centrifugal compressors. Background Technology

[0002] Hermetic compressors are commonly used in refrigeration equipment due to their compact structure and light weight. Traditional hermetic compressors are mostly reciprocating or scroll compressors, with centrifugal compressors accounting for a smaller proportion. However, centrifugal compressors can convert mechanical energy into gas pressure energy and kinetic energy through the high-speed rotation of the impeller. They have the characteristics of fewer vulnerable parts, reliable operation, and long service life. Therefore, a hermetic centrifugal compressor can be designed.

[0003] Centrifugal compressors driven by electric motors generate heat when they are working. Therefore, such compressors need to be designed to cool the motor, such as by adding a coolant channel or an external cooling device. Such designs increase the difficulty of machining parts and the cooling efficiency is not high.

[0004] Air suspension bearings and magnetic suspension bearings are two advanced contactless bearing technologies that completely eliminate friction, wear, and vibration caused by mechanical contact, providing a near-ideal working environment.

[0005] Centrifugal compressors are divided into single-stage centrifugal compressors and multi-stage centrifugal compressors. Single-stage compressors have a simpler structure and fewer parts compared to multi-stage centrifugal compressors.

[0006] Therefore, this utility model provides a fully enclosed single-stage centrifugal compressor to solve the above problems. Summary of the Invention

[0007] To solve the above-mentioned technical problems, this utility model provides a fully enclosed single-stage centrifugal compressor, including a lower casing (1), an upper casing (2), an impeller (3), a rotating main shaft (4), and a motor stator (5); wherein the rotating main shaft (4) is provided with an impeller (3) and a thrust disk (42) on one side, and the two sides of the rotating main shaft (4) are rotatably connected to the upper casing (2) and the internal fixed seat (11) of the lower casing (1) respectively through a compression end radial bearing (44) and a support end radial bearing (45). The main body of the rotating spindle (4) is rotatably installed in the motor stator (5), and the impeller (3), rotating spindle (4), motor stator (5), upper housing (2), and lower housing (1) internal fixing seat (11) are in the same axial position; the motor stator (5) is fixedly installed on the lower housing (1) internal fixing seat (11) by heat assembly, and a lower cover plate (6) and an upper cover plate (7) are provided between the motor stator (5) and the impeller (3); the upper housing (2) and the lower housing (1) are connected by welding.

[0008] Preferably, the lower housing (1) has a refrigerant inlet (12) on its side, and the bottom surface of the lower housing (1) is fixedly installed with the fixed seat (11) by thermal assembly; a support end radial bearing (45) is fixed on the fixed seat (11) by screws.

[0009] Preferably, the upper housing (2) includes a refrigerant outlet (21), a refrigerant flow channel (22), a diffuser (23), and a cooling channel (24); the upper housing (2) is a non-rotating component, and the refrigerant flow channel (22) is designed to avoid the refrigerant outlet (21); when the upper housing (2) is installed, the gap between the diffuser (23) and the impeller (3) is 0.2-1mm; a lower cover plate (6) is fixed to the upper housing (2) by threads, and an upper cover plate (7) is fixed to the lower cover plate (6) by threads. A compression end radial bearing (44) is fixed to the lower cover plate (6) by screws. A first thrust bearing (41), a thrust plate (42), and a second thrust bearing (43) are provided between the upper cover plate (7) and the lower cover plate (6).

[0010] Preferably, the rotating spindle (4) is fixed with an impeller (3) using a fixing nut (8), and a thrust disk (42) is provided below the impeller (3).

[0011] Preferably, the compression end radial bearing (44), the support end radial bearing (45), the first thrust bearing (41), and the second thrust bearing (43) are all air suspension bearings or magnetic suspension bearings.

[0012] Preferably, when the refrigerant is used as the compression medium of the compressor, the refrigerant enters the lower housing (1) from the refrigerant inlet (12) on the side of the lower housing (1) to cool the motor stator (5), and then enters the upper housing (2) diffuser (23) through the cooling channel (24) of the upper housing (2) and is compressed by the impeller (3) before flowing out from the refrigerant outlet (21) of the upper housing (2).

[0013] The advantages of this utility model are:

[0014] When using refrigerant as the compressor medium, this invention can make full use of the large volume between the motor and the lower casing to cool the motor stator and the working area of ​​the compressor. There is no need to design a special cooling channel, which reduces the design requirements of the parts. Moreover, the air inlet is designed on the lower casing. The refrigerant first cools the motor and then enters the diffuser through the flow channel and is compressed by the impeller, thus completing the cooling and compression work and making the compressor more energy-efficient as a whole.

[0015] Ordinary oil bearings require lubricating oil to reduce friction and also require additional oil supply and return routes, increasing the design complexity of the parts. In contrast, air bearings and magnetic bearings not only have the advantage of high-speed motion but also do not require lubricating oil, reducing the complexity of product design.

[0016] Because the upper and lower housings of this invention are connected by welding, the product is fully sealed except for the air inlet and outlet, resulting in zero leakage of the working medium and eliminating the need for additional sealing methods. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the assembly structure of the fully enclosed single-stage centrifugal compressor of this utility model.

[0018] Figure 2 This is an external view of the fully enclosed single-stage centrifugal compressor of this utility model.

[0019] The attached diagram shows the markings and corresponding component names: 1. Lower casing; 11. Mounting base; 12. Air inlet; 2. Upper casing; 21. Air outlet; 22. Refrigerant flow channel; 23. Diffuser; 24. Cooling channel; 3. Impeller; 4. Rotating main shaft; 41. First thrust bearing; 42. Thrust disc; 43. Second thrust bearing; 44. Compression end radial bearing; 45. Support end radial bearing; 5. Motor stator; Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0021] Example

[0022] See Figures 1-2 The fully enclosed single-stage centrifugal compressor of this utility model includes a lower casing (1), an upper casing (2), an impeller (3), a rotating main shaft (4), and a motor stator (5).

[0023] The lower housing (1) has a refrigerant inlet (12) on its side. The bottom surface of the lower housing (1) is thermally assembled and fixed to the fixed seat (11). A support end radial bearing (45) is fixed to the fixed seat (11) by screws.

[0024] The upper housing (2) includes a refrigerant outlet (21), a refrigerant flow channel (22), a diffuser (23), and a cooling channel (24). The upper housing (2) is a non-rotating component, and the refrigerant flow channel (22) must be designed to avoid the refrigerant outlet (21). When the upper housing (2) is installed, the gap between the diffuser (23) and the impeller (3) is 0.2-1mm. The upper housing (2) is fixed with a lower cover plate (6) by threads, and the upper cover plate (7) is fixed to the lower cover plate (6) by screws. A first thrust bearing (41), a thrust plate (42), and a second thrust bearing (43) are provided between the upper cover plate (7) and the lower cover plate (6). A compression end radial bearing (44) is fixed to the lower cover plate (6) by screws.

[0025] The compression end radial bearing (44), the support end radial bearing (45), the first thrust bearing (41), and the second thrust bearing (43) are all air suspension bearings or magnetic suspension bearings.

[0026] It should be noted that the refrigerant selection must meet the usage requirements of air suspension bearings or magnetic suspension bearings.

[0027] When designing the impeller (3) and the upper casing (2) parts, thermal calculations are required to obtain the optimal values.

[0028] An impeller (3) is fixedly installed on one side of the rotating main shaft (4) using a fixing nut, and a thrust disk (42) is fixed below the impeller (3). The main body of the rotating main shaft (4) is rotatably connected to the inner fixed seat (11) of the upper housing (2) and the lower housing (1) respectively through the compression end radial bearing (44) and the support end radial bearing (45). The main body of the rotating main shaft (4) is rotatably installed in the motor stator (5), and the impeller (3), the rotating main shaft (4), the motor stator (5), the upper housing (2), and the inner fixed seat (11) of the lower housing (1) are in the same axial position.

[0029] The motor stator (5) is fixedly mounted on the internal mounting base (11) of the lower housing (1) by thermal assembly.

[0030] The upper housing (2) and the lower housing (1) are connected by welding.

[0031] When the compressor is working, the refrigerant, which is the compression medium, enters the lower casing (1) through the refrigerant inlet (12) on the side of the lower casing (1) to cool the motor stator (5), and then enters the upper casing (2) diffuser (23) through the cooling channel (24) of the upper casing (2) and is compressed by the impeller (3) before flowing out from the refrigerant outlet (21) of the upper casing (2).

Claims

1. A fully enclosed single-stage centrifugal compressor, characterized in that: The compressor includes a lower housing (1), an upper housing (2), an impeller (3), a rotating main shaft (4), and a motor stator (5). The rotating main shaft (4) has an impeller (3) and a thrust disk (42) on one side. The main body of the rotating main shaft (4) is rotatably connected to the inner fixed seat (11) of the upper housing (2) and the lower housing (1) respectively through a compression end radial bearing (44) and a support end radial bearing (45). The main body of the rotating main shaft (4) is rotatably installed in the motor stator (5), and the impeller (3), the rotating main shaft (4), the motor stator (5), the upper housing (2), and the inner fixed seat (11) of the lower housing (1) are in a coaxial position. The motor stator (5) is fixedly installed on the inner fixed seat (11) of the lower housing (1) by thermal assembly. A lower cover plate (6) and an upper cover plate (7) are provided between the motor stator (5) and the impeller (3). The upper housing (2) and the lower housing (1) are connected by welding. The working medium of the compressor is refrigerant.

2. The fully enclosed single-stage centrifugal compressor as described in claim 1, characterized in that: The lower housing (1) has a refrigerant inlet (12) on its side. The bottom surface of the lower housing (1) is fixed to the fixed seat (11) by thermal assembly. A support end radial bearing (45) is fixed to the fixed seat (11) by thread.

3. The fully enclosed single-stage centrifugal compressor as described in claim 1, characterized in that: The upper housing (2) includes a refrigerant outlet (21), a refrigerant flow channel (22), a diffuser (23), and a cooling channel (24). The upper housing (2) is a non-rotating component, and the refrigerant flow channel (22) is designed to avoid the refrigerant outlet (21). When the upper housing (2) is installed, the gap between the diffuser (23) and the impeller (3) is 0.2-1mm. The upper housing (2) is fixed with a lower cover plate (6) by threads, and the upper cover plate (7) is fixed with threads on the lower cover plate (6). The lower cover plate (6) is fixed with a compression end radial bearing (44) by screws. A first thrust bearing (41), a thrust plate (42), and a second thrust bearing (43) are provided between the upper cover plate (7) and the lower cover plate (6).

4. A fully enclosed single-stage centrifugal compressor as described in claim 1, characterized in that: The compression end radial bearing (44), the support end radial bearing (45), the first thrust bearing (41), and the second thrust bearing (43) are all air suspension bearings or magnetic suspension bearings.

5. A fully enclosed single-stage centrifugal compressor as described in claim 1, characterized in that: The refrigerant enters the lower housing (1) from the refrigerant inlet (12) on the side of the lower housing (1) to cool the motor stator (5), and enters the upper housing (2) diffuser (23) through the cooling channel (24) of the upper housing (2) and is compressed by the impeller (3) before flowing out from the refrigerant outlet (21) of the upper housing (2).

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