Centrifugal compressor, water chilling unit and electrical equipment

Abstract

The utility model discloses a centrifugal compressor, chiller and electrical equipment, the centrifugal compressor comprises: a housing, a first-stage compression space and a second-stage compression space are formed in the housing, a first-stage impeller is arranged in the first-stage compression space, and a second-stage impeller is arranged in the second-stage compression space; the driving structure is installed between the first-stage compression space and the second-stage compression space and comprises a stator assembly and a rotor assembly, the stator assembly is distributed around the rotor assembly, the two ends of the rotor assembly are connected with the first-stage impeller and the second-stage impeller correspondingly, and the rotor assembly comprises magnetic steel; the magnetic steel is provided with a magnetic steel center line, and the magnetic steel center line is configured to be inclined relative to the axial direction of the stator assembly. According to the centrifugal compressor, the load generated on the axial structure can be reduced, the working performance of the two impellers can be improved, and the running stability and smoothness of the rotor assembly can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to a centrifugal compressor, a chiller with the centrifugal compressor and an electrical device with the centrifugal compressor. Background Art

[0002] Centrifuges are widely used in the industrial field, mainly including centrifugal refrigeration compressors, air compressors, blowers and other high-speed rotating machinery. The common feature of these is that the impeller rotates at high speed to centrifugally compress the gas. While the impeller is compressing, an axial force will be generated due to the inconsistent pressure between the wheel cover and the wheel back. At the same time, an axial force will be generated when the impeller compresses the gas. Finally, the impeller will generate an axial resultant force, and the axial thrust bearing of the centrifugal machinery is ultimately required to balance the axial resultant force. The axial bearing capacity generated by the air bearing is smaller than that of the traditional oil film bearing, which makes the axial load of the air bearing larger, affecting the rotation performance of the rotor assembly. There is room for improvement. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a centrifugal compressor, which can balance the axial force generated by part of the first-stage impeller and the second-stage impeller, thereby reducing the load generated on the axial structure, thereby improving the life and reliability of the axial structure, and can improve the axial bearing capacity of the two impellers.

[0004] According to the centrifugal compressor of the embodiment of the utility model, it includes: a shell, a primary compression space and a secondary compression space are formed in the shell, a primary impeller is arranged in the primary compression space, and a secondary impeller is arranged in the secondary compression space; a driving structure, the driving structure is installed between the primary compression space and the secondary compression space, the driving structure includes a stator assembly and a rotor assembly, the stator assembly is distributed around the rotor assembly, the two ends of the rotor assembly are respectively connected to the primary impeller and the secondary impeller, the rotor assembly includes a magnetic steel, the magnetic steel has a magnetic steel center line and the magnetic steel center line is constructed to be inclined relative to the axial direction of the stator assembly; wherein the primary impeller and the secondary impeller form an axial resultant force when they rotate with the rotor assembly, and the magnetic steel forms an axial component force when the rotor assembly rotates, and the axial component force is opposite to the direction of the axial resultant force.

[0005] According to the centrifugal compressor of the embodiment of the utility model, by setting the center line of the magnetic steel to be inclined relative to the axial direction of the stator assembly, the center line of the magnetic steel is inclined a certain distance from the axial direction of the stator assembly, so that the generated magnetic field force can balance a part of the axial resultant force of the impeller, thereby reducing the load on the axial structure, and ensuring the reliability of the axial structure. Moreover, since an axial resultant force is formed, a part of the driving force on the rotor assembly can be reduced, which can reduce the toothing torque and rotation pulse of the rotor assembly, increase the stability and smoothness of the operation of the rotor assembly, improve the operation accuracy of the rotor assembly, reduce the noise of the centrifugal compressor, and improve the working performance of the centrifugal compressor.

[0006] According to the centrifugal compressor of the embodiment of the utility model, the rotor assembly also includes a first rotor, a magnetic conductive block and a second rotor, the first rotor is connected to one end of the magnetic conductive block and is connected to the first-stage impeller, the second rotor is connected to the other end of the magnetic conductive block and is connected to the second-stage impeller, the magnetic conductive block is penetrated through the stator assembly, and the magnetic steel is installed outside the magnetic conductive block and is located between the magnetic conductive block and the stator assembly.

[0007] According to the centrifugal compressor of the embodiment of the utility model, the magnetic steel has a magnetic steel plane facing the magnetic conductive block and a magnetic steel curved surface away from the magnetic conductive block; the magnetic steel extends along the axial direction of the rotor assembly, and the distance between at least a partial area of ​​the magnetic steel curved surface and the magnetic steel plane is set to gradually change from one end of the magnetic steel to the other end.

[0008] According to the centrifugal compressor of the utility model embodiment, the magnetic steel curved surface has a first side and a second side relatively distributed along the circumference of the rotor assembly, and the change trend of the distance from the first side to the magnetic steel plane is opposite to the change trend of the distance from the second side to the magnetic steel plane.

[0009] According to the centrifugal compressor of the embodiment of the utility model, there are multiple magnetic steels, and the outer surface of the magnetic conductive block forms multiple accommodating grooves spaced apart along the circumferential direction, and the multiple magnetic steels are installed in the multiple accommodating grooves in a one-to-one correspondence.

[0010] According to the centrifugal compressor of the embodiment of the utility model, the magnetic steel curved surfaces of the plurality of magnetic steels are located on a cylindrical surface with the same outer diameter.

[0011] According to the centrifugal compressor of the embodiment of the utility model, there are multiple magnets, and the multiple magnets are distributed in multiple groups on the magnetic conductive block, and each group has two magnets; wherein the two magnets in each group are relatively distributed in the radial direction of the rotor assembly, and the magnetic center lines of the two magnets in each group have the same inclination angle relative to the axial direction of the stator assembly.

[0012] According to the centrifugal compressor of the embodiment of the utility model, the centrifugal compressor further includes a thrust plate, which is installed at an end of the first rotor away from the magnetic conductive block, and the thrust plate is used to axially limit the first rotor.

[0013] According to the centrifugal compressor of the embodiment of the utility model, the centrifugal compressor further includes an axial bearing, and the axial bearings are two and are respectively supported on two axial sides of the thrust plate.

[0014] According to the centrifugal compressor of the embodiment of the utility model, the centrifugal compressor also includes a first radial bearing and a second radial bearing, the first rotor is inserted into the first radial bearing and is rotatably supported in the housing through the first radial bearing, and the second rotor is inserted into the second radial bearing and is rotatably supported in the housing through the second radial bearing.

[0015] According to the centrifugal compressor of the embodiment of the utility model, the centrifugal compressor further comprises a sleeve, which is disposed outside the rotor assembly and is used to separate the magnetic steel from the stator assembly.

[0016] According to the centrifugal compressor of the embodiment of the utility model, when the rotation direction of the rotor assembly is counterclockwise when viewed from the primary side, the oblique poles of the rotor assembly and the magnetic steel both rotate and rise from bottom to top to the right, and when the rotation direction of the rotor assembly is clockwise when viewed from the primary side, the oblique poles of the rotor assembly and the magnetic steel both rotate and rise from bottom to top to the left.

[0017] According to the centrifugal compressor of the embodiment of the utility model, the housing includes a primary volute, a primary diffuser, an intermediate housing, a secondary diffuser and a secondary volute, the primary volute and the secondary volute are located at both ends of the intermediate housing, the primary compression space is formed in the primary volute, the secondary compression space is formed in the secondary volute, and the driving structure is installed in the intermediate housing;

[0018] Among them, a primary diffuser flow channel connected to the primary compression space is defined between the primary diffuser and the primary volute, and a secondary diffuser flow channel connected to the secondary compression space is defined between the secondary diffuser and the secondary volute.

[0019] The utility model also provides a water chiller.

[0020] According to the embodiment of the utility model, the water chiller is provided with a centrifugal compressor according to any one of the above embodiments.

[0021] The utility model also provides an electrical appliance.

[0022] The electrical equipment according to the embodiment of the utility model is provided with a centrifugal compressor according to any one of the above embodiments.

[0023] The advantages of the chiller, the electrical equipment and the centrifugal compressor mentioned above are the same as those of the prior art and will not be described in detail here.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0026] Figure 1 is a cross-sectional view of a centrifugal compressor according to some embodiments of the utility model;

[0027] Figure 2 It is a schematic diagram of the structure of the magnetic steel of the centrifugal compressor according to some embodiments of the utility model;

[0028] Figure 3 It is a schematic diagram of the structure of the magnetic steel of the centrifugal compressor according to other embodiments of the utility model;

[0029] Figure 4 It is a schematic diagram of the structure of the magnetic steel of the centrifugal compressor according to some other embodiments of the utility model;

[0030] Figure 5 It is a structural schematic diagram of a magnetic conductive block of a centrifugal compressor according to some embodiments of the utility model;

[0031] Figure 6 It is a structural schematic diagram of a magnetic conductive block of a centrifugal compressor according to other embodiments of the utility model;

[0032] Figure 7 It is a structural schematic diagram of the magnetic conductive block and the magnetic steel when assembled according to some embodiments of the utility model;

[0033] Figure 8 It is a structural schematic diagram of the magnetic conductive block and the magnetic steel when assembled according to other embodiments of the utility model.

[0034] Reference numerals:

[0035] Centrifugal compressor 100,

[0036] Casing 1, primary compression space 11, primary impeller 111, secondary compression space 12, secondary impeller 121, primary volute 13, primary diffuser 14, primary diffuser flow channel 141, intermediate casing 15, secondary diffuser 16, secondary diffuser flow channel 161, secondary volute 17,

[0037] Driving structure 2, stator assembly 21, rotor assembly 22, magnetic steel 221, magnetic steel plane 2211, magnetic steel curved surface 2212, first side 2213, second side 2214, magnetic steel center line 2215, first rotor 222, magnetic guide block 223, receiving groove 2231, second rotor 224, sheath 23,

[0038] Thrust plate 3, axial bearing 4, first radial bearing 5, second radial bearing 6. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] In the description of the present utility model, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Reference below Figure 1-Figure 8 A centrifugal compressor 100 according to an embodiment of the utility model is described. The centrifugal compressor 100 can balance part of the axial forces generated by the first-stage impeller 111 and the second-stage impeller 121, thereby reducing the load on the axial structure to improve the life and reliability of the axial structure, and can improve the axial bearing capacity of the two impellers.

[0043] like Figure 1-Figure 8 As shown, a centrifugal compressor 100 according to an embodiment of the present invention includes: a shell 1 and a driving structure 2.

[0044] A primary compression space 11 and a secondary compression space 12 are formed in the shell 1 . A primary impeller 111 is disposed in the primary compression space 11 , and a secondary impeller 121 is disposed in the secondary compression space 12 .

[0045] Specifically, the centrifugal compressor 100 performs centrifugal compression on the gas when the impeller rotates at a high speed. The first-stage compression space 11 is used to perform first-stage compression on the gas, and the second-stage compression space 12 is used to perform second-stage compression on the gas. The first-stage compression space 11 and the second-stage compression space 12 are spaced apart and distributed along the axial direction of the shell 1. A first-stage impeller 111 is provided in the first-stage compression space 11, and a second-stage impeller 121 is provided in the second-stage compression space 12. When the first-stage impeller 111 and the second-stage impeller 121 compress the air, the gas is axially inlet and radially outlet. Figure 1 As shown, the primary compression space 11 is located on the left side, and the secondary compression space 12 is located on the right side. In this way, when the primary impeller 111 rotates at a high speed, the gas enters axially from the left side, and is discharged radially after being compressed by the high-speed rotation of the primary impeller 111, thereby realizing the primary compression of the gas. When the gas enters axially from the right side, and is discharged radially after being compressed by the high-speed rotation of the secondary impeller 121, thereby realizing the secondary compression of the gas.

[0046] The driving structure 2 is installed between the primary compression space 11 and the secondary compression space 12. The driving structure 2 includes a stator assembly 21 and a rotor assembly 22. The stator assembly 21 is distributed around the rotor assembly 22. The two ends of the rotor assembly 22 are respectively connected to the primary impeller 111 and the secondary impeller 121. The rotor assembly 22 includes a magnet 221. The magnet 221 has a magnet center line 2215, and the magnet center line 2215 is constructed to be inclined relative to the axial direction of the stator assembly 21.

[0047] Specifically, the driving structure 2 can be constructed as a driving motor, which is installed in the intermediate housing 15. The driving structure 2 is located between the primary compression space 11 and the secondary compression space 12, wherein the rotor assembly 22 is extended in the left-right direction, the stator assembly 21 is distributed around the outer circumference of the rotor assembly 22, and the axial ends of the rotor assembly 22 are respectively connected with the primary impeller 111 and the secondary impeller 121, wherein the left end of the rotor assembly 22 extends into the primary compression space 11 and is connected to the primary impeller 111, and the right end extends into the secondary compression space 12 and is connected to the secondary impeller 121, and the rotor assembly 22 includes a magnetic steel 22 1. The magnet 221 is used to generate a magnetic field around the rotor, and interacts with the magnetic field generated by the stator assembly 21 to generate an electromagnetic force. The electromagnetic force causes the rotor assembly 22 to rotate due to the torque, thereby realizing the rotation of the drive motor. The magnet center line 2215 of the magnet 221 is constructed to be inclined relative to the axial direction of the stator assembly 21, that is, the magnet 221 has a skewed pole, which can make the rotor assembly 22 interact with the stator assembly 21 at different positions with a phase difference, so that the distribution and change of the magnetic field are more uniform and connected in space and time, that is, the output torque of the drive motor is more stable.

[0048] Therefore, after the stator assembly 21 is energized, the magnetic field it generates can drive the rotor assembly 22 to rotate smoothly. The rotation of the rotor assembly 22 drives the primary impeller 111 and the secondary impeller 121 to rotate, respectively realizing primary compression and secondary compression of the gas.

[0049] The first-stage impeller 111 and the second-stage impeller 121 form an axial resultant force when rotating with the rotor assembly 22 , and the magnet 221 forms an axial component force when the rotor assembly 22 rotates, and the direction of the axial component force is opposite to that of the axial resultant force.

[0050] Specifically, Figure 1As shown in the figure, the first-stage impeller 111 and the second-stage impeller 121 are spaced apart in the left-right direction and distributed at both ends of the rotor assembly 22. During the centrifugal compression process, the pressures on both sides of the impeller axis are inconsistent, which will generate an axial force. At the same time, the impeller will also generate an axial force when compressing the gas. Finally, the impeller will generate an axial resultant force. During the first-stage compression process, the first-stage impeller 111 will generate an axial resultant force to the right, and during the second-stage compression process, the second-stage impeller 121 will generate an axial resultant force to the left. The gas pressure during the second-stage compression is greater, and the axial resultant force to the left of the second-stage compression is greater than the axial resultant force to the right of the first-stage compression, and the overall axial resultant force to the left is generated. In the following description, the axial resultant force to the left is taken as an example. The magnetic steel center line 2215 of the magnetic steel 221 is tilted relative to the axial direction of the stator assembly 21, so that the stator assembly 21 generates a magnetic field force perpendicular to the magnetic steel center line 2215 on the rotor assembly 22, and the radial component of the magnetic field force can drive the rotor assembly 22 to rotate, and when looking from the side of the first-stage impeller 111 to the side of the second-stage impeller 121, the rotor assembly 22 rotates counterclockwise, and the magnetic field force forms a rightward axial component when the rotor assembly 22 rotates. The axial component is opposite to the direction of the axial resultant force, and can offset a part of the leftward axial resultant force, thereby reducing the load on the axial structure, and can improve the life and reliability of the axial structure. At the same time, it can improve the axial bearing capacity of the two impellers.

[0051] Therefore, by setting the magnetic steel center line 2215 to be inclined relative to the axial direction of the stator assembly 21, the magnetic steel center line 2215 is inclined a certain distance from the axial direction of the stator assembly 21, so that the generated magnetic field force can balance a part of the impeller axial force, thereby reducing the load on the axial structure, and ensuring the reliability of the axial structure. Moreover, since an axial force is formed, a part of the driving force on the rotor assembly 22 can be reduced, and the tooth torque and rotation pulse of the rotor assembly 22 can be reduced, thereby increasing the stability and smoothness of the operation of the rotor assembly 22, improving the operation accuracy of the rotor assembly 22, reducing the noise of the centrifugal compressor 100, and improving the working performance of the centrifugal compressor 100.

[0052] In some embodiments, the rotor assembly 22 also includes a first rotor 222, a magnetic block 223 and a second rotor 224, the first rotor 222 is connected to one end of the magnetic block 223 and is connected to the first-stage impeller 111, the second rotor 224 is connected to the other end of the magnetic block 223 and is connected to the second-stage impeller 121, the magnetic block 223 is inserted through the stator assembly 21, and the magnet 221 is installed outside the magnetic block 223 and is located between the magnetic block 223 and the stator assembly 21.

[0053] Specifically, Figure 1As shown, the first rotor 222, the magnetic block 223 and the second rotor 224 are coaxially distributed in sequence, one end of the first rotor 222 is fixedly connected to one end of the magnetic block 223, and one end of the second rotor 224 is fixedly connected to the other end of the magnetic block 223. The connection method can be interference fit, inlay or connection with fasteners such as bolts, and can be connected by welding, and can be bonded with high-strength adhesives, etc., to ensure that the two ends of the magnetic block 223 are firmly connected to the first rotor 222 and the second rotor 224 respectively.

[0054] The other end of the first rotor 222 is connected to the first-stage impeller 111, and the other end of the second rotor 224 is connected to the second-stage impeller 121, which can be connected by fasteners such as bolts. The magnetic block 223 is located between the first rotor 222 and the second rotor 224, and the magnetic block 223 is penetrated by the stator assembly 21, that is, the stator assembly 21 is provided with an axial central hole so that the magnetic block 223 can pass through the stator assembly 21, so that the stator assembly 21 is located at the periphery of the magnetic block 223. The magnetic block 223 can guide and enhance the magnetic field, thereby improving the uniformity of the operation of the rotor assembly 22. The uniformity and stability of the magnetic block 223 are improved, and the magnetic steel 221 is installed outside the magnetic block 223 and between the magnetic block 223 and the stator assembly 21. The magnetic block 223 and the magnetic steel 221 are installed in coordination, so that the magnetic field generated by the magnetic steel 221 can be made more stable and stronger, and the utilization efficiency of the magnetic field is enhanced. In this way, after the stator assembly 21 is powered on, the magnetic block 223, the first rotor 222 and the second rotor 224 installed with the magnetic steel 221 are driven to rotate together, and the primary impeller 111 and the secondary impeller 121 can be driven to rotate respectively, so as to realize the primary compression and the secondary compression of the gas respectively.

[0055] In some embodiments, the magnetic steel 221 has a magnetic steel flat surface 2211 facing the magnetic guide block 223 and a magnetic steel curved surface 2212 facing away from the magnetic guide block 223 .

[0056] Specifically, Figure 3 and Figure 6 As shown, the magnetic block 223 can be constructed as a rectangular block structure, and the magnetic steel 221 is installed on its outer surface, wherein the magnetic steel 221 has a relative magnetic steel plane 2211 and a magnetic steel curved surface 2212, the magnetic steel plane 2211 is installed facing the outer surface of the magnetic block 223, and the magnetic steel curved surface 2212 is installed away from the magnetic block 223, and the installation surface facing the magnetic block 223 is designed to be a plane, which is adapted to the outer peripheral surface of the magnetic block 223, so as to facilitate better fitting and installation of the outer peripheral surface of the magnetic block 223 and improve the connection stability between the two, and the installation surface facing the magnetic block 223 is designed to be a curved surface, so that after the magnetic steel 221 is installed outside the magnetic block 223, the overall structure of the magnetic steel 221 and the magnetic block 223 can form a cylindrical structure, which can be adapted to the shape of the first rotor 222 and the second rotor 224, so as to be better connected to the first rotor 222 and the second rotor 224.

[0057] At the same time, the outer peripheral surface of the overall structure of the magnetic steel 221 and the magnetic conductive block 223 is set to a curved surface adapted to the central channel of the stator assembly 21, which is more conducive to forming a relatively uniform magnetic field distribution in the circumferential direction, making the torque output more uniform, better adapting to the rotation characteristics of the rotor assembly 22, and reducing interference caused by irregular shapes.

[0058] In some embodiments, the magnetic steel 221 extends axially along the rotor assembly 22 , and the distance between at least a portion of the magnetic steel curved surface 2212 and the magnetic steel flat surface 2211 is set to gradually change from one end to the other end of the magnetic steel 221 .

[0059] Specifically, Figure 1 and Figure 2 As shown, the magnet 221 extends axially along the first rotor 222, the second rotor 224 and the magnetic block 223, and the distance between the magnet curved surface 2212 and the magnet plane 2211 gradually increases or decreases from one end to the other end of the magnet 221, so that the magnet center line 2215 is inclined axially with the stator assembly 21.

[0060] In some embodiments, the magnetic steel 221 may be configured to have six surfaces, one of which is connected to the magnetic conductive block 223 .

[0061] Specifically, Figure 2 and Figure 3 As shown, the magnet 221 has five planes and one curved surface, the lower plane is the magnet plane 2211, and the upper curved surface is the magnet curved surface 2212, wherein the planes on the left and right sides are installed in alignment with the surfaces on the left and right sides of the magnetic block 223, so that after the magnetic block 223 and the magnet 221 are installed, the side surfaces are flat surfaces, which are convenient for installation and connection with the first rotor 222 and the second rotor 224, and the projection of the magnet curved surface 2212 in the direction of the magnet plane 2211 is a quadrilateral, such as a parallelogram, and its axial center line is inclined a certain distance relative to the axial direction of the stator assembly 21, and the cross-section of the magnet 221 in the axial direction is an arc shape.

[0062] In actual design, the magnetic steel 221 can be set as Figure 2 The integral magnetic steel 221 shown in the figure may also be configured as follows Figure 3 The split magnetic steel 221 shown can be composed of small pieces of magnetic steel 221 spliced ​​into an integral magnetic steel 221 . This arrangement is more conducive to increasing the resistance of the magnetic steel 221 and reducing the eddy current loss of the magnetic steel 221 .

[0063] In some embodiments, the magnetic steel curved surface 2212 has a first side 2213 and a second side 2214 relatively distributed along the circumference of the rotor assembly 22, and the change trend of the distance between the first side 2213 and the magnetic steel plane 2211 is opposite to the change trend of the distance between the second side 2214 and the magnetic steel plane 2211.

[0064] Specifically, Figure 2 and Figure 3 As shown, the magnetic steel curved surface 2212 has a first side 2213 and a second side 2214 which are relatively distributed along the circumference of the rotor assembly 22, that is, the first side 2213 and the second side 2214 are relatively arranged with respect to the side of the magnetic steel plane 2211, and the distance between the first side 2213 and the magnetic steel plane 2211 can gradually decrease, and the distance between the second side 2214 and the magnetic steel plane 2211 can gradually decrease and increase, or the distance between the first side 2213 and the magnetic steel plane 2211 can gradually decrease and increase, and the distance between the second side 2214 and the magnetic steel plane 2211 can gradually decrease and increase, wherein, the greater the change trend of the distance between the first side 2213, the second side 2214 and the magnetic steel plane 2211, the greater the change of the magnetic steel curved surface 2212.

[0065] Thus, the diagonal heights of the magnetic steel curved surface 2212 can be made equal, and the magnetic steel 221 can be seen to be twisted relative to the axial direction of the rotor assembly 22, which is conducive to the inclination of the magnetic steel center line 2215 relative to the axial direction of the stator assembly 21.

[0066] It should be noted that the magnetic field force transmitted from the stator assembly 21 to the rotor assembly 22 is perpendicular to the magnetic steel center line 2215. Figure 4 As shown, when the rotor assembly 22 rotates counterclockwise, the stator assembly 21 gives the rotor assembly 22 a radial component force F1 to drive the rotor assembly 22 to rotate, and gives the rotor assembly 22 a rightward axial component force F2, and F2 is proportional to the torque of the driving structure 22. The axial component force generated increases with the increase of the load. At the same time, the axial tilt distance X of the magnetic steel center line 2215 relative to the stator assembly 21 can be adjusted according to the size of the load. The larger the axial tilt distance X, that is, the larger the angle formed between the axial direction of the stator assembly 21 and the magnetic steel center line 2215, the larger the axial component force F2 generated, which can offset the axial resultant force generated by the impeller to a certain extent, thereby allowing the centrifugal compressor 100 to operate at a larger pressure ratio. In actual design, the tilt distance X can be selected as 1 or 2 stator slot widths, which can ensure that the performance of the drive structure 2 is guaranteed while better offsetting the axial resultant force generated by the impeller, which is beneficial to better generate dynamic pressure gas between the rotor assembly 22 and the bearing, thereby achieving more stable suspension, and can also reduce the tooth torque of the drive structure 2 and make the rotor assembly 22 run more smoothly.

[0067] It can be understood that when the rotor assembly 22 rotates clockwise, the stator assembly 21 applies a leftward axial force to the rotor assembly 22 , and the axial inclination direction of the magnetic steel center line 2215 relative to the stator assembly 21 is also correspondingly opposite.

[0068] In some embodiments, there are multiple magnetic steels 221 , and the outer surface of the magnetic conductive block 223 forms multiple accommodating grooves 2231 spaced apart along the circumferential direction. The multiple magnetic steels 221 are installed in the multiple accommodating grooves 2231 in a one-to-one correspondence.

[0069] Specifically, the number of magnets 221 can be set to two, three, four or even more. Installing multiple magnets 221 on the magnetic conductive block 223 is beneficial to enhancing the magnetic field strength and magnetic field uniformity, improving the effect of the magnetic field, and further facilitating the formation of an axial component force to offset the axial resultant force generated by the first-stage impeller 111 and the second-stage impeller 121.

[0070] Among them, a receiving groove 2231 with a shape and size that matches the shape and size of the magnet 221 is formed on the outer surface of the magnetic block 223, and the number of the receiving grooves 2231 corresponds to the number of the magnets 221, that is, the axial center line of the receiving groove 2231 is inclined a certain distance relative to the axial direction of the stator assembly 21, so that after the magnet 221 is installed on the receiving groove 2231, the magnetic center line 2215 of the magnet 221 can be inclined a certain distance relative to the axial direction of the stator assembly 21, so that an axial component force can be formed when the rotor assembly 22 rotates, which can offset the axial resultant force generated by the first-stage impeller 111 and the second-stage impeller 121.

[0071] like Figure 5 and Figure 6 As shown, the four sides of the magnetic conductive block 223 protrude outward to form a receiving groove 2231, and the outward protrusion distance is the same as the height of the magnet 221, so that the magnet 221 can be clamped in the receiving groove 2231. In practice, the magnet 221 and the receiving groove 2231 can be bonded by an adhesive to ensure a close fit and improve the firmness of the connection. The inner wall of the receiving groove 2231 can limit the magnet 221 to further prevent the magnet 221 from falling.

[0072] In actual design, the receiving groove 2231 can be milled on the magnetic conductive block 223, and the wall thickness of the receiving groove 2231 needs to be less than 1 mm to avoid excessive magnetic leakage.

[0073] In some embodiments, the curved magnetic steel surfaces 2212 of the plurality of magnetic steels 221 are located on a cylindrical surface with the same outer diameter.

[0074] Specifically, Figure 8As shown, a plurality of receiving grooves 2231 are provided on the magnetic block 223, and a plurality of magnets 221 are correspondingly installed in the receiving grooves 2231. The magnetic steel plane 2211 faces the magnetic block 223 and is connected to the inner wall of the receiving groove 2231, so that the magnetic steel curved surface 2212 turns away from the magnetic block 223 and can form a cylindrical surface with the same outer diameter in the circumferential direction, that is, the magnet 221 and the magnetic block 223 can form a cylindrical structure together, which is beneficial to the matching connection with the first rotor 222 and the second rotor 224, and is beneficial to generate a uniform magnetic field in the circumferential direction.

[0075] In some embodiments, there are multiple magnetic steels 221, that is, the number of magnetic steels 221 can be set to two, three, four or even more, and the multiple magnetic steels 221 are distributed in multiple groups on the magnetic conductive block 223, and each group has two magnetic steels 221.

[0076] The two magnets 221 in each group are relatively distributed in the radial direction of the rotor assembly 22 , and the magnet center lines 2215 of the two magnets 221 in each group are inclined at the same angle relative to the axial direction of the stator assembly 21 .

[0077] Specifically, Figure 7 and Figure 8 As shown, four magnets 221, i.e., two groups of magnets 221, are provided. The two magnets 221 in each group are relatively distributed in the radial direction of the rotor assembly 22, so that the magnetic conductive blocks 223 are provided with magnets 221 at circumferential positions, which is conducive to generating a uniform, stable and strong magnetic field. The magnet center lines 2215 of the two magnets 221 in each group, i.e., the magnet center lines 2215 of the upper and lower and left and right magnets 221 shown in the figure, are inclined at the same angle relative to the axial direction of the stator assembly 21, so that the four magnets 221 are all inclined at the same axial distance X from the stator assembly 21, which is conducive to the mutual coordination of the effects generated by the four magnets 221, more effectively reducing torque pulsation, ensuring uniform and consistent magnetic field distribution, and further facilitating the magnets 221 to form a stable axial component force when the rotor assembly 22 rotates.

[0078] Of course, the number of magnets 221 is not limited to that described in this embodiment, and any other number of magnets 221 can be set, as long as the outer peripheral surface of the magnet 221 and the magnetic block 223 is assembled to be a cylindrical surface, and the axial inclination angle of the magnet center line 2215 relative to the stator assembly 21 is the same.

[0079] In some embodiments, the centrifugal compressor 100 further includes a thrust plate 3 , which is mounted on an end of the first rotor 222 away from the magnetic block 223 , and is used to axially limit the first rotor 222 .

[0080] Specifically, the thrust plate 3 is located between the primary impeller 111 and the first rotor 222, and the thrust plate 3 is connected to the end of the first rotor 222 that faces away from the magnetic block 223. The thrust plate 3 is coaxially connected to the first rotor 222. The thrust plate 3 can be constructed in a circular ring shape. The inner diameter of the thrust plate 3 is smaller than the outer diameter of the first rotor 222, and the side of the thrust plate 3 close to the first rotor 222 is in contact and connected with the first rotor 222, so that the first rotor 222 can be axially limited. When the stator assembly 21 drives the rotor assembly 22 to move, in the axial direction of the rotor assembly 22, the primary impeller 111 and the secondary impeller 121 will generate a left axial resultant force, and the first rotor 222 can be axially limited by the thrust plate 3 to prevent the first rotor 222 from excessively moving in the axial direction. Under normal working conditions, the thrust plate 3 has a slight axial float according to the dynamic change of force to ensure the smooth operation of the rotor assembly 22.

[0081] Furthermore, the thrust plate 3 is not required to be provided at the end of the second rotor 224 away from the magnetic block 223. The secondary impeller 121 generates a leftward axial force, which can reduce the rightward movement of the second rotor 224. In this way, the number of parts can be reduced and the cost can be reduced.

[0082] In some embodiments, the centrifugal compressor 100 further includes two axial bearings 4 , which are respectively supported on two axial sides of the thrust plate 3 .

[0083] Specifically, the axial bearing 4 is used to support the end of the first rotor 222. The axial bearing 4 is located between the first-stage impeller 111 and the first rotor 222, and the two axial bearings 4 are distributed on both axial sides of the thrust plate 3, and are respectively supported on both axial sides of the thrust plate 3. The outer ring of the axial bearing 4 is rotatably supported by the housing 1, and the inner ring is supported by the first rotor 222. In this way, the first rotor 222 and the first-stage impeller 111 can be ensured to move smoothly, the torque output accuracy of the rotor assembly 22 is improved, and the gas compression performance of the first-stage impeller 111 is ensured.

[0084] When the first-stage impeller 111 and the second-stage impeller 121 rotate, a leftward axial force is generated, and a part of the axial load can be borne by the thrust plate 3 and the axial bearing 4. Moreover, through the axial inclination of the magnetic steel center line 2215 relative to the stator assembly 21, the stator assembly 21 generates a rightward axial component force on the rotor assembly 22, which can offset a part of the axial force generated by the impeller, thereby reducing the axial load on the thrust plate 3 and the axial bearing 4, increasing the life and reliability of the axial bearing 4, and facilitating better generation of dynamic pressure gas between the rotor assembly 22 and the axial bearing 4, thereby achieving more stable suspension. At the same time, it allows the impeller to work under a larger axial load, thereby improving the gas compression performance of the impeller.

[0085] In some embodiments, the centrifugal compressor 100 also includes a first radial bearing 5 and a second radial bearing 6, the first rotor 222 is inserted through the first radial bearing 5 and is rotatably supported in the housing 1 through the first radial bearing 5, and the second rotor 224 is inserted through the second radial bearing 6 and is rotatably supported in the housing 1 through the second radial bearing 6.

[0086] Specifically, the first radial bearing 5 is located between the magnetic block 223 and the axial bearing 4, and is coaxially connected to the first rotor 222. The first rotor 222 is inserted into the first radial bearing 5, and the outer ring of the first radial bearing 5 is supported and connected to the housing 1. The second radial bearing 6 is located between the magnetic block 223 and the secondary impeller 121, and is coaxially connected to the second rotor 224. The second rotor 224 is inserted into the second radial bearing 6, and the outer ring of the second radial bearing 6 is supported and connected to the housing 1. In this way, the first radial bearing 5 and the second radial bearing 6 respectively bear the weight of the first rotor 222 and the second rotor 224 and various radial forces generated by rotation, which helps to suppress the radial vibration of the first rotor 222 and the second rotor 224, ensure that the first rotor 222 and the second rotor 224 maintain a stable position during operation, improve the output accuracy of the torque of the stator assembly 21, enable the centrifugal compressor 100 to operate smoothly and efficiently, and prevent the rotor from direct contact and friction with other components, reduce wear, and extend the service life of the equipment.

[0087] In some embodiments, the centrifugal compressor 100 further includes a sheath 23 , which is sleeved outside the rotor assembly 22 and is used to separate the magnetic steel 221 from the stator assembly 21 .

[0088] That is, the sleeve 23 can be constructed in an annular shape and sleeved on the outside of the rotor assembly 22. By setting the sleeve 23 to separate the magnet 221 from the stator assembly 21, the magnet 221 can be prevented from directly contacting the stator assembly 21, avoiding collision, friction, etc. between the two that may cause damage to the magnet 221, and reducing interference between the magnet 221 and the stator assembly 21, thereby ensuring the normal operation of the drive structure 2. The sleeve 23 can enhance the insulation effect between the magnet 221 and the stator assembly 21 and reduce the risk of leakage, thereby ensuring the reliability of the axial component force generated by the magnet 221 to offset the axial combined force of the first-stage impeller 111 and the second-stage impeller 121.

[0089] like Figure 1 As shown, the sheath 23 is sleeved outside the rotor assembly 22 to completely separate the magnetic steel 221 from the stator assembly 21 to avoid direct contact between the two, thereby protecting the magnetic steel 221.

[0090] In some embodiments, when the rotation direction of the rotor assembly 22 is counterclockwise when viewed from the primary side, the oblique poles and the magnetic steel 221 of the rotor assembly 22 both rise from bottom to top to rotate to the right, and when the rotation direction of the rotor assembly 22 is clockwise when viewed from the primary side, the oblique poles and the magnetic steel 221 of the rotor assembly 22 both rise from bottom to top to rotate to the left.

[0091] Specifically, Figure 1 As shown, looking from left to right in the direction shown in the figure, that is, from the primary side to the secondary side, when it is observed that the rotation direction of the rotor assembly 22 is counterclockwise, at this time, the oblique poles and the magnetic steel 221 of the rotor assembly 22 are both rotating and rising to the right from bottom to top, that is, the oblique poles and the magnetic steel 221 both show a tendency to tilt and rise to the right, which can enable the rotor assembly 22 to better interact with the stator assembly 21 in the magnetic field when rotating, and generate an axial component force to the right, thereby effectively offsetting a part of the impeller's axial resultant force to the left and reducing the load on the axial structure.

[0092] Similarly, when it is observed that the rotation direction of the rotor assembly 22 is clockwise, at this time, the oblique poles and the magnetic steel 221 of the rotor assembly 22 are both rotating and rising to the left from bottom to top, that is, the oblique poles and the magnetic steel 221 both show a tendency to tilt and rise to the left, which can enable the rotor assembly 22 to better interact with the stator assembly 21 in the magnetic field during rotation, generating a left axial component force, thereby effectively offsetting a part of the impeller's right axial force and reducing the load on the axial structure.

[0093] In some embodiments, Figure 1 As shown, the casing 1 includes a first-stage volute 13, a first-stage diffuser 14, an intermediate casing 1, a second-stage diffuser 16 and a second-stage volute 17, and are distributed in sequence along the axial direction, wherein the first-stage volute 13 and the second-stage volute 17 are located at both ends of the intermediate casing 1, the first-stage volute 13 is detachably connected to the intermediate casing 1, and the intermediate casing 1 is detachably connected to the second-stage volute 17, a first-stage compression space 11 is formed in the first-stage volute 13, and a first-stage impeller 111 is installed in the first-stage volute 13, a second-stage compression space 12 is formed in the second-stage volute 17, and a second-stage impeller 121 is installed in the second-stage volute 17, and a driving structure 2 is installed in the intermediate casing 1, so that the driving structure 2 transmits the driving force from the middle output to the first-stage impeller 111 and the second-stage impeller 121 at both ends, respectively driving the two impellers to rotate.

[0094] And an adjusting mechanism is provided at the air inlet end of the first-stage volute 13, and the adjusting mechanism is detachably connected to the first-stage volute 13. The adjusting mechanism is provided to adjust the cross-section of the inlet of the centrifugal compressor 100 to adjust the air intake of the compressor. The adjusting mechanism can change the pre-swirl of the airflow entering the first-stage impeller 111 by changing the installation angle of the guide vane, increasing the air flow speed, modifying the flow angle or establishing a flow path recirculation, thereby adjusting the air intake of the compressor, so that the output of the compressor can be matched with the actual needs of the system, and the operating efficiency and performance of the compressor can be improved. In addition, during the startup process of the compressor, the adjusting mechanism can also adjust the air intake to zero or as small a value as possible to facilitate the motor to start under a small load state, reduce the starting current, shorten the starting time, reduce the voltage fluctuation and save electric energy. At the same time, it can also avoid accidents caused by overweight due to excessive pressure difference between the high and low pressure sides, which may cause the starting device or even the drive motor to burn out.

[0095] Among them, a first-stage diffusion flow channel connected to the first-stage compression space 11 is defined between the first-stage diffuser 14 and the first-stage volute 13, which is used to connect the compressed gas in the first-stage compression space 11 with the first-stage diffuser 14 to perform the first-stage boosting of the compressed gas. A second-stage diffusion flow channel connected to the second-stage compression space 12 is defined between the second-stage diffuser 16 and the second-stage volute 17, which is used to connect the compressed gas in the second-stage compression space 12 with the second-stage diffuser 16 to perform the second-stage boosting of the compressed gas.

[0096] An interstage pipe may be connected between the primary diffuser flow channel 141 and the secondary diffuser flow channel 161, and the interstage pipe is located on the outside of the shell 1. When the gas enters the primary compression space 11, the rotor assembly 22 of the driving structure 2 drives the primary impeller 111 to rotate at a high speed to generate centrifugal force to perform primary compression on the gas. The compressed gas enters the primary diffuser flow channel 141 for further deceleration and pressurization. The high-pressure gas enters the secondary compression space 12 from the interstage pipe, and the secondary impeller 121 rotates at a high speed to generate centrifugal force to perform secondary compression on the gas. The compressed gas enters the secondary diffuser flow channel 161 for further deceleration and pressurization. Finally, the high-pressure gas is discharged from the exhaust port of the secondary diffuser flow channel 161 to achieve secondary compression of the gas to achieve the required high-pressure gas.

[0097] The utility model also provides a water chiller.

[0098] According to the chiller of the embodiment of the utility model, a centrifugal compressor 100 of any one of the above embodiments is provided. By providing the centrifugal compressor 100, the gas compression performance of the chiller can be improved, so that the chiller can operate efficiently and stably, and the noise and vibration generated by the chiller can be reduced.

[0099] The utility model also provides an electrical appliance.

[0100] According to the electrical equipment of the embodiment of the utility model, a centrifugal compressor 100 of any one of the above-mentioned embodiments is provided, and the center line 2215 of the magnetic steel is set to be inclined relative to the axial direction of the stator assembly 21, so that the center line 2215 of the magnetic steel is inclined a certain distance from the axial direction of the stator assembly 21, so that the generated magnetic field force can balance a part of the impeller axial force, thereby reducing the load on the axial structure, and ensuring the reliability of the axial structure. Moreover, since the axial force is formed, a part of the driving force on the rotor assembly 22 can be reduced, and the tooth slot torque and rotation pulse of the rotor assembly 22 can be reduced, and the stability and smoothness of the operation of the rotor assembly 22 are increased, and the operation accuracy of the rotor assembly 22 is improved, and the noise of the centrifugal compressor 100 is reduced, and the working performance of the centrifugal compressor 100 is improved, thereby improving the gas compression performance of the electrical equipment, and improving its operating efficiency and reliability.

[0101] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0102] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A centrifugal compressor, characterized in that: include: A casing, wherein a primary compression space and a secondary compression space are formed in the casing, a primary impeller is arranged in the primary compression space, and a secondary impeller is arranged in the secondary compression space; A driving structure, the driving structure is installed between the primary compression space and the secondary compression space, the driving structure comprises a stator assembly and a rotor assembly, the stator assembly is distributed around the rotor assembly, two ends of the rotor assembly are respectively connected to the primary impeller and the secondary impeller, the rotor assembly comprises a magnetic steel, the magnetic steel has a magnetic steel center line, and the magnetic steel center line is configured to be inclined relative to the axial direction of the stator assembly; The first-stage impeller and the second-stage impeller form an axial resultant force when rotating with the rotor assembly, and the magnetic steel forms an axial component force when the rotor assembly rotates, and the axial component force is opposite to the direction of the axial resultant force.

2. The centrifugal compressor according to claim 1, characterized in that: The rotor assembly also includes a first rotor, a magnetic block and a second rotor, the first rotor is connected to one end of the magnetic block and is connected to the first-stage impeller, the second rotor is connected to the other end of the magnetic block and is connected to the second-stage impeller, the magnetic block is inserted through the stator assembly, and the magnet is installed outside the magnetic block and is located between the magnetic block and the stator assembly.

3. The centrifugal compressor according to claim 2, characterized in that: The magnetic steel has a magnetic steel plane facing the magnetic conductive block and a magnetic steel curved surface away from the magnetic conductive block; The magnetic steel extends along the axial direction of the rotor assembly, and the distance between at least a partial area of ​​the magnetic steel curved surface and the magnetic steel plane is set to gradually change from one end to the other end of the magnetic steel.

4. The centrifugal compressor according to claim 3, characterized in that: The magnetic steel curved surface has a first side and a second side that are relatively distributed along the circumference of the rotor assembly, and a variation trend of the distance from the first side to the magnetic steel plane is opposite to a variation trend of the distance from the second side to the magnetic steel plane.

5. The centrifugal compressor according to claim 3, characterized in that: There are a plurality of magnetic steels, and a plurality of accommodating grooves spaced apart along the circumferential direction are formed on the outer surface of the magnetic conductive block. The plurality of magnetic steels are installed in the plurality of accommodating grooves in a one-to-one correspondence.

6. The centrifugal compressor according to claim 5, characterized in that: The magnetic steel curved surfaces of the plurality of magnetic steels are located on a cylindrical surface with the same outer diameter.

7. The centrifugal compressor according to claim 2, characterized in that: There are multiple magnetic steels, and the multiple magnetic steels are distributed in multiple groups on the magnetic conductive block, and each group has two magnetic steels; The two magnetic steels in each group are relatively distributed in the radial direction of the rotor assembly, and the magnetic steel center lines of the two magnetic steels in each group are inclined at the same angle relative to the axial direction of the stator assembly.

8. The centrifugal compressor according to claim 2, characterized in that: It also includes a thrust plate, which is installed at one end of the first rotor away from the magnetic conductive block, and is used to axially limit the first rotor.

9. The centrifugal compressor according to claim 8, characterized in that: It also includes two axial bearings, which are respectively supported on two axial sides of the thrust plate.

10. The centrifugal compressor according to claim 2, characterized in that: It also includes a first radial bearing and a second radial bearing. The first rotor is inserted into the first radial bearing and is rotatably supported in the housing through the first radial bearing. The second rotor is inserted into the second radial bearing and is rotatably supported in the housing through the second radial bearing.

11. The centrifugal compressor according to claim 2, characterized in that: The invention also comprises a sheath which is sleeved outside the rotor assembly and used for separating the magnetic steel from the stator assembly.

12. The centrifugal compressor according to claim 1, characterized in that: When the rotation direction of the rotor assembly is counterclockwise when viewed from the primary side, the oblique poles of the rotor assembly and the magnetic steel both rotate upward from bottom to top and toward the right, and when the rotation direction of the rotor assembly is clockwise when viewed from the primary side, the oblique poles of the rotor assembly and the magnetic steel both rotate upward from bottom to top and toward the left.

13. The centrifugal compressor according to claim 1, characterized in that: The housing comprises a primary volute, a primary diffuser, an intermediate housing, a secondary diffuser and a secondary volute, wherein the primary volute and the secondary volute are located at two ends of the intermediate housing, the primary compression space is formed in the primary volute, the secondary compression space is formed in the secondary volute, and the driving structure is installed in the intermediate housing; Among them, a primary diffuser flow channel connected to the primary compression space is defined between the primary diffuser and the primary volute, and a secondary diffuser flow channel connected to the secondary compression space is defined between the secondary diffuser and the secondary volute.

14. A chiller, characterized in that: A centrifugal compressor according to any one of claims 1 to 13 is provided.

15. An electrical device, characterized in that: A centrifugal compressor according to any one of claims 1 to 13 is provided.

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