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 stator assembly comprises a motor stator and a stator winding; winding skewed slots are formed in the motor stator, the winding skewed slots are configured to obliquely extend relative to the axial direction of the rotor assembly, and at least part of the stator winding is located in the winding skewed slots and extends in the same direction as the winding skewed slots. According to the centrifugal compressor, the load generated on the axial structure can be reduced, the working performance of the two impellers is improved, and the running smoothness of the rotor assembly is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to a centrifugal compressor and a chiller and electrical equipment having 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 proposes a centrifugal compressor that can balance the axial force generated by part of the first-stage impeller and the second-stage impeller, thereby reducing the load on the axial structure, improving the working performance of the two impellers, and reducing the cogging torque and rotation pulse of the motor rotor, improving the operating accuracy of the rotor assembly, increasing the stability and smoothness of the operation of the rotor assembly, and reducing the noise of the centrifugal compressor.

[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, and the two ends of the rotor assembly are respectively connected to the primary impeller and the secondary impeller, the stator assembly includes a motor stator and a stator winding, a winding skew groove is formed in the motor stator, the winding skew groove is configured to extend obliquely relative to the axial direction of the rotor assembly, at least part of the stator winding is located in the winding skew groove and extends in the same direction as the winding skew groove; wherein, the primary impeller and the secondary impeller form an axial resultant force when rotating with the rotor assembly, and the motor stator forms an axial component force when driving the rotor assembly to rotate, 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 providing a winding bevel groove inclined relative to the axial direction of the rotor assembly in the motor stator, an axial component force can be formed when the motor stator drives the rotor assembly to rotate, which can balance the axial force generated by part of the first-stage impeller and the second-stage impeller, thereby reducing the load on the axial structure, improving the working performance of the two impellers, reducing the toothing torque and rotation pulse of the rotor assembly, improving the operating accuracy of the rotor assembly, increasing the stability and smoothness of the operation of the rotor assembly, and reducing the noise of the centrifugal compressor.

[0006] According to the centrifugal compressor of the embodiment of the utility model, the motor stator is provided with a central hole, the rotor assembly is passed through the central hole, there are multiple winding bevel grooves, and the multiple winding bevel grooves are distributed around the central hole.

[0007] According to the centrifugal compressor of the embodiment of the utility model, the plurality of winding slots are constructed to be open toward the central channel, the winding slots pass through both ends of the motor stator, and the motor stator is provided with a stator tooth portion between two adjacent winding slots, the stator winding is wound around the stator tooth portion, and the extension direction of the stator tooth portion is the same as that of the winding slots.

[0008] According to the centrifugal compressor of the embodiment of the utility model, the width of the winding skew slot is set to gradually decrease or increase in the radial direction of the motor stator along the direction approaching the central channel.

[0009] According to the centrifugal compressor of the embodiment of the utility model, the span between the two ends of the winding skew slot in the circumferential direction of the motor stator is equal to the tooth pitch of one or two stator teeth.

[0010] According to the centrifugal compressor of the embodiment of the utility model, the extension direction of the plurality of winding skew slots is inclined at the same angle relative to the axial direction of the rotor assembly;

[0011] And / or, the extension directions of the plurality of winding skew slots are in the same direction of inclination relative to the axial direction of the rotor assembly, and the plurality of winding skew slots are spaced apart in parallel.

[0012] According to the centrifugal compressor of the embodiment of the utility model, the motor stator is integrally formed;

[0013] And / or, the motor stator is formed by stacking a plurality of stator punching sheets.

[0014] According to the centrifugal compressor of the embodiment of the utility model, a plurality of stator punching sheets are formed with winding openings on the inner sides thereof, and the winding openings of the plurality of stator punching sheets together form the winding skew slot;

[0015] And / or, welding openings are formed on the outer sides of the plurality of stator punching sheets, and the welding openings of the plurality of stator punching sheets together form the welding chute.

[0016] According to the centrifugal compressor of the embodiment of the utility model, the extension direction of the winding skew slot is the same as the extension direction of the welding skew slot.

[0017] According to the centrifugal compressor of the embodiment of the utility model, when the rotor assembly is viewed from the primary side and the rotation direction is counterclockwise, the welding chute and the winding chute both rise from bottom to top and rotate rightward;

[0018] Furthermore, when the rotor assembly is viewed from the primary side and its rotation direction is clockwise, both the welding chute and the winding chute are rotated upward from bottom to top and in a left-hand direction.

[0019] 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, and the magnetic conductive block is inserted through the stator assembly.

[0020] According to the centrifugal compressor of the embodiment of the utility model, it also includes a thrust plate, which is installed at one end of the first rotor away from the magnetic conductive block, and the thrust plate is used to axially limit the first rotor.

[0021] The centrifugal compressor according to the embodiment of the utility model further includes an axial bearing, and the axial bearings are two and are respectively supported on two axial sides of the thrust plate.

[0022] According to the centrifugal compressor of the embodiment of the utility model, 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.

[0023] 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;

[0024] 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.

[0025] The utility model also provides a water chiller.

[0026] 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.

[0027] The utility model also provides an electrical appliance.

[0028] 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.

[0029] The advantages of the electrical equipment and the above-mentioned chiller and centrifugal compressor over the prior art are the same and will not be described in detail here.

[0030] 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

[0031] 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:

[0032] Figure 1 is a cross-sectional view of a centrifugal compressor according to an embodiment of the utility model;

[0033] Figure 2 is a cross-sectional view of a stator assembly of a centrifugal compressor according to an embodiment of the utility model;

[0034] Figure 3 It is a structural schematic diagram of a motor stator of a centrifugal compressor according to an embodiment of the utility model;

[0035] Figure 4 It is a schematic structural diagram of a stator punching sheet of a centrifugal compressor according to an embodiment of the utility model.

[0036] Reference numerals:

[0037] Centrifugal compressor 100,

[0038] 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, adjustment mechanism 18, drive structure 2, stator assembly 21, motor stator 211, winding skew slot 2111, center channel 2112, stator tooth 2113, stator punching sheet 2114, winding mouth 2115, welding mouth 2116, welding skew slot 2117, center hole 2118, stator winding 212, rotor assembly 22, first rotor 221, magnetic block 222, second rotor 223, thrust plate 224, axial bearing 225, first radial bearing 226, second radial bearing 227, interstage pipeline 3. 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 4The centrifugal compressor 100 according to the embodiment of the utility model is described. By setting the winding bevel groove 2111 in the motor stator 211, the motor stator 211 will also generate an axial component force when driving the rotor assembly 22, which can balance part of the axial force generated by the first-stage impeller 111 and the second-stage impeller 121, thereby reducing the load on the axial structure, so as 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 4 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 stator assembly 21 includes a motor stator 211 and a stator winding 212. A winding bevel groove 2111 is formed in the motor stator 211. The winding bevel groove 2111 is constructed to extend obliquely relative to the axial direction of the rotor assembly 22. At least part of the stator winding 212 is located in the winding bevel groove 2111 and extends in the same direction as the winding bevel groove 2111.

[0047] Specifically, the driving structure 2 can be configured as a driving motor, and 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 to 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 12 1 is connected, and a winding skew slot 2111 is formed in the motor stator 211 of the stator assembly 21 for accommodating the stator winding 212. The extension direction of at least a part of the stator winding 212 is the same as that of the winding skew slot 2111, so that the stator winding 212 is tilted in the motor stator 211. Therefore, after the stator winding 212 is energized, a magnetic field is generated to drive the rotor assembly 22 to rotate. The rotation of the rotor assembly 22 drives the primary impeller 111 and the secondary impeller 121 to rotate, thereby respectively realizing the primary compression and the secondary compression of the gas.

[0048] 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 motor stator 211 forms an axial component force when driving the rotor assembly 22 to rotate, and the axial component force is opposite to the direction of the axial resultant force.

[0049] Specifically, during the centrifugal compression process, the pressure on both sides of the impeller axis is 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 force to the right, and during the second-stage compression process, the second-stage impeller 121 will generate an axial force to the left. The gas pressure during the second-stage compression is greater, and the axial force to the left of the second-stage compression is greater than the axial force to the right of the first-stage compression, and an overall axial resultant force to the left is generated. In the following description, the axial resultant force to the left is used as an example for description, and the winding bevel 2111 extends obliquely relative to the axis of the rotor assembly 22, so that the stator winding 212 generates a magnetic field force perpendicular to the winding bevel 2111 on the rotor assembly 22. The radial component of this magnetic field force can drive the rotor assembly 22 to rotate, and the magnetic field force forms an axial component to the right, which is opposite to the direction of the axial resultant force and can offset a part of the axial resultant force to the left, thereby reducing the load on the axial structure, improving the life and reliability of the axial structure, and at the same time improving the axial bearing capacity of the two impellers.

[0050] Therefore, by setting a winding bevel slot 2111 at the motor stator 211, the winding angle of the stator winding 212 can be changed, 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, due to the formation of the axial force, a part of the driving force on the rotor assembly 22 can be reduced, which can reduce the tooth torque and rotation pulse of the rotor assembly 22, increase the stability and smoothness of the operation of the rotor assembly 22, improve the operation accuracy of the rotor assembly 22, reduce the noise of the centrifugal compressor 100, and improve the working performance of the centrifugal compressor 100.

[0051] In some embodiments, the motor stator 211 is provided with a central hole 2112 , the rotor assembly 22 is passed through the central hole 2112 , there are multiple winding skew slots 2111 , and the multiple winding skew slots 2111 are distributed around the central hole 2112 .

[0052] Specifically, Figure 3 As shown, the motor stator 211 is constructed as a cylinder, and a central hole 2112 is provided inside the cylinder. The central hole 2112 penetrates the motor stator 211 along the axial direction. The outer diameter of the rotor assembly 22 is smaller than the inner diameter of the central hole 2112. The rotor assembly 22 is penetrated in the central hole 2112, and a gap is left between the two, so that the stator assembly 21 can drive the rotor assembly 22 to rotate, and the winding skew slots 2111 are provided in plurality, and the plurality of winding skew slots 2111 are distributed around the central hole 2112 and are spaced apart and distributed in the circumferential direction of the central hole 2112. In this way, multiple groups of stator windings 212 can be formed in the motor stator 211. In this way, after power is turned on, the multiple groups of stator windings 212 generate a magnetic field and a magnetic field force on the rotor assembly 22. The radial component force formed by the magnetic field force drives the rotor assembly 22 to rotate, and the axial component force formed by the magnetic field force is used to offset part of the axial force of the impeller. This ensures that the motor stator 211 also balances part of the axial force of the impeller when driving the rotor assembly 22 to rotate, thereby improving the stability and smoothness of the operation of the rotor assembly 22 and reducing the noise of the centrifugal compressor 100.

[0053] Among them, Figure 3 As shown, there are 24 winding skew slots 2111.

[0054] In some embodiments, multiple winding slots 2111 are constructed to be open toward the center channel 2112, the winding slots 2111 pass through both ends of the motor stator 211, and the motor stator 211 is provided with a stator tooth 2113 between two adjacent winding slots 2111, the stator winding 212 is wound around the stator tooth 2113, and the extension direction of the stator tooth 2113 is the same as that of the winding slots 2111.

[0055] Specifically, multiple winding bevel slots 2111 are open on the side facing the central channel 2112, and the opening size is small to ensure that the stator winding 212 is limited on one side of the central channel 2112. The winding bevel slots 2111 extend along the axial direction inclined to the motor stator 211, and pass through the axial ends of the motor stator 211, and a stator tooth portion 2113 is formed between two adjacent winding bevel slots 2111, that is, multiple winding bevel slots 2111 correspond to multiple stator teeth 2113, and the stator teeth 2113 extend along the axial direction inclined to the motor stator 211, and the extension direction is the same as the extension direction of the winding bevel slots 2111. In this way, the stator winding 212 is wound along the extension direction of the stator teeth 2113, and the stator winding 212 in the stator teeth 2113 part is also extended obliquely, which can change the direction of the generated magnetic field.

[0056] Among them, Figure 2 As shown, the winding bevel slot 2111 is inclined from left to right in the running direction of the rotor assembly 22 on the motor stator 211. At this time, the rotor assembly 22 rotates counterclockwise when viewed from the first-stage impeller 111 to the second-stage impeller 121. When the rotor assembly 22 rotates clockwise, the corresponding winding bevel slot 2111 is inclined in the opposite direction.

[0057] In some embodiments, the width of the winding slot 2111 is configured to gradually decrease or increase in the radial direction of the motor stator 211 in a direction approaching the central hole 2112 .

[0058] Specifically, Figure 3 As shown, the width of the winding slots 2111 is different in the radial direction of the motor stator 211, and gradually decreases in the direction approaching the center hole 2112. Because the motor stator 211 is constructed as a cylindrical structure, the stator teeth 2113 between two adjacent winding slots 2111 have the same width in the radial direction of the motor stator 211. In this way, the widths of multiple winding slots 2111 are constructed to gradually decrease in the direction approaching the center hole 2112, and transition arcs are provided at both ends of the length direction of the winding slots 2111 to ensure a smooth structure. The width of the winding slots 2111 on one side of the center hole 2112 is greater than the width of the stator winding 212. In this way, the winding of the stator winding 212 is more convenient, and the stator teeth 2113 are evenly spaced and distributed in the circumferential direction to meet the circumferential winding method of the stator winding 212.

[0059] Moreover, the width of the winding bevel slot 2111 gradually increases in the direction close to the center hole 2112 along the radial direction of the motor stator 211. When the motor stator 211 is constructed as a cylindrical structure, the width of the stator tooth 2113 between two adjacent winding bevel slots 2111 is different, and gradually decreases in the radial direction of the motor stator 211 close to the center hole 2112, and the winding of the stator winding 212 can also be achieved. The width of the winding bevel slot 212 can also be the same in the radial direction of the motor stator 211. The setting method is diverse and can be flexibly selected according to actual design requirements.

[0060] In some embodiments, the span between the two ends of the winding slot 2111 in the circumferential direction of the motor stator 211 is one or two tooth pitches of the stator teeth 2113 .

[0061] Specifically, the winding skew slot 2111 is inclined relative to the axis of the motor stator 211, and the inclination angle is set according to actual needs, and the inclination angle can be adjusted by the span in the axial direction. In actual design, the pitch of the left and right ends of the winding skew slot 2111 in the circumferential direction of the motor stator 211 is an integer multiple of the span, which can be the pitch of one stator tooth portion 2113, or the pitch of two stator teeth portions 2113. In this embodiment, Figure 3 As shown, the span of the left and right ends of the winding inclined slot 2111 in the circumferential direction of the motor stator 211 is the pitch of a stator tooth 2113. In this way, tilting the pitch of a stator tooth 2113 in the circumferential direction can not only offset part of the axial force generated by the impeller, but also reduce the tooth torque of the drive structure 2, make the rotor assembly 22 run more smoothly, and improve the mechanical performance of the drive structure 2.

[0062] It should be noted that the magnetic field force transmitted from the motor stator 211 to the rotor assembly 22 is perpendicular to the stator teeth 2113. Figure 2 As shown, when the rotor assembly 22 rotates counterclockwise, the motor stator 211 gives the rotor assembly 22 a radial force F1 to drive the rotor assembly 22 to rotate, and gives the rotor assembly 22 a rightward axial force F2, and F2 is proportional to the torque of the driving structure 2, and the axial force generated increases with the increase of the load. At the same time, the angle of the winding skew slot 2111 can be adjusted according to the size of the load. The larger the angle of the winding skew slot 2111, the greater the axial force F2 generated, which can offset the axial resultant force generated by the impeller to a certain extent.

[0063] In some embodiments, the extension directions of the multiple winding slots 2111 are inclined at the same angle relative to the axial direction of the rotor assembly 22, and / or the extension directions of the multiple winding slots 2111 are inclined at the same angle relative to the axial direction of the rotor assembly 22, and the multiple winding slots 2111 are spaced apart in parallel.

[0064] Specifically, Figure 2 and Figure 3 As shown, the extension directions of the plurality of winding bevel slots 2111 are inclined at the same angle relative to the axial direction of the rotor assembly 22 toward the running direction of the rotor assembly 22, so that a plurality of inclined winding bevel slots 2111 are formed in the circumferential direction of the central hole 2112 of the motor stator 211, and the spacing between two adjacent winding bevel slots 2111 may be the same or different. In the present embodiment, the spacing between two adjacent winding bevel slots 2111 is the same, that is, a plurality of evenly spaced winding bevel slots 2111 are formed in the circumferential direction of the central hole 2112, so that the spacing between each group of stator windings 212 is also the same, the magnetic field formed in the motor stator 211 is uniform, the driving of the rotor assembly 22 in the central hole 2112 is more stable and reliable, and the overall structure of the motor stator 211 is evenly distributed and regular.

[0065] In some embodiments, the motor stator 211 is integrally formed, that is, the motor stator 211 can be machined into multiple winding slots 2111 at one time by mechanical processing, thereby saving processing time and setting of other connection methods.

[0066] And / or, the motor stator 211 is formed by stacking a plurality of stator punching sheets 2114, that is, the motor stator 211 is stacked with a plurality of stator punching sheets 2114, and can be connected as a whole by welding, or positioned and connected by other positioning structures. Specifically, the stator punching sheet 2114 can be made of silicon steel, and a silicon steel sheet with a thickness of 0.1 to 0.5 mm is stamped by a mold. Figure 4 The stator punching sheets 2114 shown are then stacked one by one in a stacked manner and rotated, and the process can be assisted by special tooling. Finally, multiple stator punching sheets 2114 are connected together in sequence to realize the forming of the motor stator 211. This forming method has more steps, but the time for processing a single stator punching sheet 2114 is shorter, and the structure of each stator punching sheet 2114 is consistent, which makes processing more convenient and has higher processing accuracy. Therefore, the forming methods of the motor stator 211 are diverse and can be flexibly selected.

[0067] In some embodiments, a plurality of stator sheets 2114 are formed with winding openings 2115 on their inner sides, and the winding openings 2115 of the plurality of stator sheets 2114 together form a winding skew slot 2111. Specifically, as Figure 4As shown, the stator sheet 2114 is annular, and a center hole 2118 is formed therein, and a winding opening 2115 is formed on the inner side of each stator sheet 2114, and the width of the winding opening 2115 is configured to gradually decrease in a direction close to the inner side of the stator sheet 2114, and there are multiple winding openings 2115, and the multiple winding openings 2115 are evenly spaced and distributed along the circumference of the stator sheet 2114, and the multiple stator sheets 2114 are stacked in a manner so that each stator sheet 2114 has a winding opening 2115. 2114 are stacked up in sequence and rotated at a certain angle, and a plurality of winding openings 2115 in the height direction jointly form a winding bevel slot 2111 to form a motor stator 211, and a plurality of center holes 2118 jointly form a center channel 2112, and a plurality of winding bevel slots 2111 are formed in the circumferential direction of the motor stator 211, and a stator tooth portion 2113 is formed between two adjacent winding bevel slots 2111, so that the manufacturing and forming of the motor stator 211 is realized.

[0068] And / or, a plurality of stator punching sheets 2114 are formed with welding openings 2116 on their outer sides, and the welding openings 2116 of the plurality of stator punching sheets 2114 together form a welding chute 2117. Specifically, Figure 4 As shown, a welding opening 2116 is formed on the outer circumference of each stator punching sheet 2114 for welding a plurality of stator punching sheets 2114. The welding opening 2116 can be constructed as a slot hole. The welding opening 2116 is constructed to be open on the outer side of the stator punching sheet 2114, which is convenient for welding the stator punching sheets 2114. After the plurality of stator punching sheets 2114 are stacked, the plurality of welding openings 2116 in the height direction jointly form a welding bevel 2117. The plurality of stator punching sheets 2114 are fixedly connected by the welding bevel 2117. Each stator punching sheet 2114 is provided with a plurality of welding openings 2116. The plurality of welding openings 2116 of the plurality of stator punching sheets 2114 jointly form a plurality of welding bevel 2117. Multiple welding can be achieved in the circumferential direction of the motor stator 211, thereby ensuring that the internal structure of the motor stator 211 is firmly and reliably fixed.

[0069] In some embodiments, the extension direction of the winding chute 2111 is the same as the extension direction of the welding chute 2117, each stator punching sheet 2114 has the same structure, and multiple stator punching sheets 2114 are rotated and stacked in the same direction in sequence along a preset inclination angle, and the formed welding chute 2117 and the winding chute 2111 have the same extension direction. Figure 4 As shown, eight welding openings 2116 are provided on the outer periphery of the stator punching sheet 2114. The eight welding openings 2116 of multiple stator punching sheets 2114 together form eight welding bevels 2117. The extension direction of the eight welding bevels 2117 is the same as the extension direction of the winding bevels 2111, so that the welding direction conforms to the extension direction of the winding bevels 2111, thereby ensuring the reliability of welding between each winding bevel 2111 and improving the manufacturing accuracy of this forming method. In addition, the provision of the welding bevels 2117 makes the welding process simple and quick.

[0070] In some embodiments, when the rotor assembly 22 rotates counterclockwise when viewed from the primary side, the welding bevel 2117 and the winding bevel 2111 both rotate rightward and rise from bottom to top. In this way, the motor stator 211 can give the rotor assembly 22 a radial component force F1 to drive the rotor assembly 22 to rotate counterclockwise.

[0071] Specifically, Figure 2 The figure shows a partial cross-sectional view of the motor stator 211. The plurality of winding skew slots 2111 all rotate upward from bottom to top and rightward, and the stator tooth portion 2113 between the two winding skew slots 2111 also rotates upward from bottom to top and rightward, so that the stator winding 212 and the stator tooth portion 2113 can be tilted in the same direction, so that the motor stator 211 can apply a downward radial component force F1 to the rotor assembly 22 to drive the rotor assembly 22 to rotate counterclockwise, and the motor stator 211 also applies a rightward axial component force F2 to the rotor assembly 22. The axial component force F2 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. The extension direction of the welding bevel 2117 is consistent with the extension direction of the winding bevel 2111, so that the welding direction conforms to the extension direction of the winding bevel 2111, ensuring the reliability of welding between each winding bevel 2111, improving the manufacturing accuracy of this forming method, and the processing of the welding bevel 2117 and the winding bevel 2111 is simpler, making the processing of the motor stator 211 more convenient.

[0072] Furthermore, when the rotor assembly 22 rotates clockwise when viewed from the primary side, the welding bevel 2117 and the winding bevel 2111 both rotate upward from bottom to top and rotate counterclockwise. In this way, the motor stator 211 can give the rotor assembly 22 a radial component force F1 to drive the rotor assembly 22 to rotate clockwise.

[0073] Specifically, the plurality of winding skew slots 2111 all rotate upward and leftward from bottom to top, and the stator tooth portion 2113 between the two winding skew slots 2111 also rotates upward and leftward from bottom to top, so that the stator winding 212 and the stator tooth portion 2113 are inclined in the same direction, so that the motor stator 211 can apply an upward radial component force F1 to the rotor assembly 22 to drive the rotor assembly 22 to rotate clockwise, and the motor stator 211 also applies an axial component force F2 to the right to the rotor assembly 22, and the axial component force F 2 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. The extension direction of the welding bevel 2117 is consistent with the extension direction of the winding bevel 2111, so that the welding direction conforms to the extension direction of the winding bevel 2111, ensuring the reliability of welding between each winding bevel 2111, improving the manufacturing accuracy of this molding method, and the processing of the welding bevel 2117 and the winding bevel 2111 is simpler, making the processing of the motor stator 211 more convenient.

[0074] In some embodiments, the rotor assembly 22 also includes a first rotor 221, a magnetic block 222 and a second rotor 223. The first rotor 221 is connected to one end of the magnetic block 222 and is connected to the first-stage impeller 111. The second rotor 223 is connected to the other end of the magnetic block 222 and is connected to the second-stage impeller 121. The magnetic block 222 is inserted into the stator assembly 21.

[0075] Specifically, Figure 1 As shown, the first rotor 221, the magnetic block 222 and the second rotor 223 are coaxially distributed in sequence, wherein the first rotor 221 and the magnetic block 222 and the magnetic block 222 and the second rotor 223 are fixedly connected respectively, and 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 222 are firmly connected to the first rotor 221 and the second rotor 223 respectively.

[0076] The first rotor 221 is connected to the first-stage impeller 111, and the second rotor 223 is connected to the second-stage impeller 121, which can be connected by fasteners such as bolts. The magnetic block 222 is located between the first rotor 221 and the second rotor 223, and is penetrated into the central channel 2112 of the stator assembly 21. In this way, after the stator winding 212 is energized, the magnetic block 222, the first rotor 221 and the second rotor 223 are driven to rotate together, which can respectively drive the first-stage impeller 111 and the second-stage impeller 121 to rotate, so as to respectively realize the first-stage compression and the second-stage compression of the gas. The provision of the magnetic block 222 can make the magnetic field more concentrated and uniform, thereby improving the uniformity and stability of the operation of the rotor assembly 22.

[0077] In some embodiments, the centrifugal compressor 100 further includes a thrust plate 224 . The thrust plate 224 is installed at one end of the first rotor 221 away from the magnetic conductive block 222 . The thrust plate 224 is used to axially limit the first rotor 221 .

[0078] Specifically, the thrust plate 224 is located between the primary impeller 111 and the first rotor 221, and the thrust plate 224 is connected to the end of the first rotor 221 that faces away from the magnetic block 222. The thrust plate 224 is coaxially connected to the first rotor 221. The thrust plate 224 is constructed in a circular ring shape. The inner diameter of the thrust plate 224 is smaller than the outer diameter of the first rotor 221, and the side of the thrust plate 224 close to the first rotor 221 is in contact and connected with the first rotor 221, so that the first rotor 221 can be axially limited. When the motor stator 211 drives the rotor assembly 22 to move, the primary impeller 111 and the secondary impeller 121 will generate a left axial resultant force in the axial direction of the rotor assembly 22. The first rotor 221 can be axially limited by the thrust plate 224 to prevent the first rotor 221 from excessively moving in the axial direction. Under normal working conditions, the thrust plate 224 has a slight axial float according to the dynamic change of the force to ensure the smooth operation of the rotor assembly 22.

[0079] Furthermore, the thrust plate 224 need not be provided at the end of the second rotor 223 away from the magnetic block 222. The secondary impeller 121 generates a leftward axial force, which can reduce the rightward movement of the second rotor 223. Thus, the number of parts can be reduced and the cost can be reduced.

[0080] In some embodiments, the centrifugal compressor 100 further includes two axial bearings 225 , which are respectively supported on two axial sides of the thrust plate 224 .

[0081] Specifically, the axial bearing 225 is used to support the end of the first rotor 221. The axial bearing 225 is located between the first-stage impeller 111 and the first rotor 221, and the two axial bearings 225 are distributed on both axial sides of the thrust plate 224, and are respectively supported on both axial sides of the thrust plate 224. The outer ring of the axial bearing 225 is rotatably supported by the housing 1, and the inner ring is supported by the first rotor 221. In this way, the first rotor 221 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.

[0082] 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 224 and the axial bearing 225. By setting the winding bevel groove 2111 inside the motor stator 211, the motor stator 211 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 224 and the axial bearing 225, increasing the life and reliability of the axial bearing 225, and facilitating better generation of dynamic pressure gas between the rotor assembly 22 and the axial bearing 225, 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.

[0083] In some embodiments, the centrifugal compressor 100 also includes a first radial bearing 226 and a second radial bearing 227, the first rotor 221 is inserted through the first radial bearing 226 and is rotatably supported in the housing 1 through the first radial bearing 226, and the second rotor 223 is inserted through the second radial bearing 227 and is rotatably supported in the housing 1 through the second radial bearing 227.

[0084] Specifically, the first radial bearing 226 is located between the magnetic block 222 and the axial bearing 225, and is coaxially connected to the first rotor 221. The first rotor 221 is inserted into the first radial bearing 226, and the outer ring of the first radial bearing 226 is supported and connected to the housing 1. The second radial bearing 227 is located between the magnetic block 222 and the secondary impeller 121, and is coaxially connected to the second rotor 223. The second rotor 223 is inserted into the second radial bearing 227, and the outer ring of the second radial bearing 227 is supported and connected to the housing 1. In this way, the first radial bearing 226 and the second radial bearing 227 respectively bear the weight of the first rotor 221 and the second rotor 223 and various radial forces generated by the rotation, which helps to suppress the radial vibration of the first rotor 221 and the second rotor 223, ensure that the first rotor 221 and the second rotor 223 maintain a stable position during operation, improve the output accuracy of the torque of the motor stator 211, 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.

[0085] In some embodiments, Figure 1 As shown, the casing 1 includes a first-stage volute 13, a first-stage diffuser 14, an intermediate casing 151, 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 151, the first-stage volute 13 is detachably connected to the intermediate casing 151, and the intermediate casing 151 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 151, 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.

[0086] And at the air inlet end of the first-stage volute 13, an adjusting mechanism 18 is provided, and the adjusting mechanism 18 is detachably connected to the first-stage volute 13. The adjusting mechanism 18 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 18 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 18 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 burn the starting device or even the drive motor.

[0087] Among them, a first-stage diffusion flow channel 141 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 161 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.

[0088] In addition, an interstage pipe 3 is connected between the first-stage diffuser flow channel 141 and the second-stage diffuser flow channel 161, and the interstage pipe 3 is located on the outside of the shell 1. When the gas enters the first-stage compression space 11, the rotor assembly 22 of the driving structure 2 drives the first-stage impeller 111 to rotate at a high speed to generate centrifugal force to perform first-stage compression on the gas. The compressed gas enters the first-stage diffuser flow channel 141 for further deceleration and pressurization. The high-pressure gas enters the second-stage compression space 12 from the interstage pipe 3, and the second-stage impeller 121 rotates at a high speed to generate centrifugal force to perform second-stage compression on the gas. The compressed gas enters the second-stage diffuser flow channel 161 for further deceleration and pressurization. Finally, the high-pressure gas is discharged from the exhaust port of the second-stage diffuser flow channel 161 to achieve secondary compression of the gas to achieve the required high-pressure gas.

[0089] The utility model also provides a water chiller.

[0090] According to the chiller of the embodiment of the utility model, a centrifugal compressor of any one of the above-mentioned embodiments is provided, and a winding bevel groove 2111 inclined axially relative to the rotor assembly 22 is formed in the motor stator 211, so that an axial component force can be formed when the motor stator 211 drives the rotor assembly 22 to rotate, and the axial force generated by part of the first-stage impeller 111 and the second-stage impeller 121 can be balanced, thereby reducing the load on the axial structure, improving the working performance of the two impellers, and reducing the tooth torque and rotation pulse of the rotor assembly 22, thereby improving the operating accuracy of the rotor assembly 22, increasing the stability and smoothness of the operation of the rotor assembly 22, and reducing the noise of the centrifugal compressor 100, thereby improving the gas compression performance of the chiller.

[0091] The utility model also provides an electrical appliance.

[0092] 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 a winding bevel groove 2111 inclined axially relative to the rotor assembly 22 is formed in the motor stator 211, so that an axial component force can be formed when the motor stator 211 drives the rotor assembly 22 to rotate, and the axial force generated by part of the first-stage impeller 111 and the second-stage impeller 121 can be balanced, thereby reducing the load on the axial structure, improving the working performance of the two impellers, and reducing the tooth torque and rotation pulse of the rotor assembly 22, thereby improving the operating accuracy of the rotor assembly 22, increasing the stability and smoothness of the operation of the rotor assembly 22, and reducing the noise of the centrifugal compressor 100, thereby improving the gas compression performance of the electrical equipment.

[0093] 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.

[0094] 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 stator assembly comprises a motor stator and a stator winding, a winding skew slot is formed in the motor stator, the winding skew slot is configured to extend obliquely relative to the axial direction of the rotor assembly, at least part of the stator winding is located in the winding skew slot and extends in the same direction as the winding skew slot; The first-stage impeller and the second-stage impeller form an axial resultant force when rotating with the rotor assembly, and the motor stator forms an axial component force when driving the rotor assembly to rotate, 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 motor stator is provided with a central hole, the rotor assembly is passed through the central hole, there are a plurality of winding skew slots, and the plurality of winding skew slots are distributed around the central hole.

3. The centrifugal compressor according to claim 2, characterized in that: The plurality of winding slots are all constructed to be open toward the central channel, the winding slots pass through both ends of the motor stator, and the motor stator is provided with a stator tooth portion between two adjacent winding slots, the stator winding is wound around the stator tooth portion, and the extension direction of the stator tooth portion is the same as that of the winding slots.

4. The centrifugal compressor according to claim 3, characterized in that: The width of the winding skew slot is configured to gradually decrease or increase in the radial direction of the motor stator in a direction approaching the central hole.

5. The centrifugal compressor according to claim 3, characterized in that: The span between the two ends of the winding skew slot in the circumferential direction of the motor stator is equal to the tooth pitch of one or two stator teeth.

6. The centrifugal compressor according to claim 2, characterized in that: The extending directions of the plurality of winding skew slots are inclined at the same angle relative to the axial direction of the rotor assembly; And / or, the extension directions of the plurality of winding skew slots are in the same direction of inclination relative to the axial direction of the rotor assembly, and the plurality of winding skew slots are spaced apart in parallel.

7. The centrifugal compressor according to any one of claims 1 to 6, characterized in that: The motor stator is integrally formed; And / or, the motor stator is formed by stacking a plurality of stator punching sheets.

8. The centrifugal compressor according to claim 7, characterized in that: A winding opening is formed on the inner side of the plurality of stator punching sheets, and the winding openings of the plurality of stator punching sheets together form the winding skew slot; And / or, welding openings are formed on the outer sides of the plurality of stator punching sheets, and the welding openings of the plurality of stator punching sheets together form a welding chute.

9. The centrifugal compressor according to claim 8, characterized in that: The extending direction of the winding skew slot is the same as the extending direction of the welding skew slot.

10. The centrifugal compressor according to claim 8, characterized in that: When the rotor assembly is viewed from the primary side and the rotation direction is counterclockwise, the welding chute and the winding chute both rise from bottom to top in a clockwise direction; Furthermore, when the rotor assembly is viewed from the primary side and its rotation direction is clockwise, both the welding chute and the winding chute are rotated upward from bottom to top and in a left-hand direction.

11. The centrifugal compressor according to any one of claims 1 to 6, 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, and 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.

12. The centrifugal compressor according to claim 11, 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.

13. The centrifugal compressor according to claim 12, characterized in that: It also includes two axial bearings, which are respectively supported on two axial sides of the thrust plate.

14. The centrifugal compressor according to claim 11, 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.

15. 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.

16. A chiller, characterized in that: A centrifugal compressor according to any one of claims 1 to 15 is provided.

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

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