Magnetic levitation active three-degree-of-freedom bearing, motor and compressor

Abstract

The application provides a magnetic suspension active three-degree-of-freedom bearing, a motor and a compressor, a rotating shaft, a bearing rotor and a radial stator and a first axial stator and a second axial stator, the radial stator has a plurality of pole columns extending towards the side of the bearing rotor; in the cross section of the rotating shaft, the plurality of pole columns are centrally symmetrical about the center of the rotating shaft and are distributed in four quadrants; each quadrant has a first pole column and a second pole column; the circumferential width of the first pole column is greater than the circumferential width of the second pole column; and the first axial stator, the second axial stator and the bearing rotor form an accommodation space, and the radial stator is located in the accommodation space. The application does not need to separately assemble a thrust disc on the rotating shaft, the structure is more compact, the process is simplified, the bearing volume is effectively reduced, the rotating shaft length is shortened, the rotor critical speed is improved, and the operation stability of the magnetic suspension system is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnetic suspension bearings, and particularly relates to a magnetic suspension active three-degree-of-freedom bearing, a motor and a compressor. BACKGROUND

[0002] At present, a magnetic suspension bearing (referred to as a magnetic bearing) uses electromagnetic force on a rotor to suspend a rotating shaft, and the rotating shaft and a stator are in a non-contact state, thus having advantages of no wear, high rotating speed, high precision, long service life and the like. The magnetic bearing can be divided into three types according to working principles: an active magnetic bearing, a passive magnetic bearing and a hybrid magnetic bearing.

[0003] The magnetic bearing is further divided into a radial magnetic suspension bearing and an axial magnetic suspension bearing. The radial magnetic suspension bearing adjusts the radial position of the rotating shaft through electromagnetic force between the radial rotor and the rotating shaft, and the axial magnetic suspension bearing adjusts the axial position of the rotating shaft through electromagnetic force between the rotating shaft and a thrust disc. In a magnetic suspension system, the radial magnetic suspension bearing and the axial magnetic suspension bearing are arranged at both ends of the rotating shaft, so as to adjust the three-degree-of-freedom direction position of the rotating shaft.

[0004] However, the related art needs to install the thrust disc, the radial-axial stator is large in size, and the rotor is long, which makes the processing technology complex, the product large in size, and further affects the stability and applicability of the magnetic suspension system.

[0005] Therefore, how to provide a magnetic suspension active three-degree-of-freedom bearing, a motor and a compressor capable of reducing the size of the radial-axial stator and shortening the length of the rotor, improving the critical rotating speed of the rotor, and improving the stability and applicability of the magnetic suspension system has become a problem to be solved by those skilled in the art. SUMMARY

[0006] Therefore, the technical problem to be solved by the application is to provide a magnetic suspension active three-degree-of-freedom bearing, a motor and a compressor capable of reducing the size of the radial-axial stator and shortening the length of the rotor, improving the critical rotating speed of the rotor, and improving the stability and applicability of the magnetic suspension system.

[0007] In order to solve the above problems, the application provides a magnetic suspension active three-degree-of-freedom bearing, comprising:

[0008] a rotating shaft;

[0009] a bearing rotor, which is sleeved on the rotating shaft;

[0010] a radial stator, which is sleeved outside the bearing rotor; the radial stator has a plurality of pole columns extending towards one side of the bearing rotor; in a cross section of the rotating shaft, the plurality of pole columns are centrally symmetric about the center of the rotating shaft and are distributed in four quadrants;

[0011] Each quadrant has a first pole column and a second pole column; the circumferential width of the first pole column is greater than the circumferential width of the second pole column;

[0012] The first axial stator and the second axial stator are arranged outside the rotating shaft, and are arranged on the axial two sides of the bearing rotor respectively, and the first axial stator, the second axial stator and the bearing rotor form a containing space, and the radial stator is located in the containing space; the first axial stator and the second axial stator form an axial magnetic circuit with the bearing rotor and the radial stator to adjust the axial position of the bearing rotor, and the radial stator forms a radial magnetic circuit with the bearing rotor to adjust the radial position of the bearing rotor.

[0013] Further, the magnetic suspension active three-degree-of-freedom bearing further comprises an axial winding; the axial winding is arranged between the first axial stator and the second axial stator; the axial winding is arranged around the circumference of the rotating shaft.

[0014] Further, the radial winding around each pole column is in series with the radial winding around the two second pole columns.

[0015] Further, the first axial stator has a first inner magnetic ring and a first outer magnetic ring, and the axial winding is between the first inner magnetic ring and the first outer magnetic ring, wherein a first axial inner working gap is formed between the first inner magnetic ring and the left end surface of the bearing rotor, and the first outer magnetic ring is radially outside the radial winding.

[0016] Further, the second axial stator has a second inner magnetic ring and a second outer magnetic ring, and the axial winding is between the second inner magnetic ring and the second outer magnetic ring, wherein a second axial inner working gap is formed between the second inner magnetic ring and the right end surface of the bearing rotor, and the second outer magnetic ring is radially outside the radial winding.

[0017] Further, the first axial stator further comprises a first connecting section connecting the first inner magnetic ring and the first outer magnetic ring; the second axial stator further comprises a second connecting section connecting the second inner magnetic ring and the second outer magnetic ring; the first inner magnetic ring and the second inner magnetic ring are respectively located on the axial two sides of the bearing rotor, and the first outer magnetic ring and the second outer magnetic ring are in contact, so that the first axial stator, the second axial stator and the bearing rotor form a containing space; the axial winding is arranged in the containing space and located on the axial two sides of the radial stator.

[0018] Further, the control of the radial winding around the first pole column in each quadrant is independent of the control of the radial winding around the second pole column.

[0019] Further, the current flowing in the axial winding in the first axial stator is opposite to the current flowing in the axial winding in the second axial stator.

[0020] Further, the plurality of pole columns is 12 pole columns; each quadrant has one first pole column and two second pole columns; the two second pole columns are located on the circumferential two sides of the first pole column respectively;

[0021] Alternatively, the plurality of pole columns is 8 pole columns; each quadrant has one first pole column and one second pole column; the second pole column is arranged in sequence with the first pole column in the circumferential direction.

[0022] Further, the magnetic flux direction of the radial magnetic circuit in the first pole column is opposite to the magnetic flux direction of the axial magnetic circuit in the first pole column;

[0023] And / or, the magnetic flux direction of the radial magnetic circuit in the second pole column is the same as the magnetic flux direction of the axial magnetic circuit in the first pole column.

[0024] The application also provides an electric machine comprising the above-mentioned magnetic suspension active three-degree-of-freedom bearing.

[0025] The application also provides a compressor comprising the above-mentioned electric machine.

[0026] The magnetic suspension active three-degree-of-freedom bearing, the electric machine and the compressor provided by the application do not need to separately assemble a thrust disc on the rotating shaft, the overall structure and the manufacturing process are simplified, the assembly is facilitated, the degree of integration is higher, the structure is more compact, the bearing volume is effectively reduced, the rotating shaft length is shortened, the rotor critical speed is improved, and the operation stability of the magnetic suspension system is improved; the application can reduce the radial-axial stator size and shorten the rotor length, improve the rotor critical speed, and improve the stability and applicability of the magnetic suspension system. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is an internal structure diagram of the magnetic suspension active three-degree-of-freedom bearing of the embodiment of the application, and the dashed arrow in the figure shows the flow direction of the axial magnetic circuit;

[0028] Figure 2 It is the relative position relationship between the radial stator of the 12-stage radial bearing and the bearing rotor, the dashed arrow in the figure shows the flow direction of the axial magnetic circuit, and the solid arrow in the figure shows the flow direction of the radial magnetic circuit;

[0029] Figure 3 It is the relative position relationship between the radial stator of the 8-stage radial bearing and the bearing rotor, the dashed arrow in the figure shows the flow direction of the axial magnetic circuit, and the solid arrow in the figure shows the flow direction of the radial magnetic circuit.

[0030] The signs are represented as:

[0031] 1, bearing rotor; 10, rotating shaft; 21, radial stator; 211, first pole column; 212, second pole column; 213, stator yoke; 214, stator pole column; 31, first axial stator; 311, first inner magnetic ring; 312, first outer magnetic ring; 41, second axial stator; 411, second inner magnetic ring; 412, second outer magnetic ring; 51, axial winding; 52, radial winding; 001, axial magnetic circuit; 002, radial magnetic circuit; 003, radial working gap; 004, first axial inner side working gap; 005, second axial inner side working gap. DETAILED DESCRIPTION

[0032] CONJUNCTION WITH Figures 1 to 3 As shown in the figure, a magnetic suspension active three-degree-of-freedom bearing includes a rotating shaft 10, a bearing rotor 1, a radial stator 21, a first axial stator 31, and a second axial stator 41. The bearing rotor 1 is sleeved on the rotating shaft 10. The radial stator 21 is sleeved outside the bearing rotor 1. The radial stator 21 has a plurality of pole columns extending towards one side of the bearing rotor 1. In the cross section of the rotating shaft 10, the plurality of pole columns are centrally symmetric about the center of the rotating shaft 10 and are distributed in four quadrants. Each quadrant has a first pole column 211 and a second pole column 212. The circumferential width of the first pole column 211 is greater than that of the second pole column 212.

[0033] The first axial stator 31 and the second axial stator 41 are sleeved outside the rotating shaft 10, and are respectively arranged on the axial two sides of the bearing rotor 1. The first axial stator 31, the second axial stator 41, and the bearing rotor 1 enclose a containing space, and the radial stator 21 is located in the containing space. The first axial stator 31 and the second axial stator 41 form an axial magnetic circuit 001 with the bearing rotor 1 and the radial stator 21 to adjust the axial position of the bearing rotor 1. The radial stator 21 forms a radial magnetic circuit 002 with the bearing rotor 1 to adjust the radial position of the bearing rotor 1. The radial stator 21 further includes a stator pole column 214.

[0034] The active three-degree-of-freedom magnetic bearing provided in the present application removes the thrust disc, replaces it with the bearing rotor 1, and integrates the radial bearing and the axial bearing. Compared with the conventional active magnetic bearing, the active three-degree-of-freedom magnetic bearing does not need to install a thrust disc, has a compact structure, and is simple in process. Compared with the conventional hybrid three-degree-of-freedom magnetic bearing, the active three-degree-of-freedom magnetic bearing does not have a permanent magnet, provides a bias magnetic field and a control magnetic field by electromagnetic force, has large carrying capacity, high stiffness, and flexible control, can operate at high power and high critical speed, and improves the stability and applicability of the magnetic suspension system.

[0035] The present application integrates the radial bearing and the axial bearing, removes the thrust disc, has a compact structure, greatly reduces the size of the radial-axial stator and shortens the length of the rotor, improves the critical speed of the rotor, and improves the stability and applicability of the magnetic suspension system.

[0036] Compared with the pole located beside the pole column of the radial stator 21, the application can greatly shorten the outer diameter of the radial stator 21 and the thickness of the axial stator, and reduce the volume of the bearing stator under the same radial and axial output.

[0037] The application adopts a 12-stage radial bearing, has simple processing and manufacturing process, and convenient radial magnetic circuit 002 control. The application has no permanent magnet, low cost, convenient assembly, large bearing capacity, and can operate at high power. The application is integrated in the radial and axial directions, has no thrust disc, reduces the cost, has compact structure, simple process, high critical speed, and stable performance.

[0038] The four quadrants refer to taking the center of the rotating shaft 10 as the coordinate origin O, establishing an orthogonal coordinate system XOY through the O point, and separating the axial projection into four adjacent quadrants. This aspect is not described in detail as basic geometric knowledge. In the technical solution, the bearing rotor 1 serves as the conduction component of the axial magnetic circuit 001 and the radial magnetic circuit 002, integrates the thrust disc and the bearing rotor 1 in the prior art, further improves the integration degree of the bearing, does not need to separately assemble the thrust disc on the rotating shaft 10, and the bearing rotor 1 is shared by the magnetic circuits of the radial stator 21 and the axial stator. The overall structure and processing and manufacturing process are simplified, assembly is facilitated, the integration degree is high, the structure is more compact, the bearing volume is effectively reduced, the length of the rotating shaft 10 is shortened, the rotor critical speed is improved, and the running stability of the magnetic suspension system is improved.

[0039] The application also discloses some embodiments. The magnetic suspension active three-degree-of-freedom bearing further comprises an axial winding 51; the axial winding 51 is arranged between the first axial stator 31 and the second axial stator 41; and the axial winding 51 is arranged around the circumference of the rotating shaft 10. The axial winding 51 adopts a single-coil mode, is installed in the left and right axial stators, and is located at both ends of the radial stator yoke 213 (fixed to the axial stator or fixed to the radial stator yoke 213), thereby saving space and providing the axial magnetic circuit 001 to control the axial movement of the bearing rotor 1.

[0040] The application also discloses some embodiments. The radial winding 52 is arranged around each pole column, and the radial windings 52 arranged around the two second pole columns 212 are connected in series.

[0041] The application also discloses some embodiments. The first axial stator 31 has a first inner magnetic ring 311 and a first outer magnetic ring 312, the axial winding 51 is between the first inner magnetic ring 311 and the first outer magnetic ring 312, a first axial inner side working gap 004 is formed between the first inner magnetic ring 311 and the left end surface of the bearing rotor 1, and the first outer magnetic ring 312 is on the radial outer side of the radial winding 52.

[0042] The application also discloses some embodiments of the second axial stator 41, the second axial stator 41 has a second inner magnetic ring 411 and a second outer magnetic ring 412, and the axial winding 51 is between the second inner magnetic ring 411 and the second outer magnetic ring 412, wherein the second inner magnetic ring 411 and the right end surface of the bearing rotor 1 form a second axial inner side working gap 005, and the second outer magnetic ring 412 is on the radial outer side of the radial winding 52.

[0043] The application also discloses some embodiments of the first axial stator 31, the first axial stator 31 further comprises a first connecting section, the first connecting section connects the first inner magnetic ring 311 and the first outer magnetic ring 312; the second axial stator 41 further comprises a second connecting section, the second connecting section connects the second inner magnetic ring 411 and the second outer magnetic ring 412; the first inner magnetic ring 311 and the second inner magnetic ring 411 are respectively located on the axial two sides of the bearing rotor 1, and the first outer magnetic ring 312 and the second outer magnetic ring 412 are in contact, so that the first axial stator 31, the second axial stator 41 and the bearing rotor 1 form an accommodation space; the axial winding 51 is arranged in the accommodation space and located on the axial two sides of the radial stator 21.

[0044] The application also discloses some embodiments of the first axial stator 31, the first axial stator 31 further comprises a first connecting section, the first connecting section connects the first inner magnetic ring 311 and the first outer magnetic ring 312; the second axial stator 41 further comprises a second connecting section, the second connecting section connects the second inner magnetic ring 411 and the second outer magnetic ring 412; the first inner magnetic ring 311 and the second inner magnetic ring 411 are respectively located on the axial two sides of the bearing rotor 1, and the first outer magnetic ring 312 and the second outer magnetic ring 412 are in contact, so that the first axial stator 31, the second axial stator 41 and the bearing rotor 1 form an accommodation space; the axial winding 51 is arranged in the accommodation space and located on the axial two sides of the radial stator 21.

[0045] The application also discloses some embodiments of the first axial stator 31, the first axial stator 31 further comprises a first connecting section, the first connecting section connects the first inner magnetic ring 311 and the first outer magnetic ring 312; the second axial stator 41 further comprises a second connecting section, the second connecting section connects the second inner magnetic ring 411 and the second outer magnetic ring 412; the first inner magnetic ring 311 and the second inner magnetic ring 411 are respectively located on the axial two sides of the bearing rotor 1, and the first outer magnetic ring 312 and the second outer magnetic ring 412 are in contact, so that the first axial stator 31, the second axial stator 41 and the bearing rotor 1 form an accommodation space; the axial winding 51 is arranged in the accommodation space and located on the axial two sides of the radial stator 21.

[0046] The application also discloses some embodiments of the first axial stator 31, the first axial stator 31 further comprises a first connecting section, the first connecting section connects the first inner magnetic ring 311 and the first outer magnetic ring 312; the second axial stator 41 further comprises a second connecting section, the second connecting section connects the second inner magnetic ring 411 and the second outer magnetic ring 412; the first inner magnetic ring 311 and the second inner magnetic ring 411 are respectively located on the axial two sides of the bearing rotor 1, and the first outer magnetic ring 312 and the second outer magnetic ring 412 are in contact, so that the first axial stator 31, the second axial stator 41 and the bearing rotor 1 form an accommodation space; the axial winding 51 is arranged in the accommodation space and located on the axial two sides of the radial stator 21.

[0047] Alternatively, the plurality of poles is 8 poles; each quadrant has a first pole 211 and a second pole 212; the second pole 212 and the first pole 211 are arranged in sequence in the circumferential direction. Figure 3 As shown, the radial magnetic circuit (002) is shown as a solid line, and is distributed in the space in the form of SSNNSSNN (or NNSSNNSS), and the bias magnetic circuit 001 provided in the axial direction is shown as Figure 2 As shown by the dotted line, when all the axial bias magnetic paths point toward the circumference, the radial air gap magnetic field at the upper and lower ends increases, while the radial air gap magnetic field at the left and right ends decreases. Conversely, when all the axial bias magnetic paths point toward the center of the circle, the radial air gap magnetic field at the left and right ends increases, while the radial air gap magnetic field at the upper and lower ends decreases. When there are eight poles, each tooth has the same size.

[0048] The present application integrates radial bearings and axial bearings, has no thrust plate, and has a compact structure. It greatly reduces the radial and axial stator sizes and shortens the rotor length, increases the critical speed of the rotor, and improves the stability and applicability of the magnetic levitation system. In terms of technology, compared with the axial magnetic poles located next to the radial stator poles, the outer diameter of the radial stator and the thickness of the axial stator can be greatly shortened under the same radial and axial output conditions, thereby reducing the volume of the bearing stator. 12-level or 8-level radial bearings are used, with simple processing and manufacturing processes and convenient radial magnetic circuit control. There are no permanent magnets, low cost, easy assembly, large load-bearing capacity, and high-power operation. The radial and axial integration is high, there is no thrust plate, which reduces costs, has a compact structure, simple process, high critical speed, and stable performance.

[0049] The present application also discloses some embodiments in which the direction of the magnetic lines of force of the radial magnetic circuit 002 within the first pole 211 is opposite to the direction of the magnetic lines of force of the axial magnetic circuit 001 within the first pole 211;

[0050] And / or, the direction of the magnetic lines of force of the radial magnetic circuit 002 in the second pole 212 is the same as the direction of the magnetic lines of force of the axial magnetic circuit 001 in the first pole 211 .

[0051] The active three-degree-of-freedom magnetic bearing structure is as follows Figure 1 As shown, compared with the traditional active magnetic bearing structure, the thrust plate is removed and replaced by a bearing rotor, the axial stator is located at both ends of the radial stator, and the radial bearing and the axial bearing are integrated. The structure mainly consists of a left axial stator 1, a right axial stator 2, a left axial winding 3, a right axial winding 4, a radial winding 5, a radial stator 6, a bearing rotor 7, a rotating shaft 8 and other parts.

[0052] Figure 1The figure shows the axial magnetic circuit of an active three-degree-of-freedom axial bearing. The axial stator structure is shown in the figure. The upper magnetic pole of the axial stator is connected to the radial stator yoke 213, and the lower magnetic pole of the axial stator is located at both ends of the bearing rotor 1. The axial magnetic circuit 001 generated by the axial winding includes a left axial magnetic circuit and a right axial magnetic circuit. The left axial magnetic circuit passes through the left axial upper magnetic pole-radial stator yoke-radial stator pole-radial working gap 003-bearing rotor 1-axial working gap-left axial stator lower magnetic pole and returns to the left axial stator to close. The right axial magnetic circuit passes through the right axial upper magnetic pole-radial stator yoke-radial stator pole-radial working gap 003-bearing rotor 1-axial working gap-right axial stator lower magnetic pole and returns to the right axial stator to close. When the bearing rotor needs to be controlled to move to the left, the current of the left bearing winding is increased, and the bearing rotor is subjected to a greater force to the left. Conversely, when the bearing rotor needs to be controlled to move to the right, the current of the right bearing winding is increased, and the bearing rotor is subjected to a greater force to the right. Therefore, the axial movement of the bearing rotor is controlled by controlling the current of the left and right axial windings.

[0053] Figure 2 The radial magnetic circuit of an active three-degree-of-freedom radial bearing is shown in the figure. The radial stator structure is shown in the figure. It has 12 magnetic poles, which are four symmetrically distributed E-shaped structures. There are small teeth at both ends and large teeth in the middle. The radial windings on the small teeth at both ends are connected in series. The magnetic circuit of each E-shaped structure is NSN (or SNS) distributed in space. The radial magnetic circuit 002 is shown in Figure 2 As shown by the solid line, the axial magnetic circuit 001 is as follows Figure 2 As shown by the dotted lines, all of the directions point toward the center of the circle. The magnetic field in the small air gaps at either end of the E-shaped structure is enhanced, while the magnetic field in the large air gap in the middle tooth is weakened. Conversely, when the axial bias magnetic circuit is directed entirely toward the circumference, the magnetic field in the small air gaps at either end of the E-shaped structure is weakened, while the magnetic field in the large air gap in the middle tooth is enhanced. To control the bearing rotor's movement toward the upper left, the upper left radial winding is energized to provide a radial force to the upper left. To control the bearing rotor's movement upward, the upper left and right radial windings are energized to provide an upward radial force to the bearing rotor. This method of radial control offers a wide range of movement and flexible control. This three-degree-of-freedom magnetic bearing structure integrates the radial and axial bearings, eliminates the thrust plate, and features a compact structure and simple process. This effectively reduces the bearing volume, shortens the rotor length, increases the rotor's critical speed, and improves system operational stability.

[0054] Specific combination Figure 2As shown, the four quadrants are respectively the first quadrant in the upper right, the second quadrant in the upper left, the third quadrant in the lower left, and the fourth quadrant in the lower right. Taking the three pole columns in the first quadrant as an example, the energization direction of each radial winding 52 is shown in the figure. The free end of the first pole column 211 presents an S pole (upper left) and an N pole (lower right), the free end of one second pole column 212 presents an N pole, and the free end of the other second pole column 212 presents an S pole. In the second pole column 212 in the upper left and the first pole column 211 in the lower right, the flow direction of the radial magnetic circuit 002 is the same as that of the axial magnetic circuit 001, which can increase the magnetic flux between the two pole columns and the bearing rotor 1, thereby increasing the radial force at the two locations. In the first pole column 211 in the upper left and the second pole column 212 in the lower right, the flow direction of the radial magnetic circuit 002 is opposite to that of the axial magnetic circuit 001, which weakens the magnetic flux between the two pole columns and the bearing rotor 1, thereby reducing the radial force at the location. The above describes the influence of axial magnetic flux on the pole column in one quadrant, and the four-quadrant enhancement and weakening of the axial magnetic flux to the radial magnetic flux are mutually offset. Although the radial magnetic circuit 002 and the axial magnetic circuit 001 of the integrated magnetic bearing both flow through the bearing rotor 1, the change of the axial magnetic circuit 001 does not affect the entire radial magnetic circuit 002, simplifying the control of the magnetic bearing.

[0055] Referring to Figure 2 As shown, the first pole column 211 is also used as a flow-through component for the magnetic flux lines in the second pole column 212. The circumferential width of the first pole column 211 is designed to be larger than the circumferential width of the adjacent pole columns, which can optimize the magnetic circuit on both sides. By connecting the first pole column 211 and the second pole column 212 in series, the radial control turns and the radial current are ensured to be consistent, thereby only one current needs to be adjusted for radial movement. This control method is simple, ensures that the radial magnetic flux of the first pole column 211 is greater than that at both ends, the radial magnetic density on the four pole columns is consistent, and the magnetic circuit is not easy to saturate. At the same time, the influence of the intermediate axial magnetic circuit 001 can also be considered, and the axial magnetic density on the four pole columns is consistent and the magnetic circuit is not easy to saturate.

[0056] The active three-degree-of-freedom magnetic bearing structure is as shown in Figure 1 Compared with the traditional active magnetic bearing structure, the thrust disc is removed and replaced by the bearing rotor 1, the axial stator is located at both ends of the radial stator 21, and the radial bearing and the axial bearing are integrated. The structure mainly consists of a left axial stator, a right axial stator, a left axial winding 51, a right axial winding 51, a radial winding, a radial stator 21, a bearing rotor 1, a shaft 10, and the like.

[0057] Figure 1The axial magnetic circuit 001 is shown, the axial stator structure is as shown, the axial stator upper magnetic pole is connected with the radial stator magnetic yoke 213, the axial stator lower magnetic pole is located at both ends of the bearing rotor 1, the axial winding 51 generates the axial magnetic circuit 001, the active three-degree-of-freedom magnetic bearing structure is as shown Figure 1 Compared with the conventional active magnetic bearing structure, the thrust disc is removed, the bearing rotor 1 is replaced, the axial stator is located at both ends of the radial stator 21, the radial bearing and the axial bearing are integrated, the structure is mainly composed of the left axial stator, the right axial stator, the left axial winding 51, the right axial winding 51, the radial winding, the radial stator 21, the bearing rotor 1, the shaft 10 and the like.

[0058] According to the embodiments of the present application, an electric machine is also provided, which comprises the above magnetic suspension active three-degree-of-freedom bearing.

[0059] According to the embodiments of the present application, a compressor is also provided, which comprises the above electric machine.

[0060] It is easy for those skilled in the art to understand that the advantageous technical features of the above-mentioned modes can be freely combined and superimposed without conflict.

[0061] The above is only the preferred embodiment of the present application, and is not intended to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only the preferred embodiment of the present application, and is not intended to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A magnetic levitation active three degree of freedom bearing, characterized by, It comprises: a rotating shaft (10); a bearing rotor (1) sleeved on the rotating shaft (10); a radial stator (21) sleeved outside the bearing rotor (1); the radial stator (21) has a plurality of pole columns extending towards one side of the bearing rotor (1); in the cross section of the rotating shaft (10), the plurality of pole columns are centrally symmetric about the center of the rotating shaft (10) and are distributed in four quadrants; each quadrant has a first pole column (211) and a second pole column (212); the circumferential width of the first pole column (211) is greater than that of the second pole column (212); and a first axial stator (31) and a second axial stator (41) sleeved outside the rotating shaft (10), and the first axial stator (31) and the second axial stator (41) are respectively arranged on the axial two sides of the bearing rotor (1), and the first axial stator (31), the second axial stator (41) and the bearing rotor (1) form an accommodation space, and the radial stator (21) is located in the accommodation space; the first axial stator (31) and the second axial stator (41) form an axial magnetic circuit (001) with the bearing rotor (1) and the radial stator (21) to adjust the axial position of the bearing rotor (1), and the radial stator (21) forms a radial magnetic circuit (002) with the bearing rotor (1) to adjust the radial position of the bearing rotor (1); the axial magnetic circuit (001) and the radial magnetic circuit (002) share the first pole column (211) and the second pole column (212).

2. The magnetic levitation active three degree of freedom bearing of claim 1, wherein, The magnetic suspension active three-degree-of-freedom bearing further comprises an axial winding (51); the axial winding (51) is arranged between the first axial stator (31) and the second axial stator (41); the axial winding (51) is arranged around the circumference of the rotating shaft (10).

3. The magnetic levitation active three degree of freedom bearing of claim 2, wherein, A radial winding (52) is arranged on each pole column, and the radial windings (52) arranged on the two second pole columns (212) are connected in series.

4. The magnetic levitation active three degree of freedom bearing of claim 3, wherein, The first axial stator (31) has a first inner magnetic ring (311) and a first outer magnetic ring (312), and the axial winding (51) is between the first inner magnetic ring (311) and the first outer magnetic ring (312), wherein a first axial inner side working gap (004) is formed between the first inner magnetic ring (311) and the left end surface of the bearing rotor (1), and the first outer magnetic ring (312) is radially outside the radial winding (52).

5. The magnetic levitation active three degree of freedom bearing of claim 4, wherein, The second axial stator (41) has a second inner magnetic ring (411) and a second outer magnetic ring (412), and the axial winding (51) is between the second inner magnetic ring (411) and the second outer magnetic ring (412), wherein a second axial inner side working gap (005) is formed between the second inner magnetic ring (411) and the right end surface of the bearing rotor (1), and the second outer magnetic ring (412) is radially outside the radial winding (52).

6. The magnetic levitation active three degree of freedom bearing of claim 5, wherein, The first axial stator (31) further comprises a first connecting section connecting the first inner magnetic ring (311) and the first outer magnetic ring (312); the second axial stator (41) further comprises a second connecting section connecting the second inner magnetic ring (411) and the second outer magnetic ring (412); the first inner magnetic ring (311) and the second inner magnetic ring (411) are respectively located on the axial two sides of the bearing rotor (1), and the first outer magnetic ring (312) and the second outer magnetic ring (412) are in contact, so that the containing space is formed between the first axial stator (31), the second axial stator (41) and the bearing rotor (1); the axial winding (51) is arranged in the containing space and located on the axial two sides of the radial stator (21).

7. The magnetic levitation active three degree of freedom bearing of claim 5, wherein, The control of the radial winding (52) wound on the first pole column (211) in each quadrant is independent of the control of the radial winding (52) wound on the second pole column (212).

8. The magnetic levitation active three degree of freedom bearing of claim 2, wherein, The current flowing in the axial winding (51) in the first axial stator is opposite to the current flowing in the axial winding (51) in the second axial stator.

9. The magnetic levitation active three degree of freedom bearing of claim 2, wherein, The plurality of pole columns are 12 pole columns; each quadrant has one first pole column (211) and two second pole columns (212); the two second pole columns (212) are respectively located on the circumferential two sides of the first pole column (211); Alternatively, the plurality of pole columns are 8 pole columns; each quadrant has one first pole column (211) and one second pole column (212); the second pole column (212) and the first pole column (211) are arranged in sequence in the circumferential direction.

10. The magnetic levitation active three degree of freedom bearing of claim 1, wherein, The magnetic field direction of the radial magnetic circuit (002) in the first pole column (211) is opposite to the magnetic field direction of the axial magnetic circuit (001) in the first pole column (211); And / or, the magnetic field direction of the radial magnetic circuit (002) in the second pole column (212) is the same as the magnetic field direction of the axial magnetic circuit (001) in the first pole column (211).

11. An electric machine characterized by The magnetic suspension active three-degree-of-freedom bearing of any one of claims 1 to 10.

12. A compressor characterized by, The motor of claim 11.

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