Permanent magnet synchronous motor supported by magnetic bearing and magnetic bearing thereof

Abstract

A permanent magnet synchronous motor supported by a magnetic bearing and its magnetic bearing include a motor mounting seat, a motor shaft and a magnetic bearing. The motor shaft is rotatably mounted in the motor mounting seat. Magnetic bearings are mounted on both ends of the motor shaft. A bearing mounting member is mounted on the motor mounting seat. The magnetic bearing is mounted on the bearing mounting member. The magnetic bearing adopts a double magnetic flux loop. The permanent magnet magnetic flux bears the load and load of the high-speed shaft and the components on the shaft. The coil magnetic circuit controls the load fluctuation of the high-speed shaft and improves the stability of the high-speed rotating shaft.

Description

Technical Field

[0001] The present invention belongs to the field of synchronous motors, and in particular relates to a permanent magnet synchronous motor supported by a magnetic bearing and a magnetic bearing thereof. Background Art

[0002] During the rotation of the high-speed spindle, due to the high speed, ordinary bearings heat up significantly. When the thermal stress generated by friction exceeds the speed limit of the bearing, it is very easy to cause structural failure and reduce reliability. The use of non-contact magnetic bearings and air bearing systems has become an alternative solution to reduce mechanical friction and wear, energy loss, and increase the operating speed of the system.

[0003] Using magnetic bearings to support the rotating spindle can further reduce the length of the spindle, increase the critical speed of the spindle, better control the stability of the spindle, and improve the utilization rate of electric energy. With the development of power electronics technology and the reduction in the price of electronic devices, the application of magnetic bearings will become more and more extensive. Since there is no physical contact between the magnetic bearing and the high-speed rotating spindle, the energy utilization rate will reach about 97%.

[0004] The traditional five-degree-of-freedom magnetic bearing mainly controls the five degrees of freedom of the rotating spindle through two radial magnetic bearings and one axial magnetic bearing, and keeps the spindle rotating at high speed around the spindle. There are problems such as a large number of bearings, complex structure, low integration, and complex shaft processing and manufacturing. Summary of the invention

[0005] In view of the above shortcomings, the technical problem to be solved by the present invention is to provide a permanent magnet synchronous motor supported by a magnetic bearing and its magnetic bearing, which adopts a dual magnetic linkage circuit. The permanent magnet magnetic linkage bears the load and load of the high-speed shaft and the components on the shaft; the coil magnetic circuit controls the load fluctuation of the high-speed shaft and improves the stability of the high-speed rotating shaft.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A permanent magnet synchronous motor supported by a magnetic bearing comprises a motor mounting seat, a motor shaft and a magnetic bearing. The motor shaft is rotatably mounted in the motor mounting seat, magnetic bearings are mounted at both ends of the motor shaft, a bearing mounting member is mounted on the motor mounting seat, and the magnetic bearing is mounted on the bearing mounting member.

[0008] Furthermore, the bearing mounting member includes mounting blocks arranged opposite to each other in pairs, the mounting blocks are provided with bearing limiting grooves, and the magnetic bearing is installed between two adjacent bearing limiting grooves.

[0009] Furthermore, the motor mounting seat includes a mounting seat plate, a motor barrel and a motor permanent magnet. The two ends of the motor barrel are respectively fixedly connected with the mounting seat plates. The motor permanent magnet is fixedly installed in the motor barrel, and the motor shaft is rotatably installed in the installation cavity surrounded by the motor permanent magnet.

[0010] The magnetic bearing of the above-mentioned permanent magnet synchronous motor includes a stator core, a rotor core assembly, a stator permanent magnet, a stator radial coil and a stator axial coil. The stator radial coil is evenly wound on the inner wall of the stator core, the stator permanent magnet is fixedly installed between adjacent stator radial coils, and the stator axial coil is fixedly installed on one side end of the stator core. The stator permanent magnet, the stator radial coil and the stator axial coil together form a rotor installation cavity, and the rotor core assembly is installed in the rotor installation cavity.

[0011] Furthermore, the rotor core assembly includes a rotor radial core, a rotor axial core and a magnetic isolation plate. The rotor radial core and the rotor axial core are respectively fixedly mounted on both ends of the magnetic isolation plate, and the rotor axial core is arranged close to the stator axial coil.

[0012] Furthermore, the magnetic isolation plate includes a magnetic isolation flange and an iron core partition plate, the iron core partition plate is vertically connected to the magnetic isolation flange, and the rotor radial iron core and the rotor axial iron core are respectively installed at both ends of the magnetic isolation flange.

[0013] Furthermore, an axial coil installation cavity and a radial coil installation cavity are provided in the stator core, the stator permanent magnet and the stator radial coil are fixedly installed in the radial coil installation cavity, and the stator axial coil is installed in the axial coil installation cavity.

[0014] Furthermore, a coil post is fixedly connected in the radial coil installation cavity.

[0015] Furthermore, a coil groove is dug on the inner side wall of the stator core, and the coil post is fixedly connected in the coil groove.

[0016] Furthermore, the stator permanent magnets are magnetized along the radial direction of the entire magnetic bearing, and the magnetization directions of all stator permanent magnets in the same magnetic bearing are consistent, pointing radially inward or radially outward.

[0017] The beneficial effects of the present invention are: 1. Compared with traditional bearings, there is no mechanical contact between the magnetic bearing of the present invention and the high-speed rotating main shaft, which reduces the heat generated by mechanical friction, improves the operating power and reliability of the system, and the operating speed can be further increased. There is no mechanical contact between the high-speed rotating rotor and the support body, which can further improve the operating efficiency of the system.

[0018] 2. The present invention adopts the magnetic bearing to replace the traditional bearing support. The traditional bearing support is a mechanical contact support, which can avoid the problems of mechanical contact, friction, wear and heat generation of traditional bearings. The transmission efficiency of the magnetic bearing is higher and the spindle speed can be further improved.

[0019] 3. The present invention reduces the number of magnetic bearings supporting the high-speed rotating spindle. The magnetic bearing structure of the present invention is more compact and the control system is more efficient.

[0020] 4. The present invention adopts a dual magnetic flux circuit approach to control the radial force of the rotating spindle. The permanent magnet magnetic flux circuit bears the load and load effect of the high-speed rotating spindle and components on the rotating spindle; the coil magnetic flux circuit controls the load and load fluctuation of the rotating spindle and components on the rotating spindle, thereby improving the stability of the high-speed rotating spindle.

[0021] 5. The radial stator permanent magnet of the present invention is mainly used to bear the axial weight and radial load of the high-speed rotating main shaft. The fluctuation of the radial load is mainly suppressed by the electromagnetic force generated by the stator radial control coil. The radial stator permanent magnet is used to offset the axial weight and the radial load on the rotating main shaft, which can reduce the control power and improve the energy utilization.

[0022] 6. The present invention adopts a magnetic bearing installation positioning adjustment block to adjust the center line of the magnetic bearing stator and the center line of the high-speed rotating shaft to be consistent, thereby reducing the centrifugal force of the high-speed rotating shaft and improving its stability. The magnetic bearing installation positioning adjustment block can adjust the height and radial position of the center line of the magnetic bearing over a large range. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of the stator core.

[0024] Figure 2 It is a cross-sectional view of the stator core.

[0025] Figure 3 It is a structural diagram of a magnetic bearing.

[0026] Figure 4 is an exploded diagram of a magnetic bearing.

[0027] Figure 5 It is a structural diagram of a permanent magnet synchronous motor.

[0028] Figure 6 It is an exploded view of a permanent magnet synchronous motor.

[0029] Figure numerals: motor mounting seat 1, motor shaft 2, magnetic bearing 3, bearing mounting member 4, mounting block 5, bearing limit groove 6, mounting seat plate 7, motor cylinder 8, motor permanent magnet 9, stator core 10, rotor core assembly 11, stator permanent magnet 12, stator radial coil 13, stator axial coil 14, rotor radial core 15, rotor axial core 16, magnetic isolation plate 17, magnetic isolation flange 18, core partition plate 19, axial coil mounting cavity 20, radial coil mounting cavity 21, coil column 22, coil groove 23. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings.

[0031] A permanent magnet synchronous motor supported by a magnetic bearing comprises a motor mounting base 1, a motor shaft 2 and a magnetic bearing 3. The motor shaft 2 is rotatably mounted in the motor mounting base 1. Magnetic bearings 3 are mounted on both ends of the motor shaft 2. A bearing mounting member 4 is mounted on the motor mounting base 1. The magnetic bearing 3 is mounted on the bearing mounting member 4. The magnetic bearing 3 adopts a double magnetic flux loop, and the permanent magnet magnetic flux bears the load and load of the high-speed shaft and the components on the shaft; the coil magnetic circuit controls the load fluctuation of the high-speed shaft and improves the stability of the high-speed rotating shaft.

[0032] The bearing mounting member 4 includes mounting blocks 5 arranged opposite to each other in pairs, and bearing limit grooves 6 are dug on the mounting blocks 5. The magnetic bearing 3 is installed between two adjacent bearing limit grooves 6. Preferably, the mounting blocks 5 are wedge-shaped blocks. The coaxiality of the two magnetic bearings 3 can be adjusted by changing the spacing between the mounting blocks 5, thereby improving the service life of the magnetic bearings 3. In addition, the setting of the bearing limit grooves 6 facilitates the positioning and installation of the magnetic bearings 3.

[0033] The motor mounting seat 1 includes a mounting seat plate 7, a motor barrel 8 and a motor permanent magnet 9. The two ends of the motor barrel 8 are fixedly connected with the mounting seat plate 7. The motor permanent magnet 9 is fixedly installed in the motor barrel 8. The motor shaft 2 is rotatably installed in the installation cavity surrounded by the motor permanent magnet 9.

[0034] The magnetic bearing of the permanent magnet synchronous motor comprises a stator core 10, a rotor core assembly 11, a stator permanent magnet 12, a stator radial coil 13 and a stator axial coil 14. The stator radial coil 13 is evenly wound on the inner wall of the stator core 10. The stator permanent magnet 12 is fixedly installed between adjacent stator radial coils 13. The stator axial coil 14 is fixedly installed on one side end of the stator core 10. The stator permanent magnet 12, the stator radial coil 13 and the stator axial coil 14 together form a rotor installation cavity. The rotor core assembly 11 is installed in the rotor installation cavity. Preferably, an air gap is left between the stator permanent magnet 12 and the radial rotor core assembly 11. The magnetic bearing adopts a double magnetic flux loop. The permanent magnet magnetic flux bears the load and load of the high-speed shaft and the components on the shaft. The coil magnetic circuit controls the load fluctuation of the high-speed shaft and improves the stability of the high-speed rotating shaft.

[0035] The rotor core assembly 11 includes a rotor radial core 15, a rotor axial core 16 and a magnetic isolation plate 17. The rotor radial core 15 and the rotor axial core 16 are respectively fixedly mounted at both ends of the magnetic isolation plate 17. The rotor radial core 15 is arranged close to the stator axial coil 14. Correspondingly, the rotor radial core 15 is arranged close to the stator radial coil 13.

[0036] When a direct current is passed through the stator radial coil 13, magnetic flux is generated on the coil end face and the coil column of the stator core 10, and a first magnetic flux loop is formed between the coil end face and the rotor radial core 15 and the air gap. The first magnetic flux loop compensates for the fluctuation of the rotating main shaft and the radial load on the rotating main shaft to control stability; the magnitude of the magnetic flux of the stator radial coil 13 is controlled according to the current magnitude of the direct current power supply passed through the stator radial coil 13, and an electromagnetic attraction is generated between the stator radial coil 13 and the rotor radial core 15; a second magnetic flux loop is formed between the stator permanent magnet 12, the rotor radial core 15, and the air gap between the stator permanent magnet 12 and the rotor radial core 15, and the electromagnetic force generated by the second magnetic flux loop is used to suppress the rotating main shaft and the stable load on the rotating main shaft; when a direct current is passed through the stator axial coil 14, magnetic flux is generated, and the rotor axial core 16, the stator axial coil 14, the coil column, and the air gap between them jointly form a third magnetic flux loop, and the third magnetic flux loop is used to control the axial single direction degree of freedom of the main shaft.

[0037] The magnetic isolation plate 17 includes a magnetic isolation flange 18 and a core separator 19. The core separator 19 is vertically connected to the magnetic isolation flange 18. The rotor radial core 15 and the rotor axial core 16 are respectively installed at the two ends of the magnetic isolation flange 18. The magnetic isolation flange 18 is used to separate the magnetic lines of flux in the rotor radial core 15 and the rotor axial core 16. The core separator 19 is provided to facilitate the installation of the rotor radial core 15 and the rotor axial core 16. The rotor radial core and the rotor axial core are plugged into the core separator and are connected to the motor shaft 2 by surface pasting and gluing, and there is no relative movement.

[0038] Four core partition plates 19 are respectively arranged on the left and right sides of the magnetic isolation flange 18, and the four core partition plates 19 are evenly distributed coaxially. Preferably, the magnetic isolation plate 17 is made of a weakly magnetic conductive material, such as an aluminum alloy sheet that is stamped and welded.

[0039] An axial coil installation cavity 20 and a radial coil installation cavity 21 are provided in the stator core 10 . The stator permanent magnet 12 and the stator radial coil 13 are fixedly installed in the radial coil installation cavity 21 , and the stator axial coil 14 is wound in the axial coil installation cavity 20 .

[0040] A coil post 22 is fixedly connected in the radial coil installation cavity 21 , and the stator radial coil 13 is wound on the coil post 22 .

[0041] A coil groove 23 is dug on the inner wall of the stator core 10, and the coil post 22 is fixedly connected in the coil groove 23. The setting of the coil groove 23 can reduce the protrusion of the coil post 22 and reduce the volume of the magnetic bearing.

[0042] The stator permanent magnets 12 are magnetized along the radial direction of the entire magnetic bearing, and the magnetization directions of all stator permanent magnets 12 in the same magnetic bearing are consistent, pointing radially inward or radially outward.

[0043] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention; therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0044] Although this article uses more terms corresponding to the figure marks in the figures, it does not exclude the possibility of using other terms; these terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A permanent magnet synchronous motor supported by a magnetic bearing, characterized in that: The motor comprises a motor mounting seat (1), a motor shaft (2) and a magnetic bearing (3), wherein the motor shaft (2) is rotatably mounted in the motor mounting seat (1), magnetic bearings (3) are mounted on both ends of the motor shaft (2), a bearing mounting member (4) is mounted on the motor mounting seat (1), and the magnetic bearing (3) is mounted on the bearing mounting member (4); The magnetic bearing (3) comprises a stator core (10), a rotor core assembly (11), a stator permanent magnet (12), a stator radial coil (13) and a stator axial coil (14); the stator radial coil (13) is evenly wound on the inner side wall of the stator core (10); the stator permanent magnet (12) is fixedly mounted between adjacent stator radial coils (13); the stator axial coil (14) is fixedly mounted on one side end of the stator core (10); the stator permanent magnet (12), the stator radial coil (13) and the stator axial coil (14) together form a rotor installation cavity; and the rotor core assembly (11) is mounted in the rotor installation cavity; The rotor core assembly (11) comprises a rotor radial core (15), a rotor axial core (16) and a magnetic isolation plate (17). The rotor radial core (15) and the rotor axial core (16) are respectively fixedly mounted at two ends of the magnetic isolation plate (17). The rotor axial core (16) is arranged close to the stator axial coil (14), and the rotor radial core (15) is arranged close to the stator radial coil (13). The stator radial coil (13) is evenly wound on the inner wall of the stator core (10). The stator permanent magnet (12) is fixedly mounted between adjacent stator radial coils (13). The stator axial coil (14) is fixedly mounted on one end of the stator core (10). The stator permanent magnet (12), the stator radial coil (13) and the stator axial coil (14) together form a rotor installation cavity. The rotor core assembly (11) is installed in the rotor installation cavity.

2. The permanent magnet synchronous motor supported by a magnetic bearing according to claim 1, characterized in that: The bearing mounting member (4) comprises mounting blocks (5) arranged opposite to each other in pairs, the mounting blocks (5) being provided with bearing limiting grooves (6), and the magnetic bearing (3) being mounted between two adjacent bearing limiting grooves (6).

3. The permanent magnet synchronous motor supported by a magnetic bearing according to claim 1, characterized in that: The motor mounting seat (1) comprises a mounting seat plate (7), a motor barrel (8) and a motor permanent magnet (9); the two ends of the motor barrel (8) are respectively fixedly connected to the mounting seat plates (7); the motor permanent magnet (9) is fixedly mounted in the motor barrel (8); and the motor shaft (2) is rotatably mounted in a mounting cavity surrounded by the motor permanent magnet (9).

4. The permanent magnet synchronous motor supported by a magnetic bearing according to claim 1, characterized in that: The magnetic isolation plate (17) comprises a magnetic isolation flange (18) and an iron core partition plate (19). The iron core partition plate (19) is vertically connected to the magnetic isolation flange (18). The rotor radial iron core (15) and the rotor axial iron core (16) are respectively mounted at two ends of the magnetic isolation flange (18).

5. The permanent magnet synchronous motor supported by magnetic bearings according to claim 1, characterized in that: An axial coil installation cavity (20) and a radial coil installation cavity (21) are provided in the stator iron core (10); the stator permanent magnet (12) and the stator radial coil (13) are fixedly installed in the radial coil installation cavity (21); and the stator axial coil (14) is installed in the axial coil installation cavity (20).

6. The permanent magnet synchronous motor supported by a magnetic bearing according to claim 5, characterized in that: A coil post (22) is fixedly connected in the radial coil installation cavity (21).

7. The permanent magnet synchronous motor supported by a magnetic bearing according to claim 6, characterized in that: A coil groove (23) is excavated on the inner side wall of the stator core (10), and the coil column (22) is fixedly connected in the coil groove (23).

8. The permanent magnet synchronous motor supported by a magnetic bearing according to claim 1, characterized in that: The stator permanent magnets (12) are magnetized along the radial direction of the entire magnetic bearing (3), and the magnetization directions of all stator permanent magnets in the same magnetic bearing (3) are consistent, pointing radially inward or radially outward.

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