Rotor thrust balancing device and high-speed motor

Abstract

The utility model provides a rotor thrust balancing device and a high-speed motor. The rotor thrust balancing device comprises a permanent magnet, a magnet mounting ring and a thrust disc, and the thrust disc is arranged at the non-driving end of the rotor; the permanent magnet is fixed on the axial outer side of the thrust disc through the magnet mounting ring; the thrust disc is a magnetic conductive component, the magnet mounting ring is located between the permanent magnet and the thrust disc, and when the rotor moves towards the driving end under the action of a load, a magnetic circuit of the permanent magnet forms a closed magnetic circuit through the magnet mounting ring and the thrust disc. The high-speed motor comprises a shell, two tail covers, a rotor, a stator and the rotor thrust balancing device, and the rotor thrust balancing device is arranged at the non-bearing end of the rotor and located in the shell. The motor has the advantages of simple and compact structure, improved operation stability, prolonged service life and the like.

Description

Technical Field

[0001] The utility model relates to the field of motors, and particularly to a rotor thrust balance device and a high-speed motor. Background Art

[0002] With the rapid development of high-speed motor (generally referring to a motor with a rotational speed exceeding 10,000 r / min) technology, high-speed motors are widely used in many fields. When the load end of a high-speed motor (such as a fan, a pump load, etc.) is operating, a large axial thrust will be generated on the rotor. At this time, a rolling bearing cannot bear the axial force of the rotor and is prone to large losses, which will further cause the high-speed motor to fail to reach the preset rotational speed, affecting the stability and safety of the high-speed motor operation, and the service life of the motor is low; at the same time, a rolling bearing has the advantages of simple structure and low cost, while the existing structure limits the application of the rolling bearing in high-speed motors. To solve the above technical problems, the existing method is to use a pneumatic balance cylinder to achieve the balance of the rotor axial force, but the structure of the balance cylinder is complex, occupies a large space, has a high cost, and still cannot ensure the stability and safety of the high-speed motor operation. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a rotor thrust balance device and a high-speed motor with a simple and compact structure, which improve the operation stability and service life of the motor.

[0004] To solve the above technical problem, the technical solution proposed by the utility model is as follows:

[0005] A rotor thrust balance device includes a permanent magnet, a magnet mounting ring, and a thrust disk. Among them, the thrust disk is arranged at the non-driving end of the rotor; the permanent magnet is fixed to the axial outer side of the thrust disk through the magnet mounting ring; the thrust disk is a magnetic conduction component, the magnet mounting ring is located between the permanent magnet and the thrust disk, and the permanent magnet forms a closed magnetic circuit through the magnet mounting ring and the thrust disk.

[0006] As a further improvement of the above technical solution:

[0007] The permanent magnet is an annular permanent magnet composed of a plurality of permanent magnet blocks; when magnetized radially along the permanent magnet, the same magnetic circuit will be generated by each permanent magnet block in any radial cross-section; the magnet mounting ring is a magnetic conduction component, and the closed magnetic circuit is from the radial direction of the permanent magnet, sequentially passing through the magnet mounting ring and the thrust disk and returning to the permanent magnet block; or the permanent magnet adopts the Halbach array arrangement of a combination of radial and parallel arrangements of permanent magnet blocks, the magnet mounting ring is a non-magnetic conduction component, and the closed magnetic circuit is formed between the permanent magnet and the thrust disk.

[0008] The rotor thrust balance device further includes a tail cover, which is a non-magnetic tail cover. The magnet mounting ring is provided with a permanent magnet annular mounting groove, and the annular mounting groove and the tail cover enclose a magnet placement area for placing the annular permanent magnet.

[0009] The magnet mounting ring is provided with a flange for mounting and fixing to the tail cover. The thrust disk is provided with a stop and mounting holes for mounting and fixing to the rotor. The magnet mounting ring is mounted on the tail cover through fasteners at the flange position, and the thrust disk is mounted on the rotor through fasteners at the mounting hole positions.

[0010] An overcurrent end cover is sleeved outside the thrust disk. A balance device accommodation area is formed between the tail cover and the overcurrent end cover. The tail cover is provided with a cooling air inlet. An air passage gap is provided between the overcurrent end cover and the thrust disk. The cooling air inlet, the balance device accommodation area, and the air passage gap are communicated in sequence.

[0011] When the rotor moves towards the non-driving end under the action of load, the thrust disk is provided with the permanent magnet and the magnet mounting ring. The permanent magnet located on the thrust disk is fixed through the magnet mounting ring and is arranged in a mirror image relative to the permanent magnet located outside the non-driving end of the rotor. The magnetic poles of the opposite end faces of the two permanent magnets are the same, so as to generate a repulsive force when the rotor moves.

[0012] Leakage magnetic flux prevention grooves for preventing the divergence of the magnetic circuit and leakage of magnetic flux are provided at positions axially opposite to the permanent magnet on both the magnet mounting ring and the thrust disk. The leakage magnetic flux prevention grooves are arranged along the circumferential direction of the magnet mounting ring or the thrust disk.

[0013] An air gap is provided between the magnet mounting ring and the thrust disk. The magnitude of the axial magnetic force generated by the rotor thrust balance device is adjusted by the size of the air gap.

[0014] A high-speed motor includes a housing, two tail covers, a rotor, a stator, and the rotor thrust balance device described above. The rotor thrust balance device is arranged at the non-bearing end of the rotor and is located inside the housing.

[0015] As a further improvement of the above technical solution:

[0016] The high-speed motor further includes a motor cooling air path. The motor cooling air path includes a thrust balance cooling section and a stator-rotor cooling section that are interconnected. An installation sleeve with cooling through holes is provided between the stator and the thrust disk. The thrust balance cooling section and the stator-rotor cooling section are communicated through the cooling through holes. The installation sleeve is installed between the housing and the tail cover.

[0017] Compared with the prior art, the advantages of the present utility model are as follows:

[0018] The rotor thrust balance device of the present utility model includes a permanent magnet, a magnet mounting ring, and a thrust disc. The thrust disc is arranged at the non-driving end of the rotor and can move together with the rotor, being a moving part; the permanent magnet is fixed to the outer side of the thrust disc axially through the magnet mounting ring and is a stationary part. The form that the permanent magnet is stationary and not arranged on the rotor avoids the influence of rotor vibration and centrifugal force on the permanent magnet, ensuring that the permanent magnet provides stable and reliable magnetic force during the high-speed operation of the motor and guaranteeing the effect of thrust balance. The rotor thrust balance device of the present utility model only needs to be arranged at the non-driving end of the rotor, with a simple and compact structure, small occupied space, and low cost.

[0019] Meanwhile, both the magnet mounting ring and the thrust disc are magnetic conductive parts. The magnet mounting ring is located between the permanent magnet and the thrust disc. When the permanent magnet is magnetized, a closed magnetic circuit is formed with the magnet mounting ring and the thrust disc. It can be seen that the present utility model forms a closed magnetic circuit through the position setting of the permanent magnet and the magnetic field distribution. The closed magnetic circuit enables the rotor to generate a magnetic force opposite to the axial thrust borne by the motor rotor when an outward acting force is generated under the action of a load (the load ends of fans and pumps in high-speed motors are usually outward acting forces), thereby realizing the real-time balance of the rotor thrust, making the rotor not generate axial acting force or generate a very small axial acting force, ensuring that the rolling bearing is not easily worn during the high-speed operation of the motor, providing an effective guarantee for the application of the rolling bearing in high-speed motors, and improving the operation stability and service life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Hereinafter, the present utility model will be described in more detail based on embodiments and with reference to the drawings. Among them:

[0021] Figure 1 is a schematic structural diagram of the rotor thrust balance device of the present utility model;

[0022] Figure 2 is Figure 1 an enlarged schematic view of part A in

[0023] Figure 3 is Figure 1 a cross-sectional view taken along the B-B section in

[0024] Figure 4 is a schematic view of another magnetization form of the permanent magnet of the present utility model;

[0025] Figure 5 is a schematic structural diagram of Embodiment 2 of the present utility model.

[0026] Each label in the figure represents:

[0027] 1. Permanent magnet; 2. Magnet mounting ring; 3. Thrust disc; 4. Rotor; 5. Tail cover; 6. Closed magnetic circuit; 7. Annular mounting groove; 8. Air gap; 9. Outer shell; 10. Stator; 11. Rolling bearing; 12. Damper; 13. Mounting sleeve; 14. Overcurrent end cover; 15. Cooling through hole; 16. Air passing gap; 17. Magnetic leakage prevention groove; 18. Balance device accommodation area. Detailed implementation manners

[0028] The present utility model will be further described in detail below in conjunction with the specification drawings and specific embodiments, but the protection scope of the present utility model is not limited thereby.

[0029] Embodiment 1

[0030] Figure 1 and Figure 2 An embodiment of the rotor thrust balance device of the present utility model is shown. The rotor thrust balance device includes a permanent magnet 1, a magnet mounting ring 2, and a thrust disc 3. Among them, the thrust disc 3 is arranged at the non-driving end of the rotor 4; the permanent magnet 1 is fixed to the axial outer side of the thrust disc 3 through the magnet mounting ring 2; the thrust disc 3 is a magnetic conductive component, and the magnet mounting ring 2 is located between the permanent magnet 1 and the thrust disc 3; when the rotor 4 moves towards the driving end under the action of a load, the permanent magnet 1 forms a closed magnetic circuit 6 through the magnet mounting ring 2 and the thrust disc 3, that is, the magnetic circuit when the permanent magnet 1 is magnetized sequentially passes through the magnet mounting ring 2, the thrust disc 3, and returns to the permanent magnet 1.

[0031] The thrust disc 3 of the present utility model is arranged at the non-driving end of the rotor 4 and can move together with the rotor 4, being a moving component; the permanent magnet 1 is fixed to the axial outer side of the thrust disc 3 through the magnet mounting ring 2 and is a stationary component. The form that the permanent magnet 1 is stationary and not arranged on the rotor 4 avoids the influence of the vibration and centrifugal force of the rotor 4 on the permanent magnet 1, ensures that the permanent magnet 1 provides stable and reliable magnetic force during the high-speed operation of the motor, and ensures the effect of thrust balance. The rotor thrust balance device of the present utility model only needs to be arranged at the non-driving end of the rotor 4, has a simple and compact structure, occupies a small space, and has a low cost.

[0032] When the existing rotor 4 undergoes axial movement under the action of a load, the rolling bearing 11 will deflect axially. At this time, the rolling bearing 11 suffers serious losses. In this embodiment, the rotor 4 is subjected to a force acting towards the drive end under the action of a load. For example, the fan and pump load ends of a high-speed motor usually provide a force for the rotor 4 to move towards the drive end. And the present utility model forms a closed magnetic circuit 6 through the position setting of the permanent magnet 1 and the magnetic field distribution. At this time, the closed magnetic circuit 6 will generate a magnetic force opposite to the axial thrust borne by the motor rotor 4, that is, a magnetic suction force opposite to the movement of the rotor towards the drive end, so as to realize the real-time balance of the thrust of the rotor 4, so that the rotor 4 does not generate axial force or generates a very small axial force, ensuring that the rolling bearing 11 is not easily damaged during the operation of the high-speed motor, providing an effective guarantee for the application of the rolling bearing 11 in the high-speed motor, and improving the operation stability and service life of the motor.

[0033] Furthermore, the permanent magnet 1 is an annular permanent magnet composed of a plurality of permanent magnet blocks. As Figure 3 shown, when magnetized radially along the permanent magnet 1, the same magnetic path will be generated by each permanent magnet block in any radial cross-section; the magnet mounting ring 2 is a magnetic conduction component, and the closed magnetic circuit 6 sequentially passes through the radial direction of the permanent magnet 1, the magnet mounting ring 2 and the thrust disk 3 and returns to the permanent magnet block to provide sufficient magnetic suction force to achieve the purpose of balancing the axial thrust of the rotor 4; at the same time, the magnetic suction force generated by the radial magnetization direction is large and the magnetization is convenient.

[0034] In other embodiments, as long as the magnetization method that can ensure the magnetic conduction of the permanent magnet 1 and the magnetic path passes through the magnet mounting ring 2 and the thrust disk 3 to form a closed loop is within the protection scope of the present utility model, the specific magnetization direction can be selected according to the requirements of the magnetic force magnitude, etc. As Figure 4 shown, the permanent magnet 1 can also adopt the Halbach array arrangement of the combination of the radial and parallel arrangements of the permanent magnet blocks. The magnet mounting ring 2 is a non-magnetic conduction component, and the closed magnetic circuit 6 is formed between the permanent magnet 1 and the thrust disk 3. In this embodiment, the permanent magnet can be magnetized by a magnetizer.

[0035] As Figure 2 shown, the rotor thrust balance device further includes a tail cover 5. The tail cover 5 is a non-magnetic conduction tail cover. The magnet mounting ring 2 is provided with an annular mounting groove 7. The annular mounting groove 7 and the tail cover 5 enclose a magnet placement area. The annular permanent magnet is placed in the magnet placement area. Its installation structure is simple and compact, and it makes the permanent magnet 1 be reliably installed and fixed, ensuring that the permanent magnet 1 provides stable and reliable magnetic force during the high-speed operation of the motor.

[0036] Preferably, the magnet mounting ring 2 is provided with a flange for mounting and fixing to the end cap 5, the thrust disc 3 is provided with a counterbore and mounting holes for mounting and fixing to the rotor 4, the magnet mounting ring 2 is mounted on the end cap 5 through fasteners at the flange position, and the thrust disc 3 is mounted on the rotor 4 through fasteners at the mounting hole positions. Its assembly is convenient and the structure is simple. In other embodiments, the thrust disc 3 can be integrally formed with the rotor 4. When the diameter of the magnet mounting ring 2 is small, the magnet mounting ring 2 can also be fixed to the end cap 5 through fasteners in the middle of the magnet mounting ring 2.

[0037] Preferably, as Figure 1 and Figure 2 shown, an overcurrent end cap 14 is sleeved outside the thrust disc 3, a balance device accommodating area 18 is formed between the end cap 5 and the overcurrent end cap 14, the end cap 5 is provided with a cooling gas inlet, an air passing gap 16 is provided between the overcurrent end cap 14 and the thrust disc 3, and the cooling gas inlet, the balance device accommodating area 18 and the air passing gap 16 are communicated in sequence. The corresponding cooling gas path is arranged on the basis of the structure of the rotor thrust balance device of the present invention, so that the rotor thrust balance device can dissipate heat effectively, ensuring the reliable and safe operation of the rotor thrust balance device.

[0038] Preferably, as Figure 2 shown, leakage magnetic prevention grooves 17 are provided at positions of the magnet mounting ring 2 and the thrust disc 3 axially opposite to the permanent magnet 1. The leakage magnetic prevention grooves 17 are arranged along the circumferential direction of the magnet mounting ring 2 or the thrust disc 3 to ensure that the magnetic circuit passes through in a preset direction, with a small magnetic resistance of the magnetic circuit, avoiding the occurrence of magnetic circuit divergence and magnetic leakage phenomena, so as to provide sufficient magnetic force. The magnetic conduction area of the leakage magnetic prevention grooves 17 can be set according to the magnetic conduction flux and the required magnetic force magnitude.

[0039] In this embodiment, an air gap 8 is provided between the magnet mounting ring 2 and the thrust disc 3. The magnitude of the axial magnetic force generated by the rotor thrust balance device can be adjusted by the size of the air gap 8. The magnitude of the axial magnetic force is determined according to the axial force generated at the load end, and the magnitude of the axial magnetic force can also be adjusted by the magnetic field strength, magnetic field area, etc., playing a role in balancing the thrust of the rotor 4.

[0040] Figure 1 The high-speed motor of this embodiment is shown, which includes a housing 9, two end caps 5, a rotor 4, a stator 10 and the rotor thrust balance device of the above embodiment. The rotor thrust balance device is arranged on the non-bearing end side of the rotor 4 and is located inside the housing 9. The high-speed motor of the present invention also has the above advantages of the rotor thrust balance device, and is compact in structure and low in cost.

[0041] Furthermore, the high-speed motor further includes a motor cooling air path, which includes a thrust balance cooling section and a stator-rotor cooling section that are interconnected. An installation sleeve 13 is provided between the stator 10 and the thrust disk 3. The installation ring is installed between the outer shell 9 and the end cover 5. The installation sleeve 13 is provided with cooling through holes 15. The thrust balance cooling section and the stator-rotor cooling section are connected through the cooling through holes 15. This enables a connected cooling air path to be formed inside the motor, allowing the internal components of the motor to be effectively cooled, ensuring the safe and reliable operation of the motor, and having a simple overall structure.

[0042] In this embodiment, a rolling bearing 11, a damper 12, and an installation sleeve 13 are sequentially sleeved on the rotor 4 in the radial direction. The overcurrent end cover 14 is installed on the installation sleeve 13. The thrust disk 3 passes through the overcurrent end cover 14 and is connected to the rotor 4. An air passage gap 16 is left between the thrust disk 3 and the overcurrent end cover 14. The thrust balance cooling section includes a cooling air inlet provided in the end cover 5, a balance device accommodation area 18, and the air passage gap 16 that are sequentially connected; the stator-rotor cooling section includes an overcurrent gap provided between the rotor 4 and the stator 10. The specific motor cooling air path is shown in Attachment Figure 1 The path II in it. The motor cooling air path II is discharged after passing through the end cover 5, the balance device accommodation area 18, the air passage gap 16, the cooling through holes 15, the gap between the rotor 4 and the stator 10, and the outer shell 9 in sequence. This enables the rotor thrust balance device to dissipate heat effectively, ensuring the reliable and safe operation of the rotor thrust balance device.

[0043] Embodiment 2

[0044] Figure 5 An embodiment of another rotor thrust balance device of the present invention is shown. This embodiment is basically the same as the previous embodiment, except that this embodiment is applied to an environment where the rotor 4 moves towards the non-driving end under the action of a load. In Embodiment 2, permanent magnets 1 and magnet mounting rings 2 are provided on the thrust disk 3. The permanent magnets 1 located on the thrust disk 3 are fixed through the magnet mounting rings 2, and the permanent magnets 1 located on the thrust disk 3 are arranged in a mirror image relative to the permanent magnets 1 on the outer side of the non-driving end of the rotor 4, and the magnetic poles of the opposite end faces of the two permanent magnets 1 are the same. The two permanent magnets 1 generate a repulsive force when the rotor 4 moves towards the non-driving end to balance the thrust of the rotor 4. In this embodiment, the permanent magnets 1 are magnetized radially or axially.

[0045] Although the present invention has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A rotor thrust balancing device, characterized in that: It includes a permanent magnet, a magnet mounting ring and a thrust plate, wherein the thrust plate is arranged at the non-driving end of the rotor; the permanent magnet is fixed to the axial outer side of the thrust plate through the magnet mounting ring, and the magnet mounting ring is located between the permanent magnet and the thrust plate; the thrust plate is a magnetic conductive component; when the rotor moves toward the driving end under the action of a load, the magnetic circuit of the permanent magnet forms a closed magnetic circuit through the magnet mounting ring and the thrust plate.

2. The rotor thrust balancing device according to claim 1, characterized in that: The permanent magnet is an annular permanent magnet composed of multiple permanent magnet blocks; when magnetized radially along the permanent magnet, each permanent magnet block will generate the same magnetic circuit in any radial cross section; the magnet mounting ring is a magnetic conductive component, and the closed magnetic circuit returns to the permanent magnet block in sequence through the radial direction of the permanent magnet, the magnet mounting ring and the thrust plate; or the permanent magnet adopts a Halbach arrangement method that combines radial and parallel arrangements of permanent magnet blocks, the magnet mounting ring is a non-magnetic conductive component, and the closed magnetic circuit is formed between the permanent magnet and the thrust plate.

3. The rotor thrust balancing device according to claim 2, characterized in that: It also includes a tail cover, which is a non-magnetic tail cover. The magnet mounting ring is provided with a permanent magnet annular mounting groove, and the annular mounting groove and the tail cover are enclosed to form a magnet placement area for placing the annular permanent magnet.

4. The rotor thrust balancing device according to claim 3, characterized in that: The magnet mounting ring is provided with a flange mounted and fixed to the tail cover, the thrust plate is provided with a stopper and a mounting hole mounted and fixed to the rotor, the magnet mounting ring is mounted on the tail cover via fasteners at the flange position, and the thrust plate is mounted on the rotor via fasteners at the mounting hole.

5. The rotor thrust balancing device according to claim 3, characterized in that: The thrust plate outer shell is provided with a flow end cover, a balancing device accommodating area is formed between the tail cover and the flow end cover, the tail cover is provided with a cooling air inlet, an air gap is provided between the flow end cover and the thrust plate, and the cooling air inlet, the balancing device accommodating area and the air gap are connected in sequence.

6. The rotor thrust balancing device according to any one of claims 1 to 5, characterized in that: When the rotor moves toward the non-driving end under the action of a load, the thrust plate is provided with the permanent magnet and the magnet mounting ring. The permanent magnet located on the thrust plate is fixed by the magnet mounting ring and is arranged opposite to the permanent magnet located on the outer side of the non-driving end of the rotor in a mirror image. The magnetic poles of the two permanent magnets on the opposite end faces are the same, so as to generate a repulsive force when the rotor moves.

7. The rotor thrust balancing device according to any one of claims 1 to 5, characterized in that: The magnet mounting ring and the thrust plate are both provided with anti-magnetic leakage grooves for preventing magnetic circuit divergence and magnetic leakage at positions opposite to the permanent magnet axially. The anti-magnetic leakage grooves are arranged along the circumference of the magnet mounting ring or the thrust plate.

8. The rotor thrust balancing device according to claim 7, characterized in that: An air gap is provided between the magnet mounting ring and the thrust disk, and the magnitude of the axial magnetic force generated by the rotor thrust balancing device is adjusted by the size of the air gap.

9. A high-speed motor, characterized in that: It comprises a housing, two tail covers, a rotor, a stator and a rotor thrust balancing device according to any one of claims 1 to 8, wherein the rotor thrust balancing device is arranged at a non-load-bearing end of the rotor and is located inside the housing.

10. The high-speed motor according to claim 9, characterized in that: It also includes a motor cooling air circuit, which includes a thrust balance cooling section and a rotor-stator cooling section that are interconnected. A mounting sleeve with a cooling through hole is provided between the stator and the thrust plate. The thrust balance cooling section and the rotor-stator cooling section are connected through the cooling through hole. The mounting sleeve is installed between the outer shell and the tail cover.

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