Axial magnetic limiting magnetic suspension motor

Abstract

The invention discloses an axial magnetic limiting magnetic suspension motor which comprises a shell, a stator and a rotating shaft, the stator is fixedly arranged on the inner side wall of the shell, the rotating shaft is located in the shell, a rotating shaft magnet opposite to the stator is arranged on the rotating shaft, the rotating shaft is matched with a radial magnetic bearing supporting the rotating shaft to rotate, and a rear end bearing seat is arranged at the tail of the shell. The rear end bearing seat is installed in the shell, a first magnetic limiting ring and a second magnetic limiting ring are installed in the rear end bearing seat, a third magnetic limiting ring is installed at the tail of the rotating shaft, and the third magnetic limiting ring is located between the first magnetic limiting ring and the second magnetic limiting ring. The first magnetic limiting ring, the second magnetic limiting ring and the third magnetic limiting ring are used for limiting the axial movement of the rotating shaft, an axial magnetic bearing in the prior art is replaced, and the effect of stabilizing the rotating shaft of the motor is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric machines, in particular to a motor for a magnetic suspension vacuum pump. BACKGROUND

[0002] A magnetic suspension vacuum pump uses magnetic suspension bearings to achieve non-contact suspension of the rotating shaft, and a magnetic suspension motor is the core of the magnetic suspension vacuum pump. A patent document with publication number CN 120750082 A discloses a magnetic suspension motor with integrated protection and a magnetic suspension vacuum pump. In the magnetic suspension motor, the front end of the casing is provided with a front back plate, the rear end of the casing is provided with a tail end cover and a tail end cover, and the casing, the front back plate, the tail end cover and the tail end cover form an installation cavity. The front protection bearing seat, the front radial magnetic bearing seat, the rear protection bearing seat and the rear radial magnetic bearing seat are installed inside the installation cavity to avoid the joints and connecting surfaces between the bearing seats being exposed to the outside. Only one air inlet and one air outlet are provided on the casing. The design of the single air inlet and air outlet reduces the leakage points.

[0003] In the above-mentioned magnetic suspension motor, an axial magnetic bearing is used to prevent axial movement of the motor shaft. The axial magnetic bearing is arranged at the tail end of the motor. SUMMARY

[0004] The technical problem solved by the present application is to provide an alternative solution for an axial magnetic bearing to prevent axial movement of the motor shaft.

[0005] To solve the above technical problems, the present application provides the following technical solution: a magnetic suspension motor with axial magnetic limiting, comprising a casing, a stator and a rotating shaft, the stator is fixedly arranged on the inner side wall of the casing, the rotating shaft is located in the casing, the rotating shaft is provided with a rotating shaft magnet opposite to the stator, the rotating shaft is provided with a radial magnetic bearing supporting the rotation of the rotating shaft, the tail end of the casing is provided with a rear end bearing seat, the rear end bearing seat is installed in the casing, the first magnetic limiting ring and the second magnetic limiting ring are installed in the rear end bearing seat, the first magnetic limiting ring and the second magnetic limiting ring have an axial gap therebetween, the first magnetic limiting ring and the rotating shaft have a radial gap therebetween, the second magnetic limiting ring and the rotating shaft have a radial gap therebetween, the tail end of the rotating shaft is provided with a third magnetic limiting ring, the third magnetic limiting ring is located between the first magnetic limiting ring and the second magnetic limiting ring, the third magnetic limiting ring and the first magnetic limiting ring have an axial gap therebetween, the third magnetic limiting ring and the second magnetic limiting ring have an axial gap therebetween, and the third magnetic limiting ring and the inner side wall of the rear end bearing seat have a radial gap therebetween.

[0006] According to the technical scheme, the first magnetic limiting ring and the second magnetic limiting ring limit the third magnetic limiting ring located between the first magnetic limiting ring and the second magnetic limiting ring through magnetic force therebetween, so that the third magnetic limiting ring is stably positioned between the first magnetic limiting ring and the second magnetic limiting ring. Since the third magnetic limiting ring is fixedly connected with the rotating shaft, the first magnetic limiting ring and the second magnetic limiting ring are fixedly connected with the rear bearing seat, and the rear bearing seat is fixedly connected with the shell, the axial position of the rotating shaft is positioned under the action of the first magnetic limiting ring, the second magnetic limiting ring and the third magnetic limiting ring.

[0007] The inner side wall of the rear bearing seat is provided with a first limiting step and a second limiting step, the first magnetic limiting ring is stopped at the first limiting step, the second magnetic limiting ring is stopped at the second limiting step, and the second magnetic limiting ring is matched with a first fixing ring. The tail part of the rotating shaft is provided with a third limiting step, the third magnetic limiting ring is stopped at the third limiting step, and the third magnetic limiting ring is matched with a second fixing ring. The first fixing ring fixes the second magnetic limiting ring to stabilize the position thereof. Similarly, the second fixing ring fixes the third magnetic limiting ring to stabilize the position thereof on the rotating shaft.

[0008] The front part of the shell is provided with a front bearing seat, the front bearing seat is installed in the shell, the front radial magnetic bearing is matched between the rotating shaft and the front bearing seat, and the rear radial magnetic bearing is matched between the rotating shaft and the rear bearing seat. The front radial magnetic bearing and the rear radial magnetic bearing position the rotating shaft in the radial direction.

[0009] The rear bearing seat is provided with an axial flow guide hole, the front bearing seat is provided with a first radial flow guide hole, and the shell is provided with a second radial flow guide hole; the rear bearing seat is installed with a flow guide cover, the tail end of the rotating shaft is installed with a fan blade, the fan blade rotates with the rotating shaft to input external airflow into the shell, and the airflow flows out of the shell after passing through the gap between the first magnetic limiting ring, the second magnetic limiting ring and the third magnetic limiting ring, the gap between the rear radial magnetic bearing, the stator and the rotating shaft, the front radial magnetic bearing, the first radial flow guide hole and the second radial flow guide hole. The gap between the first magnetic limiting ring, the second magnetic limiting ring and the third magnetic limiting ring and the airflow passage formed by the rear radial magnetic bearing are in a parallel relationship with the airflow passage of the axial flow guide hole.

[0010] The tail end surface of the shell is installed with a rear end cover, and the rear end cover is installed with a protective cover. The protective cover is a hollow cover, and the airflow can enter the flow guide cover through the protective cover.

[0011] The front end surface of the shell is installed with a front end cover, the front end cover is located at the periphery of the front bearing seat, the outer end surface of the front end cover is flush with the outer end surface of the front bearing seat, a sealed space is formed between the front end cover and the front bearing seat, and the second radial flow guide hole realizes the communication between the sealed space and the outside.

[0012] Technical effects of the application: Firstly, the first magnetic limiting ring, the second magnetic limiting ring and the third magnetic limiting ring are adopted to limit the axial movement of the rotating shaft, and the axial magnetic bearing in the prior art is replaced, so that the motor rotating shaft is stabilized. Secondly, the fan blade rotates with the rotating shaft, and the external airflow is input into the shell, and the airflow flows out of the shell through the gap between the axial guide hole, the first magnetic limiting ring, the second magnetic limiting ring, the third magnetic limiting ring, the rear end radial magnetic bearing, the gap between the stator and the rotating shaft, the front end radial magnetic bearing, the first radial guide hole and the second radial guide hole, so that the main parts of the motor are cooled, and the service life of the motor is improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 Schematic view of the axial magnetic limiting magnetic suspension motor; Figure 2 Schematic view of the airflow flowing in the axial magnetic limiting magnetic suspension motor; Figure 3 Schematic view of the rear end bearing seat 40; Figure 4 Schematic view of the rear end bearing seat 40; Figure 3 Schematic view of the rear end bearing seat 40; Figure 5 Schematic view of the front end bearing seat 50; Figure 6 Schematic view of the front end bearing seat 50; Figure 5 Schematic view of the front end bearing seat 50.

[0014] Explanation of symbols in the drawing: 10, shell; 11, second radial guide hole; 20, stator; 30, rotating shaft; 31, rotating shaft magnet; 32, third magnetic limiting ring; 33, second fixed ring; 34, fan blade; 40, rear end bearing seat; 41, first magnetic limiting ring; 42, second magnetic limiting ring; 43, first fixed ring; 44, rear end radial magnetic bearing; 45, axial guide hole; 50, front end bearing seat; 51, front end radial magnetic bearing; 52, first radial guide hole; 60, flow guide cover; 70, rear end cover; 71, protective cover; 80, front end cover; 81, closed space. DETAILED DESCRIPTION

[0015] As Figure 1The application discloses an axial magnetic limiting magnetic suspension motor, which comprises a shell 10, a stator 20 and a rotating shaft 30, the stator is fixedly arranged on the inner side wall of the shell, the rotating shaft is arranged in the shell, the rotating shaft is provided with a rotating shaft magnet 31 opposite to the stator, the rotating shaft is provided with a radial magnetic bearing supporting the rotation of the rotating shaft, the tail part of the shell is provided with a rear end bearing seat 40, the rear end bearing seat is arranged in the shell 10, the rear end bearing seat is provided with a first magnetic limiting ring 41 and a second magnetic limiting ring 42, the first magnetic limiting ring and the second magnetic limiting ring have an axial gap therebetween, the first magnetic limiting ring and the rotating shaft have a radial gap therebetween, the second magnetic limiting ring and the rotating shaft have a radial gap therebetween, the tail part of the rotating shaft 30 is provided with a third magnetic limiting ring 32, the third magnetic limiting ring is arranged between the first magnetic limiting ring and the second magnetic limiting ring, the third magnetic limiting ring and the first magnetic limiting ring have an axial gap therebetween, the third magnetic limiting ring and the second magnetic limiting ring have an axial gap therebetween, and the third magnetic limiting ring and the inner side wall of the rear end bearing seat 40 have a radial gap therebetween.

[0016] The inner side wall of the rear end bearing seat 40 is provided with a first limiting step and a second limiting step, the first magnetic limiting ring 41 is stopped at the first limiting step, the second magnetic limiting ring 42 is stopped at the second limiting step, and the second magnetic limiting ring is provided with a first fixing ring 43. The tail part of the rotating shaft 30 is provided with a third limiting step, the third magnetic limiting ring 32 is stopped at the third limiting step, and the third magnetic limiting ring is provided with a second fixing ring 33.

[0017] The front part of the shell 10 is provided with a front end bearing seat 50, the front end bearing seat is arranged in the shell, a front end radial magnetic bearing 51 is arranged between the rotating shaft 30 and the front end bearing seat, and a rear end radial magnetic bearing 44 is arranged between the rotating shaft and the rear end bearing seat 40.

[0018] In combination Figure 1 , Figure 2 , the rear end bearing seat 40 is provided with an axial flow guide hole 45, the front end bearing seat 50 is provided with a first radial flow guide hole 52, and the shell 10 is provided with a second radial flow guide hole 11; a flow guide cover 60 is arranged on the rear end bearing seat, a fan blade 34 is arranged at the tail end of the rotating shaft 30, the fan blade rotates along with the rotating shaft, external airflow is input into the shell, and the airflow flows out of the shell through the gaps among the axial flow guide hole 45, the first magnetic limiting ring 41, the second magnetic limiting ring 42 and the third magnetic limiting ring 32, the gap between the rear end radial magnetic bearing 44, the stator 20 and the rotating shaft 30, the front end radial magnetic bearing 51, the first radial flow guide hole 52 and the second radial flow guide hole 11.

[0019] A rear end cover 70 is arranged on the tail end surface of the shell 10, and a protective cover 71 is arranged on the rear end cover.

[0020] The front end cover 80 is installed on the front end face of the shell 10, and is located at the periphery of the front end bearing seat 50, the outer end face of the front end cover is flush with the outer end face of the front end bearing seat, and a closed space 81 is formed between the front end cover and the front end bearing seat, and the second radial flow hole 11 realizes the communication between the closed space and the outside.

[0021] The first magnetic limiting ring and the second magnetic limiting ring limit the third magnetic limiting ring located therebetween through magnetic force therebetween, so that the third magnetic limiting ring is stably positioned between the first magnetic limiting ring and the second magnetic limiting ring. Since the third magnetic limiting ring is fixedly connected with the rotating shaft, the first magnetic limiting ring and the second magnetic limiting ring are fixedly connected with the rear end bearing seat, and the rear end bearing seat is fixedly connected with the shell, therefore, the axial position of the rotating shaft is positioned under the action of the first magnetic limiting ring, the second magnetic limiting ring and the third magnetic limiting ring.

[0022] The first fixed ring fixes the second magnetic limiting ring to stabilize the position thereof. Similarly, the second fixed ring fixes the third magnetic limiting ring to stabilize the position of the third magnetic limiting ring on the rotating shaft. The front end radial magnetic bearing and the rear end radial magnetic bearing position the rotating shaft in the radial direction.

[0023] The flow path of the airflow: the protective cover 71, the flow guide cover 60, the axial flow hole 45, the gap between the first magnetic limiting ring 41, the second magnetic limiting ring 42 and the third magnetic limiting ring 32, the rear end radial magnetic bearing 44, the gap between the stator 20 and the rotating shaft 30, the front end radial magnetic bearing 51, the first radial flow hole 52 and the second radial flow hole 11, and the airflow flows out of the shell. Among them, the gap between the first magnetic limiting ring, the second magnetic limiting ring and the third magnetic limiting ring, and the gap formed by the rear end radial magnetic bearing and the axial flow hole are in parallel relationship. The protective cover 71 is a hollow cover, and the airflow can enter the flow guide cover 60 through the protective cover.

[0024] The above is only the preferred embodiment of the present application, and for those skilled in the art, according to the idea of the present application, the specific embodiment and application range can be changed, and the content of the description should not be understood as a limitation of the present application.

Claims

1. An axial magnetic limit magnetic suspension motor, comprising a shell (10), a stator (20) and a rotating shaft (30), the stator is fixedly arranged on the inner side wall of the shell, the rotating shaft is located in the shell, the rotating shaft is provided with a rotating shaft magnet (31) opposite to the stator, and the rotating shaft is matched with a radial magnetic bearing supporting rotation of the rotating shaft, characterized in that: The tail of the shell is provided with a rear end bearing seat (40) which is installed in the shell (10), a first magnetic limit ring (41) and a second magnetic limit ring (42) are installed in the rear end bearing seat, the first magnetic limit ring and the second magnetic limit ring have an axial gap therebetween, the first magnetic limit ring and the rotating shaft have a radial gap therebetween, the second magnetic limit ring and the rotating shaft have a radial gap therebetween, the tail of the rotating shaft (30) is provided with a third magnetic limit ring (32), the third magnetic limit ring is located between the first magnetic limit ring and the second magnetic limit ring, the third magnetic limit ring and the first magnetic limit ring have an axial gap therebetween, the third magnetic limit ring and the second magnetic limit ring have an axial gap therebetween, and the third magnetic limit ring and the inner side wall of the rear end bearing seat (40) have a radial gap therebetween.

2. The axial magnetic-limited magnetic levitation motor as set forth in claim 1, wherein: The inner side wall of the rear end bearing seat (40) is provided with a first limit step and a second limit step, the first magnetic limit ring (41) is stopped at the first limit step, the second magnetic limit ring (42) is stopped at the second limit step, and the second magnetic limit ring is matched with a first fixed ring (43); The tail of the rotating shaft (30) is provided with a third limit step, the third magnetic limit ring (32) is stopped at the third limit step, and the third magnetic limit ring is matched with a second fixed ring (33).

3. The axially magnetically limited magnetic levitation motor of claim 1, wherein: The front of the shell (10) is provided with a front end bearing seat (50) which is installed in the shell, a front end radial magnetic bearing (51) is matched between the rotating shaft (30) and the front end bearing seat, and a rear end radial magnetic bearing (44) is matched between the rotating shaft and the rear end bearing seat (40).

4. The axially magnetically limited magnetic levitation motor of claim 3, wherein: The rear end bearing seat (40) is provided with an axial flow guide hole (45), the front end bearing seat (50) is provided with a first radial flow guide hole (52), and the shell (10) is provided with a second radial flow guide hole (11); a flow guide cover (60) is installed on the rear end bearing seat, a fan blade (34) is installed at the tail end of the rotating shaft (30), the fan blade rotates with the rotating shaft to input external airflow into the shell, and the airflow flows out of the shell after passing through the gap between the axial flow guide hole (45), the first magnetic limit ring (41), the second magnetic limit ring (42), the third magnetic limit ring (32), the gap between the rear end radial magnetic bearing (44), the stator (20) and the rotating shaft (30), the front end radial magnetic bearing (51), the first radial flow guide hole (52) and the second radial flow guide hole (11).

5. The axial magnetic stop magnetic levitation motor of claim 4, wherein: A rear end cover (70) is installed on the tail end surface of the shell (10), and a protective cover (71) is installed on the rear end cover.

6. The axial magnetic detent magnetic levitation motor of claim 4, wherein: A front end cover (80) is installed on the front end surface of the shell (10), the front end cover is located at the periphery of the front end bearing seat (50), the outer end surface of the front end cover is flush with the outer end surface of the front end bearing seat, a closed space (81) is formed between the front end cover and the front end bearing seat, and the second radial flow guide hole (11) realizes the communication between the closed space and the outside.

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