Shield pump for aviation and surface-mounted brushless direct current motor without position sensor

Abstract

The utility model discloses a shield pump for aviation and a surface-mounted brushless direct current motor without a position sensor, and relates to the technical field of surface-mounted brushless direct current motors for aviation. The shaft, the rotor assembly and the stator assembly are sequentially arranged in a shell from inside to outside, a through hole is formed in the shaft, an upper graphite bearing is arranged at the upper end of the shaft, and a lower graphite bearing is arranged at the lower end of the shaft; the rotor assembly comprises a rotor iron core and a permanent magnet; the stator assembly at the bottom of the shaft is provided with a shielding sleeve. According to the utility model, the circulation of a cooling medium in the motor can be realized only by arranging the through hole on the shaft without arranging other complex side holes, and each component of the whole motor can be effectively cooled, so that the part processing time is greatly shortened, and the production efficiency is improved; according to the utility model, the cooling of each component of the motor can be realized without complicated waterway cooling calculation, the research and development time is reduced, and the design cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of a surface-mounted brushless DC motor for aviation, in particular to an aviation shielded pump and a surface-mounted brushless DC motor without a position sensor. Background Art

[0002] The rotor shaft of the existing aviation shielded pump has a plurality of side holes connected to the shaft hole on the side to allow cooling medium to flow through so as to reduce the temperature of the bearing in the bearing chamber. However, the side holes on the rotor shaft are difficult to machine and require complex water channel calculations.

[0003] In the existing aviation shielded pump permanent magnet surface-mounted brushless DC motor, the permanent magnet is in direct contact with the cooling medium. The permanent magnet is relatively brittle. If a collision occurs during the assembly process, small magnetic fragments are likely to be generated. The magnetic fragments are likely to adhere to other components of the motor and the fragments enter the cooling medium, making the shielded pump medium easily contaminated.

[0004] Most of the existing surface-mount brushless DC motors for aviation use a rotor position sensor to control the operation of the motor. This method requires adjustment of the Hall sensor position angle during assembly, which consumes a lot of assembly time. The Hall sensor has a high failure rate, so the reliability of the motor is low and the price is expensive. The motor with a Hall rotor position sensor has a larger structure and heavier weight, and it is also necessary to consider mechanical positioning and installation, and the connection between the Hall sensor and the drive circuit.

[0005] In order to solve the problems of cooling the bearings of aviation shielded pumps and the problem of impurities being mixed in, it is necessary to develop an aviation shielded pump and a position sensor-free surface-mounted brushless DC motor. Utility Model Content

[0006] The purpose of the utility model is to overcome the shortcomings of the above-mentioned background technology and to provide a shielded pump for aviation and a position sensor-free surface-mounted brushless DC motor.

[0007] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is: a shielded pump for aviation and a brushless DC motor without position sensor surface mounting, comprising a shaft, a rotor assembly, and a stator assembly arranged in sequence from the inside to the outside in a housing, characterized in that: a through hole is provided inside the shaft, an upper graphite bearing is provided at the upper end of the shaft, and a lower graphite bearing is provided at the lower end;

[0008] The rotor assembly comprises a rotor core and a permanent magnet, wherein the permanent magnet is located on a side of the rotor core close to the shaft, and a rotor assembly protective sleeve is provided at the connection between the permanent magnet and the rotor core;

[0009] A shielding sleeve is provided on the stator assembly located at the bottom of the shaft;

[0010] There is an air gap between the rotor component protection sleeve and the shielding sleeve.

[0011] In the above technical solution, a circuit board assembly is also included below the shaft.

[0012] In the above technical solution, two bosses are arranged on the shaft at intervals, and the permanent magnet is located in a groove formed by the two bosses.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] 1) The utility model only needs to set a through hole on the shaft, and no other complex side holes are required to realize the circulation of the cooling medium in the motor, and all components of the entire motor can be effectively cooled, which greatly shortens the parts processing time and improves production efficiency; the utility model does not need to perform complex water cooling calculations to realize the cooling of the motor components, reduces R&D design time, and saves design costs.

[0015] 2) The protective cover of the rotor assembly of the utility model is made of carbon fiber material to reduce eddy current loss and improve motor efficiency; the boss structure of the shaft and the use of the protective cover of the rotor assembly can surround the permanent magnet to prevent magnetic fragments generated by collision during assembly from entering the cooling medium and adhering to other components, thereby improving product reliability and avoiding contamination of the cooling medium of the shielded pump.

[0016] 3) The utility model eliminates the expensive Hall rotor position sensor and adopts a rotor-free position sensor, which solves the problems of mechanical positioning and installation of the Hall rotor position sensor and the connection between the sensor and the drive circuit. The utility model is lighter, smaller, has a higher power density, higher operating reliability, and a lower price. It does not require Hall position positioning, which shortens the assembly time and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Among them, 1-shaft, 11-through hole, 12-boss, 2-rotor assembly, 21-rotor core, 22-permanent magnet, 23-rotor assembly protective sleeve, 3-stator assembly, 41-upper graphite bearing, 42-lower graphite bearing, 5-shielding sleeve, 6-circuit board assembly. DETAILED DESCRIPTION

[0019] The following is a detailed description of the implementation of the utility model in conjunction with the accompanying drawings, but they do not constitute a limitation of the utility model and are only used as examples. At the same time, the advantages of the utility model will become clearer and easier to understand through the description.

[0020] Referring to the attached drawings, it can be seen that: an aviation shielded pump and a position sensor-free surface-mounted brushless DC motor, comprising a shaft 1, a rotor assembly 2, and a stator assembly 3 arranged in sequence from the inside to the outside in a housing, characterized in that: a through hole 11 is provided inside the shaft 1, an upper graphite bearing 41 is provided at the upper end of the shaft 1, and a lower graphite bearing 42 is provided at the lower end;

[0021] The rotor assembly 2 includes a rotor core 21 and a permanent magnet 22. The permanent magnet 22 is located on the side of the rotor core 21 close to the shaft 1. A rotor assembly protective sleeve 23 is provided at the connection between the permanent magnet 22 and the rotor core 21.

[0022] A shielding sleeve 5 is provided on the stator assembly 3 located at the bottom of the shaft 1;

[0023] There is an air gap between the rotor assembly protection sleeve 23 and the shielding sleeve 5 .

[0024] Also included is a circuit board assembly 6 located below the shaft 1 .

[0025] Two bosses 12 are spaced apart on the shaft 1 , and the permanent magnet 22 is located in a groove formed by the two bosses 12 .

[0026] In actual use, the cooling medium flows through the through hole 11 inside the shaft 1 through the air gap between the shielding sleeve 5 and the rotor assembly protective sleeve 23 and the lower graphite bearing 42, thereby realizing the circulation of the cooling medium in the motor. The cooling medium flowing through the through hole 11 can effectively reduce the temperature of the rotor core 21 and the permanent magnet 22. The cooling medium flowing between the shielding sleeve 5 and the rotor assembly protective sleeve 23 can effectively reduce the stator core temperature of the stator assembly 3. The cooling medium flows through the upper and lower graphite bearings to reduce the temperature of the graphite bearings. Therefore, all components of the entire motor can be effectively cooled down. The utility model can realize the circulation of the coolant in the motor without setting other complex side holes, and all components of the entire motor can be effectively cooled down.

[0027] The shielding sleeve 5 of the shielded pump is arranged on the stator assembly 3, and the permanent magnet 22 is glued to the rotor core 21 by gluing to form the rotor assembly 2. After the rotor assembly 2 is formed, the general assembly is performed. In the general assembly process, in order to prevent the smaller fragments of the permanent magnet 22 generated by the collision during the installation process from entering the cooling medium; a carbon fiber rotor assembly protective sleeve 23 is arranged on the rotor assembly 2, which can reduce eddy current loss and improve motor efficiency; and by arranging a boss 12 on the shaft 1, the permanent magnet 22 is fully surrounded. Therefore, even if the rotor assembly 2 is bumped during the general assembly, no magnetic fragments will adhere to other components of the motor and will not contaminate the cooling medium, thereby improving product reliability and avoiding contamination of the cooling medium.

[0028] The utility model adopts a rotor position sensor-free control method to control the operation of the motor. The control part only needs two circuit board components 6 to realize the function, and only needs four screws to install and position. The utility model is lighter in weight, smaller in size, higher in power density, higher in operating reliability, lower in price, and simple in assembly to improve production efficiency.

[0029] Other parts not described belong to the prior art.

Claims

1. A shielded pump for aviation and a brushless DC motor without position sensor, comprising a shaft (1), a rotor assembly (2), and a stator assembly (3) arranged in sequence from the inside to the outside in a housing, characterized in that: A through hole (11) is provided inside the shaft (1); an upper graphite bearing (41) is provided at the upper end of the shaft (1), and a lower graphite bearing (42) is provided at the lower end of the shaft (1); The rotor assembly (2) comprises a rotor core (21) and a permanent magnet (22), wherein the permanent magnet (22) is located on a side of the rotor core (21) close to the shaft (1), and a rotor assembly protective sleeve (23) is provided at the connection between the permanent magnet (22) and the rotor core (21); A shielding sleeve (5) is provided on the stator assembly (3) located at the bottom of the shaft (1); There is an air gap between the rotor assembly protection sleeve (23) and the shielding sleeve (5).

2. The shielded pump and position sensorless surface mounted brushless DC motor for aviation according to claim 1, characterized in that: Also included is a circuit board assembly (6) located below the shaft (1).

3. The shielded pump and position sensorless surface mounted brushless DC motor for aviation according to claim 1, characterized in that: Two bosses (12) are arranged on the shaft (1) at intervals, and the permanent magnet (22) is located in a groove formed by the two bosses (12).

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