Permanent magnet synchronous servo motor

Abstract

The invention relates to the technical field of motors, in particular to a permanent magnet synchronous servo motor which comprises a motor shell and is characterized in that the permanent magnet synchronous servo motor further comprises a front end cover and a rear end cover which are symmetrically installed on the two side walls of the motor shell, a front end bearing is arranged in the front end cover, a rear end bearing is arranged in the rear end cover, and the front end bearing and the rear end bearing are arranged in the motor shell. The front end bearing and the rear end bearing are jointly connected with a main shaft penetrating through the interior of the motor shell, the side wall of the main shaft is sleeved with the rotor, a stator is arranged on the inner wall of the motor shell, and a heat dissipation mechanism is arranged in the motor shell. The T-shaped heat dissipation mechanism is arranged in the air path of the air-cooled motor, so that in the operation process of the motor, airflow (such as air) is continuously damaged along the boundary layer of the wall surface in the motor, the Knooseer coefficient of the wall surface is increased, and heat convection is enhanced.

Description

Technical Field

[0001] This invention relates to the field of motor technology, specifically to a permanent magnet synchronous servo motor. Background Technology

[0002] The mechanical losses of a high-speed permanent magnet synchronous motor mainly consist of rotor wind friction loss and bearing loss. In the temperature field calculation of ordinary motors, mechanical losses are generally ignored because they are relatively small. However, in high-speed permanent magnet synchronous motors, due to the increase in speed, the mechanical losses, which are positively correlated with the speed, also increase significantly and become non-negligible.

[0003] High-speed motors, with their advantages of high efficiency, high power density, small size, and the ability to eliminate the need for a speed increaser, have become a research hotspot both domestically and internationally in recent years. Research on high-speed motors began earlier abroad, with power ranges from several kilowatts to tens of megawatts. In contrast, research in my country started later, and most studies remain at the low-power stage below tens of kilowatts. Due to their high frequency, high-speed permanent magnet motors generate significant high-frequency iron and copper losses in the stator and windings. Furthermore, the rotor of a high-speed permanent magnet motor uses sintered NdFeB permanent magnet material, which struggles to withstand the enormous centrifugal force under high-speed rotation. Protective measures are necessary for the permanent magnets. Currently, the most common protective measures are binding the permanent magnets with carbon fiber and adding a high-strength, non-magnetic alloy protective sleeve. However, alloy protection generates significant eddy current losses within the protective sleeve, and the carbon fiber sleeve has extremely poor heat transfer characteristics. Both protective measures pose significant challenges to motor heat dissipation. Moreover, permanent magnets can undergo irreversible demagnetization under high temperatures, especially for megawatt-class high-speed permanent magnet synchronous motors.

[0004] To address this, a permanent magnet synchronous servo motor is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a permanent magnet synchronous servo motor that reduces the irreversible demagnetization of permanent magnets under high temperatures by lowering the rotor ventilation and heat dissipation efficiency, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A permanent magnet synchronous servo motor includes a motor housing, characterized in that it further includes a front end cover and a rear end cover symmetrically installed on the two side walls of the motor housing; The front end cover is equipped with a front bearing, and the rear end cover is equipped with a rear bearing. The front bearing and the rear bearing are connected to a main shaft that passes through the inside of the motor housing. The rotor is sleeved on the side wall of the main shaft. The inner wall of the motor housing is equipped with a stator, and a heat dissipation mechanism is provided inside the motor housing.

[0007] Preferably, the heat dissipation mechanism includes an air inlet on the motor housing, the air inlet being connected to a ventilation slot on the rotor, the ventilation slot being connected to an air gap between the rotor and the stator, and exhaust fans being provided at both ends of the main shaft for exhausting air. The exhaust fans work with the movement of the main shaft and always exhaust air.

[0008] Preferably, both the front cover and the rear cover are provided with dustproof nets, the dustproof nets are made of activated carbon, and the filter pore size of the dustproof nets is 200 mesh.

[0009] Preferably, the stator outer diameter is 470mm, the stator inner diameter is 186mm, and the air gap is 3mm.

[0010] Preferably, the heat dissipation mechanism adopts a T-shaped hybrid ventilation system that combines axial and radial ventilation, with the ventilation system mainly used for rotor heat dissipation.

[0011] Preferably, the stator core is divided into two sections with a radial air duct of a certain width reserved in the middle. Near the air gap in the stator slot, there is an axial air duct with a height of 1 / 3 of the slot depth. Cold air flows in from the radial air duct, carries away the heat of the stator and rotor through the axial air duct, and the hot air is carried to the outside of the motor housing by the exhaust fans on both sides of the main shaft.

[0012] Preferably, a shock-absorbing pad is fixed to the bottom of the motor housing, and the shock-absorbing pad is a component made of 3mm thick natural rubber.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a T-shaped heat dissipation mechanism within the airflow path of an air-cooled motor. During motor operation, the boundary layer of the airflow (e.g., air) along the motor's internal walls is continuously disrupted, increasing the Nusselt coefficient and enhancing convective heat transfer. Simultaneously, the T-cell structure reduces the friction coefficient between the wall and the airflow, minimizing airflow recirculation within the motor and reducing losses caused by airflow friction. Therefore, this invention improves the cooling performance of the motor's ventilation and cooling structure, thereby enhancing the motor's stability, reliability, and operating efficiency. Furthermore, the invention's simple structure facilitates manufacturing and is suitable for large-scale application.

[0014] Furthermore, by providing uniformly recessed cells on the inner surface of the base, the inner surface of the stator core, the outer surface of the rotor core, and the inner surface of the rotor ventilation holes, this invention not only improves the heat dissipation efficiency of the motor's ventilation and cooling structure but also facilitates dynamic balance control during motor operation.

[0015] Furthermore, by enhancing the radial heat dissipation capacity of the stator core on the leeward side of the stator wind channel, this invention increases the effective heat dissipation path inside the motor and improves the heat dissipation efficiency of the motor's ventilation and cooling structure. Attached Figure Description

[0016] Figure 1 This is a front structural cross-sectional view of the present invention; Figure 2 This is a schematic diagram of the airflow direction of the heat dissipation mechanism of the present invention; Figure 3 This is a schematic diagram of the air gap in this invention; In the diagram: 1. Motor housing; 2. Front cover; 3. Rear cover; 4. Front bearing; 5. Rear bearing; 6. Main shaft; 7. Rotor; 8. Stator; 9. Dustproof screen; 10. Filter hole; 11. Air inlet; 12. Ventilation slot; 13. Air gap; 14. Exhaust fan. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Please see Figures 1 to 3This invention provides a permanent magnet synchronous servo motor, the technical solution of which is as follows: A permanent magnet synchronous servo motor includes a motor housing 1, and a front cover 2 and a rear cover 3 symmetrically installed on the two side walls of the motor housing 1. The front cover 2 has a front bearing 4 inside, and the rear cover 3 has a rear shaft 5 inside. The front bearing 4 and the rear bearing 5 are connected together to a main shaft 6 that passes through the inside of the motor housing 1. The main shaft 6 has a rotor 7 sleeved on its side wall. The inner wall of the motor housing 1 has a stator 8. The motor housing 1 has a heat dissipation mechanism inside.

[0021] Specifically, the heat dissipation mechanism includes an air inlet 11 on the motor housing 10, which is connected to a ventilation slot 12 on the rotor 7. The ventilation slot 12 is connected to an air gap 13 between the rotor 7 and the stator 8. Both ends of the main shaft 6 are equipped with exhaust fans 14 for ventilation. The exhaust fans 14 work with the movement of the main shaft 6 and always exhaust air.

[0022] Specifically, both the front cover 2 and the rear cover 3 are equipped with dustproof nets. The dustproof nets are made of activated carbon and have a pore size of 200 mesh.

[0023] Specifically, the outer diameter of stator 8 is 470mm, the inner diameter of stator 8 is 186mm, and the air gap 13 is 3mm.

[0024] Specifically, the heat dissipation mechanism adopts a T-type hybrid ventilation system that combines axial and radial ventilation, with the main function of the ventilation system being to dissipate heat from the rotor 7.

[0025] Specifically, the stator 8 core is divided into two sections with a radial air duct of a certain width reserved in the middle. Near the air gap 13 in the slot of the stator 8, there is an axial air duct with a height of 1 / 3 of the slot depth. Cold air flows in from the radial air duct, carries away the heat of the stator and rotor 7 through the axial air duct, and brings the hot air to the outside of the motor housing 1 through the exhaust fans 14 on both sides of the main shaft 6.

[0026] Specifically, a shock-absorbing pad is fixed to the bottom of the motor housing 1. The shock-absorbing pad is made of 3mm thick natural rubber.

[0027] Working principle: A cooling system combining air cooling and external stator water cooling is adopted, such as... Figure 1As shown, the stator outer diameter is 470 mm, the stator inner diameter is 186 mm, and the air gap is 3 mm. The air-cooling system adopts an L-shaped hybrid ventilation system that combines axial and radial ventilation. The ventilation system is mainly for rotor heat dissipation. The stator core is divided into two sections with a radial air duct of a certain width reserved in the middle. Near the air gap in the stator slot, there is an axial air duct with a height of 1 / 3 of the slot depth. Cold air flows in from the radial air duct, carries away the heat of the stator and rotor through the axial air duct, and the hot air is carried to the outside of the casing by the exhaust fans on both sides of the shaft. In the hybrid ventilation system, the axial air duct height is 25 mm and the radial air duct width is 35 mm.

[0028] The proposed motor ventilation and cooling structure (referred to as the air-cooled structure) uses an exhaust fan 14 driven by the output shaft to drive air through the air duct. By utilizing the boundary layer that cuts off the airflow along the internal wall of the motor, the Nusselt coefficient of the inner surface of the air duct inside the frame, the inner surface of the stator core, the outer surface of the rotor core, and the inner surface of the rotor ventilation hole is increased, thereby enhancing the convective heat transfer of air on each wall inside the motor and improving the effect of convective heat transfer. At the same time, the air resistance of the inner surface of the air duct inside the frame, the inner surface of the stator core, the outer surface of the rotor core, and the inner surface of the rotor ventilation hole is reduced, thereby enhancing the motor's heat dissipation capacity while reducing mechanical and thermal losses caused by friction.

[0029] The key challenge in motor cooling lies in the significant temperature difference between the motor frame (the lowest temperature point) and the rotor core (the highest temperature point) when the temperature field reaches a steady state. Existing water-cooling structures based on microcells only cool the motor frame, failing to adequately cool the internal components of the motor. The air-cooling structure of this invention primarily enhances heat exchange between the motor's internal components and the frame, reducing the temperature difference and significantly improving cooling performance. Furthermore, air-cooled motors, due to their lighter weight, simpler structure, and lower sealing requirements compared to water-cooled motors, possess irreplaceable advantages in fields such as automation, electric vehicles, and aerospace.

[0030] In this invention, because the cells continuously truncate the boundary layer and improve the backflow and vortex problems inside the motor, the velocity distribution of the airflow field inside the motor is more uniform, reducing the friction between air and thus reducing the noise of the air-cooled motor. Theoretically, this can reduce the noise by more than 3%.

[0031] All electrical components mentioned in this article are connected to an external main controller and 220V AC mains power via transformers. The main controller can be a conventional known device such as a computer for control. The product models provided in this invention are only for use based on the structural features of the product in this technical solution. The product will be adjusted and modified after purchase to better match and conform to the technical solution of this invention. It is an optimal application of this technical solution. The product models can be replaced and modified according to the required technical parameters. This is well known to those skilled in the art. Therefore, those skilled in the art can clearly obtain the corresponding usage effects through the technical solution provided by this invention.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A permanent magnet synchronous servo motor, comprising a motor housing (1), characterized in that, It also includes a front cover (2) and a rear cover (3) symmetrically installed on both sides of the motor housing (1); The front end cover (2) is provided with a front end bearing (4), the rear end cover (3) is provided with a rear end bearing (5), the front end bearing (4) and the rear end bearing (5) are connected together to a main shaft (6) that passes through the inside of the motor housing (1), the rotor (7) is sleeved on the side wall of the main shaft (6), the inner wall of the motor housing (1) is provided with a stator (8), and a heat dissipation mechanism is provided inside the motor housing (1).

2. The permanent magnet synchronous servo motor according to claim 1, characterized in that: The heat dissipation mechanism includes an air inlet (11) provided on the motor housing (1), the air inlet (11) being connected to a ventilation slot (12) opened on the rotor (7), the ventilation slot (12) being connected to an air gap (13) between the rotor (7) and the stator (8), and exhaust fans (14) for exhausting air being provided at both ends of the main shaft (6), the exhaust fans (14) working with the movement of the main shaft (6), and the exhaust fans (14) always exhausting air.

3. A permanent magnet synchronous servo motor according to claim 1, characterized in that: Both the front cover (2) and the rear cover (3) are provided with dustproof nets (9). The dustproof nets (9) are made of activated carbon and the filter holes (10) of the dustproof nets have a pore size of 200 mesh.

4. A permanent magnet synchronous servo motor according to claim 1, characterized in that: The stator (8) has an outer diameter of 470 mm, an inner diameter of 186 mm, and an air gap (13) of 3 mm.

5. A permanent magnet synchronous servo motor according to claim 1, characterized in that: The heat dissipation mechanism adopts a T-type hybrid ventilation system that combines axial ventilation and radial ventilation. The ventilation system is mainly for rotor (7) heat dissipation.

6. A permanent magnet synchronous servo motor according to claim 1, characterized in that: The stator (8) core is divided into two sections with a certain width of radial air duct reserved in the middle. An axial air duct with a height of 1 / 3 of the slot depth is reserved near the air gap (13) of the slot hole of the stator (8). Cold air flows in from the radial air duct, carries away the heat of the stator and rotor (7) through the axial air duct, and brings the hot air to the outside of the motor housing (1) through the exhaust fans (14) on both sides of the main shaft (6).

7. A permanent magnet synchronous servo motor according to claim 1, characterized in that: The bottom end of the motor housing (1) is fixed with a shock-absorbing pad, which is made of 3mm thick natural rubber.

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