CN110729834A - Air-cooled rotor structure of permanent magnet synchronous motor - Google Patents

Abstract

The utility model provides an air-cooled rotor structure of PMSM, including first clamp plate and the second clamp plate of locating rotor core both ends, rotor core is equipped with axial ventilation groove, be equipped with first air intake on the first clamp plate, first air intake and ventilation groove switch-on, wherein be equipped with a confined cavity in the second clamp plate and with the second air intake of cavity and ventilation groove switch-on, air inlet channel is constituteed to first air intake, ventilation groove and second air intake, second clamp plate side is equipped with the air outlet, the air outlet switches-on with the cavity, be equipped with the flabellum in the cavity. In the high-speed rotation process of the rotor, the fan blades in the second pressure plate cavity rotate, a large negative pressure can be formed in the cavity due to the action of centrifugal force, air in the motor enters the cavity through the air inlet channel and flows out of the air outlet, air circulation inside the motor is formed, and heat inside the rotor is continuously taken out. The air inlet channel is the only air inlet source, and the cooling effect is good; and other part structures of the motor do not need to be changed, the structure is compact, and the reliability is high.

Description

An air-cooled rotor structure of a permanent magnet synchronous motor

technical field

The invention belongs to the technical field of motors, and in particular relates to a rotor of a permanent magnet synchronous motor.

Background technique

At present, new energy vehicle motors are gradually trending towards high power density and high speed, and the problem of motor temperature rise is gradually becoming more prominent. The magnetic steel inside the motor is very sensitive to the working temperature. When the temperature of the magnetic steel is too high, the magnetic performance of the magnetic steel will drop sharply, resulting in a serious decline in the thermal performance of the motor, and even lead to permanent demagnetization of the magnetic steel. Most of the magnets of the permanent magnet synchronous motor for vehicles are located inside the rotor, the internal structure of the motor is compact, and the rotor is in a high-speed rotation state during the working process, which brings great difficulty to the cooling of the rotor.

Most of the existing solutions use oil cooling to cool the motor rotor. The hollow shaft oil cooling solution is used to dissipate heat from the motor rotor, and the centrifugal force of the high-speed rotation of the motor is used to drive the cooling oil to spray onto the rotor. The structure of this solution is relatively complicated. , the cost is high, and a set of oil cooling equipment needs to be added, and the cost is high.

In addition to the oil-cooled solution, there is also a rotor air-cooled solution. Patent CN205377574U discloses an air-cooled motor. The main structure includes pressure plates arranged at both ends of the rotor, blades on the pressure plates and axial ventilation slots opened on the outer circle of the stator. A circulating airflow is formed to improve the heat dissipation capacity of the motor. The circulating air flow includes a main circulating air flow. The air flows from the vanes of the front pressure plate through the axial ventilation holes on the rotor, the vanes on the rear pressure plate, the gap between the ventilation slots on the outer circle of the stator and the casing, and the front end cover returns to the front end. Platen; may also include a secondary air flow that flows between the rear platen and the rear cover. This heat dissipation structure uses open blades. The disadvantage is that there are many sources of air intake, which may cause the fan blades to ineffectively agitate the air inside the motor, and cannot ensure sufficient air volume to pass through the rotor ventilation slots.

Patent CN104124850A discloses another air-cooled motor, including a cooling fan and a windshield, the windshield is arranged between the air inlet of the motor and the cooling fan, and the negative pressure generated by the cooling fan sucks the air flow from the air inlet of the motor After the motor is inside, it needs to pass through the windshield to flow to the rotor. During this process, the windshield can make the air flow into the motor more concentrated, so as to avoid the air flow in the motor body and affect the cooling effect. Although the setting of the wind deflector achieves the effect of making the air flow more concentrated, since the air flow needs to pass through the wind deflector, a space needs to be left before and after the wind deflector to facilitate the normal flow of the air flow, resulting in a larger axial direction. Space requirements, occupying the internal space of the motor, there will be many restrictions in practical applications.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide an air-cooled rotor structure of a permanent magnet synchronous motor with concentrated airflow, good cooling effect and compact structure.

In order to solve the above technical problems, the present invention is achieved through the following technical solutions: an air-cooled rotor structure of a permanent magnet synchronous motor, comprising a first pressure plate and a second pressure plate arranged at both ends of a rotor iron core, and the rotor iron core is provided with an axial The ventilation slot, the first pressure plate is provided with a first air inlet, the first air inlet is connected with the ventilation slot, the second pressure plate is provided with a closed cavity and a second air inlet connecting the cavity and the ventilation slot, The first air inlet, the ventilation groove and the second air inlet form an air inlet channel, the side of the second pressing plate is provided with an air outlet, the air outlet is connected with the cavity, and the cavity is provided with a fan blade.

Further, the second air inlet is arranged between the blades of the fan blade.

Further, the air outlet is a fan ring.

Further, the inner edge of the second air inlet is in close contact with the inner ring of the fan blade.

Further, the second pressing plate includes an upper pressing plate and a lower pressing plate which are connected together.

Further, the blades of the fan blades are evenly distributed in the second pressing plate.

Further, the first air inlets are evenly distributed along the circumferential direction on the first pressing plate, and the second air inlets are evenly distributed along the circumferential direction on the second pressing plate.

Further, the air outlets are evenly distributed along the circumferential direction on the side surface of the second pressing plate.

The advantage of the present invention is that during the high-speed rotation of the rotor, the fan blades in the cavity of the second platen rotate, and due to the centrifugal force, a large negative pressure will be formed in the cavity, and the air in the motor will enter the cavity through the air inlet channel, The air flows out from the air outlet to form the air circulation inside the motor, which continuously brings out the heat inside the rotor. The cavity of the second platen is a closed structure, and the air inlet channel is the only air inlet source, which can effectively prevent the fan blades from ineffectively stirring the air inside the motor, and has a good cooling effect. This rotor structure is only based on the original structure, and the internal structure of the second platen is modified without changing the structure of other components of the motor. It has a compact structure, high reliability, and is easy to remove the weight of the rotor, which can effectively reduce the magnetic steel of the motor under high-speed conditions. The temperature rise increases the thermal performance of the motor.

Description of drawings

Fig. 1 is the overall schematic diagram of the present invention;

Fig. 2 is the schematic diagram one of the second pressing plate;

FIG. 3 is a second schematic diagram of the second pressing plate;

FIG. 4 is a cross-sectional view of the second pressing plate.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments:

An embodiment of the present invention is shown in Figures 1 to 4. An air-cooled rotor structure of a permanent magnet synchronous motor includes a first pressure plate 4 and a second pressure plate 3 arranged at both ends of the rotor iron core 2. The rotor iron core 2 is provided with axial There is a first air inlet 41 on the first pressure plate 4, the first air inlet 41 is connected with the ventilation groove, and the second pressure plate 3 is provided with a closed cavity and a connection between the cavity and the ventilation groove. The second air inlet 35, the first air inlet 41, the ventilation groove and the second air inlet 35 form an air inlet channel, and the side of the second pressing plate 3 is provided with an air outlet 34, which is connected to the cavity, and the cavity is provided with an air outlet 34. There are fan blades 33 .

During the high-speed rotation of the rotor, the fan blade 33 in the cavity of the second platen 3 rotates, which drives the air flow in the cavity. The first air inlet 41, the ventilation slot of the rotor core 2, and the second air inlet 35 on the second pressure plate 3 enter the cavity of the second pressure plate 3, and finally flow out from the air outlet 34 of the second pressure plate 3, forming the air inside the motor cycle, thereby continuously taking out the heat inside the rotor. After the heat inside the rotor is carried out by the air, it can be exhausted by the ventilation holes of the motor casing.

The cavity of the second platen 3 is a closed structure. When the air is in, the air inlet channel composed of the first air inlet 41, the ventilation slot and the second air inlet 35 is the only source of air intake, which can effectively prevent the fan blades 33 from ineffectively stirring the motor. Internal air, the generated airflow is completely used to take out the heat of the rotor core 2, and the cooling effect is good.

This rotor structure is only based on the original structure, and the internal structure of the second pressure plate 2 is modified. A cavity is set in the second pressure plate 2, and fan blades 33 are installed in the cavity to generate negative pressure when the rotor rotates to drive the air flow. , and set the second air inlet 35 for air intake, and the air outlet 34 for air exhaust. This rotor structure does not need to change the structure of other parts of the motor, has a compact structure, high reliability, and is easy to remove the weight of the rotor, which can effectively reduce the temperature rise of the magnetic steel of the motor under high-speed conditions and improve the thermal performance of the motor.

In this embodiment, the second air inlet 35 is provided between the blades of the fan blade 33 , as shown in FIG. 4 .

In this embodiment, the air outlet 34 is fan-shaped, as shown in FIGS. 2 and 3 . The fan ring structure can make the flow rate of the air outlet 34 larger, make it easier to exhaust air, and can also reduce the material of the second pressing plate 3 , thereby reducing the weight of the second pressing plate 3 .

In this embodiment, the inner edge of the second air inlet 35 is in close contact with the inner ring 36 of the fan blade 33, as shown in FIG. 4, which is more convenient for air flow.

In this embodiment, the second pressure plate 3 includes an upper pressure plate 31 and a lower pressure plate 32, and the upper pressure plate 31 and the lower pressure plate 32 are connected to form the second pressure plate 3. If necessary, a seal such as an O-ring can be added at the connection. After the fan blade 33 is put into the cavity between the upper pressing plate 31 and the lower pressing plate 32 , the second pressing plate 3 is formed by connecting the upper pressing plate 31 and the lower pressing plate 32 .

As a preferred embodiment, the blades of the fan blades 33 are evenly distributed in the second pressing plate 3 , the first air inlets 41 are evenly distributed along the circumferential direction on the first pressing plate 4 , and the second air inlets 35 are evenly distributed on the second pressing plate 3 along the circumferential direction. The air outlets 34 are evenly distributed in the circumferential direction, and the air outlets 34 are evenly distributed along the circumferential direction on the side surface of the second pressing plate 3 .

It should be emphasized that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are Still belong to the scope of the technical solution of the present invention.

Claims (8)

1. An air-cooled rotor structure of a permanent magnet synchronous motor, comprising a first pressure plate and a second pressure plate arranged at both ends of the rotor iron core, the rotor iron core is provided with an axial ventilation groove, and the first pressure plate is provided with a first air inlet , the first air inlet is connected to the ventilation groove, and it is characterized in that: the second pressure plate is provided with a closed cavity and a second air inlet connecting the cavity and the ventilation groove, the first air inlet, the ventilation The slot and the second air inlet form an air inlet channel, the side of the second pressing plate is provided with an air outlet, the air outlet is connected with the cavity, and a fan blade is arranged in the cavity. 2 . The air-cooled rotor structure of a permanent magnet synchronous motor according to claim 1 , wherein the second air inlet is arranged between the blades of the fan blade. 3 . 3 . The air-cooled rotor structure of a permanent magnet synchronous motor according to claim 1 , wherein the air outlet is a fan ring. 4 . 4 . The air-cooled rotor structure of a permanent magnet synchronous motor according to claim 1 , wherein the inner edge of the second air inlet is in close contact with the inner ring of the fan blade. 5 . 5 . The air-cooled rotor structure of a permanent magnet synchronous motor according to claim 1 , wherein the second pressing plate comprises an upper pressing plate and a lower pressing plate which are connected together. 6 . 6 . The air-cooled rotor structure of a permanent magnet synchronous motor according to claim 1 , wherein the blades of the fan blades are evenly distributed in the second pressure plate. 7 . 7 . The air-cooled rotor structure of a permanent magnet synchronous motor according to claim 1 , wherein the first air inlets are evenly distributed along the circumferential direction on the first pressing plate, and the second air inlets are on the second pressing plate. 8 . Evenly distributed along the circumference. 8 . The air-cooled rotor structure of a permanent magnet synchronous motor according to claim 1 , wherein the air outlets are evenly distributed along the circumferential direction on the side surface of the second pressing plate. 9 .

Images