CN106849509B - A cooling structure for hollow rotor of ultra-high speed permanent magnet motor - Google Patents

Abstract

The hollow rotor cooling structure of the ultra-high speed permanent magnet motor is characterized in that a rotating shaft adopts a hollow structure, and a central pore canal of the rotating shaft is a rotor axial cooling water channel; the outer part of the shell is sleeved with a cooling water jacket, and a stator circumferential spiral cooling water channel is arranged in the cooling water jacket; one end of the cooling water jacket is provided with a water inlet cooling end cover which is sleeved at one end of the rotating shaft; the other end of the cooling water jacket is provided with a water outlet cooling end cover which is sleeved at the other end of the rotating shaft; the stator circumferential spiral cooling water channel is communicated with the water outlet cooling end cover sequentially through the water inlet cooling end cover and the rotor axial cooling water channel; the cooling water jacket is provided with a cooling water inlet and a cooling water outlet, the cooling water inlet is communicated with the water inlet end of the stator circumferential spiral cooling water channel, and the cooling water outlet is communicated with the water outlet end of the water outlet cooling end cover. The invention realizes stator cooling and rotor cooling for the first time, effectively improves cooling efficiency, and has the characteristics of simple cooling structure, low cooling cost, no wind abrasion and long safety operation life of the motor.

Description

A cooling structure for hollow rotor of ultra-high speed permanent magnet motor

technical field

The invention belongs to the technical field of ultra-high-speed permanent magnet motors, in particular to a cooling structure for a hollow rotor of an ultra-high-speed permanent magnet motor.

Background technique

The ultra-high-speed permanent magnet motor has the characteristics of simple structure, high force-energy density, no excitation loss and high efficiency, and can be directly connected with the workload to achieve direct drive. It is used in high-speed grinding machines, air circulation refrigeration systems, energy storage flywheels, high-speed Compressors, blowers, aerospace and other technical fields have broad application prospects.

However, under high-speed and high-frequency conditions, ultra-high-speed permanent magnet motors will significantly increase stator loss, rotor eddy current loss, and wind wear due to high fundamental frequency. Due to the difficulty in heat dissipation of ultra-high-speed permanent magnet motors, the motor is prone to overheating , resulting in irreversible demagnetization of the permanent magnet.

In order to avoid overheating of ultra-high-speed permanent magnet motors, technicians have successively developed a variety of cooling structures, which can be divided into air-cooling structures, water-cooling structures, oil-cooling structures and hydrogen-cooling structures.

At present, the air-cooling structure is the most common, mainly because the cooling structure is the simplest and the cooling cost is the lowest, but its cooling effect is the most general, especially the air-cooling method will increase wind wear and is accompanied by relatively large noise.

For the water-cooled structure and the oil-cooled structure, the cooling structure is basically the same, the main difference lies in the cooling medium, but the current water-cooled structure and oil-cooled structure are only aimed at the cooling of the stator, without considering the cooling of the rotor, so in terms of cooling effect There is still room for improvement.

For the hydrogen-cooled structure, it is divided into surface cooling and internal cooling. Although surface cooling can reduce the surface temperature of the winding, the temperature in the insulating layer hardly changes, so the cooling effect is not ideal; the internal cooling is through the solid copper wire The hollow steel pipe is clamped in the middle, and the hydrogen gas flows through the steel pipe, and then the heat in the copper wire is extracted, but the internal cooling is only suitable for large generators, so the scope of application is small.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a cooling structure for the hollow rotor of an ultra-high-speed permanent magnet motor, which for the first time realizes the cooling of the rotor while cooling the stator, and effectively improves the cooling without increasing the structural size of the whole machine. Efficiency, and has the characteristics of simple cooling structure, low cooling cost, no wind wear and long life of safe operation of the motor, especially suitable for ultra-high-speed permanent magnet motors with high power density.

In order to achieve the above object, the present invention adopts the following technical solution: a hollow rotor cooling structure of an ultra-high-speed permanent magnet motor, including a casing, an end cover, a stator and a rotor, the stator includes a stator core, a stator winding and a stator pressure plate, the The rotor includes a rotating shaft, a permanent magnet and a carbon fiber sheath; the stator core is fixed on the inner surface of the casing, the stator winding is fixed on the stator core, and the stator pressure plate is fixed on both ends of the stator core; the end cover is fixed on the At both ends of the casing, the rotating shaft is connected to the end cover through bearings, the permanent magnet is fixed on the surface of the rotating shaft, and the carbon fiber sheath is set on the outside of the permanent magnet; its characteristics are: the rotating shaft adopts a hollow structure, and the central hole of the rotating shaft is the rotor shaft To the cooling water channel; a cooling water jacket is installed outside the casing, and a stator circumferential spiral cooling water channel is arranged inside the cooling water jacket; one end of the cooling water jacket is provided with a water inlet cooling end cover, and the water inlet cooling end cover is set At one end of the rotating shaft; the other end of the cooling water jacket is provided with a water outlet cooling end cover, and the outlet cooling end cover is set on the other end of the rotating shaft; the stator circumferential spiral cooling water channel passes through the water inlet cooling end cover and the rotor axial cooling water channel in turn. The water outlet cooling end cover is connected; the cooling water jacket is provided with a cooling water inlet and a cooling water outlet. end connected.

The stator circumferential spiral cooling water channel adopts a parallel double spiral water channel.

The water inlet cooling end cover is provided with an annular water channel on the water inlet circumferential side, a water inlet radial water channel and an annular water channel on the water inlet center side. The water outlets are connected, and the annular water channel on the water inlet circumference side communicates with the annular water channel on the water inlet center side through the water inlet radial channel; The annular water channel on the center side of the water circle communicates with the axial cooling water channel of the rotor through the water inlet hole of the rotating shaft; on both sides of the annular water channel on the center side of the water inlet in the axial direction, seals are installed on the water inlet cooling end cover, and the rotating shaft passes through The seal is matched with the rotary seal of the water inlet cooling end cover.

The number of water inlet holes of the rotating shaft is several, and the water inlet holes of the rotating shaft are uniformly arranged; the axial center line of the water inlet holes of the rotating shaft has an inclination angle with the outer surface of the rotating shaft, and the inclination angle ranges from 30° to 40°.

There are several water inlet radial waterways, and several water inlet radial waterways are evenly distributed.

The water outlet cooling end cover is provided with an annular water channel on the water outlet circumferential side, a water outlet radial water channel and an annular water channel on the water outlet center side; the water outlet circumferential side annular water channel communicates with the cooling water outlet, and the water outlet circumferential side annular water channel passes through The water outlet radial water channel communicates with the annular water channel on the center side of the water outlet; on the rotating shaft facing the annular water channel on the center side of the water outlet, there is a shaft water outlet hole, and the annular water channel on the center side of the water outlet communicates with the axial cooling water channel of the rotor through the water outlet hole of the rotating shaft On both sides in the axial direction of the annular waterway at the center of the water outlet, seals are installed on the water outlet cooling end cover, and the rotating shaft is in rotation and sealing cooperation with the water outlet cooling end cover through the seal.

The number of water outlet holes of the rotating shaft is several, and the water outlet holes of the rotating shaft are uniformly arranged; the axial centerline of the water outlet holes of the rotating shaft has an inclination angle with the outer surface of the rotating shaft, and the inclination angle ranges from 30° to 40°.

There are several water outlet radial waterways, and the water outlet radial waterways are evenly distributed.

The aperture of the water outlet hole of the rotating shaft is larger than the aperture of the water inlet hole of the rotating shaft.

Beneficial effects of the present invention:

Compared with the prior art, the present invention achieves the cooling of the rotor while cooling the stator for the first time, effectively improves the cooling efficiency without increasing the structural size of the whole machine, and has the advantages of simple cooling structure, low cooling cost, and no wind It is especially suitable for ultra-high-speed permanent magnet motors with high power density due to the characteristics of high wear and tear and safe operation life of the motor.

Description of drawings

Fig. 1 is a schematic diagram of a hollow rotor cooling structure of an ultra-high-speed permanent magnet motor of the present invention;

Fig. 2 is A-A sectional view among Fig. 1;

Fig. 3 is B-B sectional view among Fig. 1;

In the figure, 1—casing, 2—end cover, 3—stator core, 4—stator winding, 5—stator pressure plate, 6—rotating shaft, 7—permanent magnet, 8—carbon fiber sheath, 9—bearing, 10—rotor Axial cooling water channel, 11—cooling water jacket, 12—circumferential spiral cooling water channel of stator, 13—water inlet cooling end cover, 14—water outlet cooling end cover, 15—cooling water inlet, 16—cooling water outlet, 17—inlet Circular water channel on the water circumference side, 18—radial water channel at water inlet, 19—annular water channel at the center of water inlet, 20—water inlet hole of rotating shaft, 21—annular water channel at water outlet peripheral side, 22—radial water channel at water outlet, 23— The annular water channel at the side of the water outlet circle, 24—the water outlet hole of the rotating shaft, and 25—the seal.

Detailed ways

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

As shown in Figures 1 to 3, a hollow rotor cooling structure of an ultra-high-speed permanent magnet motor includes a casing 1, an end cover 2, a stator, and a rotor. The stator includes a stator core 3, a stator winding 4, and a stator pressure plate 5. The rotor includes a rotating shaft 6, a permanent magnet 7 and a carbon fiber sheath 8; the stator core 3 is fixed on the inner surface of the casing 1, the stator winding 4 is fixed on the stator core 3, and the stator pressing plate 5 is fixed on the stator core 3 Both ends; the end cover 2 is fixedly arranged at both ends of the casing 1, the rotating shaft 6 is connected to the end cover 2 through a bearing 9, the permanent magnet 7 is fixedly arranged on the surface of the rotating shaft 6, and the carbon fiber sheath 8 is set on the outside of the permanent magnet 7 The rotating shaft 6 adopts a hollow structure, and the central hole of the rotating shaft 6 is a rotor axial cooling water channel 10; a cooling water jacket 11 is set outside the casing 1, and a stator circumferential spiral cooling water channel is arranged inside the cooling water jacket 11 12. One end of the cooling water jacket 11 is provided with a water inlet cooling end cover 13, and the water inlet cooling end cover 13 is set on one end of the rotating shaft 6; the other end of the cooling water jacket 11 is provided with an outlet cooling end cover 14, and the outlet water cooling end cover 14 is set on the other end of the rotating shaft 6; the stator circumferential spiral cooling water channel 12 is connected with the water outlet cooling end cover 14 through the water inlet cooling end cover 13 and the rotor axial cooling water channel 10 in turn; There is a cooling water inlet 15 and a cooling water outlet 16, the cooling water inlet 15 communicates with the water inlet end of the stator circumferential spiral cooling channel 12, and the cooling water outlet 16 communicates with the water outlet end of the water outlet cooling end cover 14.

The stator circumferential spiral cooling water channel 12 adopts a parallel double-helical water channel, which can effectively increase the heat dissipation area while reducing the resistance along the process, and effectively take away the heat generated by the stator loss, so that the temperature rise of the stator is more uniform. Avoid excessive local temperature rise and reduce the life of the motor.

The water inlet cooling end cover 13 is provided with an annular water channel 17 on the water inlet circumferential side, a water inlet radial water channel 18 and an annular water channel 19 on the water inlet center side. It communicates with the water outlet end of the spiral cooling water channel 12, and the annular water channel 17 on the water inlet circumferential side communicates with the annular water channel 19 on the water inlet center side through the water inlet radial channel 18; the annular water channel 19 on the water inlet center side is opposite The rotating shaft 6 is provided with a rotating shaft water inlet hole 20, and the annular water channel 19 on the water inlet center side communicates with the rotor axial cooling water channel 10 through the rotating shaft water inlet hole 20; On the side, a seal 25 is installed on the water inlet cooling end cover 13 , and the rotating shaft 6 is rotationally and sealingly matched with the water inlet cooling end cover 13 through the seal 25 .

The number of the rotating shaft water inlets 20 is several, and several rotating shaft water inlets 20 are evenly distributed. In this embodiment, there are four rotating shaft water inlets 20; The outer surface of 6 has an inclination angle ranging from 30° to 40°.

The number of said water inlet radial waterways 18 is several, and several water inlet radial waterways 18 are uniformly arranged. In this embodiment, there are totally four water inlet radial water channels 18 .

The water outlet cooling end cover 14 is provided with an annular water channel 21 on the water outlet circumferential side, a water outlet radial water channel 22 and an annular water channel 23 on the water outlet center side; the water outlet circumferential side annular water channel 21 communicates with the cooling water outlet 16, and The annular waterway 21 on the circumferential side communicates with the annular waterway 23 on the center side of the water outlet through the water outlet radial waterway 22; a shaft water outlet 24 is provided on the rotating shaft 6 facing the annular waterway 23 on the center side of the water outlet circle. The water channel 23 communicates with the rotor axial cooling water channel 10 through the water outlet hole 24 of the rotating shaft; on both sides in the axial direction of the annular water channel 23 on the side of the water outlet circle, a seal 25 is installed on the water outlet cooling end cover 14, and the rotating shaft 6 passes through the seal. 25 and the water outlet cooling end cover 14 are rotated and sealed.

The number of the rotating shaft water outlet holes 24 is several, and the several rotating shaft water outlet holes 24 are evenly distributed. In this embodiment, there are four water outlet holes 24 of the rotating shaft; the axial centerline of the water outlet holes 24 has an inclination angle with the outer surface of the rotating shaft 6, and the inclination angle ranges from 30° to 40°.

The number of said water outlet radial waterways 22 is several, and several water outlet radial waterways 22 are uniformly arranged. In this embodiment, there are totally four outlet radial water channels 22 .

The diameter of the water outlet hole 24 of the rotating shaft is larger than that of the water inlet hole 20 of the rotating shaft, which can effectively increase the pressure drop of the water inlet and outlet of the entire cooling water channel system, and make the water flow in the entire cooling water channel system smoother. In this embodiment, the diameter of the water outlet hole 24 of the rotating shaft is 10 mm, and the diameter of the water inlet hole 20 of the rotating shaft is 8 mm.

The use process of the present invention is illustrated below in conjunction with accompanying drawing:

First, the cooling water inlet 15 is connected with the water supply port of the cooling water circulation system, and the cooling water outlet 16 is connected with the water return port of the cooling water circulation system at the same time, the cooling water circulation system is first started, and then the ultra-high-speed permanent magnet motor is started.

The cooling water first enters the stator circumferential spiral cooling water channel 12 inside the cooling water jacket 11 through the cooling water inlet 15, and the cooling water flows in the circumferential spiral cooling water channel 12, and then takes away the heat generated by the stator loss, so that the temperature rise of the stator is more uniform , to avoid excessive local temperature rise and reduce the life of the motor.

The cooling water flows directly from the outlet end of the stator circumferential spiral cooling water channel 12 into the water inlet circumferential side annular water channel 17 of the water inlet cooling end cover 13, and then enters the water inlet center side annular water channel 19 through the water inlet radial water channel 18, The annular water channel 19 on the center side of the water inlet has a certain degree of water storage capacity. During the high-speed rotation of the rotating shaft 6, the cooling water in the annular water channel 19 on the center side of the water inlet will enter through the water inlet hole 20 of the rotating shaft evenly and continuously. In the rotor axial cooling water channel 10, since the axial center line of the rotating shaft water outlet hole 24 has an inclination angle with the outer surface of the rotating shaft 6, it can be further ensured that the cooling water can enter the rotor axial cooling water channel 10 evenly and continuously. The axial flow of the rotor in the cooling water channel 10 will directly take away the heat generated by the rotor loss, so that the temperature of the rotor will rise more evenly, and at the same time avoid the deformation of the rotor due to uneven temperature rise, and it can also directly take away the heat in the bearing 9, further improving The service life of bearing 9.

The cooling water flows out of the rotating shaft 6 from the water outlet hole 24 of the rotating shaft, and directly enters the annular water channel 23 on the side of the water outlet circle center of the water outlet cooling end cover 14, and then enters the annular water channel 21 on the water outlet circumferential side through the water outlet radial channel 22, and the cooling water finally Flow out from cooling water outlet 16.

The solutions in the embodiments are not intended to limit the scope of patent protection of the present invention, and all equivalent implementations or changes that do not deviate from the present invention are included in the patent scope of this case.

Claims (7)

1. A hollow rotor cooling structure of an ultra-high-speed permanent magnet motor, comprising a casing, an end cover, a stator and a rotor, the stator comprising a stator core, a stator winding and a stator pressing plate, and the rotor comprising a rotating shaft, a permanent magnet and a carbon fiber sheath The stator core is fixed on the inner surface of the casing, the stator winding is fixed on the stator core, and the stator pressure plate is fixed on both ends of the stator core; the end cover is fixed on both ends of the casing, and the rotating shaft passes through the bearing Connected with the end cover, the permanent magnet is fixed on the surface of the rotating shaft, and the carbon fiber sheath is set on the outside of the permanent magnet; it is characterized in that: the rotating shaft adopts a hollow structure, and the central hole of the rotating shaft is the axial cooling water channel of the rotor; outside the casing A cooling water jacket is installed, and a stator circumferential spiral cooling water channel is arranged inside the cooling water jacket; one end of the cooling water jacket is provided with a water inlet cooling end cover, and the water inlet cooling end cover is set on one end of the rotating shaft; the cooling water jacket is another One end is provided with a water outlet cooling end cover, and the water outlet cooling end cover is set on the other end of the rotating shaft; the stator circumferential spiral cooling water channel is connected with the water outlet cooling end cover through the water inlet cooling end cover and the rotor axial cooling water channel in turn; The cooling water jacket is provided with a cooling water inlet and a cooling water outlet, the cooling water inlet communicates with the water inlet end of the stator circumferential spiral cooling water channel, and the cooling water outlet communicates with the water outlet end of the water outlet cooling end cover; at the water inlet cooling end The cover is provided with an annular water channel on the water inlet circumference side, a water inlet radial water channel and an annular water channel on the water inlet center side. The side annular waterway communicates with the side annular waterway of the water inlet center through the water inlet radial waterway; a shaft water inlet hole is opened on the rotating shaft facing the water inlet center side annular waterway, and the water inlet center side annular waterway passes through The water inlet hole of the rotating shaft communicates with the axial cooling water channel of the rotor; on both sides in the axial direction of the annular water channel at the center of the water inlet, seals are installed on the water inlet cooling end cover, and the rotating shaft is connected to the water inlet cooling end cover through the seal. Rotation and sealing fit; in the water outlet cooling end cover, there are annular water channels on the water outlet circumferential side, water outlet radial water channels and water outlet center side annular water channels; the water outlet circumferential side annular water channel communicates with the cooling water outlet, and the water outlet peripheral side The annular water channel communicates with the annular water channel on the center side of the water outlet through the water outlet radial channel; on the rotating shaft facing the annular water channel on the center side of the water outlet, there is a water outlet hole of the rotating shaft, and the annular water channel on the center side of the water outlet connects with the rotor shaft through the water outlet hole of the rotating shaft It communicates with the cooling water channel; on both sides in the axial direction of the annular water channel at the center of the water outlet, seals are installed on the water outlet cooling end cover, and the rotating shaft is rotated and sealed with the water outlet cooling end cover through the seal. 2. A cooling structure for a hollow rotor of an ultra-high-speed permanent magnet motor according to claim 1, wherein the stator circumferential spiral cooling water channel adopts a parallel double-helical water channel. 3. A cooling structure for a hollow rotor of an ultra-high-speed permanent magnet motor according to claim 1, characterized in that: the number of water inlet holes of the rotating shaft is several, and the water inlet holes of the rotating shaft are uniformly arranged; the water inlet holes of the rotating shaft There is an inclination angle between the axial center line and the outer surface of the rotating shaft, and the inclination angle ranges from 30° to 40°. 4. A cooling structure for a hollow rotor of an ultra-high-speed permanent magnet motor according to claim 1, characterized in that: there are several water inlet radial water channels, and several water inlet radial water channels are evenly distributed. 5. A hollow rotor cooling structure for an ultra-high-speed permanent magnet motor according to claim 1, characterized in that: the number of water outlet holes of the rotating shaft is several, and the water outlet holes of the rotating shaft are evenly distributed; the axial center of the water outlet holes of the rotating shaft There is an inclination angle between the wire and the outer surface of the rotating shaft, and the inclination angle ranges from 30° to 40°. 6. A cooling structure for a hollow rotor of an ultra-high-speed permanent magnet motor according to claim 1, characterized in that: there are several water outlet radial water channels, and several water outlet radial water channels are evenly distributed. 7. A cooling structure for a hollow rotor of an ultra-high-speed permanent magnet motor according to claim 1, wherein the diameter of the water outlet hole of the rotating shaft is larger than that of the water inlet hole of the rotating shaft.

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