CN216672699U

CN216672699U - High-power high-speed permanent magnet motor with cooling system

Info

Publication number: CN216672699U
Application number: CN202122663550.XU
Authority: CN
Inventors: 张家玉; 杨智; 李姗; 陈磊; 蒋山; 张洋; 孙嘉男
Original assignee: 704th Research Institute of CSIC
Current assignee: 704th Research Institute of CSIC
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2022-06-03
Anticipated expiration: 2031-11-02

Abstract

The utility model relates to a high-power high-speed permanent magnet motor with a cooling system, which comprises a rotor, a stator, a base, two air-water coolers, two externally-hung fans and a cooling chamber, wherein the rotor is connected with the stator through the base; the stator is fixedly arranged in the machine base, the rotor is sleeved in the stator, and an air gap is formed between the stator and the rotor; the two air-water coolers are respectively arranged on two sides of the cooling chamber above the base, and the two external fans are respectively corresponding to the two air-water coolers and are symmetrically externally hung on the left side and the right side of the cooling chamber along the axial direction of the motor. And the two external fans blow cooling air into the motor from the two air inlets at the upper end of the base to cool the stator and the rotor, and hot air flows out of the air outlet in the middle of the top plate at the upper part of the base to the two air-water coolers and then enters the motor again after being cooled by the cooling water pipes of the air-water coolers. The problem of difficult heat dissipation caused by overlong axial length of the high-power rotor is solved; the stator is effectively cooled while the rotor is cooled.

Description

High-power high-speed permanent magnet motor with cooling system

Technical Field

The utility model relates to a cooling technology of a high-speed permanent magnet motor, in particular to a high-power high-speed permanent magnet motor with a cooling system.

Background

The high-power high-speed permanent magnet motor, especially the 20MW high-speed permanent magnet motor, has high power density and great loss density, and the permanent magnet rotor is used as one of the main heat sources of the high-speed permanent magnet motor, so that the temperature rise management of the high-speed permanent magnet motor rotor is difficult due to the obvious increase of high-frequency eddy current loss in a rotor core and the rapid increase of air friction loss on the surface of the rotor caused by high speed. Under the condition of high temperature, the permanent magnet on the rotor is easy to generate irreversible demagnetization, and the reliable operation of the motor is seriously influenced.

At present, the common rotor cooling includes an air cooling mode of externally arranging a fan and opening an axial air duct on a rotor, or a water cooling and air cooling mode of arranging a water jacket on the outer side of a stator casing and arranging a fan at the end part of the rotor, but the axial length of the rotor of a 20 MW-level high-power high-speed permanent magnet motor is generally longer, the heat dissipation of the rotor is difficult, and the methods can not meet the heat dissipation requirements. Therefore, on the premise of meeting the electrical requirements, designing a high-efficiency rotor cooling method and a high-efficiency rotor cooling system is particularly important for a high-power high-speed permanent magnet motor.

Disclosure of Invention

Aiming at the problems of temperature rise caused by high loss density and magnetic loss risk of permanent magnets in the existing rotor design of a 20 MW-grade high-speed permanent magnet synchronous motor, the high-power high-speed permanent magnet motor with the cooling system is provided, and the cooling system beneficial to heat dissipation of the high-power high-speed permanent magnet motor is designed on the basis of ensuring the electromagnetic and structural performance indexes of the motor.

The technical scheme of the utility model is as follows: a high-power high-speed permanent magnet motor with a cooling system comprises a rotor, a stator, a base, two air-water coolers, two external fans and a cooling chamber; the rotor comprises a rotor iron core, a permanent magnet fixed outside the rotor iron core and a sheath wound outside the permanent magnet; the stator comprises a stator iron core, a stator winding and stator end covers at two ends of the stator iron core; the stator is sleeved outside the rotor, and an air gap is formed between the stator and the rotor; the stator is fixedly installed in the base, the two air-water coolers are respectively arranged in a cooling chamber above the base, and the two externally-hung fans are respectively corresponding to the two air-water coolers and are symmetrically externally hung outside the left side and the right side of the cooling chamber along the axial direction of the motor; the top plate at the upper part of the machine base is respectively provided with an air inlet at the left side and the right side, two external fans blow cooling air into the motor inside the machine base from the air inlets at the two sides at the upper end of the machine base, and hot air flows out from two middle air outlets at the upper part of the machine base to two air-water coolers for cooling.

Preferably, the stator core is formed by laminating silicon steel sheets, and is divided into a plurality of sections by a plurality of radial ventilation channels according to requirements, so that effective heat dissipation of the stator is guaranteed.

Preferably, the rotor core is an integral forging and comprises a middle rotor core section and shaft extension sections at two ends of the rotor core section, and axial vent holes and radial vent holes are machined in the rotor core section.

Preferably, the permanent magnet and the protective sleeve of the rotor are divided into two sections which are symmetrical along the axial central line of the rotor core and have the same size and structure, the middle of each section is separated by a positioning rib on the rotor core, and the middle and the outer of each section are limited and fixed by an inner end plate and an outer end plate respectively.

Preferably, the axial ventilation holes penetrate through the rotor core section, the number of the axial ventilation holes is 12, the axial ventilation holes are uniformly distributed on the radial end face of the rotor core section in an annular manner, and the axial ventilation holes are uniformly distributed on the circumference which is concentric with the rotating shaft and has a diameter between the inner diameter and the outer diameter of the rotor core section.

Preferably, the radial ventilation holes are located on the rotor core section which is separated by the positioning ribs and is free of the permanent magnets and the protective sleeve, every two side-by-side through holes form a group of radial ventilation holes, and the radial ventilation holes extend inwards to be crossed with the axial ventilation holes.

Preferably, the sheath is made of carbon fiber composite materials and is fixed on the outer circle of the permanent magnet in a winding mode.

The utility model has the beneficial effects that: according to the high-power high-speed permanent magnet motor with the cooling system, the axial vent hole and the radial vent hole are formed in the rotor iron core section and are matched with the air-water cooler and the fan, so that two symmetrical motor circulation air paths are formed, and the problem of difficulty in heat dissipation caused by the overlong axial length of the high-power rotor is solved; the cooling system effectively cools the stator while cooling the rotor; the rotor and the cooling system are simple in structure and convenient to machine, manufacture and assemble.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a high-power high-speed permanent magnet motor with a cooling system;

FIG. 2 is a schematic view of the positions of the air inlet and outlet of the top plate of the base in the motor of the present invention;

FIG. 3 is a schematic view of a stator structure of the motor of the present invention;

FIG. 4 is a schematic view of a rotor structure of the motor of the present invention;

fig. 5 is a schematic view of the cooling path of the cooling air through the rotor in the motor of the present invention.

Detailed Description

The utility model is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

As shown in fig. 1, the overall structure of the high-power high-speed permanent magnet motor with a cooling system includes a rotor, a stator, a base 9, two air-water coolers 13, two external fans 14, and a cooling chamber 22. The rotor comprises a rotor iron core 1, a permanent magnet 2 fixed outside the rotor iron core 1, a sheath 3 wound outside the permanent magnet 2, an inner end plate 4 and an outer end plate 5; the stator comprises a stator core 6, a stator winding 7 and stator end covers 8 at both ends of the stator core 6.

The stator is sleeved outside the rotor, and an air gap is formed between the stator and the rotor. The stator is fixedly installed in the base 9, the two air-water coolers 13 are respectively arranged in a cooling chamber 22 above the base, and the two external fans 14 are respectively corresponding to the two air-water coolers 13 and symmetrically externally hung outside the left side and the right side of the cooling chamber 22 along the axial direction of the motor.

As shown in fig. 1 and 2, the left end and the right end of the top plate 10 of the upper portion of the base 9 are respectively provided with an air inlet 11, two external fans 14 blow cooling air into the motor from the two air inlets 11 at the upper end of the base 9 to cool the stator and the rotor, hot air flows out from an air outlet 12 in the middle of the top plate 10 of the upper portion of the base 9 to two air-water coolers 13, and enters the motor again after being cooled by cooling water pipes of the air-water coolers 13. The positions of the air inlet 11 and the air outlet 12 on the engine base 9 reasonably correspond to the positions of the two air-water coolers 13.

As shown in the schematic diagram of the stator structure shown in fig. 3, the stator core 6 is formed by laminating silicon steel sheets, and is divided into a plurality of sections by the plurality of radial ventilation ducts 15 as required, so that effective heat dissipation of the stator can be ensured;

as shown in fig. 1 and 4, the rotor structure schematic diagram is that the permanent magnet 2 and the sheath 3 of the rotor are divided into two sections which are symmetrical along the axial center line of the rotor core 1 and have the same size and structure, the middle of each section is separated by a positioning rib 16 on the rotor core 1, and the middle and the outer of each section are respectively limited and fixed by an inner end plate 4 and an outer end plate 5.

The permanent magnet 2 is a cylinder formed by a plurality of tile-shaped magnetic steels 17 along the axial direction and the radial direction, and the magnetic steels 17 are fixed on the excircle of the rotor core 1 by glue. The sheath 3 is made of carbon fiber composite materials and is fixed on the excircle of the permanent magnet 2 in a winding mode; the inner end plate 4 is sleeved on the section surface in a hot mode and is positioned on one side, close to the positioning rib 16, of the two sections of the symmetrical permanent magnets 2 and the protective sleeve 3, and the outer end plate 5 is installed on the end surface of the outer side of the rotor core section.

The rotor core 1 is an integral forging and comprises a rotor core section 18 in the middle and shaft extension sections 19 at two ends of the rotor core section 18, and axial vent holes 20 and radial vent holes 21 are machined in the rotor core section 18.

The axial ventilation holes 20 extend symmetrically through the rotor core segment 18. The number of the axial ventilation holes 20 is 12, the axial ventilation holes 20 are uniformly distributed on the radial end surface of the rotor core section 18 in a ring shape, the axial ventilation holes 20 are uniformly distributed on the circumference which is concentric with the rotating shaft but the diameter of the axial ventilation holes is between the inner diameter and the outer diameter of the rotor core section 18, and the number and the positions of the axial ventilation holes 20 can be correspondingly adjusted according to the outer diameter of the rotor core section 18, the air quantity required by cooling, the magnetic density distribution on the rotor core 1 and the mechanical strength of the rotor during design.

The radial vent holes 21 are positioned on the rotor core section 18 without the permanent magnet 2 and the sheath 3, which is separated by the positioning ribs 16, and the radial vent holes 21 extend inwards to intersect with the axial vent holes 20; every two through holes side by side form a group of radial vent holes 21, and the specific number and hole radius are determined by the heat dissipation requirement and the structural strength of the rotor.

In the high-power high-speed permanent magnet rotor cooling system, as shown in fig. 1 and 5, the path of cooling air passing through the rotor is schematically illustrated, air cooled by two air-water coolers 13 is blown into the motor from an air inlet 11 on a base 9, and then the cooling air is divided into two paths: one path flows through the end part of the stator winding 7, enters an air gap, then flows out of a radial ventilation duct 15 of the stator, and then flows out of an air outlet 12 at the top of the machine base 9; the other path flows out from a middle radial vent hole 21 of the rotor shaft through a rotor axial vent hole 20 and then flows out from an air outlet 12 on the base 9 through a stator radial vent channel 15; hot air flowing out of an air outlet 12 at the top of the base 9 is cooled by two air-water coolers 13 and then enters an air inlet 11 of the base 9, so that a two-way symmetrical closed circulating air cooling system is formed.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A high-power high-speed permanent magnet motor with a cooling system is characterized by comprising a rotor, a stator, a machine base, two air-water coolers, two external fans and a cooling chamber; the rotor comprises a rotor iron core, a permanent magnet fixed outside the rotor iron core and a sheath wound outside the permanent magnet; the stator comprises a stator iron core, a stator winding and stator end covers at two ends of the stator iron core; the stator is sleeved outside the rotor, and an air gap is formed between the stator and the rotor; the stator is fixedly installed in the base, the two air-water coolers are respectively arranged in a cooling chamber above the base, and the two externally-hung fans are respectively corresponding to the two air-water coolers and are symmetrically externally hung outside the left side and the right side of the cooling chamber along the axial direction of the motor; the top plate of the upper part of the base is respectively provided with an air inlet at the left side and the right side, two external fans blow cooling air into the motor in the base from the air inlets at the two sides of the upper end of the base, and hot air flows out from two middle air outlets at the upper part of the base to two air-water coolers for cooling.

2. The high-power high-speed permanent magnet motor with the cooling system according to claim 1, wherein the stator core is formed by laminating silicon steel sheets, and is divided into a plurality of sections by a plurality of radial ventilation channels as required to ensure effective heat dissipation of the stator.

3. The high-power high-speed permanent magnet motor with the cooling system according to claim 1 or 2, wherein the rotor core is a one-piece forged part and comprises a middle rotor core section and shaft extension sections at two ends of the rotor core section, and axial ventilation holes and radial ventilation holes are formed in the rotor core section.

4. The high-power high-speed permanent magnet motor with the cooling system according to claim 3, wherein the permanent magnet and the sheath of the rotor are divided into two sections which are symmetrical along the axial center line of the rotor core and have the same size and structure, the middle of each section is separated by a positioning rib on the rotor core, and the sections are limited and fixed by the inner end plate and the outer end plate respectively.

5. The high-power high-speed permanent magnet motor with the cooling system according to claim 4, wherein the axial ventilation holes penetrate through the rotor core section, the number of the axial ventilation holes is 12, the axial ventilation holes are annularly and uniformly distributed on the radial end surface of the rotor core section, and the axial ventilation holes are uniformly distributed on a circumference which is concentric with the rotating shaft and has a diameter between the inner diameter and the outer diameter of the rotor core section.

6. The high-power high-speed permanent magnet motor with the cooling system according to claim 5, wherein the radial ventilation holes are formed in the rotor core section without the permanent magnets and the sheath, which is partitioned by the positioning ribs, and every two side-by-side through holes form a group of radial ventilation holes, and the radial ventilation holes extend inwards to intersect with the axial ventilation holes.

7. The high-power high-speed permanent magnet motor with the cooling system according to any one of claims 4 to 6, wherein the sheath is made of carbon fiber composite material and is fixed on the outer circle of the permanent magnet in a winding manner.