CN105471142A - Built-in type rotor magnetic pole structure for high-speed permanent magnet motor - Google Patents

Abstract

A built-in rotor pole structure of a high-speed permanent magnet motor, including a rotor core with a non-uniform air gap structure, composed of several rotor punches with protruding outer edges sequentially stacked on the rotating shaft, and the rotor punches are punched with along The multi-section permanent magnets divided in the circumferential direction and the dumbbell-shaped reinforcing ribs made of non-magnetic alloy steel are placed. At the same time, magnetic isolation bridges and rivet holes are punched. A dumbbell-shaped reinforcing rib made of non-magnetic alloy steel is inserted between the multi-segment permanent magnets of one pole and the magnetic isolation bridges of two adjacent magnetic poles, and the two-end baffles made of non-magnetic material are covered along the rivet holes, and the The overall structure is welded and fixed on the motor shaft. The built-in rotor magnetic pole structure of the high-speed permanent magnet motor of the present invention has simple manufacturing process, reliable mechanical performance and high practicability, can be widely used in high-speed permanent magnet motors, effectively improves the reliability and service life of the motor during high-speed operation, and The processing cost is reduced.

Description

A built-in rotor pole structure of high-speed permanent magnet motor

technical field

The invention relates to the technical field of electrical engineering, in particular to a built-in rotor magnetic pole structure of a high-speed permanent magnet motor.

Background technique

This patent is funded by the National 863 Project (2012AA061303) and the National Major Scientific Instrument and Equipment Development Project (2012YQ05024207). High-speed permanent magnet motors have the advantages of small size, high power density, fast response, wide speed range, and can directly drive high-speed loads. They can be used in aerospace, flywheel energy storage, precision instrument manufacturing and other fields. When a high-speed motor is running, its speed is above 10,000r/min. High speed will generate a huge centrifugal force inside the motor rotor, and the tensile strength of the permanent magnet material in the rotor is low, so the rational design of the magnetic pole structure is particularly important.

At present, the pole structures used in high-speed permanent magnet motors are mainly surface-mounted rotor pole structures and built-in rotor pole structures. The manufacturing process of the surface-mounted rotor magnetic pole structure has low cost and less magnetic flux leakage, but when the rotor speed is high, the mechanical strength of the rotor is poor, and the magnetic poles are subjected to a large centrifugal force. The rotor sheath is required to protect the magnetic poles. Complicated and expensive. The magnetic flux leakage coefficient of the built-in rotor pole structure is small, and the pole arc coefficient is easy to control. Its permanent magnets are directly embedded in the rotor core without a rotor sheath. However, the utilization rate of the permanent magnets of the built-in tangential rotor pole structure is low, which increases The manufacturing cost of the motor, another built-in radial rotor pole structure, the radial length of the permanent magnet is longer, the bending stress generated when the rotor runs at high speed is easy to break the permanent magnet, and the centrifugal force generated on the pole shoe and permanent magnet is controlled by the rotor In order to ensure the magnetic isolation performance, the magnetic isolation bridge is generally thin, so the mechanical strength is relatively fragile.

Aiming at the many problems of above-mentioned existence, some researches have been carried out at home and abroad, and some patents have been applied for. In terms of strengthening the mechanical strength of the surface-mounted rotor of the high-speed permanent magnet motor, the patent number: 201510267300.0, the name is a permanent magnet fixing structure of the surface-mounted high-speed permanent magnet motor. Permanent magnets are placed between the stages, and the permanent magnets are fixed with non-magnetic metal protective sleeves to further strengthen the mechanical strength of the rotor. Patent No.: 201310451701.2, the name is the magnetic steel fastening structure of medium and large-scale high-speed rare earth permanent magnet motors. It is proposed to set ribs on the outer surface of the rotor core and set T-shaped slots and wedges between the ribs to achieve radial and circumferential alignment. The magnetic poles are fixed in the direction, and the rotor sheath is omitted while strengthening the mechanical structure of the rotor. But above-mentioned two kinds of schemes all have the shortcomings such as complex structure, difficult processing technology. In terms of strengthening the mechanical strength of the built-in rotor of the high-speed permanent magnet motor, the patent number: 201420434523.2, the name is a high-speed permanent magnet electric spindle built-in motor rotor punching structure, and it is proposed to divide the permanent magnet of the permanent magnet motor into the radial rotor pole structure. There are two or more pieces, a magnetic isolation bridge is set between each permanent magnet, and the bottom of the magnetic isolation bridge is designed as a boss structure, which increases the mechanical strength of the magnetic isolation bridge and the rotor poles, but the rotor punching structure In particular, the processing technology is difficult, and there is still magnetic flux leakage between poles after the permanent magnet is divided into blocks, which increases the amount of permanent magnets and increases the cost in disguise.

Contents of the invention

Purpose of the invention: The present invention is a built-in rotor magnetic pole structure of a high-speed permanent magnet motor. The bending stress generated at the time is easy to cause the permanent magnet to break and other problems.

Technical solutions:

A built-in rotor pole structure of a high-speed permanent magnet motor, characterized in that: the structure includes a rotor core; multi-segment permanent magnets arranged on the rotor core along the circumferential direction; The reinforcing rib between them; the baffle plate covered on the rotor iron core along the rivet hole, the baffle plate is riveted with the rotor iron core through rivets; the rotor iron core is punched with a magnetic isolation bridge, and the magnetic isolation bridge A reinforcing rib is inserted; the rotor core is welded and fixed on the motor shaft; the reinforcing rib is made of non-magnetic alloy steel.

The built-in rotor magnetic pole structure of the high-speed permanent magnet motor is characterized in that the width of each permanent magnet in the multi-segment permanent magnets is more than twice its thickness.

The built-in rotor pole structure of the high-speed permanent magnet motor is characterized in that: the rotor iron core has an uneven air gap structure, and is composed of several rotor punches with protruding outer edges sequentially stacked on the motor shaft.

The built-in rotor magnetic pole structure of the high-speed permanent magnet motor is characterized in that: the rotor punch is punched with placement grooves for multi-section permanent magnets and reinforcing ribs along the circumferential direction; the rotor punch is punched with magnetic isolation bridges and Rivet holes.

Advantages and effects: The high-speed permanent magnet motor built-in rotor magnetic pole structure of the present invention has simple manufacturing process, reliable mechanical performance and high practicability, and can be widely used in high-speed permanent magnet motors, effectively improving the reliability and reliability of the motor during high-speed operation. service life, and reduce processing and manufacturing costs.

Description of drawings:

Fig. 1 is the schematic diagram of rotor structure of the present invention;

Fig. 2 is the structural representation of baffle plate of the present invention;

Fig. 3 is a schematic diagram of reinforcing ribs;

Figure 4 is a schematic diagram of the rotor core.

Labeled in the figure:

1. Rotor core, 2. Multi-segment permanent magnet, 3. Rib, 4. Magnetic isolation bridge, 5. Motor shaft, 6. Rivet hole, 7. Rivet, 8. Baffle.

Specific implementation method: the present invention is a built-in rotor magnetic pole structure of a high-speed permanent magnet motor. The technical idea of the present invention is: divide the permanent magnet of each pole of the built-in radial magnetic pole structure into multiple sections along the circumferential direction to reduce the centrifugal force distribution of the rotor The length of the arm of the load reduces the bending stress on the permanent magnets and the magnetic isolation bridge; a dumbbell-shaped non-magnetic alloy steel is inserted between each two permanent magnets as a reinforcing rib to change the stress distribution of the rotor and transfer the maximum stress point On the non-magnetic alloy steel with high tensile strength, it can improve the mechanical strength of the rotor and the safety of high-speed operation; because the non-magnetic alloy is just a non-magnetic material, it eliminates the gap between the poles after the permanent magnet is segmented Flux leakage improves the utilization rate of permanent magnets. The dumbbell-shaped non-magnetic alloy steel plays a role in fixing permanent magnets and rotor punching plates without affecting the main magnetic circuit. The same non-magnetic alloy steel is also inserted between the magnetic isolation bridges of two adjacent magnetic poles to enhance the magnetic isolation capacity and tensile strength of the magnetic isolation bridge; the rotor core is made of laminated rotor punches to avoid eddy current loss The heat causes irreversible demagnetization of the permanent magnet; the outer edge of the rotor punch is raised, and after being laminated into the rotor core, an uneven air gap structure is formed to improve the smoothness of the motor operation, and rivet holes are punched on the rotor punch for The baffles made of non-magnetic materials are installed at both ends of the rotor to fix the permanent magnets and punching pieces. The structure is easy to install and safe and reliable.

The specific structure of the present invention is to divide the permanent magnet with the built-in radial magnetic pole structure often used in high-speed permanent magnet motors into multiple sections along the circumference, and the total number of permanent magnet sections is the number of poles of the motor multiplied by the number of sections of each pole permanent magnet along the circumference A dumbbell-shaped non-magnetic alloy steel is inserted between every two permanent magnets as a reinforcing rib 3, and the same reinforcing rib 3 is also inserted between the magnetic isolation bridges of two adjacent magnetic poles. The specific structure of the rotor mainly includes a rotor core 1, a multi-section permanent magnet 2 divided along the circumferential direction, a dumbbell-shaped rib 3 made of non-magnetic alloy steel, and a baffle 8 made of non-magnetic material. As shown in Figure 1, the rotor core 1 adopts a non-uniform air gap structure (the rotor core is a non-uniform air gap structure, specifically, several rotor punches as shown in Figure 1 are axially laminated on the The outer surface of the formed rotor core 1 protrudes outward, making the air gap between the stator and rotor uneven.), and several rotor punches with protruding outer edges are laminated on the motor shaft 5 in sequence. The rotor punching sheet is punched with a magnetic isolation bridge 4 and a rivet hole 6, and the multi-section permanent magnet 2 divided along the circumferential direction is inserted into the rotor core 1, between the multi-section permanent magnet 2 of each pole and the magnetic isolation between two adjacent magnetic poles. A dumbbell-shaped rib 3 made of non-magnetic alloy steel is inserted between the bridges 4 to bear the tensile stress generated when the rotor runs at high speed, and to fix the multi-segment permanent magnet 2 and the rotor punch without affecting the magnetic circuit. , improve the strength of the mechanical structure of the rotor, reduce magnetic flux leakage, and improve the utilization rate of permanent magnets. The baffle plate 8 made of non-magnetic material is also drilled with rivets at the positions corresponding to the rivet holes 6 on the rotor punching sheet hole, cover the two ends baffle plates 8 along the rivet holes 6, and the two ends are riveted with rivets 7 to fix the multi-section permanent magnets 2 and the rotor core 1, and then the overall structure is welded and fixed on the motor shaft 5. So far, the built-in rotor poles of the high-speed permanent magnet motor have been assembled.

In the above structure, the permanent magnets of each pole built in the rotor of the high-speed permanent magnet motor are segmented along the circumference, and the number of segments should be as many as possible, but it must be ensured that the width of each permanent magnet is more than twice its thickness , and a reinforcing rib independent of the rotor core is inserted between every two permanent magnets, and the same reinforcing rib is also inserted between the magnetic isolation bridges of two adjacent magnetic poles. The reinforcing rib is made of non-magnetic alloy steel with a shape of It is dumbbell-shaped, and the baffle and rivets are made of non-magnetic materials.

The beneficial effects of the present invention are:

The built-in rotor magnetic pole structure of the high-speed permanent magnet motor described in the present invention, compared with the current high-speed permanent magnet motor, adopts more surface-mounted rotor magnetic pole structures, and its magnetic flux leakage coefficient is small, and the pole arc coefficient is easy to control, which improves the performance of the permanent magnet. The utilization rate, and the permanent magnet is directly embedded in the rotor core, without the need for a rotor sheath, which reduces the manufacturing cost, reduces the equivalent air gap length of the motor, and improves the power-torque density ratio of the motor. After the permanent magnets are divided into multiple segments along the circumference, the strength of the mechanical structure of the rotor and the maximum safe operating speed of the motor are also greatly improved.

The built-in rotor magnetic pole structure of the high-speed permanent magnet motor described in the present invention, compared with the built-in tangential magnetic pole structure, reduces magnetic flux leakage and reduces the amount of permanent magnets; compared with the built-in radial magnetic pole structure, the permanent magnets are divided along the circumference It is multi-stage, avoiding the centrifugal force generated when the rotor runs at high speed to damage the permanent magnet, and at the same time transfer most of the bending stress applied to the magnetic isolation bridge to the dumbbell shape made of non-magnetic alloy steel inserted between the two permanent magnets On the reinforcement rib, the tensile capacity of the rotor core is improved, and the reinforcement rib is made of non-magnetic material, which eliminates the magnetic flux leakage between the poles of the permanent magnet and improves the utilization rate of the permanent magnet. The dumbbell-shaped reinforcement does not affect the magnetic field. At the same time, it also plays the role of fixing the permanent magnet and the rotor punch. The same reinforcing rib is inserted between the magnetic isolation bridges of two adjacent magnetic poles to enhance the magnetic isolation capacity and tensile strength of the magnetic isolation bridge. The rotor core adopts a non-uniform air gap structure, which improves the smoothness of the motor operation and reduces the vibration and noise.

The built-in rotor magnetic pole structure of the high-speed permanent magnet motor of the present invention has simple manufacturing process, reliable mechanical performance and high practicability, can be widely used in high-speed permanent magnet motors, effectively improves the reliability and service life of the motor during high-speed operation, and The processing cost is reduced.

Claims (4)

1. A built-in rotor pole structure of a high-speed permanent magnet motor, characterized in that: the structure includes a rotor core (1); multi-segment permanent magnets (2) arranged on the rotor core (1) along the circumferential direction ; the reinforcing rib (3) inserted between the magnetic poles of the multi-segment permanent magnet (2); the baffle (8) covering the rotor core (1) along the rivet hole (6), the baffle (8) riveted with the rotor core (1) through rivets (7); the rotor core (1) is punched with a magnetic isolation bridge (4), and a reinforcing rib (3) is inserted in the magnetic isolation bridge (4) ); the rotor core (1) is welded and fixed on the motor shaft (5); the reinforcing rib (3) is a reinforcing rib made of non-magnetic alloy steel. 2. The built-in rotor magnetic pole structure of a high-speed permanent magnet motor according to claim 1, characterized in that: the width of each permanent magnet in the multi-segment permanent magnets (2) is more than twice its thickness. 3. The built-in rotor pole structure of high-speed permanent magnet motor according to claim 1, characterized in that: the rotor core (1) is an uneven air gap structure, and consists of several rotor punches with protruding outer edges It is sequentially stacked on the motor shaft (5) to form. 4. The built-in rotor magnetic pole structure of high-speed permanent magnet motor according to claim 3, characterized in that: the rotor punch is punched with slots for placing multi-section permanent magnets (2) and reinforcing ribs (3) along the circumferential direction ; The rotor punch is punched with a magnetic isolation bridge (4) and a rivet hole (6).