CN108712048A - A kind of stator permanent-magnet five degree of freedom taper bearing-free switch reluctance motor - Google Patents

Abstract

The invention discloses a stator permanent magnet type five-degree-of-freedom conical bearingless switched reluctance motor, which includes a stator and a rotor. The inner wall of the stator core is conical, and several floating teeth are evenly arranged along the circumferential direction. The inner wall of the stator core between adjacent floating teeth is connected with a magnetic isolation block, and several magnetic isolation blocks are evenly arranged on the magnetic isolation block. Torque teeth, the suspension teeth and the torque teeth are respectively wound with suspension windings and torque windings; the rotor consists of a rotor core that runs through the permanent magnet ring, and a rotor core that is coaxially connected to the rotor core and extends to the outside of the stator core. The two ends of the rotor core are tapered to match the inner wall of the stator core, and several rotor teeth are uniformly arranged on the side wall of the tapered shape.

Description

A stator permanent magnet five-degree-of-freedom conical bearingless switched reluctance motor

technical field

The invention relates to the field of magnetic levitation motors with bearingless technology, in particular to a stator permanent magnet five-degree-of-freedom conical bearingless switched reluctance motor.

Background technique

Bearingless motors have no friction, no wear, no lubrication and no seals, and are easy to achieve higher speed and higher power operation. They have broad application prospects in aerospace, turbomolecular pumps, flywheel energy storage, sealed pumps, high-speed electric spindles, etc. . Bearingless motors are mainly divided into three types: bearingless asynchronous (induction) motors, bearingless permanent magnet synchronous motors and bearingless switched reluctance motors. In particular, the bearingless switched reluctance motor has the advantages of simple structure, high mechanical strength, flexible control, good fault tolerance, and good robustness, and has broad application prospects in electric vehicles, general industries, and household appliances.

In order to realize the stable suspension of the rotor of the bearingless switched reluctance motor, the active control force must be applied simultaneously on the four radial degrees of freedom and the axial single degree of freedom. The traditional five-degree-of-freedom bearingless switched reluctance motor usually has the following three structures:

1. It is composed of 1 bearing magnetic bearing and 2 two-degree-of-freedom bearingless switched reluctance motors;

2. It is composed of an axial magnetic bearing, a radial magnetic bearing and a two-degree-of-freedom bearingless switched reluctance motor;

3. It is composed of a three-degree-of-freedom radial-axial magnetic bearing and a bearingless switched reluctance motor;

These three structures all need to use axial magnetic bearings, which increases the axial length of the system, reduces the critical speed of the system, and limits the further improvement of the speed and power. In addition, each stator tooth of the traditional bearingless switched reluctance motor has Two sets of windings are wound, namely the suspension winding and the torque winding, and the number of pole pairs of the two sets of windings must satisfy the relationship of addition and subtraction. By coordinating and controlling the current of the torque winding and the suspension winding, torque and suspension force are generated at the same time. Torque There is a strong coupling between control and suspension control.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the existing five-degree-of-freedom bearingless switched reluctance motor, and provide a motor with simple and compact structure, small volume, light weight, more perfect functions, high power density, large bearing capacity, and high reliability. , The stator permanent magnet five-degree-of-freedom conical bearingless switched reluctance motor with independent suspension control and torque control.

The present invention is realized through the following technical solutions:

A stator permanent magnet five-degree-of-freedom conical bearingless switched reluctance motor, including a stator and a rotor, the stator is composed of an axially magnetized permanent magnet ring and an annular stator core symmetrically connected to both ends of the permanent magnet ring, The inner wall of the stator core is tapered, and several suspension teeth are evenly arranged along the circumferential direction. The inner wall of the stator core between adjacent suspension teeth is connected with a magnetic isolation block, and several torque teeth are evenly arranged on the magnetic isolation block. The suspension teeth and torque teeth are respectively wound with suspension windings and torque windings; the rotor is composed of a rotor core passing through the permanent magnet ring, and a rotating shaft coaxially connected to the rotor core and extending to the outside of the stator core. Both ends of the rotor core are tapered to match the inner wall of the stator core, and several rotor teeth are uniformly arranged on the tapered side wall.

A further solution of the present invention is that the tooth width and tooth thickness of the rotor teeth are the same as the tooth width and tooth thickness of the torque teeth.

A further solution of the present invention is that the tooth width of the suspension teeth is larger than the tooth width of the torque teeth, and the tooth width of the suspension teeth is larger than one pole pitch of the motor.

A further solution of the present invention is that the permanent magnet ring is made of rare earth permanent magnets or ferrite permanent magnets.

The advantage of the present invention compared with prior art is:

An axially magnetized permanent magnet ring provides bias flux to the stator core of the conical switched reluctance motor on both sides. The suspension winding is energized to generate the suspension control flux. The suspension control flux adjusts the static bias flux respectively. In the rotor The levitation force is generated on the rotor, and the rotor is controlled to levitate stably with five degrees of freedom; compared with the bearingless switched reluctance motor with two sets of windings on each stator tooth, the levitation control and torque control are independent of each other, and the control is simple and easy to implement; Compared with ordinary five-degree-of-freedom bearingless switching motors, it has a shorter axial length, can achieve high-speed/ultra-high-speed operation, and requires fewer displacement sensors, fewer drive circuits, and simple control system hardware. It can be widely used in Flywheel energy storage, various high-speed machine tool spindle motors and sealed pumps, centrifuges, compressors, high-speed small hard disk drives and other high-speed direct drive fields.

Description of drawings

Figure 1 is an exploded view of the present invention.

Fig. 2 is an assembly drawing of the present invention.

Fig. 3 is a schematic diagram of a right side cross-section of the present invention.

Fig. 4 is a left side sectional schematic view of the present invention.

Fig. 5 is a schematic diagram of the rotor structure of the present invention.

Fig. 6 is a left side view of the present invention.

Fig. 7 is a schematic diagram of the generation of suspension force in the present invention.

Fig. 8 is a schematic diagram of radial levitation winding wiring of the present invention.

Fig. 9 is a schematic diagram of the A-phase torque winding of the present invention.

Fig. 10 is a schematic diagram of the B-phase torque winding of the present invention.

Detailed ways

A stator permanent magnet five-degree-of-freedom conical bearingless switched reluctance motor as shown in Figures 1 to 8, taking the number of stator teeth/rotor teeth 12/14 as an example; it includes a stator and a rotor, and the stator is magnetized by the axial direction The permanent magnet ring 8, and the ring-shaped left stator core 1 and right stator core 11 symmetrically connected to the left and right ends of the permanent magnet ring 8, the inner walls of the left stator core 1 and the right stator core 11 are gradually gathered from the inside to the outside It is tapered, and four left floating teeth 12 and right floating teeth 18 are evenly arranged along the circumferential direction. The inner wall of the left stator core 1 between the adjacent left floating teeth 12 is connected with an aluminum left magnetic block 2, and the adjacent The right stator core 11 inner wall between the right floating teeth 18 is connected with the right magnetic isolation block 10 made of aluminum, and the left magnetic isolation block 2 and the right magnetic isolation block 10 are evenly provided with two left torque teeth 13 and a right magnetic isolation block 10 respectively. Torque tooth 19, the tooth width of described left suspension tooth 12, right suspension tooth 18 is greater than the tooth width of left torque tooth 13, right torque tooth 19, and the tooth width of left suspension tooth 12, right suspension tooth 18 is greater than motor a pole pitch, the left suspension teeth 12, the right suspension teeth 18, the left torque teeth 13, and the right torque teeth 19 are respectively wound with left suspension windings 14, right suspension windings 20, left torque windings 15, right The torque winding 21, the left suspension winding 14, the right suspension winding 20, the left torque winding 15, and the right torque winding 21 are all concentrated windings, which are made of electromagnetic coils with good conductivity and then dried with paint.

The rotor is composed of a rotor core 5 that runs through the permanent magnet ring 8, and a rotating shaft 7 that is coaxially connected to the rotor core 5 and extends to the outside of the stator core. The left and right ends of the rotor core 5 are connected to the left stator core 1, The inner wall of the right stator core 11 is tapered, and the tapered side wall is evenly provided with fourteen left rotor teeth 4 and right rotor teeth 6, and the left rotor teeth 4 and right rotor teeth 6 The tooth width, the tooth thickness are identical with the tooth width and the tooth thickness of the left torque tooth 13 and the right torque tooth 19.

The permanent magnetic ring 8 is made of rare earth permanent magnet or ferrite permanent magnet, the left stator core 1, the left suspension winding 14, the left torque winding 15, the left magnetic isolation block 2, the right magnetic isolation block 10, the right The suspension winding 20, the right torque winding 21, and the right stator core 11 are laminated in the axial direction; the left stator core 1, the right stator core 11, and the rotor core 5 are all made of a monolithic material with good magnetic permeability; the left suspension teeth 12, The right floating tooth 18, the left torque tooth 13, the right torque tooth 19, the left rotor tooth 4, and the right rotor tooth 6 are all formed by laminating thin silicon steel sheets.

The principle of suspension is:

The generation mechanism of the levitation force in the X and Y directions is the same, and the levitation force in the Y direction is taken as an example to illustrate, as shown in Fig. Teeth 12, left air gap, left rotor teeth 4, rotor core 5, right rotor teeth 6, right suspension teeth 18, and right stator core 11 form an axial closed path bias flux 16; two suspensions in the Y direction The windings on the teeth are connected in parallel or in series in the same direction, and the left suspension winding 14 is energized to form a radial closed path passing through the left suspension tooth 12 in the Y direction, the left rotor tooth 4, the air gap and the left stator core 1 on the left. The left suspension controls the magnetic flux 17; the right suspension winding 20 is energized, and the right suspension tooth 18, the right rotor tooth 6, the rotor core 5, the air gap and the right stator core 11 in the Y direction are formed on the right side to form a radial closed path The right levitation controls the magnetic flux 22 .

The left levitation control flux 17 and the right levitation control flux 22 respectively adjust the bias flux 16 to generate a levitation force perpendicular to the conical surface on the rotor. According to the existing technology, displacement sensors are respectively installed on the left stator core 1 and the right stator core 11. The displacement sensors are perpendicular to the rotor surface to establish a closed-loop displacement control. When the rotor deviates from the equilibrium position, the left suspension winding 14 and the right suspension winding 20 are adjusted. The electric current generates the levitation force that makes the rotor return to the equilibrium position, and realizes the stable levitation of the rotor with five degrees of freedom.

The principle of rotation is: as shown in Figure 9 and Figure 10, the left torque winding 15 and the right torque winding 21 are connected in series or parallel in the same direction and then divided into multi-phase structures. Taking two as an example, the A phase and the B phase are energized successively , The magnetic field of the torque winding forms a closed path between the torque teeth and the rotor teeth, which generates magnetic resistance, generates torque, and realizes the rotation of the rotor.

Claims (4)

1. A stator permanent magnet type five-degree-of-freedom conical bearingless switched reluctance motor, including a stator and a rotor, characterized in that: the stator is composed of an axially magnetized permanent magnet ring (8) and is symmetrically connected to the permanent magnet Ring (8) is composed of annular stator cores at both ends. The inner wall of the stator core is conical, and several suspension teeth are evenly arranged along the circumferential direction. The inner wall of the stator core between adjacent suspension teeth is connected with a magnetic isolation block. Several torque teeth are evenly arranged on the magnetic isolation block, and the suspension teeth and the torque teeth are respectively wound with suspension windings and torque windings; the rotor consists of a rotor core (5) that runs through the permanent magnet ring (8), and a rotating shaft (7) coaxially connected to the rotor core (5) and extending to the outside of the stator core. The two ends of the rotor core (5) are tapered to match the inner wall of the stator core, and the tapered side walls Several rotor teeth are also uniformly arranged. 2. A stator permanent magnet type five-degree-of-freedom conical bearingless switched reluctance motor as claimed in claim 1, characterized in that: the tooth width and tooth thickness of the rotor teeth and the tooth width and tooth thickness of the torque teeth Same thickness. 3. A stator permanent magnet type five-degree-of-freedom conical bearingless switched reluctance motor as claimed in claim 1, characterized in that: the tooth width of the suspension teeth is greater than the tooth width of the torque teeth, and the suspension teeth The width is greater than one pole pitch of the motor. 4. A stator permanent magnet five-degree-of-freedom conical bearingless switched reluctance motor as claimed in claim 1, characterized in that: said permanent magnet ring (8) adopts rare earth permanent magnet or ferrite permanent magnet system to make.