CN108832786B - Five-degree-of-freedom bearingless asynchronous motor - Google Patents

Abstract

The invention discloses a five-degree-of-freedom bearingless asynchronous motor, comprising a rotor and a stator, wherein the rotor comprises a mandrel, and a radial rotor core, a radial boss and a rotating shaft respectively coaxially connected to the mandrel. The rotor core is located in the middle of the mandrel, and its outer circumference is connected with an axial rotor core through a radially magnetized permanent magnet ring. Both ends of the axial rotor core are evenly provided with an even number of axial rotor bars or rotor windings. , the radial bosses are located at both ends of the mandrel, and an even number of radial rotor bars or rotor windings are evenly arranged on the radial bosses; the stator includes two stator cores symmetrically arranged on both sides of the rotor , each stator core is provided with an axial end facing the axial rotor core, and a radial end facing the radial boss, and the axial end is provided with an axial suspension winding and an axial torque winding. The radial ends are provided with radial suspension windings and radial torque windings.

Description

A five-degree-of-freedom bearingless asynchronous motor

technical field

The invention relates to the technical field of motor manufacturing, in particular to a five-degree-of-freedom bearingless asynchronous motor.

Background technique

Bearingless motors have no friction, wear, lubrication and sealing, 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 motorized spindles and other fields. . Bearingless motors are mainly divided into bearingless asynchronous (induction) motors, bearingless permanent magnet synchronous motors and bearingless switched reluctance motors.

At present, the bearingless asynchronous motor uses a set of additional suspension windings superimposed on the torque winding of the stator slot of the traditional asynchronous motor. The magnetic field of the winding, and the pole pairs of the magnetic field of the suspension winding is P _B , the magnetic field of the torque winding is P _M , and only when the relationship between the two satisfies the relationship of P _B = P _M ±1, can a stable and controllable radial direction be generated on the rotor. Suspension force. To realize the stable suspension of the rotor with five degrees of freedom, it needs to be composed of an axial magnetic bearing + a radial two-degree-of-freedom magnetic bearing + a two-degree-of-freedom bearingless asynchronous motor, or an axial magnetic bearing + two two-degree-of-freedom bearingless asynchronous motors The motor, or a two-degree-of-freedom bearingless asynchronous motor + a three-degree-of-freedom magnetic bearing constitute a five-degree-of-freedom suspension drive system, resulting in a long axial length and a high critical speed of the five-degree-of-freedom bearingless asynchronous motor system. It rotates at high speed, and is bulky and expensive.

Therefore, the study of a bearingless asynchronous motor with five degrees of freedom suspension function is of great significance to reduce the volume and cost of the five degrees of freedom bearingless asynchronous motor, and to promote the development of the industrial application process of the bearingless asynchronous motor.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the existing five-degree-of-freedom bearingless asynchronous motor, to provide a five-degree-of-freedom bearingless asynchronous motor capable of realizing the rotor five-degree-of-freedom suspension operation in one unit, and to provide a new type of motor for special electrical transmission. solution.

The present invention is achieved through the following technical solutions:

A five-degree-of-freedom bearingless asynchronous motor includes a rotor and a stator, the rotor includes a mandrel, and a radial rotor core, a radial boss, and a rotating shaft that are coaxially connected to the mandrel, the radial rotor core is located at In the middle of the mandrel, the outer circumference is connected with an axial rotor core through a radially magnetized permanent magnet ring, and both ends of the axial rotor core are evenly provided with an even number of axial rotor bars or rotor windings. The radial bosses are located at both ends of the mandrel, and an even number of radial rotor bars or rotor windings are evenly arranged on the radial bosses; the stator includes two stator cores symmetrically arranged on both sides of the rotor, each stator The iron core is provided with an axial end facing the axial rotor iron core, and a radial end facing the radial boss, the axial end is provided with an axial suspension winding and an axial torque winding, and the radial end is provided with an axial suspension winding and an axial torque winding. There are radial suspension windings and radial torque windings, and the rotating shaft extends to the outside of the stator core.

A further scheme of the present invention is that the motor speed is n , the current frequency and pole pair number of the radial torque winding are f _j , P _j respectively, and the current frequency and pole pair number of the axial torque winding are f _z , P respectively _z , satisfying: f _j × P _z = P _j × f _z .

A further solution of the present invention is that the axial suspension winding is located outside the axial torque winding relative to the rotor; the radial suspension winding is located outside the radial torque winding relative to the rotor.

A further solution of the present invention is that the number of pole pairs of the axial suspension winding, the radial suspension winding and the axial torque winding and the radial torque winding are different.

A further solution of the present invention is that the axial rotor bars or rotor windings, and the radial rotor bars or rotor windings all adopt a phase-separated structure, and the number of pole pairs is respectively the same as that of the axial torque winding and the radial torque winding. The number of pole pairs is the same.

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 advantages of the present invention compared with the prior art are:

A radially magnetized permanent magnet ring provides radial and axial static bias magnetic flux, the axial suspension winding is energized to generate the axial suspension control magnetic flux, the radial suspension winding is energized to generate the radial suspension control magnetic flux, and the axial suspension is energized. The suspension control magnetic flux and the radial suspension control magnetic flux adjust the static bias magnetic flux respectively to generate the axial and radial suspension forces that make the rotor stably levitate. The torque is generated by the energization of the axial torque winding and the radial torque winding. The five-degree-of-freedom bearingless asynchronous motor of this structure realizes the stable suspension and rotation of the rotor in one unit, and has the advantages of small size, light weight and high power density, and provides a new solution for special electric transmission.

Description of drawings

FIG. 1 is a schematic diagram of the axial structure and magnetic flux of the present invention.

FIG. 2 is a left side view of the present invention at position A. FIG.

FIG. 3 is a right side view of the present invention at position B. FIG.

Detailed ways

As shown in Figures 1 to 3, a five-degree-of-freedom bearingless asynchronous motor, taking the number of stator slots at both ends of the left and right stator cores equal to 12 as an example, includes a rotor and a stator, the rotor includes a mandrel 3, and coaxial The radial rotor core 2, the radial boss, and the rotating shaft 5 are connected to the mandrel 3. The radial rotor core 2 is located in the middle of the mandrel 3, and its outer circumference is connected to the axial direction through the radially magnetized permanent magnet ring 4. The rotor core 1, the left and right ends of the axial rotor core 1 are respectively provided with twelve left axial rotor bars or rotor windings 6 and right axial rotor bars or rotor windings 7, the said The radial bosses are located at the left and right ends of the mandrel 3, and twelve left radial rotor bars or rotor windings 8 and right radial rotor bars or rotor windings are evenly arranged on the radial bosses 9.

The stator includes a left stator iron core 10 and a right stator iron core 11 symmetrically arranged on the left and right sides of the rotor. The left stator iron core 10 and the right stator iron core 11 are connected by annular radial parts and axial parts respectively. The axial end of the radial portion faces the axial rotor core 1, and the radial end of the radial portion faces the radial boss. The axial ends of the left stator core 10 and the right stator core 11 are respectively provided with axial stator slots, so The left axial suspension winding 12 and the left axial torque winding 13, the right axial suspension winding 15 and the right axial torque winding 14 are embedded in the axial stator slots. The radial ends are respectively provided with radial stator slots, and the radial stator slots are embedded with the left radial suspension winding 16 and the left radial torque winding 17, the right radial suspension winding 18 and the right radial torque winding 19, The left axial suspension winding 12 and the right axial suspension winding 15 are respectively located on the outer sides of the left axial torque winding 13 and the right axial torque winding 14 relative to the rotor; the left radial suspension winding 16 and the right radial suspension winding 18 are respectively located on the outer side of the left radial torque winding 17 and the right radial torque winding 19 relative to the rotor; the left axial suspension winding 12, the right axial suspension winding 15, the left radial suspension winding 16, the right radial suspension winding The number of pole pairs of the suspension winding 18 and the left axial torque winding 13, the right axial torque winding 14, the left radial torque winding 17, and the right radial torque winding 19 are not equal; The bars or rotor windings 6, the right axial rotor bars or rotor windings 7, the left radial rotor bars or rotor windings 8, and the right radial rotor bars or rotor windings 9 all adopt a phase-separated structure, and are respectively connected with the The number of pole pairs of the left axial torque winding 13 , the right axial torque winding 14 , the left radial torque winding 17 , and the right radial torque winding 19 are the same; the left and right ends of the rotating shaft 5 respectively extend to the left Outside the stator iron core 10 and the right stator iron core 11 .

The permanent magnet ring 4 is made of rare earth permanent magnets or ferrite permanent magnets. The left axial suspension winding 12, the right axial suspension winding 15, the left radial suspension winding 16 and the right radial suspension winding 18 are concentrated windings. It is made of electromagnetic coils with good electrical conductivity and then varnished and dried; the axial rotor core 1, the radial rotor core 2, the mandrel 3, the left stator core 10 and the right stator core 11 are all made of materials with good magnetic conductivity .

The left axial torque winding 13, the right axial torque winding 14, the left radial torque winding 17, and the right radial torque winding 19 are energized to drive the motor to rotate. Assuming that the motor speed is n , the left radial torque winding 17, The current frequency and the number of pole pairs of the right radial torque winding 19 are respectively f _j and P _j , and the current frequency and number of pole pairs of the left axial torque winding 13 and the right axial torque winding 14 are respectively f _z and P _z , then it must satisfy: f _j × P _z = P _j × f _z .

The permanent magnet ring 4 magnetized in the radial direction is arranged between the axial rotor core 1 and the radial rotor core 2 to provide the motor with a left static bias magnetic flux 20 and a right static bias magnetic flux 21; the left axial suspension winding 12 , the right axial suspension winding 15 is energized to generate the axial suspension control magnetic flux 22, the left radial suspension winding 16 and the right radial suspension winding 18 are energized to generate the left radial suspension control magnetic flux 23 and the right radial suspension control magnetic flux 24, The axial suspension control magnetic flux 22 , the left radial suspension control magnetic flux 23 , and the right radial suspension control magnetic flux 24 respectively adjust the left static bias magnetic flux 20 and the right static bias magnetic flux 21 to generate a suspension force that stably suspends the rotor , the torque is the resultant torque generated by the energization of the left axial torque winding 13 , the right axial torque winding 14 , the left radial torque winding 17 , and the right radial torque winding 19 .

The arrangement of the left axial torque winding 13 and the right axial torque winding 14 is similar to that of an ordinary asynchronous motor; the left axial suspension winding 12 and the right axial suspension winding 15 are concentrated windings, which are connected in series or in parallel in the same direction.

The outer layer of the radial stator slot is the radial torque winding, and the arrangement is the same as that of the ordinary asynchronous motor; the radial suspension winding is the concentrated winding, which is divided into the x-direction suspension control winding and the y-direction suspension control winding, and the +x direction and the -x direction are three. The windings on each tooth are connected in series to form the suspension control winding in the x direction; the windings on the three teeth in the +y direction and the -y direction are connected in series to form the suspension control winding in the y direction; as shown in Figure 3, the shaft at the left end of the axial rotor core 1 The left axial rotor bar or rotor winding 6 is poured into the rotor slot, the outer layer of the left axial rotor bar or rotor winding 6 is insulated, and the phases are separated by the termination part, and the left axial rotor bar or The phases of the rotor winding 6 are: 6a, 6d, 6g, 6j are short-circuited to form one phase; 6c, 6f, 6i, 6l are short-circuited to form a phase; 6b, 6e, 6h, and 6k are short-circuited to form a phase; into a closed loop. The right axial rotor bar or rotor winding 7 is identical to the left axial rotor bar or rotor winding 6 .

The phase separation of the left radial rotor bar or rotor winding 8 and the right radial rotor bar or rotor winding 9 is: the 1st, 4th, 7th, and 10th bars are connected as one phase, and the 2nd, 5th, 6th, The 11th bar is connected as one phase, and the 3rd, 6th, 9th and 12th bars are connected as one phase.

In this way, when the motor is running, the rotor bar or the rotor winding only cuts the torque winding magnetic field to generate the rotor rotating magnetic field, and the bias magnetic field generated by the cutting suspension winding magnetic field and the permanent magnet does not generate the rotor induced magnetic field.

Claims (6)

1. A bearingless asynchronous motor with five degrees of freedom, comprising a rotor and a stator, characterized in that: the rotor comprises a mandrel (3), and a radial rotor core (2) coaxially connected to the mandrel (3) respectively , radial boss, rotating shaft (5), the radial rotor core (2) is located in the middle of the mandrel (3), and its outer circumference is connected with an axial rotor core (4) through a radially magnetized permanent magnet ring (4). 1), both ends of the axial rotor core (1) are evenly provided with an even number of axial rotor bars or rotor windings, the radial bosses are located at both ends of the core shaft (3), the radial An even number of radial rotor bars or rotor windings are evenly arranged on the boss; the stator includes two stator iron cores symmetrically arranged on both sides of the rotor, and each stator iron core is provided with two stator iron cores facing the axial rotor iron core (1). The axial end, and the radial end facing the radial boss, the axial end is provided with an axial suspension winding and an axial torque winding, and the radial end is provided with a radial suspension winding and a radial torque winding , the rotating shaft (5) extends to the outside of the stator core. 2. a kind of five degrees of freedom bearingless asynchronous motor as claimed in claim 1 is characterized in that: motor speed is n , the current frequency and pole pair number of radial torque winding are respectively fj , _{Pj ,} axial direction The current frequency and number of pole pairs of the torque winding are respectively f _z and P _z , satisfying: f _j × P _z = P _j × f _z . 3. A bearingless asynchronous motor with five degrees of freedom as claimed in claim 1, characterized in that: the axial suspension winding is located on the outer side of the axial torque winding relative to the rotor; the radial suspension winding is located at the radial torque winding The outer side of the windings relative to the rotor. 4. A bearingless asynchronous motor with five degrees of freedom as claimed in claim 1, characterized in that: the number of pole pairs of the axial suspension winding, the radial suspension winding and the axial torque winding and the radial torque winding not wait. 5. A five-degree-of-freedom bearingless asynchronous motor as claimed in claim 1, characterized in that: the axial rotor bars or the rotor windings, the radial rotor bars or the rotor windings all adopt a phase-separated structure, and the poles The number of pairs is the same as the number of pole pairs of the axial torque winding and the radial torque winding, respectively. 6 . The five-degree-of-freedom bearingless asynchronous motor according to claim 1 , wherein the permanent magnet ring ( 4 ) is made of rare earth permanent magnets or ferrite permanent magnets. 7 .

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