CN101789676B - Fault-tolerance permanent magnet linear motor - Google Patents

Abstract

The invention discloses a fault-tolerant permanent magnet linear motor applied in the field of high reliability and high efficiency linear drive, which comprises a stator, a mover and an armature winding. Armature teeth, the armature windings are wound on the armature teeth, a set of armature windings is set in the tooth slot of each armature tooth, and a spacer tooth is set between every two adjacent armature teeth; The magnet is mounted on the end of the armature teeth, and the height of the isolated teeth is greater than that of the armature teeth on which the permanent magnets are mounted; the mover is in a salient pole shape composed of a mover iron core and a plurality of mover teeth. The invention has the advantages of simple structure, high power density and high reliability, and is beneficial to reduce the cogging force of the motor. There are physical isolation, thermal isolation and magnetic circuit decoupling between the phases of the motor, and the permanent magnet is suitable for heat dissipation. Strong fault tolerance.

Description

A fault-tolerant permanent magnet linear motor

technical field

The invention relates to a permanent magnet linear motor in the field of electric engineering and motor technology, which is applied to the field of high reliability and high efficiency linear drive such as artificial heart and electromagnetic gun.

Background technique

Linear motor is an additional device that can realize direct transmission without converting rotary motion into linear motion. It can eliminate various positioning errors caused by intermediate links, improve the positioning accuracy of the entire system, simplify the structure of the system, and reduce the system. weight and volume.

At present, there are two types of linear motors commonly used: one is an electric excitation motor based on a linear induction motor, and its defects are: the power factor, power density and efficiency are not high; the other is a permanent magnet linear synchronous motor. The main permanent magnet motor, compared with the linear induction motor, has a high force index, small size, light weight, and has the function of generating brake. It has the dual advantages of both the permanent magnet motor and the linear motor, but its defect is: fault tolerance Poor performance, unable to meet the high requirements of high reliability and continuous operation, such as artificial heart, electromagnetic gun, etc.

The rotary stator permanent magnet motor with doubly salient pole structure has simple structure and high reliability. It has three structures: doubly salient pole permanent magnet motor, flux switching permanent magnet motor and flux inversion motor. The magnets are respectively placed on the stator yoke of the motor, between the teeth of the stator, and mounted on the surface of the salient poles of the stator. Among them, the doubly salient permanent magnet motor has a unipolar permanent magnet flux linkage because its permanent magnet is placed on the stator yoke of the motor, and the power density of the motor is lower than that of the flux switching permanent magnet motor and the flux reversal motor . Since the permanent magnet of the flux-switching permanent magnet motor is surrounded by the motor winding, when the motor has a winding short-circuit fault, the temperature rise caused by the short-circuit current will cause the permanent magnet to permanently demagnetize, which limits the fault-tolerant performance of this type of motor. The flux reversal motor with bipolar permanent magnet flux linkage has the advantages of high reliability while having high power density.

The primary permanent magnet linear motor with double salient pole structure is a new type of permanent magnet linear motor that has appeared in recent years. This type of motor combines many advantages of the rotary stator permanent magnet motor and the linear motor, and has a simple structure, low manufacturing cost, High efficiency; but on the other hand, the primary permanent magnet linear motor adopts the traditional structure of 2 sets of windings per slot, and short-circuit faults between phase windings may occur, and its magnetic flux path forms a loop through adjacent phases, resulting in a large mutual inductance between phases , when one of the phases fails, it will affect the normal operation of the other non-faulty phases of the motor.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, based on the structure of the current rotary stator permanent magnet motor and the primary permanent magnet linear motor, propose a high reliability, independent magnetic circuit between phases of the motor, Permanent magnet linear motors with fault tolerance.

The technical scheme adopted in the present invention is: including stator, mover and armature winding, the length of mover is less than the length of stator, a plurality of armature teeth are evenly distributed on the stator, and armature winding is wound on the armature teeth, each A set of armature windings is set in the tooth groove of the armature teeth, and a spacer tooth is set between every two adjacent armature teeth; the permanent magnet is attached to the end of the armature teeth, and the height of the spacer teeth is greater than that of the sticker. The height of the armature teeth equipped with permanent magnets; the mover is a salient pole shape composed of a mover iron core and a plurality of mover teeth.

The beneficial effects of the present invention are:

1. The present invention has a double salient pole multi-tooth structure with spacer teeth, simple structure, high power density, and high reliability; it is beneficial to reduce the cogging force of the motor, thereby reducing the thrust fluctuation of the motor.

2. The armature winding on the stator of the motor is a centralized winding, which is convenient for making embedded wires, the end of the winding is short, and the resistance and copper loss are small.

3. The winding adopts the form of only one set of windings per slot, and the stator teeth without windings are used as isolation teeth, which play the role of physical isolation, thermal isolation and magnetic circuit decoupling between motor phases.

4. The mover adopts a simple salient pole structure, no winding, no brush, no permanent magnet, easy to maintain.

5. The permanent magnet is mounted on the surface of the stator teeth, which has the advantages of high power density of the motor and the permanent magnet is suitable for heat dissipation. The bipolar permanent magnet flux linkage can be designed according to the actual needs. The back electromotive force of the motor is sine wave and trapezoidal wave.

6. The motor adopts segmented independent drive, which has the advantages of strong operation ability with faults and energy saving.

Description of drawings

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

Fig. 1 is a schematic diagram of the structure of the present invention.

In the figure: 1. stator; 2. mover; 3. permanent magnet; 4. armature winding; 5. isolation teeth; 6. armature teeth; 7. mover iron core; 8. mover teeth.

Detailed ways

As shown in Figure 1, the present invention consists of a stator 1, a mover 2 and a permanent magnet 3 fixed on the stator 1, an armature winding 4, an isolated tooth 5, an armature tooth 6 and an iron core 7 on the mover 2 . The length of the mover 2 is smaller than that of the stator 1 . A plurality of armature teeth 6 are evenly spaced on the stator 1, and the armature teeth 6 are laminated with sufficient punches. A spacer tooth 5 is set between every two adjacent armature teeth 6, and two pieces of opposite polarity The permanent magnet 3 is fixed on the end of the armature tooth 6 by surface mounting, so that the equivalent air gap length at the end of the armature tooth 6 increases. The height of the spacer teeth 5 is greater than the height of the armature teeth 6 on which the permanent magnets 3 are attached. The armature winding 4 is wound on the armature tooth 6, that is, the stator 1 without winding is the isolated tooth 5, the armature winding 4 adopts the method of concentrated winding, and only one set of armature is set in the tooth slot of each armature tooth 6 Winding 4, all the armature windings 4 on the stator 1 adopt the method of grouping and independent power supply, for example, the windings A1, B1, and C1 of the armature winding 4 are the first group, and the windings A2, B2, and C2 are the second group, and so on , forming multiple groups of power supply areas of the present invention.

The mover 2 is a salient pole shape made of magnetically permeable material. There is neither winding nor permanent magnet on the mover 2. It is composed of a mover iron core 7 and a plurality of mover teeth 8, and runs in a straight line. The mover iron core 7 is formed by laminating sufficient punched sheets, and the magnetically conductive part of the mover iron core 7 is formed by laminating punched sheets of commonly used D23 material. The number of mover teeth 8 on the mover 2 is at least such that the mover 2 spans the armature teeth 6 of two sets of power supply areas in the operating range, so as to ensure that when a certain set of power supply areas fails, the motor can run with a fault.

In the present invention, most of the magnetic flux paths of the armature winding 4 form a circuit through the isolation teeth 5, so as to realize the spatial physical interval of the armature winding 4, so that the windings of each phase of the motor are independent of each other, and the independence of the magnetic circuits between the phases is enhanced. Fundamentally avoid the occurrence of phase-to-phase short-circuit faults, realize thermal isolation, and also make the mutual inductance of the motor approximately zero. The height of the isolation teeth 5 is greater than that of the armature teeth 6 on which the permanent magnets 3 are mounted, which can ensure that the isolation teeth 5 serve as the return path of the armature flux path, improve the independence between phases, and improve the fault-tolerant performance of the motor.

Claims (1)

1. fault-tolerance permanent magnet linear motor; Comprise stator (1), mover (2) and armature winding (4), a plurality of uniformly at intervals armature tooths (6) on the stator (1), armature winding (4) are around on the armature tooth (6); One cover armature winding (4) is set in the teeth groove of each said armature tooth (6); Be provided with one between every adjacent two said armature tooths (6) and isolate tooth (5), mover (2) is the salient pole shape of being made up of mover iron core (7) and a plurality of mover tooth (8), it is characterized in that:

The length of mover (2) is less than the length of stator (1), and permanent magnet (3) is mounted on armature tooth (6) end, isolates the height of the height of tooth (5) greater than the armature tooth that is pasted with permanent magnet (3) (6); It is independently-powered that said armature winding (4) has many group power supply areas and every group, the number of teeth of the mover tooth (8) on the mover (2) make at least mover (2) when operation across two groups of said power supply areas.

Images