CN111463997A

CN111463997A - Linear motor

Info

Publication number: CN111463997A
Application number: CN202010466749.0A
Authority: CN
Inventors: 冯镜超; 温东山
Original assignee: Huizhou Sanxie Magnetic Technology Co ltd
Current assignee: Huizhou Sanxie Magnetic Technology Co ltd
Priority date: 2020-05-28
Filing date: 2020-05-28
Publication date: 2020-07-28

Abstract

The linear motor is provided with the stator kit, the rotor kit and the coil assembly. In the practical application process, because each coil tooth at the tail end position extends outwards to form a tooth reducing part, and the shortest distance between the outer edges of two adjacent tooth reducing parts is 1 mm-2 mm, the rotor suite can form a whole, the tooth pitch distance of two adjacent coil teeth is reduced, namely, the tooth space force of the rotor moving along the central axis of the stator is correspondingly reduced, the rotor does not generate 'pause feeling' when moving, namely, the tooth space effect is effectively inhibited. This application compares in current the mode of permanent magnet slope, and the linear electric motor of this application can correspond under the condition that does not reduce linear electric motor overall performance and go to weaken tooth's socket force, lets linear electric motor can remove by drive unit better.

Description

Linear motor

Technical Field

The invention relates to the technical field of motors, in particular to a linear motor.

Background

At present, a linear motor is also called a linear motor, and the linear motor is a transmission device which directly converts electric energy into linear motion mechanical energy without any intermediate conversion mechanism. The rotary motor can be seen as being formed by cutting a rotary motor in the radial direction and expanding the rotary motor into a plane. The most common types of linear motors are flat and U-slot and tubular. The coil is typically composed of three phases, and brushless commutation is achieved by hall elements. The control of the linear motor is the same as that of the rotary motor. Like brushless rotating machines, movers and stators are mechanically decoupled, unlike aspects of rotating machines where mover rotation and stator position remain fixed, linear motor systems can be magnetic track actuation or thrust coil actuation. The weight and load ratio of the thrust coil is small by using the motor moving by the thrust coil. However, a highly flexible cable and its management system are required. The motors that move with the tracks are not only loaded, but also are subject to track mass, but do not require a cable management system.

The main drawback of the conventional linear motor is that the linear motor generates a certain cogging force when moving, and the cogging force affects the movement of the linear motor, so that the linear motor generates a certain "jerking" when working. As shown in fig. 1, which is a schematic structural diagram of a mover 20 of a conventional linear motor, in order to allow a coil to be wound around the mover 20, a plurality of slots 21 are formed in the mover 20, and a space is provided between two adjacent slots 21, so that a plurality of winding teeth 22 are formed on the mover 20, where the winding teeth 22 are positions where the coil is wound. When the linear motor is operated, the coil is energized, and the mover 20 is linearly moved in the central axis direction of the stator by the stator. The cogging force is generated because there are a plurality of winding teeth 22 on the mover 20, a plurality of permanent magnets are disposed on the stator, and the magnetic properties between two adjacent permanent magnets are opposite, that is, N-pole permanent magnets and S-pole permanent magnets are alternately disposed, but both the N-pole permanent magnets and S-pole permanent magnets have magnetic attraction to the winding teeth 22, when the mover 20 moves linearly, for example, one of the winding teeth 22 on the mover 20 needs to move from the S-pole permanent magnet to the N-pole permanent magnet, the winding teeth 22 need to overcome the magnetic attraction of the S-pole permanent magnet to the winding teeth 22 to do work, and because a plurality of winding teeth 22 are disposed on the mover 20, that is, each winding tooth 22 corresponds to one cogging force, the cogging force finally applied to the mover 20 is relatively large, so that "cogging" is generated when the mover 20 moves, which affects the normal operation of the linear motor.

In view of the above problems, although the conventional linear motor mostly adopts the permanent magnet to be inclined in order to reduce the cogging force, the above method may reduce the cogging force of the linear motor, but may cause a drawback that the above method may sacrifice the thrust of 40 percent of the linear motor, that is, the above method may reduce the overall performance of the linear motor, resulting in insufficient performance of the linear motor, and therefore, there is an urgent need to develop a low-cogging-force linear motor capable of effectively suppressing the cogging effect.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a linear motor which can effectively inhibit the cogging effect, reduce the cogging force and has better overall performance.

The purpose of the invention is realized by the following technical scheme:

a linear motor, comprising:

the stator assembly comprises a stator and a plurality of permanent magnets, and the permanent magnets are uniformly arranged on the stator at the same interval;

the rotor assembly comprises a rotor and a plurality of coil teeth, the coil teeth are uniformly arranged on the rotor at the same intervals, all the coil teeth at the tail end position extend outwards to form tooth lowering portions, and the shortest distance between the outer edges of every two adjacent tooth lowering portions is 1-2 mm; and

the coil assembly comprises a plurality of winding coils, and the winding coils are wound on the coil teeth in a one-to-one correspondence mode.

In one embodiment, the rotor is provided with a head end portion, the head end portion is provided with a head end surface, and the distance from the head end surface to one side surface of the permanent magnet far away from the stator is 10-15 mm.

In one embodiment, a tail end is arranged at a position of the rotor far away from the head end, a tail end surface is arranged on the tail end, and the distance from the tail end surface to one side surface of the permanent magnet far away from the stator is 10 mm-15 mm.

In one embodiment, the mover and each of the coil teeth are of an integrally formed structure.

In one embodiment, the linear motor further includes a translation stage disposed on a side of the mover away from each of the coil teeth.

In one embodiment, the linear motor further comprises a locking kit, the locking kit comprises a locking ring gasket and a locking screw, a threaded hole is formed in the rotor, a via hole is formed in the translation table, the locking screw penetrates through the locking ring gasket and the via hole in sequence, and the end of the locking screw is screwed in the threaded hole.

In one embodiment, an input terminal is provided on each winding coil.

In one embodiment, each of the teeth-reduced portions has a trapezoidal cross section.

The invention has at least the following advantages and beneficial effects:

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to these drawings without inventive efforts.

Fig. 1 is a schematic structural view of a mover in the related art;

fig. 2 is a schematic structural diagram of a linear motor according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a linear motor from another perspective in an embodiment of the present invention;

FIG. 4 is an enlarged schematic view of FIG. 3 at A;

fig. 5 is a schematic structural diagram of a mover kit according to an embodiment of the present invention.

Detailed Description

To facilitate an understanding of the invention, the following description refers to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that the linear motor is used as a driving device, and the linear motor is a device that directly converts electric energy into linear motion mechanical energy. Linear motors work on the same principle as conventional rotating motors, except that linear motors are another way of deploying a rotating motor. Linear electric motors have many advantages over conventional rotating electric machines:

1. the linear motor is not in mechanical contact, the transmission force is generated in an air gap, and no friction is generated except for a linear motor guide rail, so that the linear motor is not damaged too much;

2. the linear motor has simple structure and small volume, and can realize linear motion by the least parts;

3. the stroke of operation is not limited in theory and its performance is not affected by the change in size that it is formed.

However, for a linear motor, the biggest defect is the cogging effect, the generation of the cogging effect is caused by that when a rotor moves along the central axial direction of a stator, because a plurality of winding teeth are arranged on the rotor, the winding teeth are the positions of coil winding, and a plurality of permanent magnets are arranged on the stator, the polarities of two adjacent permanent magnets are opposite, namely one permanent magnet is an N-pole permanent magnet, the other permanent magnet is an S-pole permanent magnet, and the N-pole permanent magnet and the S-pole permanent magnet are arranged at intervals in a staggered manner. Because the rotor is provided with a plurality of winding teeth, the rotor is in a comb shape as a whole, each winding tooth can generate a corresponding tooth space force, when the tooth space forces are accumulated and superposed, the tooth space force applied to the rotor becomes very large, namely, the longer the length of the rotor is made, the larger the tooth space force applied to the rotor is, the more the rotor is moved, the pause feeling can be generated, so that the normal motion of the linear motor is seriously influenced by the tooth space effect, and the linear motor can not run and work if the tooth space force is not reduced properly.

For the problem of the cogging, the most common method of the existing linear motor is to properly incline the permanent magnet on the stator, so as to reduce the acting force of the permanent magnet on the winding teeth, and further weaken the cogging. However, this solution causes a problem of sacrificing 40% of the thrust of the linear motor, i.e. reducing the overall performance of the linear motor, and therefore is disadvantageous.

In view of the above problem, please refer to fig. 2, the present application discloses a linear motor, in which the linear motor 10 includes a stator assembly 100, a mover assembly 200, and a coil assembly 300.

As such, it should be noted that the stator assembly 100 is used for generating a rotating magnetic field to drive the mover assembly 200 to move; the mover assembly 200 is configured to move linearly relative to the stator assembly 100 under the action of the stator assembly 100; the coil assembly 300 plays a conductive role, and is used for matching the stator assembly 100 and the mover assembly 200, so that the mover assembly 200 performs a magnetic induction line cutting motion under a magnetic field generated by the stator assembly 100.

Referring to fig. 2, the stator assembly 100 includes a stator 110 and a plurality of permanent magnets 120, and the permanent magnets 120 are uniformly disposed on the stator 110 at the same interval.

Thus, it should be noted that, a plurality of permanent magnets 120 are uniformly distributed on the stator 110, and the polarities between two adjacent permanent magnets 120 are opposite, that is, one is an N pole, and the other is an S pole. The number of the permanent magnets 120 is flexibly set according to actual conditions, and is not particularly limited.

Referring to fig. 2, 3, 4 and 5, the mover assembly 200 includes a mover 210 and a plurality of coil teeth 220, the coil teeth 220 are uniformly disposed on the mover 210 at the same interval, each coil tooth 220 at the tail end position extends outward to form a tooth-dropping portion 221, and the shortest distance between the outer edges of two adjacent tooth-dropping portions 221 is 1mm to 2 mm.

Referring to fig. 2, the coil assembly 300 includes a plurality of winding coils 310, and each winding coil 310 is wound on each coil tooth 220 in a one-to-one correspondence manner.

As described above, a plurality of coil teeth 220 are uniformly distributed on the mover 210, and the coil teeth 220 are positions of the winding. Because each coil tooth 220 at the tail end position extends outwards to form the falling tooth part 221, and the shortest distance between the outer edges of two adjacent falling tooth parts 221 is 1 mm-2 mm, the mover kit 200 can form a whole, the pitch distance of two adjacent coil teeth 220 is reduced, that is, the cogging force of the mover 210 moving along the central axis of the stator 110 is correspondingly reduced, and the mover 210 does not generate 'cogging feeling' when moving, that is, the cogging effect is effectively inhibited. Compare in current the mode of permanent magnet slope, the linear electric motor of this application can correspond under the condition that does not reduce linear electric motor overall performance and go to weaken tooth's socket force, lets linear electric motor can drive the part better and remove.

It should be further noted that, referring to fig. 4 again, the shortest distances between the outer edges of two adjacent tooth-lowering portions 221 are both 1mm to 2mm, that is, a gap is provided between two adjacent tooth-lowering portions 221, and the width of the gap is in the range of 1mm to 2mm, that is, the width of D1 shown in fig. 4. The design aims at that if a part of the coil teeth 220 which are not at the tail end position extends outwards to form the tooth-falling part 221, the tooth pitch between two adjacent coil teeth 220 is too large, the mover kit 200 cannot form a whole, and the mover 210 is integrally in a comb shape as the mover in the prior art, so that the permanent magnet 120 on the stator 110 generates a tooth space force for each coil tooth 220, and the tooth space force applied to the mover 210 by the last tooth space force accumulation and superposition can cause the tooth space force applied to the mover 210 to be very large, and the mover 210 is not beneficial to making a linear motion on the stator 110; in contrast to this application, since the tail end of each coil tooth 220 is provided with the tooth-lowering portion 221, and the shortest distance between the outer edges of two adjacent tooth-lowering portions 221 is 1mm to 2mm, the mover kit 200 is integrated (although the inside is hollow, the hollow portion is the position where the coil 310 is accommodated), so that each coil tooth 220 on the mover 210 is not subjected to the cogging effect, but the integrated mover kit 200 is subjected to the cogging force, which greatly reduces the cogging effect, and allows the mover 210 to perform linear movement on the stator 110 well.

It should be further noted that, since the tooth-lowering portion 221 is only processed at the tail end position of the coil tooth 220, that is, the tail end position of the coil tooth 220 is far away from the mover 210, the processing difficulty of the coil tooth 220 can be greatly reduced, the entire coil tooth 220 does not need to be processed, and the final mover kit 200 can be formed into a whole while the processing difficulty is reduced.

It should be noted that, because the tooth-dropping portion 221 extends outward, that is, the width of the tooth-dropping portion 221 is greater than the width of the coil tooth 220, when an assembler winds the winding coil 310 on the coil tooth 220, the existence of the tooth-dropping portion 221 can also well prevent the coil 310 wound on the coil tooth 220 from falling off from the coil tooth 220, that is, the tooth-dropping portion 221 can play a role of pre-positioning, so that the assembler can assemble the winding coil 310 more easily, and the assembly efficiency is greatly improved.

Further, referring to fig. 3 again, in an embodiment, the mover 210 is provided with a head end portion 211, the head end portion 211 is provided with a head end surface 211a, and a distance from the head end surface 211a to a side surface of the permanent magnet 120 away from the stator 110 is 10mm to 15 mm.

As described above, the distance from the head end surface 211a to the side surface of the permanent magnet 120 away from the stator 110 is 10mm to 15mm, that is, the length range of D2 shown in fig. 3 is 10mm to 15mm, and this design aims to reduce the distance from the head end portion 211 to the permanent magnet 120, and also to reduce the problem of excessive cogging force of the permanent magnet 120 on the head end portion 211 due to the movement of the mover 210, so that the cogging effect is further reduced, the mover 210 can move more stably and quickly, and the problem of excessive cogging force is effectively prevented.

Further, referring to fig. 3 again, in an embodiment, a position of the mover 210 away from the leading end 211 is provided with a trailing end 212, the trailing end 212 is provided with a trailing end surface 212a, and a distance from the trailing end surface 212a to a side surface of the permanent magnet 120 away from the stator 110 is 10mm to 15 mm.

As described above, the distance from the end surface 212a to the side surface of the permanent magnet 120 away from the stator 110 is 10mm to 15mm, that is, the length of D3 shown in fig. 3 is 10mm to 15mm, which is the same as the purpose of the head portion 211, and the problem of excessive cogging force of the permanent magnet 120 on the end portion 212 due to the movement of the mover 210 is also reduced, so that the cogging effect is further reduced, the mover 210 can move more smoothly and quickly, and the problem of excessive cogging force is effectively prevented.

It should be further noted that, in the prior art, because the head end and the tail end of the mover of the linear motor are too close to the permanent magnet (the mover is generally in an axisymmetric structure), and the head end and the tail end of the mover are usually about 2mm to 3mm apart from the permanent magnet, when the mover moves, the permanent magnet on the stator generates a large cogging force to the head end and the tail end of the mover, which undoubtedly generates a strong "cogging sense" when the mover moves forward or backward, and in the present application, in addition to the tail end position of each coil tooth 220, the distance between the head end 211 of the mover 210 and the tail end 212 of the mover 210 from the permanent magnet 120 is increased, and through the combination of this design, the existence of the cogging 221 can form the mover kit 200 as a whole, so that the cogging effect is reduced by the whole force; the distance between the head end part 211 of the mover 210 and the tail end part 212 of the mover 210 and the permanent magnet 120 is increased, the magnetic attraction of the permanent magnet 120 to the head end part 211 of the mover 210 and the tail end part 212 of the mover 210 can be weakened, and therefore the cogging effect is reduced.

Further, in an embodiment, the mover 210 and each of the coil teeth 211 are integrally formed.

As such, it should be noted that, the mover 210 and each coil tooth 211 are designed as an integrally formed structure, which can enhance the overall mechanical strength of the mover assembly 200 and prolong the service life of the mover assembly 200; on the other hand, the integrated design can also make the overall consistency of the mover kit 200 better.

Further, in an embodiment, the linear motor 10 further includes a translation stage disposed on a side of the mover 210 away from each coil tooth 220.

So, it should be noted that the translation stage plays the effect of bearing, and external component can place on the translation stage, relies on active cell 210 to drive the translation stage and makes linear motion along the stator.

Further, in an embodiment, the linear motor 10 further includes a locking kit, the locking kit includes a locking ring gasket and a locking screw, the mover 210 is provided with a threaded hole, the translation stage is provided with a via hole, the locking screw sequentially penetrates through the locking ring gasket and the via hole, and an end of the locking screw is screwed in the threaded hole.

Therefore, it should be noted that the arrangement of the locking sleeve, the arrangement of the via hole, and the arrangement of the threaded hole can enable the translation stage to be stably mounted on the mover 210 in a screw locking manner; the locking screw plays a role in locking; the locking ring gasket can further enhance the locking force of the locking screw.

Further, referring to fig. 2 again, in one embodiment, each winding coil 310 is provided with an input terminal 311.

In this manner, the input terminal 311 is provided to electrically connect to an external ac power source, which supplies ac power to each of the winding coils 310.

Further, referring again to fig. 2, in one embodiment, each of the teeth-lowering portions 221 has a trapezoidal cross-section.

As such, it should be noted that the shape of each of the teeth-lowering portions 221 can be flexibly set according to actual situations, for example, each of the teeth-lowering portions 221 has a trapezoidal cross section; for another example, each of the teeth-lowering portions 221 has a triangular cross-section; as another example, each of the teeth-lowering portions 221 has a rectangular cross section.

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 invention. 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 linear motor, comprising:

2. The linear motor according to claim 1, wherein the mover is provided with a head portion, the head portion is provided with a head surface, and a distance from the head surface to a side surface of the permanent magnet away from the stator is 10mm to 15 mm.

3. The linear motor according to claim 2, wherein a trailing end is disposed at a position of the mover away from the leading end, a trailing end surface is disposed at the trailing end, and a distance from the trailing end surface to a side surface of the permanent magnet away from the stator is 10mm to 15 mm.

4. The linear motor of claim 1, wherein the mover and each of the coil teeth are of an integrally formed structure.

5. The linear motor according to claim 1, further comprising a translation stage disposed on a side of the mover away from each of the coil teeth.

6. The linear motor according to claim 5, further comprising a locking kit, wherein the locking kit comprises a locking ring gasket and a locking screw, a threaded hole is formed in the mover, a via hole is formed in the translation stage, the locking screw sequentially penetrates through the locking ring gasket and the via hole, and an end of the locking screw is screwed in the threaded hole.

7. A linear motor according to claim 1, wherein an input terminal is provided on each winding coil.

8. The linear motor of claim 1, wherein each of the reduced tooth portions has a trapezoidal cross section.