WO2022047893A1

WO2022047893A1 - Linear electric motor

Info

Publication number: WO2022047893A1
Application number: PCT/CN2020/120695
Authority: WO
Inventors: 史卫领; 郭顺; 王洪兴
Original assignee: 瑞声声学科技(深圳)有限公司; 瑞声科技（南京）有限公司
Priority date: 2020-09-03
Filing date: 2020-10-13
Publication date: 2022-03-10
Also published as: CN213661415U

Abstract

A linear electric motor, comprising a housing (1), a primary (3), and a secondary (7), which is spaced apart from the primary (3) to form an air gap (5), wherein the primary (3) comprises an iron core (31) and a winding (33); the iron core (31) comprises a yoke portion (311) and a plurality of tooth portions (313); the tooth portions (313) are provided with permanent magnets (35) in an embedded manner, and the magnetic poles of every two adjacent permanent magnets (35) are opposite; each permanent magnet (35) comprises a first permanent magnet (351), a second permanent magnet (353), a third permanent magnet (355) and a fourth permanent magnet (357), which are arranged in a W-shaped structure; the first permanent magnet (351) and the second permanent magnet (353) are arranged at a first included angle and are symmetrical with respect to a first angular bisector (a) of the first included angle, and the first angular bisector (a) extends from the vertex (o) of the first included angle to the secondary (7) and is perpendicular to a plane where the secondary (7) is located; and the magnetic poles of the sides of the first permanent magnet (351), the second permanent magnet (353), the third permanent magnet (355) and the fourth permanent magnet (357) that are close to the secondary (7) are the same. According to the linear electric motor, the volumes of the embedded permanent magnets (35) can be effectively increased, such that a magnetic field on the side of the air gap (5) is significantly increased, thereby increasing the thrust density of the linear electric motor.

Description

Linear Motor

technical field

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

Background technique

A linear motor is a power device that directly converts electrical energy into mechanical energy of linear motion without any intermediate conversion mechanism. Compared with the traditional rotary motor, the linear motor not only greatly reduces the weight and volume, but also can eliminate various positioning errors caused by the intermediate links, so that it has higher positioning accuracy; therefore, the linear motor has faster response speed and higher sensitivity. It is higher and has better follow-up performance. At the same time, the linear motor can achieve frictionless force transmission between the secondary and the primary during the working process. Therefore, the linear motor has the advantages of safe work, high reliability and long service life.

A linear motor in the related art includes a primary and a secondary that forms an air gap with the primary, the primary includes an iron core and a winding wound around one end of the iron core near the air gap, and a permanent magnet is embedded in the iron core . However, the volume of permanent magnets embedded in existing structures is limited, resulting in a relatively low thrust density of linear motors.

Therefore, it is necessary to provide a new linear motor to solve the above problems.

technical problem

The purpose of the present invention is to provide a linear motor, which can effectively increase the volume of the embedded permanent magnets so that the magnetic field on the air gap side is significantly increased, thereby increasing the thrust density of the linear motor.

technical solutions

The linear motor provided by the present invention includes a housing with a receiving space, a primary housed in the housing, and a secondary spaced apart from the primary to form an air gap, and the housing includes a primary seat for fixing the primary and a fixing The secondary seat of the secondary, the primary seat and the secondary seat can slide relative to each other along the sliding direction, and the primary includes an iron core and a winding wound around one end of the iron core close to the air gap, The iron core includes a yoke fixed to the primary seat and a plurality of teeth extending from the yoke in a direction close to the air gap, and the plurality of teeth are arranged at intervals along the sliding direction, so A permanent magnet is embedded in the tooth portion, and the magnetic poles of two adjacent permanent magnets are opposite, and the permanent magnet includes a first permanent magnet, a second permanent magnet, a third permanent magnet and a The fourth permanent magnet, the first permanent magnet and the second permanent magnet are arranged at a first angle and are symmetrical about the first bisector of the first angle, and the second permanent magnet and the first angle are symmetrical. Three permanent magnets are arranged at a second angle and are symmetrical about the second bisector of the second angle, and the third permanent magnet and the fourth permanent magnet are arranged at a third angle and are about the third The third angle bisector of the included angle is symmetrical, the first angle bisector, the second angle bisector and the third angle bisector are parallel to each other, and the first angle bisector starts from the first angle bisector. The vertex extends toward the secondary and is perpendicular to the plane where the secondary is located, wherein the first permanent magnet, the second permanent magnet, the third permanent magnet and the fourth permanent magnet are close to the The magnetic poles on the secondary side are the same, the angle of the first included angle is α, and 0°<α<180°.

Preferably, the second permanent magnet, the third permanent magnet and the fourth permanent magnet are arranged at intervals in sequence.

Preferably, along the sliding direction, the second bisector divides the tooth portion into two equal parts.

Preferably, the first permanent magnet, the second permanent magnet, the third permanent magnet and the fourth permanent magnet have the same magnetic field strength.

Preferably, at least two primary stages are provided, and at least two primary stages are arranged at intervals along the sliding direction.

Preferably, the secondary comprises a main body fixed to the secondary seat and a plurality of protruding teeth extending from the main body in a direction close to the air gap, the plurality of protruding teeth sliding along the The directions are set at intervals, and the sum of the length of the primary along the sliding direction and the distance between two adjacent primarys is d, d=(N+1/m) _* p, where N is a positive integer, and m is The number of the primary, p is the sum of the distance between two adjacent protruding teeth and the width of the protruding teeth along the sliding direction.

Preferably, the secondary is provided on opposite sides of the primary, respectively.

Preferably, the primary is provided on opposite sides of the secondary, respectively.

Preferably, the plurality of tooth portions are respectively a first tooth portion located at one end of the yoke portion, a second tooth portion located at an end of the yoke portion away from the first tooth portion, and a first tooth portion located at an end of the yoke portion and A plurality of third tooth parts are arranged between the second tooth parts, and the wire group is wound around the third tooth parts.

Preferably, a winding tooth is formed on a side of the third tooth portion close to the air gap, and the wire group is wound on the winding tooth.

Preferably, the linear motor further comprises a scale accommodated in the housing and a scale read head opposite to the scale and arranged at intervals, and one of the scale and the scale read head is fixed. It is installed on the primary seat, and the other is fixed on the secondary seat.

Preferably, the primary seat and the secondary seat are slidably connected through guide rails.

beneficial effect

Compared with the related art, the linear motor provided by the present invention includes a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet by arranging the permanent magnets embedded in the teeth, and the The first permanent magnet, the second permanent magnet, the third permanent magnet and the fourth permanent magnet are arranged in a "W" shape. In this way, the volume of the permanent magnet embedded in the tooth portion can be increased, so that the magnetic field on the side of the air gap can be significantly increased, thereby effectively increasing the thrust density of the linear motor.

Description of drawings

FIG. 1 is an exploded view of Embodiment 1 of the linear motor provided by the present invention.

FIG. 2 is a schematic structural diagram of the primary stage of the linear motor shown in FIG. 1 .

FIG. 3 is a schematic structural diagram of the secondary in the linear motor shown in FIG. 1 .

FIG. 4 is a perspective view of the linear motor shown in FIG. 1 after being assembled.

FIG. 5 is a cross-sectional view of the linear motor shown in FIG. 4 along the direction A-A.

FIG. 6 is an enlarged view of part D of the linear motor shown in FIG. 5 .

FIG. 7 is a perspective view of Embodiment 2 of the linear motor provided by the present invention.

FIG. 8 is a cross-sectional view of Embodiment 3 of the linear motor provided by the present invention.

FIG. 9 is an enlarged view of part E of the linear motor shown in FIG. 8 .

FIG. 10 is a schematic structural diagram of Embodiment 4 of the linear motor provided by the present invention.

FIG. 11 is a schematic structural diagram of Embodiment 5 of the linear motor provided by the present invention.

FIG. 12a is a schematic structural diagram of an embodiment of the secondary in the linear motor shown in FIG. 11 .

FIG. 12b is a schematic structural diagram of another embodiment of the secondary in the linear motor shown in FIG. 11 .

FIG. 13 is a schematic structural diagram of Embodiment 6 of the linear motor provided by the present invention.

FIG. 14a is a schematic structural diagram of an embodiment of the primary in the linear motor shown in FIG. 13 .

FIG. 14b is a schematic structural diagram of another embodiment of the primary in the linear motor shown in FIG. 13 .

Embodiments of the present invention

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. . Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

Please refer to FIG. 1 to FIG. 6 , the linear motor includes a housing 1 having a accommodating space 1A, a primary 3 accommodated in the housing 1 , and a secondary 7 spaced from the primary 3 to form an air gap 5 .

The housing 1 includes a primary seat 11 for fixing the primary 3 and a secondary seat 13 for fixing the secondary 7 . The primary seat 11 and the secondary seat 13 can slide relative to each other along the sliding direction X. Specifically, an interaction force along the sliding direction X may be generated between the primary 3 and the secondary 7. If the primary seat 11 is fixed, the secondary 7 will be under the action of the interaction force. Make a linear motion along the sliding direction X and drive the secondary seat 13 to make a linear motion; if the secondary seat 13 is fixed, the primary 3 moves along the sliding direction X under the action of the interaction force. Linear motion and drive the primary seat 11 to do linear motion.

In this embodiment, the secondary seat 13 is fixed.

In this embodiment, the primary seat 11 and the secondary seat 13 are slidably connected through the guide rail 15 , so that the primary seat 11 and the secondary seat 13 can slide relative to each other along the sliding direction X.

As shown in FIG. 1 , the primary seat 11 has a flat plate-like structure, and the secondary seat 13 includes a base plate 131 disposed opposite to the primary seat 11 and spaced apart from the base plate 13 and approaching the primary seat from two sides of the base plate 131 . The side plate 133 is bent and extended vertically in the direction 11 , the secondary 7 is fixed on the base plate 131 , and the guide rail 15 is fixed on the side plate 133 .

The primary 3 includes an iron core 31 fixed to the primary seat 11 and a winding 33 wound around one end of the iron core 31 close to the air gap 5 . Wherein, the iron core 31 and the secondary 7 are soft magnetic bodies, and the soft magnetic bodies are usually made of silicon steel sheets.

The iron core 31 includes a yoke 311 fixed to the primary seat 11 and a plurality of teeth 313 extending from the yoke 311 toward the air gap 5 . The sliding directions X are arranged at intervals, the teeth 313 are embedded with permanent magnets 35 , and the magnetic poles of two adjacent permanent magnets 35 are opposite to each other. Specifically, the permanent magnet 35 induces a magnetic field in the secondary 7, so that an air gap magnetic field is generated in the air gap 5 between the primary 3 and the secondary 7, when the winding 33 When a suitable current is supplied, the primary 3 generates a traveling wave magnetic field so that an interaction force along the sliding direction X is generated between the primary 3 and the secondary 7 .

The permanent magnet 35 includes a first permanent magnet 351 , a second permanent magnet 353 , a third permanent magnet 355 and a fourth permanent magnet 357 arranged in sequence along the sliding direction X. The two permanent magnets 353 are arranged at a first angle and are symmetrical about the first bisector a of the first angle. The second permanent magnet 353 and the third permanent magnet 355 are arranged at a second angle and are about the first angle bisector a. The second angle bisector b of the second angle is symmetrical, the third permanent magnet 355 and the fourth permanent magnet 357 are arranged at a third angle and are about the third angle bisector c of the third angle Symmetric, the first angle bisector a, the second angle bisector b and the third angle bisector c are parallel to each other (that is, the first angle, the second angle and the third angle are The angle of the angle is the same), and the first angle bisector a extends from the vertex o of the first angle to the secondary 7 and is perpendicular to the plane where the secondary 7 is located, wherein the first The magnetic poles of the permanent magnet 351 , the second permanent magnet 353 , the third permanent magnet 355 and the fourth permanent magnet 357 close to the secondary 7 are the same, and the angle of the first included angle is α, And 0°<α<180°. That is to say, the first permanent magnet 351 , the second permanent magnet 353 , the third permanent magnet 355 and the fourth permanent magnet 357 have a “W”-shaped structure. In this way, the volume of the permanent magnet embedded in the teeth 313 can be increased, so that the magnetic field on the side of the air gap 5 can be significantly increased, thereby effectively increasing the thrust density of the linear motor.

The first permanent magnet 351 , the second permanent magnet 353 , the third permanent magnet 355 and the fourth permanent magnet 357 may be made of ferrite material or NdFeB material.

In this embodiment, the first permanent magnet 351 , the second permanent magnet 353 , the third permanent magnet 355 and the fourth permanent magnet 357 have the same magnetic field strength.

In this embodiment, the first permanent magnet 351 , the second permanent magnet 353 , the third permanent magnet 355 and the fourth permanent magnet 357 are arranged at intervals in sequence. The spaced arrangement can reduce the magnetic flux leakage between the poles. It can be understood that, when the angle of the included angle α is constant, between the first permanent magnet 351 and the second permanent magnet 353 and between the second permanent magnet 353 and the third permanent magnet 355 And the closer the third permanent magnet 355 and the fourth permanent magnet 357 are, the more beneficial it is to increase the embedded first permanent magnet 351 , the second permanent magnet 353 and the third permanent magnet 355 and the volume of the fourth permanent magnet 357, so that the magnetic field on the side of the air gap 5 is further increased, so that the thrust density of the linear motor can be further increased.

The closer the second bisector b is to the center of the tooth portion 313 , the more favorable it is to increase the embedded first permanent magnet 351 , the second permanent magnet 353 , the third permanent magnet 355 , and the rest. The volume of the fourth permanent magnet 357 is adjusted to further increase the magnetic field on the side of the air gap 5, thereby further increasing the thrust density of the linear motor. In this embodiment, along the sliding direction X, the second bisector b divides the tooth portion 313 into two identical parts.

The plurality of tooth portions 313 are respectively a first tooth portion 313A at one end of the yoke portion 311 , a second tooth portion 313B at an end of the yoke portion 311 away from the first tooth portion 313A, and a second tooth portion 313B at an end of the yoke portion 311 away from the first tooth portion 313A. A plurality of third tooth portions 313C between the tooth portion 313A and the second tooth portion 313B, and the wire group 33 is wound around the third tooth portion 313C. That is to say, the wire set 33 is only provided on the third tooth portion 313C, and the first tooth portion 313A and the second tooth portion 313B located at both ends of the yoke portion 311 are not provided with any The winding 33 can compensate the magnetic circuits at both ends of the primary so that the flux linkage of the linear motor changes uniformly, so that the end positioning force can be effectively reduced, and the reduction of the end positioning force can effectively reduce the thrust fluctuation.

As shown in FIG. 6 , there are six teeth 313 in total, and there are four third teeth 313C.

The first tooth portion 313A, the second tooth portion 313B and the third tooth portion 313C are all formed with winding teeth 315 on one side of the first tooth portion 313A, the second tooth portion 313B and the third tooth portion 313C close to the air gap 5 , and the wire group 33 is wound around the air gap 5 . Winding teeth 315 .

As shown in FIG. 6 , the first tooth portion 313A, the second tooth portion 313B and the third tooth portion 313C are all provided with three of the winding teeth 315 (that is, each tooth portion 313 has three winding teeth 315 ). There are three winding teeth 315), and each of the winding teeth 315 of the third tooth portion 313C is respectively wound with one of the wire groups 33 in a one-to-one correspondence. That is to say, there are twelve wire groups 33 in total.

The secondary 7 includes a main body portion 71 fixed to the secondary seat 13 and a plurality of protruding teeth 73 extending from the main body portion 71 toward the air gap 5 . The plurality of protruding teeth 73 are formed. They are arranged at intervals along the sliding direction X.

In this embodiment, preferably, non-magnetic conductive material may be filled between two adjacent protruding teeth 73 and between adjacent teeth 313 and between adjacent two winding teeth 315, so that the The surfaces of the primary 3 and the secondary 7 facing each other are smooth and slotless structures, and the non-magnetic conductive material filled between two adjacent winding teeth 315 also plays a role of fixing the winding 33 .

In this embodiment, the linear motor further includes a scale 8 accommodated in the housing 1 and a scale read head 9 arranged opposite to the scale 8 and spaced apart from the scale 8 . One of the scale reading heads 9 is fixed on the primary seat 11 , and the other is fixed on the secondary seat 13 . Specifically, when the linear motor is assembled, the sensing end of the scale read head 9 faces the scale 8 correspondingly, and the primary seat 11 and the secondary seat 13 slide relatively along the sliding direction X. At this time, relative displacement will also occur between the scale 8 and the scale read head 9. At this time, the scale read head 9 can read the measured value on the scale 8, so as to obtain The displacement change of the primary seat 11 and the secondary seat 13 can be used to judge the working status of the linear motor according to the information result fed back by the scale reading head 9 . This is just one of the implementations. For example, a Hall sensor can also be used to detect the relative displacement value generated when the primary seat 11 and the secondary seat 13 slide relatively along the sliding direction X.

As shown in FIG. 4 , the scale 8 is fixed on the primary base 11 , and the scale reading head 9 is fixed on the base plate 131 of the secondary base 13 . Of course, the scale 8 can also be set to be fixed on the base plate 131 of the secondary base 13 , and correspondingly, the scale read head 9 is fixed to the primary base 11 .

Embodiment 2

Referring to FIG. 7 , the difference between the second embodiment and the first embodiment is only that: the primary seat 11 is fixed; the secondary seat 13 has a flat plate-like structure, and the primary seat 11 includes a space relative to the secondary seat 13 The base plate 111 is provided and the side plates 113 are vertically bent and extended from both sides of the base plate 111 toward the secondary seat 13 . The primary 3 is fixed on the base plate 111 of the primary seat 11 . , the guide rail 15 is fixed on the side plate 113 .

As shown in FIG. 7 , the scale 8 is fixed on the base plate 111 of the primary base 11 , and the scale reading head 9 is fixed on the secondary base 13 . Of course, the scale 8 can also be set to be fixed on the secondary base 13 , and correspondingly, the scale read head 9 is fixed on the base plate 111 of the primary base 11 .

Embodiment 3

Referring to FIGS. 8 and 9 , the difference between the third embodiment and the first embodiment is only that: there are at least two primary stages 3 , and at least two primary stages 3 are arranged at intervals along the sliding direction X.

The sum of the length of the primary 3 along the sliding direction X and the distance between two adjacent primary 3 is d, d=(N+1/m) _* p, where N is a positive integer, and m is the The number of the primary 3, p is the sum of the distance between the two adjacent protruding teeth 73 and the width of the protruding teeth 73 along the sliding direction X. By adjusting the value of d, the magnetic circuits at both ends of the primary can be compensated so that the flux linkage of the linear motor changes uniformly, so that the end positioning force can be effectively reduced, and the reduction of the end positioning force can effectively reduce the thrust fluctuation.

In this embodiment, preferably, non-magnetic conductive material can be filled between two adjacent primary 3, so that there is no slot structure between two adjacent primary 3, and the two adjacent primary 3 are filled with non-magnetic material. The non-magnetic conductive material between them also plays the role of fixing the primary 3 .

As shown in FIG. 8 , the number of the primary 3 is two.

Embodiment 4

Referring to FIG. 10 , the only difference between the fourth embodiment and the third embodiment is that the primary seat 11 is fixed; the secondary seat 13 has a flat plate-like structure, and the primary seat 11 includes a space relative to the secondary seat 13 The base plate 111 is provided and the side plates 113 are vertically bent and extended from both sides of the base plate 111 toward the secondary seat 13 . The primary 3 is fixed on the base plate 111 of the primary seat 11 . , the guide rail 15 is fixed on the side plate 113 .

As shown in FIG. 10 , the scale 8 is fixed on the base plate 111 of the primary base 11 , and the scale reading head 9 is fixed on the secondary base 13 . Of course, the scale 8 can also be set to be fixed on the secondary base 13 , and correspondingly, the scale read head 9 is fixed on the base plate 111 of the primary base 11 .

Embodiment 5

Referring to FIG. 11 , the difference between the fifth embodiment and the second embodiment is only that the primary 3 is respectively provided on opposite sides of the secondary 7 . In order to clearly illustrate this embodiment, the primary 3 respectively disposed on the opposite sides of the secondary 7 are specifically defined as a first primary 3a and a second primary 3b.

The secondary seat 13 includes a plate body 131 and a fixing portion 133 extending from the plate body 131 into the receiving space 1A. The fixing portion 133 is fixedly connected to the secondary 7 .

The primary seat 11 includes a base plate 111 opposite to the plate body 131 and spaced apart, side plates 113 extending vertically from two sides of the base plate 111 toward the plate body 131 , and a side plate 113 extending from the side plate 111 . The connecting plate 114 formed by the plate 113 extending into the receiving space 1A, the connecting plate 114 is located between the plate body 131 and the secondary 7, the first primary 3a is fixed to the connecting plate 114, The second primary 3 b is fixed on the base plate 111 , and the guide rail 15 is fixed on the side plate 113 and connected with the plate body 131 .

As shown in FIG. 12 a , the secondary 7 includes a main body 71 and a plurality of protruding teeth 73 extending from the main body 71 toward the air gap 5 , wherein the main body 71 is integrally formed Structure, the plurality of protruding teeth 73 are divided into first protruding teeth 73a extending from the main body 71 toward the first primary 3a and second protruding teeth 73 extending from the main body 71 toward the second primary 3b Teeth 73b.

As shown in FIG. 12b, the main body portion 71 includes a first main body portion 711 and a second main body portion 713, the first protruding teeth 73a extend from the first main body portion 711 toward the first primary 3a, the The second protruding teeth 73b extend from the second body portion 713 toward the second primary portion 3b.

As shown in FIG. 11 , the scale 8 is fixed on the base plate 111 of the primary base 11 , and the scale reading head 9 is fixed on the fixing portion 133 of the secondary base 13 . Of course, the scale 8 can also be fixed on the fixing portion 133 of the secondary base 13 , and correspondingly, the scale reading head 9 is fixed on the base plate of the primary base 11 . 111 on.

In this embodiment, only one of the first primary 3a and the second primary 3b may be provided, or at least two may be provided. When there are at least two of the first primary 3a and the second primary 3b, at least two of the first primary 3a and at least two of the second primary 3b are arranged at intervals along the sliding direction X, And the sum of the length of the primary 3 along the sliding direction X and the distance between two adjacent primary 3 is d, d=(N+1/m) _* p.

Embodiment 6

Referring to FIG. 13 , the only difference between the sixth embodiment and the second embodiment is that the secondary 7 are respectively provided on opposite sides of the primary 3 . In order to clearly illustrate this embodiment, the secondary 7 respectively disposed on the opposite sides of the primary 3 are specifically defined as a first secondary 7a and a second secondary 7b.

The primary seat 11 includes a plate body 111 and a fixing portion 113 extending from the plate body 111 into the accommodating space 1A. The fixing portion 113 is fixedly connected to the primary 3 .

The secondary seat 13 includes a base plate 131 opposite to the plate body 111 and arranged at intervals, side plates 133 extending vertically from two sides of the base plate 131 toward the plate body 111 , and extending from the base plate 131 . A connecting plate 134 formed by the side plate 133 extending into the receiving space 1A, the connecting plate 134 is located between the plate body 111 and the primary 3 , and the first secondary 7 a is fixed to the connecting plate 134 , the second secondary 7b is fixed on the base plate 131 , the guide rail 15 is fixed on the side plate 133 and connected with the plate body 111 .

As shown in FIG. 14 a , the primary 3 includes an iron core 31 and a winding 33 wound around one end of the iron core 31 close to the air gap 5 .

The iron core 31 includes a yoke portion 311 and a plurality of tooth portions 313 extending from the yoke portion 311 toward the air gap 5 . The first teeth 313a extending from the first secondary 7a and the second teeth 313b extending from the yoke 311 toward the second secondary 7b.

As shown in FIG. 14b, the yoke portion 311 includes a first yoke portion 314 and a second yoke portion 315, and the first tooth portion 313a extends from the first yoke portion 314 toward the first secondary 7a, so The second tooth portion 313b extends from the second yoke portion 315 toward the second secondary 7b.

As shown in FIG. 13 , the scale 8 is fixed on the base plate 131 of the secondary base 13 , and the scale reading head 9 is fixed on the fixing portion 113 of the primary base 11 . Of course, the scale 8 can also be fixed on the fixing portion 113 of the primary base 11 , and correspondingly, the scale reading head 9 is fixed on the base plate of the secondary base 13 . 131 on.

In this embodiment, only one primary 3 may be provided, or at least two may be provided. When there are at least two primary stages 3 , at least two primary stages 3 are arranged at intervals along the sliding direction X, and the length of the primary primary 3 along the sliding direction X is the same as that of two adjacent primary stages 3 . The sum of the distances is d, d=(N+1/m) _* p.

Compared with the related art, the linear motor provided by the present invention includes the first permanent magnet 351 , the second permanent magnet 353 , the third permanent magnet 355 and the fourth permanent magnet 351 by arranging the permanent magnet 35 embedded in the tooth portion 313 . Permanent magnet 357, and the first permanent magnet 351, the second permanent magnet 353, the third permanent magnet 355 and the fourth permanent magnet 357 are arranged in a "W" shape. In this way, the volume of the permanent magnet embedded in the teeth portion 313 can be increased, so that the magnetic field on the side of the air gap 5 can be significantly increased, thereby effectively increasing the thrust density of the linear motor.

The above are only the embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, improvements can be made without departing from the inventive concept of the present invention, but these belong to the present invention. scope of protection.

Claims

A linear motor includes a housing with a housing space, a primary housed in the housing, and a secondary spaced from the primary to form an air gap, the housing includes a primary seat for fixing the primary and a primary seat for fixing the primary The secondary seat of the secondary, the primary seat and the secondary seat can slide relative to each other along the sliding direction, the primary includes an iron core and a winding wound around one end of the iron core close to the air gap, the The iron core includes a yoke fixed to the primary seat and a plurality of teeth extending from the yoke in a direction close to the air gap, the plurality of teeth are arranged at intervals along the sliding direction, the teeth Permanent magnets are embedded in the inner part, and the magnetic poles of two adjacent permanent magnets are opposite, and it is characterized in that: the permanent magnets include a first permanent magnet, a second permanent magnet, a third permanent magnet and a third permanent magnet arranged in sequence along the sliding direction. A magnet and a fourth permanent magnet, the first permanent magnet and the second permanent magnet are arranged at a first angle and are symmetrical about the first angle bisector of the first angle, and the second permanent magnet and the The third permanent magnet is arranged at a second included angle and is symmetrical about the second bisector of the second included angle, and the third permanent magnet and the fourth permanent magnet are arranged at a third included angle and are about the second angle bisector of the second included angle. The third angle bisector of the third included angle is symmetrical, the first angle bisector, the second angle bisector and the third angle bisector are parallel to each other, and the first angle bisector starts from the first angle bisector The vertex of the angle extends towards the secondary and is perpendicular to the plane on which the secondary is located, wherein the first permanent magnet, the second permanent magnet, the third permanent magnet and the fourth permanent magnet are close to The magnetic poles on the secondary side are the same, the angle of the first included angle is α, and 0°<α<180°.
The linear motor according to claim 1, wherein the first permanent magnet, the second permanent magnet, the third permanent magnet and the fourth permanent magnet are arranged at intervals in sequence.
The linear motor according to claim 1 or 2, characterized in that: along the sliding direction, the second bisector divides the tooth portion into two identical parts.
The linear motor according to claim 1, wherein the first permanent magnet, the second permanent magnet, the third permanent magnet and the fourth permanent magnet have the same magnetic field strength.
The linear motor according to claim 1, wherein at least two primary stages are provided, and at least two primary stages are arranged at intervals along the sliding direction.
The linear motor of claim 5, wherein the secondary comprises a main body fixed to the secondary seat and a plurality of protruding teeth extending from the main body toward the air gap , a plurality of the protruding teeth are arranged at intervals along the sliding direction, the sum of the length of the primary along the sliding direction and the distance between two adjacent primarys is d, d=(N+1/m) * p, where N is a positive integer, m is the number of the primary, and p is the sum of the distance between two adjacent convex teeth and the width of the convex teeth along the sliding direction.
The linear motor according to claim 1, 5 or 6, wherein the secondary is respectively provided on opposite sides of the primary.
The linear motor according to claim 1, 5 or 6, wherein the primary is respectively provided on opposite sides of the secondary.
The linear motor according to claim 1 or 6, wherein the plurality of tooth portions are respectively a first tooth portion located at one end of the yoke portion, and a plurality of tooth portions located at an end of the yoke portion away from the first tooth portion. A second tooth portion and a plurality of third tooth portions located between the first tooth portion and the second tooth portion, and the wire group is wound around the third tooth portion.
The linear motor according to claim 9, wherein a winding tooth is formed on a side of the third tooth portion close to the air gap, and the wire group is wound on the winding tooth.
The linear motor according to claim 1, wherein the linear motor further comprises a scale accommodated in the casing and a scale read head opposite to the scale and arranged at intervals, the scale and One of the scale read heads is fixed on the primary seat, and the other is fixed on the secondary seat.
The linear motor according to claim 1, wherein the primary seat and the secondary seat are slidably connected through a guide rail.