CN213959938U

CN213959938U - Linear motor

Info

Publication number: CN213959938U
Application number: CN202021882847.4U
Authority: CN
Inventors: 史卫领; 郭顺; 陈敏
Original assignee: Ruisheng Technology Nanjing Co Ltd
Current assignee: AAC Technologies Holdings Nanjing Co Ltd; Ruisheng Technology Nanjing Co Ltd
Priority date: 2020-09-01
Filing date: 2020-09-01
Publication date: 2021-08-13
Anticipated expiration: 2030-09-01
Also published as: WO2022047886A1

Abstract

The utility model provides a linear motor, which comprises a base; the sliding seat and the base slide relatively along the sliding direction; at least two primary assemblies arranged at intervals along a first direction perpendicular to the sliding direction and fixed on the base, wherein each primary assembly comprises a plurality of armature coils arranged at intervals along the sliding direction; the secondary assembly is fixed on the sliding seat, positioned between the at least two groups of primary assemblies and arranged at intervals along the first direction with the primary assemblies of the primary assemblies, and used for generating a secondary magnetic field; at least two brush assemblies fixed on the sliding seat, wherein the brush assemblies are electrically conducted with armature winding armature coils corresponding to the secondary assemblies so that the primary assemblies generate primary magnetic fields; the primary magnetic field interacts with the secondary magnetic field to move the sled relative to the base. The structure is simple, and the cost is reduced.

Description

Linear motor

Technical Field

The utility model discloses linear electric motor technical field especially relates to a linear electric motor of electrified brush piece.

Background

Linear motors are also known as linear motors, push rod motors. 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.

In the existing linear motor, a primary component of the linear motor is generally introduced with alternating current to generate a traveling wave magnetic field so as to generate thrust, and the primary component of the linear motor mostly adopts a three-phase winding, so that the structure is relatively complex and the cost is high; and a unilateral magnetic circuit structure is often adopted, so that the thrust of the rotor is lower and is easily influenced by normal suction.

SUMMERY OF THE UTILITY MODEL

The utility model mainly provides a new linear electric motor in order to solve the above-mentioned problem.

In order to solve the technical problem, the utility model discloses a technical scheme be: there is provided a linear motor including: a base; the sliding seat and the base slide relatively along the sliding direction; at least two primary assemblies arranged at intervals along a first direction perpendicular to the sliding direction and respectively fixed on the base, wherein each primary assembly comprises a plurality of armature coils arranged at intervals along the sliding direction; a secondary assembly fixed to the carriage and located between the at least two primary assemblies and spaced apart from the primary assemblies along the first direction, the secondary assembly being configured to generate a secondary magnetic field; at least two brush assemblies fixed on the sliding seat, wherein the brush assemblies are electrically conducted with armature coils corresponding to the secondary assemblies so that the primary assemblies generate primary magnetic fields; the primary magnetic field interacts with the secondary magnetic field to move the sled relative to the base.

Preferably, the base comprises a base plate, a first side plate and a second side plate which are bent and extended along two opposite sides of the base plate, and an extension plate which is connected with the second side plate and is opposite to the base plate at intervals; the two primary assemblies are respectively mounted on the extension plate and the base plate.

Preferably, the sliding base comprises a sliding plate in sliding fit with the first side plate and the second side plate, and a bearing plate connected with the sliding plate and used for bearing the secondary assembly and the brush assembly;

the secondary assembly and at least two of the brush assemblies are disposed on the carrier plate.

Preferably, each of the primary assemblies further comprises: an armature core; each armature coil comprises a coil body with a through hole, and a wire inlet end and a wire outlet end which extend out of the coil body; the armature core is inserted into the through hole.

Preferably, each of the primary assemblies further comprises: the first conductive pieces are respectively and electrically connected with the wire inlet end of each armature coil and are arranged at intervals along the sliding direction; the second conductive pieces are respectively electrically connected with the wire outlet end of each armature coil and are arranged at intervals along the sliding direction; the first conductive member and the second conductive member are arranged at intervals along the first direction.

Preferably, each of the brush assemblies includes a first brush piece contacting and electrically conducting with the first conductive member, a second brush piece contacting and electrically conducting with the second conductive member, and a fixing member connecting the first brush piece and the second brush piece, wherein the fixing member includes a fixing body fixedly connected with the carrier plate, and a first fixing arm and a second fixing arm bent and extended from two opposite sides of the fixing body; the first fixing arm is connected with the first electric brush piece, and the second fixing arm is connected with the second electric brush piece.

Preferably, the fixing parts of the two brush elements are connected with each other and arranged oppositely.

Preferably, the secondary assembly comprises two sets of field windings arranged opposite each other, each set of field windings facing towards the primary assembly.

Preferably, the secondary assembly comprises two groups of magnetic steels which are arranged back to back and two magnetic yokes which are respectively attached to one side, far away from the armature coil, of each magnetic steel.

Preferably, the linear motor further comprises a grating ruler and a reader, the grating ruler is arranged on one of the base and the sliding seat, the reader is arranged on one of the sliding seat and the base, and the sensing end of the reader faces the grating ruler.

The utility model also provides a linear electric motor, linear electric motor includes: a slide base; the base slides relative to the base along the sliding direction; at least two secondary assemblies are arranged at intervals along a first direction perpendicular to the sliding direction and fixed on the base, and each secondary assembly comprises at least one excitation winding or magnetic steel and is used for generating a secondary magnetic field; a primary assembly fixed to the slider and located between the at least two secondary assemblies, the primary assembly including a plurality of armature coils arranged at intervals along the sliding direction; the brush assembly is fixed on the base and used for being electrically conducted with the armature coil corresponding to the secondary assembly so as to enable the primary assembly to generate a primary magnetic field; the primary magnetic field interacts with the secondary magnetic field to move the sled relative to the base.

Preferably, the base comprises a base plate, a first side plate and a second side plate which are bent and extended along two opposite sides of the base plate, and an extension plate which is connected with the second side plate and is opposite to the base plate at intervals; the at least two secondary assemblies are respectively arranged on the base plate and the extension plate; the brush assembly is disposed on the base plate and/or the extension plate.

the primary assembly is arranged on the bearing plate.

Preferably, the brush assembly includes a first brush piece electrically connected to the first conductive member, a second brush piece electrically connected to the second conductive member, and a fixing member connecting the first brush piece and the second brush piece, the fixing member includes a fixing body fixedly connected to the carrier plate, and a first fixing arm and a second fixing arm bent and extended from opposite sides of the fixing body; the first fixing arm is connected with the first electric brush piece, and the second fixing arm is connected with the second electric brush piece.

Preferably, the primary assembly further comprises an armature core; each armature coil comprises a coil body with a through hole, and a wire inlet end and a wire outlet end which extend out of the coil body; the armature core is inserted into the through hole.

The utility model has the advantages that: be different from prior art's condition, the utility model discloses a bilateral structure has promoted thrust, has reduced the normal direction suction that slide or base received.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained without inventive work, wherein:

fig. 1 is a schematic perspective view of a linear motor according to a first embodiment of the present invention;

fig. 2 is a perspective view of a primary assembly, a secondary assembly and a brush assembly of the linear motor shown in fig. 1;

fig. 3 is a perspective view of a part of the assembly of the linear motor shown in fig. 2;

fig. 4 is a schematic cross-sectional structure of a primary assembly and a secondary assembly of the linear motor shown in fig. 1;

fig. 5 is a schematic perspective view of a linear motor according to a second embodiment of the present invention;

fig. 6 is a schematic perspective view of a linear motor according to a third embodiment of the present invention;

fig. 7 is a schematic cross-sectional structure of the primary and secondary assemblies of the linear motor shown in fig. 6;

fig. 8 is a schematic perspective view of a linear motor according to a fourth embodiment of the present invention;

fig. 9 is a schematic cross-sectional structure view of the primary assembly and the secondary assembly of the linear motor shown in fig. 8.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

It will also be understood that when an element is referred to as being "secured to" or "disposed on" 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.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

Referring to fig. 1 to 4 together, a linear motor according to a first embodiment of the present invention mainly includes a base 10, a sliding base 20, at least two primary assemblies 40, a secondary assembly 30, a brush assembly 70 and a guide rail assembly 50.

The base 10 may include a first side plate 11, a second side plate 12, a base plate 13, and an extension plate 14. The first side plate 11 is connected with a first side edge of the base plate 13 in a bending mode, the second side plate 12 is connected with a second side edge of the base plate 13 in a bending mode, the first side plate 11, the second side plate 12 and the base plate 13 can form a groove shape with an upward opening, the extension plate 14 is connected with the second side plate 12 and is opposite to the base plate 13 at intervals along a first direction Z perpendicular to the sliding direction X, and the base plate 13, the second side plate 12 and the extension plate 14 can form a groove shape with a leftward opening to form an assembly space of the primary assembly 30 and the secondary assembly 40.

The slide 20 may include a slide plate 21, a carrier plate 24. The sliding plate 21 is in sliding fit with the first side plate 11 and the second side plate 12 through the guide rail assembly 50, the bearing plate 24 is in an L shape and comprises a connecting portion and a bearing portion, the connecting portion is connected with the sliding plate 21, the bearing portion extends from the connecting portion in a bending mode, the connecting portion is arranged between the first side plate 11 and the second side plate 12, and the bearing portion is arranged between the extending plate 14 and the base plate 13.

Wherein, the slide carriage 20 and the base 10 can slide relatively along the sliding direction X by the rail assembly 50. The rail assembly 50 includes first and

second rails

51 and 52 respectively mounted to the first and

second side plates

11 and 12 and the slide plate 21, the first and

second rails

51 and 52 being slidably connected to slidably connect the base 10 and the carriage 20 together; and the base 10, the sliding base 20 and the guide rail assembly 50 together enclose a receiving space. The primary assembly 30, the secondary assembly 40 and the brush assembly 70 are accommodated in the accommodating space.

The secondary assembly 30 includes a field core 31 and a field winding 32 provided on the field core 31. The field core 31 includes a first substrate 311 having a substantially plate shape, first baffle plates 312 bent and extended from two ends of the first substrate 311, and a first tooth portion 313 disposed between the two first baffle plates 312, wherein one side of the first substrate 311 away from the first baffle plates 312 is connected to the bearing portion of the bearing plate 24. The field winding 32 includes a field winding body 321 and a first through hole 322 defined by the field winding body 321, and the field winding 32 is sleeved on the first tooth portion 313 through the first through hole 322, or directly wound on the first tooth portion 313 through the field winding body 321. The number of the first tooth portions 313 and the number of the excitation windings 32 are the same, and the number of the excitation windings 32 is at least one, so that the number of the excitation windings 32 can be increased according to the driving force required by the secondary assembly 30.

In this embodiment, the two sub-assemblies 30 are arranged with the field cores 31 of the two sub-assemblies 30 facing away from each other, and are fixedly connected to each other through the first base plate 311, and further fixed to the carrier plate 24 of the slider 20. It is understood that in other embodiments, the field core may not be provided, or the field core may not be provided with the teeth portion.

At least two primary assemblies 40 are spaced apart along the first direction Z. One of the two primary assemblies 40 is fixed to the base plate 13 and the other is fixed to the extension plate 14. Each primary assembly 40 includes an armature core 41, a plurality of armature coils 42 arranged in parallel at intervals in the sliding direction, a plurality of first conductive blocks 43 and a plurality of second conductive blocks 44 electrically connected to the plurality of armature coils 42, respectively, a plurality of first insulating members 45 connecting the adjacent first conductive blocks 43, a plurality of second insulating members 46 connecting the adjacent second conductive blocks 44, a first connecting member 47 connecting the first conductive blocks 43 and the first insulating members 45, a second connecting member 48 connecting the second conductive blocks 44 and the second insulating members 46, and a third insulating member 49 connecting the adjacent two armature coils 42. The armature core 41 is formed in a substantially square thin plate shape.

The armature coil 42 includes an armature coil body 421 having a rectangular ring shape, a second through hole 422 surrounded by the armature coil body 421, and a wire inlet end 423 and a wire outlet end 424 extending from two sides of the armature coil body 421, wherein the wire inlet end 423 and the wire outlet end 424 are arranged at an interval along the first direction Z. The length of the wire inlet end 423 in the second direction Y perpendicular to the sliding direction X is shorter than the length of the wire outlet end 424 in the second direction Y perpendicular to the sliding direction X. The armature coil body 421 includes two opposing side surfaces 4211 and two end surfaces 4212 connected to the two side surfaces 4211, the second through hole 422 penetrates the two end surfaces 4212, and the first conductive portion 423 and the second conductive portion 424 are on the same side as the two side surfaces 4211, respectively. The armature core 41 is inserted into the second through holes 422 of the plurality of pairs of armature coils 42, i.e., directly wound around the armature core 41 through the armature coil body 421. One of the side surfaces 4211 of the armature coil body 421 and the outlet end 424 are fixed to the first plate 11, and the inlet end 423 is located above the outlet end 424 and spaced apart from the first plate 11. The third insulator 49 connects the end surfaces 4212 of the adjacent two armature coils 42 which are opposite to each other. Since the side surface 4211 of the armature coil body 421 is connected to the first plate 11, the first plate 11 can mount more armature coils 42, and the thrust generated by the primary assembly 40 is increased, thereby increasing the driving performance of the linear motor 100.

The plurality of first conductive bumps 43 and the plurality of first insulating members 45 are respectively disposed at intervals in the sliding direction X. The plurality of second conductive bumps 44 and the plurality of second insulating members 46 are respectively disposed at intervals in the sliding direction X, and the first conductive bumps 43 and the second conductive bumps 44 are disposed at intervals in the first direction Z. The first conductive block 43 and the second conductive block 44 are respectively connected to the side of the wire inlet end 423 and the wire outlet end 424 away from the first substrate 11, and the first insulating member 45 and the second insulating member 46 between the first conductive block 43 and the second conductive block 44 respectively connect the first conductive block 43 and the second conductive block 44 together in an insulating manner. The first connecting piece 47 and the second connecting piece 48 are also made of an insulating material, the first connecting piece 47 connects the first conductive block 43 and one side of the first insulating block 45 away from the armature coil body 421 into a whole, the second connecting piece 48 connects the second conductive block 44 and one side of the second insulating block 46 away from the armature coil body 421 into a whole, and the first connecting piece 47 and the second connecting piece 48 are arranged at intervals. The ends of the first conductive block 43 and the second conductive block 44 away from the wire inlet end 423 and the wire outlet end 424 are connected to the brush assembly 70, respectively.

At least two of the brush assemblies 70, each brush assembly 70 is in contact with and electrically connected to its corresponding primary assembly 40. Each brush assembly includes a fixing member 71, a first brush piece 72 electrically connected to the first conductive block 43, and a second brush piece 73 electrically connected to the second conductive block 44. The fixing member 71 is substantially U-shaped, and includes a fixing body 711, and a first fixing arm 712 and a second fixing arm 713 bent and extended from two sides of the fixing body 711, wherein a length of the first fixing arm 712 along the first direction Z is shorter than a length of the second fixing arm 713 along the first direction Z, and the fixing body 711 is fixed on the bearing portion of the carrier plate 24 and is opposite to and spaced apart from the secondary assembly 30 along the second direction Y. The first brush piece 72 and the second brush piece 73 are respectively fixed to ends of the first fixing arm 712 and the second fixing arm 713 away from the fixing body 711, an end of the first brush piece 72 away from the first fixing arm 712 contacts and is electrically conducted with the corresponding first conductive block 43 and the corresponding first insulating member 45 when sliding, an end of the second brush piece 73 away from the second fixing arm 713 contacts and is electrically conducted with the corresponding second conductive block 44 and the corresponding second insulating member 46 when sliding, and the first brush piece 72 and the second brush piece 73 are respectively electrically connected with the wire inlet end 423 and the wire outlet end 424 of at least one armature coil 42 through the first conductive block 43 and the second conductive block 44, so as to electrically conduct the armature coil 42. The two brush assemblies are connected to each other by their fixing bodies 711 and are fixed together on the carrier plate 24 of the slide 20.

When the magnetic slide seat is in operation, the brush assembly 70 is electrified with direct current and inputs the direct current to the armature coil 42 corresponding to the brush assembly, so that the brush assembly generates a stable primary magnetic field, the primary magnetic field and a secondary magnetic field are interacted, so that the slide seat 20 and the base 10 generate relative motion, at least one of the primary assembly 40 and the secondary assembly 30 is two groups, a double-sided magnetic circuit can be formed, the thrust can be improved, and the normal suction force received by the mover can be reduced.

The linear motor 100 further includes a scale 810 and a reader 820, one of the scale 810 and the reader 820 is disposed on the substrate 130, and the other of the scale 810 and the reader 820 is disposed on the carriage 20. In the embodiment, the bar 810 is an elongated bar and is disposed on the substrate 130, and the reader 820 can move synchronously with the slide plate 210 to read the displacement of the slide 20 relative to the base 10.

Referring to fig. 5, a linear motor according to a second embodiment of the present invention is provided, and the same parts as those of the first embodiment are not repeated.

The difference is that the primary assembly 40 and the secondary assembly 30 are interchanged in their positions, i.e. the primary assembly 40 may comprise one set based on the carrier plate 24 and the secondary assembly 30 comprises two sets based on the base plate 13 and the extension plate 14.

Accordingly, the structure of the brush assembly is changed, the brush assembly is fixedly disposed with respect to at least one of the base plate 13 and the extension plate 14, and the first brush piece 72 is slidably engaged with the first conductive block 43; the second brush piece 73 is slidably engaged with the second conductive block 44, and the second fixing arm 712 is spaced apart from the first fixing arm 713 in a second direction Y perpendicular to the sliding direction.

Referring to fig. 6 and 7 together, a third embodiment of the present invention provides a linear motor, and the same parts as those of the first embodiment are not repeated.

The difference is that the secondary assembly 30 uses magnetic steel 33 to replace the armature coil field winding 32 and the field core 31, and preferably, in this embodiment, the secondary assembly 30 includes magnetic steel 33 and a magnetic yoke 34 attached to a side of the magnetic steel 33 away from the primary assembly 40, so as to improve magnetic performance. In this embodiment, the secondary assembly 30 preferably includes two magnetic steels and two magnetic yokes 34 attached to the magnetic steels, wherein the two magnetic yokes 34 are disposed back to back and fixedly connected together and then connected to the carrier plate 24.

Referring to fig. 8 and 9 together, a linear motor according to a fourth embodiment of the present invention is provided, and the same parts as those of the second embodiment are not repeated. The difference lies in that:

the secondary assembly 30 replaces the field winding 32 and the field core 31 with a magnetic steel 33, and preferably, in this embodiment, the secondary assembly 30 includes a magnetic steel 33 and a yoke 34 attached to a side of the magnetic steel 33 away from the primary assembly to improve magnetic performance. In this embodiment, the secondary assembly 30 preferably includes two magnetic steels and two magnetic yokes 34 attached to the magnetic steels, wherein the two magnetic yokes 34 are disposed back to back and fixedly connected together and then connected to the carrier plate 24.

Be different from prior art's condition, the utility model provides a linear electric motor adopts bilateral structure, promotes thrust, has reduced the normal direction suction that the active cell received.

The above is only the embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or equivalent processes of the present invention are used in the specification and the attached drawings, or directly or indirectly applied to other related technical fields, and all the same principles are included in the protection scope of the present invention.

Claims

1. A linear motor, characterized in that the linear motor comprises:

a base;

the sliding seat and the base slide relatively along the sliding direction;

at least two primary assemblies arranged at intervals along a first direction perpendicular to the sliding direction and respectively fixed on the base, wherein each primary assembly comprises a plurality of armature coils arranged at intervals along the sliding direction;

a secondary assembly fixed to the carriage and located between the at least two primary assemblies and spaced apart from the primary assemblies along the first direction, the secondary assembly being configured to generate a secondary magnetic field;

at least two brush assemblies fixed on the sliding seat, wherein the brush assemblies are electrically conducted with armature coils corresponding to the secondary assemblies so that the primary assemblies generate primary magnetic fields; the primary magnetic field interacts with the secondary magnetic field to move the sled relative to the base.

2. A linear motor according to claim 1, wherein:

the base comprises a base plate, a first side plate, a second side plate and an extension plate, wherein the first side plate and the second side plate are bent and extended along two opposite sides of the base plate, and the extension plate is connected with the second side plate and is opposite to the base plate at intervals; the two primary assemblies are respectively mounted on the extension plate and the base plate.

3. A linear motor according to claim 2, wherein:

the sliding seat comprises a sliding plate in sliding fit with the first side plate and the second side plate, and a bearing plate connected with the sliding plate and used for bearing the secondary assembly and the brush assembly;

4. A linear motor according to claim 3, each primary assembly further comprising an armature core; each armature coil comprises a coil body with a through hole, and a wire inlet end and a wire outlet end which extend out of the coil body; the armature core is inserted into the through hole.

5. The linear motor of claim 4, each primary assembly further comprising:

the first conductive pieces are respectively and electrically connected with the wire inlet end of each armature coil and are arranged at intervals along the sliding direction;

the second conductive pieces are respectively electrically connected with the wire outlet end of each armature coil and are arranged at intervals along the sliding direction;

the first conductive member and the second conductive member are arranged at intervals along the first direction.

6. A linear motor according to claim 5, wherein:

each electric brush assembly comprises a first electric brush piece which is contacted with the first conductive piece and is electrically conducted, a second electric brush piece which is contacted with the second conductive piece and is electrically conducted, and a fixing piece which is connected with the first electric brush piece and the second electric brush piece, wherein the fixing piece comprises a fixing body which is fixedly connected with the bearing plate, and a first fixing arm and a second fixing arm which are formed by bending and extending from two opposite sides of the fixing body; the first fixing arm is connected with the first electric brush piece, and the second fixing arm is connected with the second electric brush piece.

7. A linear motor according to claim 6, wherein the fixing members of the two brush assemblies are connected to each other and arranged facing away from each other.

8. A linear motor according to claim 1, the secondary assembly comprising two sets of field windings arranged opposite each other, each set of field windings facing towards the primary assembly.

9. The linear motor of claim 1, wherein the secondary assembly comprises two sets of magnetic steels oppositely disposed and two magnetic yokes respectively attached to a side of each magnetic steel away from the armature coil.

10. The linear motor of claim 1, further comprising a scale disposed on one of the base and the carriage and a reader disposed on one of the carriage and the base with a sensing end of the reader facing the scale.

11. A linear motor, characterized in that the linear motor comprises:

a slide base;

the base slides relative to the base along the sliding direction;

at least two secondary assemblies are arranged at intervals along a first direction perpendicular to the sliding direction and fixed on the base, and each secondary assembly comprises at least one excitation winding or magnetic steel and is used for generating a secondary magnetic field;

a primary assembly fixed to the slider and located between the at least two secondary assemblies, the primary assembly including a plurality of armature coils arranged at intervals along the sliding direction;

the brush assembly is fixed on the base and used for being electrically conducted with the armature coil corresponding to the secondary assembly so as to enable the primary assembly to generate a primary magnetic field; the primary magnetic field interacts with the secondary magnetic field to move the sled relative to the base.

12. A linear motor according to claim 11, wherein:

the base comprises a base plate, a first side plate, a second side plate and an extension plate, wherein the first side plate and the second side plate are bent and extended along two opposite sides of the base plate; the at least two secondary assemblies are respectively arranged on the base plate and the extension plate; the brush assembly is disposed on the base plate and/or the extension plate.

13. A linear motor according to claim 12, wherein:

the primary assembly is arranged on the bearing plate.

14. A linear motor according to claim 13, wherein:

the electric brush assembly comprises a first electric brush piece electrically connected with the first conductive piece, a second electric brush piece electrically connected with the second conductive piece and a fixing piece for connecting the first electric brush piece and the second electric brush piece, wherein the fixing piece comprises a fixing body fixedly connected with the bearing plate, and a first fixing arm and a second fixing arm which are formed by bending and extending from two opposite sides of the fixing body; the first fixing arm is connected with the first electric brush piece, and the second fixing arm is connected with the second electric brush piece.

15. The linear motor of claim 14, the primary assembly further comprising: an armature core; each armature coil comprises a coil body with a through hole, and a wire inlet end and a wire outlet end which extend out of the coil body; the armature core is inserted into the through hole.