WO2013172262A1

WO2013172262A1 - Linear motor

Info

Publication number: WO2013172262A1
Application number: PCT/JP2013/063146
Authority: WO
Inventors: 貴文小松; 純一郎岩城; 克也福島; 正志石井
Original assignee: Thk株式会社
Priority date: 2012-05-18
Filing date: 2013-05-10
Publication date: 2013-11-21
Also published as: JP2013258894A; TW201401733A

Abstract

An opposed linear motor (101) comprises: a plurality of magnets (111, 121) which forms a pair of magnet series (102A, 102B) disposed parallel to each other wi equal pole pitch (P); and a plurality of coils (131, 141) which forms a pair of coil series (103A, 103B) disposed parallel to each other in correspondence with the pair of magnet series (102A, 102B). The plurality of coils (131, 141) forms a pair of coil groups (103C, 103D) in which the positional relationship and the phase arrangement in columns are respectively different with respect to the magnetic poles of the pair of magnet series (102A, 102B).

Description

Linear motor

The present invention relates to a linear motor.
This application claims priority based on Japanese Patent Application No. 2012-114430 filed in Japan on May 18, 2012 and Japanese Patent Application No. 2013-094735 filed in Japan on April 26, 2013. The contents are incorporated herein.

In semiconductor manufacturing apparatuses, machine tools, etc., linear motors are used for precision feeders and precision positioning devices. When a linear motor is used for a precision feeding device or a precision positioning device, reducing cogging becomes a problem.
Patent Document 1 discloses a linear motor with reduced cogging.

JP 11-31475 A

In the opposed linear motor of Patent Literature 1, a pair of opposed magnet rows are shifted in the row direction to reduce cogging.
However, the positioning accuracy and the like required for semiconductor manufacturing apparatuses and machine tools are increasing year by year. For this reason, the technique described in Patent Document 1 is not sufficient in reducing cogging. Linear motors are required to further reduce cogging.
Further, there is a demand for reducing cogging without reducing the efficiency of the linear motor.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a linear motor that can reduce cogging without reducing efficiency.

The linear motor according to the first embodiment of the present invention includes a plurality of magnets forming a pair of magnet arrays arranged in parallel at the same magnetic pole pitch, and a pair of coil arrays arranged in parallel corresponding to the pair of magnet arrays. And the plurality of coils, the plurality of coils form a pair of coil groups having different positional relations and phase arrangements in the column direction with respect to the magnetic poles of the pair of magnet rows.

In the linear motor of the second embodiment of the present invention, in the first embodiment, the pair of coil groups differ in the positional relationship by 1/4 of the magnetic pole pitch.

In the linear motor of the third embodiment of the present invention, in the first or second embodiment, the pair of coil groups have a phase difference in which the drive current to the equivalent coil is 120 °.

A linear motor according to a fourth embodiment of the present invention is the linear motor according to any one of the first to third embodiments, wherein each of the pair of coil groups is a plurality of phases different from each other in the same number as the number of phases for each pair of coil arrays. The pair of coil groups are spaced apart in the column direction.

In the linear motor of the fifth embodiment of the present invention, in any one of the first to third embodiments, each of the pair of coil groups is one of the pair of coil arrays, and the pair of coil arrays Alternatively, the pair of magnet rows are arranged so as to be shifted in the row direction.

A linear motor according to a sixth embodiment of the present invention is the linear motor according to any one of the first to fifth embodiments, wherein each of the plurality of coils is wound and a plurality of tip surfaces facing the magnetic poles are formed. The plurality of teeth are formed so as to be inclined so that a pair of teeth arranged at both ends in the row direction are opposite to each other. Is done.

In the linear motor according to the seventh embodiment of the present invention, in any one of the first to sixth embodiments, the pair of magnet rows are arranged so that the magnetic poles facing each other are opposed to each other.

The linear motor of the present invention can sufficiently reduce cogging and obtain high feed accuracy and positioning accuracy.

It is a mimetic diagram showing a schematic structure of linear motor 101 concerning a first embodiment of the present invention. It is a figure showing a tooth tip surface 151T. It is a schematic diagram showing a linear motor 101 (101A, 101B) and a conventional linear motor 298. It is a figure which shows the comparison of the cogging generate | occur | produced in the linear motor 101 (101A, 101B), 298. FIG. It is a schematic diagram which shows schematic structure of the linear motor 201 which concerns on 2nd embodiment of this invention. It is a schematic diagram which shows the linear motor 201 and the conventional linear motor 298,299. It is a figure which shows the comparison of the cogging generate | occur | produced in the linear motor 201,298,299. It is a figure which shows the comparison of the back electromotive force constant in the linear motor 201,298,299. It is a figure explaining the reason a difference arises in the back electromotive force constant in the linear motor 201,298,299. It is the figure which put together the characteristic comparison of the linear motor 201,298,299.

Embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram showing a schematic configuration of a linear motor 101 according to the first embodiment of the present invention.

The linear motor 101 includes a magnet unit 102, a coil unit 103, and the like.
The magnet part 102 has two magnet rows (first magnet row 102A and second magnet row 102B) in which a plurality of magnets are arranged in a straight line.
The coil unit 103 has two coil arrays (first coil array 103A and second coil array 103B) in which a plurality of coils are arranged in a straight line.
The two coil arrays are arranged in parallel corresponding to the two magnet arrays. For this reason, the linear motor 101 is called an opposed linear motor.

The row direction of the first magnet row 102A, the first coil row 103A, etc. is the X direction, and the direction in which the first magnet row 102A, the first coil row 103A, etc. are arranged is the Y direction (see the coordinate axes in FIG. 1).

The first magnet row 102A and the second magnet row 102B of the magnet unit 102 are arranged in parallel.
The first magnet row 102A has a plurality of

magnets

111, 112 and the like. The plurality of

magnets

111, 112, etc., face each other in the direction (Y direction) perpendicular to the column direction (X direction). The plurality of

magnets

111, 112, etc. are arranged so that the magnetic poles alternate in the column direction.
The second magnet row 102B has a plurality of

magnets

121, 122 and the like. The plurality of

magnets

121, 122, etc. have their magnetic poles oriented in a direction perpendicular to the column direction. The plurality of

magnets

121, 122, etc. are arranged so that the magnetic poles alternate in the column direction.

The

magnets

111 and 112 and the

magnets

121 and 122 have the same shape (flat plate shape) and the same characteristics. The arrangement pitch of the

magnets

111 and 112 in the first magnet row 102A and the arrangement pitch of the

magnets

121 and 122 in the second magnet row 102B are the same.

The arrangement pitch is the distance (pitch) in the X direction between the same poles (N poles or S poles) (see FIG. 1). The arrangement pitch is also called a magnetic pole pitch P.

The first magnet row 102A and the second magnet row 102B are arranged so that the magnets facing each other face different magnetic poles. For example, the magnet 111 has an N pole surface facing the magnet 121 side (+ Y direction), and the magnet 121 has an S pole surface facing the magnet 111 side (−Y direction).

The coil portion 103 is disposed between the first magnet row 102A and the second magnet row 102B.
The coil unit 103 includes a core 104, a coil array, and the like.
The core 104 is formed with two teeth rows (first teeth row 104A, second teeth row 104B) arranged in a straight line.
The coil arrays (first coil array 103 A and second coil array 103 B) are each composed of a plurality of coils wound around the two teeth arrays of the core 104.

The core 104 is formed of a main body portion 104S, a first teeth row 104A, and a second teeth row 104B.
The main body 104S is an elongated rectangular portion along the row direction (X direction). 104 A of 1st teeth row | line | columns and the 2nd teeth row | line | column 104B are the parts which protrude in the direction orthogonal to a row direction from the both sides | surfaces of the main-body part 104S. The first teeth row 104A and the second teeth row 104B protrude in the backward direction.
The first teeth row 104A includes a plurality of teeth (saliency poles) 151, 152, and the like. The plurality of

teeth

151, 152, and the like are arranged at 2/3 pitches (2P / 3) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B in the row direction (X direction).
The second teeth row 104B has a plurality of

teeth

161, 162, and the like. The plurality of

teeth

161, 162, etc. are arranged in the row direction (X direction) at a 2/3 pitch (2P / 3) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B.
The first teeth row 104A and the second teeth row 104B are arranged in parallel. 104 A of 1st teeth row | line | columns and the 2nd teeth row | line | column 104B are arrange | positioned so that it may correspond in a row direction.
The

teeth

151, 152, etc. and the

teeth

161, 162, etc. have the same shape. The

teeth

151, 152, etc. and the

teeth

161, 162, etc. are formed in the same bar shape (round bar or square bar) from the tooth base to the tooth tip. The

teeth

151, 152, etc. protrude in the −Y direction. The

teeth

161, 162, etc. protrude in the + Y direction.

The first tooth row 104A and the second tooth row 104B are divided into two tooth groups (first tooth group 104C and second tooth group 104D) in the row direction.
The first teeth group 104 C includes

teeth

151, 152, 153 and

teeth

161, 162, 163. The second tooth group 104D includes

teeth

154, 155, 156 and

teeth

164, 165, 166.
The first teeth group 104C and the second teeth group 104D are arranged with an interval (separated) in the row direction. The first teeth group 104C and the second teeth group 104D are spaced apart by a quarter of the magnetic pole pitch P (P / 4) of the first magnet row 102A and the second magnet row 102B. The distance between the

teeth

153 and 163 and the

teeth

154 and 164 is 11/12 pitches (2P / 3 + P / 4) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B.

As shown in FIG. 1, the first teeth group 104C is separated from the second teeth group 104D in the + X direction by a quarter of the magnetic pole pitch P of the second magnet row 102B (P / 4). Be placed.

The tooth tips of the first teeth row 104A are formed so as to be separated from the first magnet row 102A by a slight gap (gap A). The tooth tips of the second teeth row 104B are formed so as to be separated from the second magnet row 102B by a slight gap (gap B).

The first coil array 103 A includes a plurality of

coils

131, 132 and the like wound around the

teeth

151, 152, etc. of the first tooth array 104 A of the core 104.
The second coil array 103B is composed of a plurality of

coils

141, 142, etc. wound around the

teeth

161, 162, etc. of the second teeth array 104B of the core 104, respectively.

The first coil group 103A and the second coil group 103B are divided into two coil groups (first coil group 103C and second coil group 103D) in the column direction (X direction).
The first coil group 103 C includes a plurality of

coils

131, 141, and the like wound around the

teeth

151, 161, etc. of the first teeth group 104 C of the core 104.
The second coil group 103D is composed of a plurality of

coils

134, 144 and the like wound around the

teeth

154, 164, etc. of the second tooth group 104D of the core 104, respectively.

The

coils

131 and 132 and the

coils

141 and 142 are formed in the same shape (number of turns, winding direction, copper wire type).
The

coils

131, 132, etc. of the first coil array 103A are formed by winding a copper wire clockwise from the tooth bases of the

teeth

151, 152, etc. to the tooth tips. The

coils

141, 142, etc. of the second coil array 103B are formed by winding a copper wire clockwise from the tooth tips of the

teeth

161, 162, etc. toward the tooth base.

The first teeth group 104C and the second teeth group 104D are arranged apart from each other in the row direction. The first teeth group 104C and the second teeth group 104D are spaced apart by a quarter (P / 4) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B in the row direction. .
For this reason, the first coil group 103C and the second coil group 103D are separated from each other by a quarter (P / 4) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B in the row direction. Be placed.

The coil unit 103 includes two coil units (a first coil unit 105 and a second coil unit 106) that are separated from each other in the column direction (X direction).

The first coil unit 105 includes a first tooth group 104C and a first coil group 103C.
The first coil unit 105 includes a plurality of coils having the same number of phases and different phases for each of the first coil array 103A and the second coil array 103B. The linear motor 101 is a three-phase induction motor. Therefore, the first coil unit 105 includes three

coils

131, 132, 133 wound around the three

teeth

151, 152, 153, and three coils 141, wound around the three

teeth

161, 162, 163. 142, 143.

The second coil unit 106 includes a second tooth group 104D and a second coil group 103D.
The second coil unit 106 includes a plurality of coils having the same number of phases and different phases for each of the first coil array 103A and the second coil array 103B. The linear motor 101 is a three-phase induction motor. Therefore, the second coil unit 106 includes three

coils

134, 135, 136 wound around the three

teeth

154, 155, 156 and three coils 144, wound around the three

teeth

164, 165, 166. 145, 146.

The first coil part 105 and the second coil part 106 are connected via the main body part 104S.
The first coil portion 105 and the second coil portion 106 are arranged in the row direction so as to be separated from each other by a quarter (P / 4) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B. . The distance between the

coils

133 and 143 and the

coils

134 and 144 is 11/12 pitches (2P / 3 + P / 4) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B.

The first coil portion 105 (first coil group 103C) and the second coil portion 106 (second coil group 103D) are different in the positional relationship in the row direction with respect to the magnetic poles of the first magnet row 102A and the second magnet row 102B.
As shown in FIG. 1, when the coil 131 faces the north pole of the first magnet row 102A and the coil 141 faces the south pole of the second magnet row 102B from the front, the coil 134 is the north pole of the first magnet row 102A. The coil 144 faces between the S pole and the N pole of the second magnet row 102B. This is because the

coils

131 and 141 and the

coils

134 and 144 are shifted by a quarter (P / 4) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B.
Similarly, the

coils

132 and 142 and the

coils

135 and 145 are different in the positional relationship in the row direction with respect to the magnetic poles of the first magnet row 102A and the second magnet row 102B.

Coils

133, 143 and coils 136, 146 differ in the positional relationship in the row direction with respect to the magnetic poles of first magnet row 102A and second magnet row 102B.

A three-phase alternating current is input as a drive current to the coil unit 103 (the first coil group 103C and the second coil group 103D).
The three-phase alternating current input to the first coil group 103C and the three-phase alternating current input to the second coil group 103D are connected so as to have a phase difference of 120 ° (electrical angle 120 °).
A three-phase alternating current having the same phase (there is no phase difference) is input to the coils (for example, the coil 131 and the coil 141, for example, the coil 134 and the coil 144) arranged to face each other in the Y direction.

In the first coil group 103C (first coil section 105), when the

coils

131, 132, and 133 of the first coil group 103A are set to the U phase, the W phase, and the V phase, respectively, the

coils

141 and 142 of the second coil group 103B. , 143 are connected so as to be the / U phase, / W phase, and / V phase, respectively. Here, / means an overline (bar).
In the second coil group 103D (second coil section 106), when the

coils

134, 135, and 136 of the first coil group 103A are V-phase, U-phase, and W-phase, respectively, the

coils

144 and 145 of the second coil group 103B are used. , 146 are connected to become the / V phase, / U phase, and / W phase, respectively.

The first coil group 103C (first coil part 105) and the second coil group 103D (second coil part 106) have a phase difference of 120 ° in drive current to the equivalent coils.
The coil 131 becomes the U phase, and the coil 134 equivalent to this becomes the V phase. The coil 132 becomes the W phase, and the coil 135 equivalent to this becomes the U phase. The coil 133 becomes the V phase, and the coil 136 equivalent to this becomes the W phase. The coil 141 becomes the / U phase, and the coil 144 equivalent to this becomes the / V phase. The coil 142 becomes the / W phase, and the coil 145 equivalent to this becomes the / U phase. The coil 143 becomes the / V phase, and the coil 146 equivalent to this becomes the / W phase.
As described above, the first coil portion 105 (first coil group 103C) and the second coil portion 106 (second coil group 103D) have different phase arrangements.

FIG. 2 is a diagram showing the tooth tip surface 151T and the like.
Each of the teeth 151 to 156 and 161 to 166 has tooth tip surfaces 151T to 156T and 161T to 166T facing the first magnet row 102A or the second magnet row 102B.
The tooth tip surfaces (for example, tooth tip surfaces 151T to 153T) of three teeth (for example, teeth 151 to 153) having different phases (U phase, W phase, V phase) by being wound around the coils (the same number as the number of phases). ) Are formed in different shapes.
Of the three teeth, the tooth tip surface of the teeth arranged at the center in the row direction (for example, the tooth tip surface 152T of the tooth 152) is formed in a plane parallel to the first magnet row 102A or the second magnet row 102B. Is done.
Of the three teeth, the tooth tip surfaces (for example, the tooth tip surfaces 151T and 153T of the teeth 151 and 153) arranged on both sides in the row direction (+ X direction and −X direction) are the first magnet row 102A or the first tooth row. It is formed in a plane inclined with respect to the two-magnet array 102B. The tooth tip surfaces (for example, the tooth tip surfaces 151T and 153T) of the teeth arranged on both sides in the row direction are formed to face each other.
The inclination angles of the tooth tip surfaces 151T, 153T, etc. can be arbitrarily set. Further, the inclination angles of the tooth tip surfaces 151T, 153T, etc. are the same. The tooth tip surfaces 151T, 152T, 153T and the like are formed symmetrically with respect to a center line extending in the Y direction of the teeth 152 and the like.

The tooth tip surfaces of the three teeth (for example, the tooth tip surfaces 151T to 153T of the teeth 151 to 153) that are wound around the coil and have different phases are formed in a trapezoidal shape as a whole.
The tooth tip surfaces of the three teeth that are different from each other when the coil is wound maintain gaps (gap A, B) with respect to the first magnet row 102A or the second magnet row 102B, respectively, on both sides in the row direction. As a whole, it is formed so as to be gradually separated from the first magnet row 102A or the second magnet row 102B.

The tooth tip surfaces 154T to 156T, 161T to 163T, and 164T to 166T of the teeth 154 to 156, 161 to 163, 164 to 166 are formed in the same shape as the tooth tip surfaces 151T to 153T.

Next, the effect of the linear motor 101 will be described in comparison with a conventional linear motor.
For convenience of explanation, the linear motor 101 described above is hereinafter referred to as a linear motor 101A. The linear motor 101B is a modification of the linear motor 101A.

FIG. 3 is a schematic diagram showing the linear motor 101 (101A, 101B) and a conventional linear motor 298. As shown in FIG.
FIG. 3A is a schematic diagram showing a conventional linear motor 298. A drive current having no phase difference is input to the two coil arrays.
FIG. 3B is a schematic diagram showing the linear motor 101A according to the first embodiment of the present invention. In the linear motor 101A, the tooth tip surfaces of the three teeth (for example, the tooth tip surfaces 151T to 153T of the teeth 151 to 153) that are different from each other when the coil is wound are formed in a trapezoidal shape as a whole. A drive current having a phase difference is input to the two coil arrays.
FIG.3 (c) is a schematic diagram which shows the linear motor 101B which concerns on 1st embodiment of this invention. However, in the linear motor 101B, all the tooth tip surfaces 151T and the like are formed in parallel to the first magnet row 102A or the second magnet row 102B. A drive current having a phase difference is input to the two coil arrays.

FIG. 4 is a diagram showing a comparison of cogging in the X direction generated in the linear motors 101 (101A, 101B) and 298. In FIG. In the linear motor 101 (101A, 101B), cogging in the Y direction hardly occurs.
FIG. 4A is a diagram showing cogging that occurs in a conventional linear motor 298.
FIG. 4B is a diagram showing cogging generated in the linear motor 101A according to the first embodiment of the present invention.
FIG.4 (c) is a figure which shows the cogging generate | occur | produced in the linear motor 101B which concerns on 1st embodiment of this invention.

As shown in FIG. 4 (a), it was confirmed that large cogging occurred in the conventional linear motor 298. The difference between the maximum value and the minimum value of cogging in the linear motor 298 is about 2.0 to 3.0N.

As shown in FIG. 4B, it was confirmed that the cogging was significantly reduced in the linear motor 101A according to the first embodiment of the present invention compared to the linear motor 298. The difference between the maximum value and the minimum value of cogging in the linear motor 101A is about 0.4N.

As shown in FIG. 4 (c), in the linear motor 101B according to the first embodiment of the present invention, it was confirmed that the cogging was greatly reduced as in the linear motor 101A. The difference between the maximum value and the minimum value of cogging in the linear motor 101B is about 0.5N.

In the linear motor 298, cogging that occurs in the coil part CA on the −X direction side (corresponding to the first coil part 105) and cogging that occurs on the coil part CB on the + X direction side (corresponding to the second coil part 106) , The phases match. For this reason, it was confirmed that cogging became large as a whole.

In the linear motors 101 A and 101 B, the cogging generated in the first coil unit 105 and the cogging generated in the second coil unit 106 are opposite in phase. For this reason, the cogging which generate | occur | produces in the 1st coil part 105 and the cogging which generate | occur | produces in the 2nd coil part 106 are canceled. Therefore, it was confirmed that cogging was reduced as a whole.

When comparing the linear motor 101A and the linear motor 101B, the cogging of the first coil unit 105 and the second coil unit 106 is larger in the linear motor 101A than in the linear motor 101B.
However, cogging in the first coil portion 105 and the second coil portion 106 of the linear motor 101A approximates a sine curve. By adjusting the inclination angles of the tooth tip surfaces 151T and 153T, the cogging in the first coil portion 105 and the second coil portion 106 of the linear motor 101A can be more approximated to a sine curve.
The cogging in the first coil portion 105 and the second coil portion 106 of the linear motor 101B is an uneven curve.
For this reason, the cogging which generate | occur | produces in the 1st coil part 105 and the cogging which generate | occur | produces in the 2nd coil part 106 are offset more favorably than the linear motor 101A compared with the linear motor 101B.
In the linear motor 101A, the tooth tip surfaces (for example, the tooth tip surfaces 151T to 153T) of three teeth (for example, the teeth 151 to 153) having different phases by winding the coil are formed in a trapezoidal shape as a whole. Thereby, it was confirmed that cogging generated in each of the first coil portion 105 and the second coil portion 106 is easily canceled.

The linear motor 101 has a first coil part 105 and a second coil part 106 that are separated in the row direction. Thereby, in the linear motor 101, the cogging generated in the first coil portion 105 and the cogging generated in the second coil portion 106 are canceled out, so that the cogging is reduced as a whole.

In particular, in the linear motor 101, the tooth tip surfaces (for example, teeth 151 to 153) of three teeth (for example, the teeth 151 to 153) having different phases (U-phase, W-phase, V-phase) are wound around the coil. For example, the tip surfaces 151T to 153T) are formed in a trapezoidal shape as a whole. Thereby, in the linear motor 101, it is easy to cancel cogging which generate | occur | produces in each of the 1st coil part 105 and the 2nd coil part 106. FIG.

Therefore, the linear motor 101 can obtain high feed accuracy and positioning accuracy without hindering smooth movement of the magnet portion. Further, the linear motor 101 hardly satisfies a reduction in efficiency, and can satisfy the demand for energy saving.

In the linear motor 101, since the core 104 around which the

coils

131, 141 and the like are wound has the same shape from the tooth base to the tooth tip, the cogging is likely to occur. However, in the linear motor 101, the

teeth

151, 161 and the like are not T-shaped, but cogging can be reduced.
In the linear motor 101, since the

teeth

151, 161, etc. have the same shape from the tooth base toward the tooth tip, the

coils

131, 141, etc. are easy to wind (easy to assemble).

The first magnet row 102A and the second magnet row 102B are arranged so that the magnetic poles facing each other are opposite to each other. The

coils

teeth

151, 152, etc. toward the tooth tips. The

coils

teeth

161, 162, etc. toward the tooth base. By making the winding directions of the copper wires of the

coils

131, 132, 141, 142, etc. of the first coil row 103A and the second coil row 103B coincide with each other, the assemblability is improved.

(Second embodiment)
FIG. 5 is a schematic diagram showing a schematic configuration of the linear motor 201 according to the second embodiment of the present invention.
The linear motor 201 includes a magnet unit 202, a coil unit 203, and the like.
The magnet unit 202 has two magnet rows (first magnet row 202A and second magnet row 202B) in which a plurality of magnets are arranged in a straight line.
The coil unit 203 has two coil rows (first coil row 203A and second coil row 203B) in which a plurality of coils are arranged in a straight line.
The two coil arrays are arranged in parallel corresponding to the two magnet arrays. For this reason, the linear motor 201 is called an opposed linear motor.

The row direction of the first magnet row 202A, the first coil row 203A, etc. is the X direction, and the direction in which the first magnet row 202A, the first coil row 203A, etc. are arranged is the Y direction (see the coordinate axes in FIG. 5).

The first magnet row 202A and the second magnet row 202B of the magnet unit 202 are arranged in parallel.
The first magnet row 202A has a plurality of

magnets

211, 212 and the like. The plurality of

magnets

211, 212, etc. have their magnetic poles oriented in the direction (Y direction) perpendicular to the column direction (X direction). The plurality of

magnets

211, 212, etc. are arranged so that the magnetic poles alternate in the column direction.
The second magnet row 202B has a plurality of

magnets

221, 222 and the like. The plurality of

magnets

221, 222, etc., face each other in the direction in which the magnetic poles are orthogonal to the column direction. The plurality of

magnets

221, 222, etc. are arranged so that the magnetic poles are alternated in the column direction.
The

magnets

211 and 212 and the

magnets

221 and 222 have the same shape (flat plate shape) and the same characteristics. The arrangement pitch of the

magnets

211, 212 and the like in the first magnet row 202A and the arrangement pitch of the

magnets

221, 222 and the like in the second magnet row 202B are the same.

The arrangement pitch is a distance (pitch) in the X direction between the same poles (N poles or S poles) (see FIG. 5). The arrangement pitch is also called a magnetic pole pitch P.

The first magnet row 202A and the second magnet row 202B are arranged such that magnets facing each other face different magnetic poles. For example, the magnet 211 has the N pole surface facing the magnet 221 side (+ Y direction), and the magnet 221 has the S pole surface facing the magnet 211 side (−Y direction).

The coil unit 203 is disposed between the first magnet row 202A and the second magnet row 202B.
The coil unit 203 includes a core 204, a coil array, and the like.
The core 204 is formed with two teeth rows (first teeth row 204A, second teeth row 204B) arranged in a straight line.
The coil arrays (first coil array 203 A and second coil array 203 B) include a plurality of coils wound around the two teeth arrays of the core 204.

The core 204 is formed of a main body portion 204S, a first teeth row 204A, and a second teeth row 204B.
The main body portion 204S is an elongated rectangular portion along the row direction (X direction). 204 A of 1st teeth row | line | columns and the 2nd teeth row | line | column 204B are the parts which protrude in the direction orthogonal to a row direction from the both sides | surfaces of the main-body part 204S. The first teeth row 204A and the second teeth row 204B protrude in the backward direction.
The first teeth row 204A includes a plurality of teeth (saliency poles) 251, 252 and the like. The plurality of

teeth

251, 252, etc. are arranged at 2/3 pitch (2P / 3) of the magnetic pole pitch P of the first magnet row 202 A and the second magnet row 202 B in the row direction (X direction).
The second teeth row 204B includes a plurality of

teeth

261, 262 and the like. The plurality of

teeth

261, 262, and the like are arranged in the row direction (X direction) at a 2/3 pitch (2P / 3) of the magnetic pole pitch P of the first magnet row 202A and the second magnet row 202B.
The first teeth row 204A and the second teeth row 204B are arranged in parallel. The

teeth

251 and 252 and the

teeth

261 and 262 have the same shape. The

teeth

251 and 252 and the

teeth

261 and 262 are formed in a bar shape (round bar or square bar) having the same shape from the tooth base toward the tooth tip. The

teeth

251, 252 and the like protrude in the −Y direction. The

teeth

261, 262 and the like protrude in the + Y direction.

The first teeth row 204A and the second teeth row 204B are arranged so as to be shifted in the row direction. The first teeth row 204A and the second teeth row 204B are arranged so as to be shifted by a quarter (P / 4) of the magnetic pole pitch P of the first magnet row 202A and the second magnet row 202B.

The first teeth row 204A and the second teeth row 204B are also referred to as two teeth groups (first teeth group 204C and second teeth group 204D).
The first tooth group 204C includes teeth 151 to 156. The second tooth group 204D includes teeth 161 to 166.
The first teeth group 204C and the second teeth group 204D are arranged so as to be shifted in the row direction. The first teeth group 204C and the second teeth group 204D are arranged so as to be shifted by a quarter (P / 4) of the magnetic pole pitch P of the first magnet row 102A and the second magnet row 102B.

As shown in FIG. 5, the first teeth row 204A is ¼ of the magnetic pole pitch P of the first magnet row 202A and the second magnet row 202B in the + X direction with respect to the second teeth row 204B (P / 4) It is shifted and arranged.
In FIG. 5, the first tooth row 204A may be shifted from the second tooth row 204B in the −X direction.

The tooth tips of the first teeth row 204A are formed so as to separate a slight gap (gap A) from the first magnet row 202A. The tooth tips of the second teeth row 204B are formed so as to be separated from the second magnet row 202B by a slight gap (gap B).

The first coil row 203A is composed of a plurality of

coils

231 and 232 wound around the

teeth

251 and 252 of the first tooth row 204A of the core 204, respectively.
The second coil array 203B includes a plurality of

coils

241 and 242 wound around the

teeth

261 and 262 of the second tooth array 204B of the core 204, respectively.

The first coil group 203A and the second coil group 203B are also referred to as two coil groups (first coil group 203C and second coil group 203D).
The first coil group 203C includes a plurality of coils 231 to 236 wound around the teeth 251 to 256 of the first teeth group 204C of the core 204, respectively.
The second coil group 203D is composed of a plurality of coils 241 to 246 wound around the teeth 261 to 266 of the second tooth group 104D of the core 104, respectively.

The

coils

231 and 232 and the like and the

coils

241 and 242 and the like are formed in the same shape (number of windings, winding direction, copper wire type).
The

coils

231, 232 and the like of the first coil row 203 A are formed by winding a copper wire clockwise from the tooth base of the

teeth

251, 252 and the like to the tooth tip. The

coils

241, 242, etc. of the second coil row 203 B are formed by winding a copper wire clockwise from the tooth tips of the

teeth

261, 262, etc. toward the tooth base.

The first teeth row 204A and the second teeth row 204B are arranged so as to be shifted by a quarter of the magnetic pole pitch P (P / 4) of the first magnet row 202A and the second magnet row 202B in the row direction.
Therefore, the first coil group 203A (first coil group 203C) and the second coil group 203B (and second coil group 203D) are magnetic pole pitches of the first magnet group 202A and the second magnet group 202B in the column direction. They are shifted by a quarter of P (P / 4).

The coil unit 203 includes two coil units (a first coil unit 205 and a second coil unit 206).
The first coil unit 205 includes coils 231 to 236 and teeth 251 to 256 forming a first coil row 203A and a first teeth row 204A.
The second coil unit 206 includes coils 241 to 246 and teeth 261 to 266 that form the second coil row 203B and the second tooth row 204B.
The first coil portion 105 and the second coil portion 106 are arranged so as to be shifted by a quarter of the magnetic pole pitch P (P / 4) of the first magnet row 202A and the second magnet row 202B in the row direction.

The first coil portion 205 (first coil group 203C) and the second coil portion 206 (second coil group 203D) are different in the positional relationship in the row direction with respect to the magnetic poles of the first magnet row 102A and the second magnet row 202B.
As shown in FIG. 5, when the coil 231 faces the north pole of the first magnet row 202A from the front, the coil 231 faces between the north and south poles of the second magnet row 202B. This is because the coil 231 and the coil 241 are shifted by a quarter (P / 4) of the magnetic pole pitch P of the first magnet row 202A and the second magnet row 202B.
Similarly, the coils 232 to 236 and the coils 242 to 246 are different in the positional relationship in the row direction with respect to the magnetic poles of the first magnet row 202A and the second magnet row 202B.

A three-phase alternating current (drive current) is input to the coil unit 203 (the first coil group 203A and the second coil group 203B).
The three-phase alternating current input to the first coil array 203A and the three-phase alternating current input to the second coil array 203B are connected so as to have a phase difference of 120 ° (electrical angle 120 °).
Three-phase alternating currents having a phase difference of 120 ° between the coils arranged opposite to each other in the Y direction (for example, the coil 231 and the coil 241, for example, the coil 232 and the coil 242, for example, the coil 233 and the coil 243) Is entered.
When the

coils

231, 232, and 233 of the first coil group 203A are U phase, W phase, and V phase, respectively, the

coils

241, 242, and 243 of the second coil group 203B are / V phase, / U phase, and / W, respectively. Connect them so that they are in phase. Here, / means an overline (bar).

The first coil group 203A (first coil part 205) and the second coil group 203B (first coil part 205) have a phase difference of 120 ° in the drive current to the equivalent coil.
The coil 231 becomes the U phase, and the coil 241 equivalent to this becomes the / V phase. The coil 232 becomes the W phase, and the coil 242 equivalent to this becomes the / U phase. The coil 233 becomes the V phase, and the coil 243 equivalent to this becomes the / W phase. The coil 234 becomes the U phase, and the coil 244 equivalent to this becomes the / V phase. The coil 235 becomes the W phase, and the coil 245 equivalent to this becomes the / U phase. The coil 236 becomes the V phase, and the coil 246 that is equivalent to this becomes the / W phase.
Thus, the first coil portion 205 (first coil group 203C) and the second coil portion 206 (second coil group 203D) have different phase arrangements.

Next, the effect of the linear motor 201 will be described in comparison with a conventional linear motor.
FIG. 6 is a schematic diagram showing a linear motor 201 according to a second embodiment of the present invention and conventional

linear motors

298 and 299.
FIG. 6A is a schematic diagram showing a conventional linear motor 298. The two coil rows wound around the teeth are not displaced in the row direction. A drive current having no phase difference is input to the two coil arrays.
FIG. 6B is a schematic diagram showing a conventional linear motor 299. There is a deviation in the row direction between the two coil rows wound around the teeth. A drive current having no phase difference is input to the two coil arrays.
FIG.6 (c) is a schematic diagram which shows the linear motor 201 which concerns on 2nd embodiment of this invention. There is a deviation in the row direction between the two coil rows (first coil row 203A and second coil row 203B) wound around the teeth. A drive current having a phase difference is input to the two coil arrays.

FIG. 7 is a diagram showing a comparison of cogging generated in the

linear motors

201, 298, and 299.
FIG. 7A is a diagram showing cogging that occurs in the conventional linear motor 298.
FIG. 7B is a diagram showing cogging that occurs in the conventional linear motor 299.
FIG.7 (c) is a figure which shows the cogging generate | occur | produced in the linear motor 201 which concerns on 2nd embodiment of this invention.

As shown in FIG. 7A, it was confirmed that large cogging occurred in the conventional linear motor 298. The difference between the maximum value and the minimum value of cogging in the linear motor 298 is about 2.0 to 3.0N.

As shown in FIG. 7B, it was confirmed that the cogging was significantly reduced in the conventional linear motor 299 compared to the linear motor 298. The difference between the maximum value and the minimum value of cogging in the linear motor 299 is about 0.5N.

As shown in FIG. 7 (c), in the linear motor 201 according to the second embodiment of the present invention, it was confirmed that cogging was greatly reduced in the linear motor 298. The difference between the maximum value and the minimum value of cogging in the linear motor 201 is about 0.4N.

By arranging two coil rows (first coil row 203A and second coil row 203B) wound around the teeth so as to be shifted by a quarter of the magnetic pole pitch P (P / 4) in the row direction, the linear motor 201 is arranged. , 298 can be significantly reduced.

FIG. 8 is a diagram showing comparison of back electromotive force constants (analyzed values) in the

linear motors

201, 298, and 299.
FIG. 8A is a diagram showing a back electromotive force constant (analysis value) in the conventional linear motor 298.
FIG. 8B is a diagram showing a counter electromotive force constant (analysis value) in the conventional linear motor 299.
FIG.8 (c) is a figure which shows the back electromotive force constant (analysis value) in the linear motor 201 which concerns on 2nd embodiment of this invention.

As shown in FIG. 8A, in the conventional linear motor 298, it was confirmed that the back electromotive force constant (EMF) of the entire coil portion was 3.5 Vrms / m / s. In the linear motor 298, it was confirmed that the variation (waveform) of the back electromotive force constant of the coil portion (U phase, V phase, W phase) was wavy. For this reason, the counter electromotive force constant (EMF) is also rippled.
In the conventional linear motor 298, when the rated current is 1 Arms, the rated thrust is 10.2N.

As shown in FIG. 8B, in the conventional linear motor 299, it was confirmed that the counter electromotive force constant (EMF) of the entire coil portion was 2.4 Vrms / m / s. In the linear motor 299, it was confirmed that the change (waveform) of the back electromotive force constant of the coil portion (U phase, V phase, W phase) was greatly undulated. For this reason, the back electromotive force constant (EMF) is also greatly waved.
In the conventional linear motor 299, when the rated current is 1 Arms, the rated thrust is 7.1 N.

As shown in FIG. 8C, in the linear motor 201 according to the second embodiment of the present invention, the overall counter electromotive force constant (EMF) of the coil unit 203 is 3.3 Vrms / m / s. confirmed. In the linear motor 201, since the connected coils are corrected together, the back electromotive force waveform is close to a sine wave. It was confirmed that almost no change (waveform) in the back electromotive force constant of the coil portion (U phase, V phase, W phase) was found. For this reason, the counter electromotive force constant (EMF) is hardly waved.
In the linear motor 201 according to the second embodiment of the present invention, when the rated current is 1 Arms, the rated thrust is 9.4 N.

In the linear motor 201, 120 ° with respect to two coil arrays (first coil array 203 A and second coil array 203 B) wound around teeth that are shifted by a quarter of the magnetic pole pitch P (P / 4). It was confirmed that the back electromotive force constant can be made comparable to that of the conventional linear motor 298 by inputting a drive current having a phase difference (electrical angle 120 °). In other words, the linear motor 201 can suppress a decrease in the back electromotive force constant as in the conventional linear motor 299.
Therefore, in the linear motor 201, the rated thrust comparable to that of the conventional linear motor 298 is obtained without lowering the rated thrust unlike the conventional linear motor 299.

FIG. 9 is a diagram for explaining the reason why the back electromotive force constants in the

linear motors

201 and 299 are different.
FIG. 9A is a diagram showing back electromotive force constants in two coil arrays of the conventional linear motor 299.
FIG. 9B is a diagram showing back electromotive force constants in the two coil arrays (first coil array 203A and second coil array 203B) of the linear motor 201 according to the second embodiment of the present invention.

As shown in FIG. 9A, in the conventional linear motor 299, the waveforms of the back electromotive force constants of the coils (for example, the coils C1 and C2 (see FIG. 6B)) arranged to face each other are It was confirmed that the peak was shifted by about 90 ° in electrical angle.
As shown in FIG. 9B, in the linear motor 201 according to the second embodiment of the present invention, the waveforms of the back electromotive force constants of the coils (for example, the coil 231 and the coil 241) arranged to face each other are respectively It was confirmed that the peak of is shifted by about 30 electrical degrees.

In the

linear motors

201 and 299, there is a difference in a difference in electrical angle between waveforms of counter electromotive force constants of coils arranged opposite to each other.
In the linear motor 299, since the difference in electrical angle between the waveforms of the counter electromotive force constants of the coils C1, C2, etc. is large, a loss occurs in the entire counter electromotive force constant of the coil unit. In the linear motor 201, since the difference in electrical angle between the waveforms of the counter electromotive force constants of the

coils

231, 241 and the like is small, there is little loss in the entire counter electromotive force constant of the coil unit 203.
Therefore, it is considered that a difference has occurred in the back electromotive force constant in the

linear motors

201 and 299.

FIG. 10 is a table summarizing comparison of characteristics of the

linear motors

201, 298, and 299.
In the conventional linear motor 298, the back electromotive force constant and the rated thrust are large, but the cogging is also large. For this reason, in the linear motor 298, smooth movement of the magnet portion is hindered by cogging.
In the conventional linear motor 299, cogging can be reduced by about 85% compared to the linear motor 298. However, in the conventional linear motor 299, the back electromotive force constant and the rated thrust are reduced by 31% and 30%, respectively, as compared with the linear motor 298. For this reason, in the linear motor 299, efficiency becomes low and the request | requirement of energy saving cannot be satisfy | filled.

In contrast, the linear motor 201 according to the second embodiment of the present invention can reduce cogging by about 88% compared to the linear motor 298. At the same time, the back electromotive force constant and the rated thrust of the linear motor 201 are only 6% and 8% lower than those of the linear motor 298, respectively.
Therefore, the linear motor 201 can obtain high feed accuracy and positioning accuracy without hindering smooth movement of the magnet portion. In addition, the linear motor 201 can satisfy the demand for energy saving with almost no decrease in efficiency.

In the linear motor 201, since the core 204 around which the

coils

231, 241 and the like are wound has the same shape from the tooth base toward the tooth tip, the cogging is likely to occur. However, in the linear motor 201, although the shapes of the

teeth

251, 261 and the like are not T-shaped, cogging can be reduced.
Since the

teeth

251, 261 and the like have the same shape from the tooth base to the tooth tip, the linear motor 201 is easy to wind the

coils

231, 241, etc. (easy to assemble).

The first magnet row 202A and the second magnet row 202B are arranged so that the magnetic poles facing each other are opposite to each other. The

coils

teeth

251, 252 and the like toward the tooth tip. The

coils

teeth

261, 262, etc. toward the tooth base. By making the winding directions of the copper wires of the

coils

231, 232, 241, 242, etc. of the first coil row 203 A and the second coil row 203 B coincide with each other, assemblability is improved.

The above-described operational effects can be similarly obtained in the linear motor 101 (101A, 101B) according to the first embodiment.

Also in the linear motor 201, like the linear motor 101 according to the first embodiment, the tooth tip surfaces of some teeth may be inclined. Although illustration is omitted, the following may be adopted (corresponding to a linear motor 201B described later).
For convenience of explanation, the linear motor 201 described above is hereinafter referred to as a linear motor 201A.

Each of the teeth 251 to 256 and 261 to 266 has tooth tip surfaces 251T to 256T and 261T to 266T facing the first magnet row 202A or the second magnet row 202B.
The tooth tip surfaces (eg, tooth tip surfaces 251T to 253T) of three teeth (for example, teeth 251 to 253) that are different phases (U phase, W phase, and V phase) have different shapes. It is formed.
Of the three teeth, the tooth tip surface (for example, the tooth tip surface 252T of the tooth 252) arranged at the center in the row direction is formed in a plane parallel to the first magnet row 202A or the second magnet row 202B. Is done.
Of the three teeth, the tooth tip surfaces (for example, the tooth tip surfaces 251T and 253T of the teeth 251 and 253) arranged on both sides in the row direction (+ X direction and −X direction) are the first magnet row 202A or the first tooth row. It forms in the plane which inclines with respect to the two magnet row | line | column 202B. The tooth tip surfaces of the teeth arranged on both sides in the row direction (for example, the tooth tip surfaces 251T and 253T) are formed to face each other.
The shapes of the tooth tip surfaces 251T to 253T and the like are the same as the shapes of the tooth tip surfaces 151T to 153 and the like.

The tooth tip surfaces of the three teeth that are different from each other (for example, the tooth tip surfaces 251T to 253T of the teeth 251 to 253) are formed in a trapezoidal shape as a whole.
The tooth tip surfaces of the three teeth in different phases maintain a gap (gap A, B) with respect to the first magnet row 202A or the second magnet row 202B, respectively, and the first magnet row as a whole on both sides in the row direction. It is formed so as to be gradually separated from 202A or the second magnet row 202B.
The tooth tip surfaces 254T to 256T, 261T to 263T, and 264T to 266T of the teeth 254 to 256, 261 to 263, 264 to 266 are formed in the same shape as the tooth tip surfaces 251T to 253T.

The X direction cogging generated in the linear motor 201 (201A, 201B, 201C) according to the second embodiment of the present invention will be compared.
The linear motors 201B and 201C are modifications of the linear motor 201A.

In the linear motor 201A, all the tooth tip surfaces 251T and the like are formed in parallel to the first magnet row 202A or the second magnet row 202B.
In the linear motor 201B, the tooth tip surfaces of the three teeth (for example, the tooth tip surfaces 251T to 253T of the teeth 251 to 253) having different phases are formed in a trapezoidal shape as a whole.
In the linear motor 201C, the tooth tip surfaces 251T, 256T, 261T, 266T are formed to be inclined with respect to the first magnet row 202A or the second magnet row 202B, and the tooth tip surfaces 253T, 254T, 263T, 264T are the first magnets. It is formed in parallel to the row 202A or the second magnet row 202B.

In the linear motor 201A, the difference between the maximum value and the minimum value of cogging in the X direction is about 0.16N.
In the linear motor 201B, the difference between the maximum value and the minimum value of cogging in the X direction is about 0.13N.
In the linear motor 201C, the difference between the maximum value and the minimum value of cogging in the X direction is about 0.14N.

Comparing the X-direction cogging generated in the linear motors 201A, 201B, and 201C, it is confirmed that the X-direction cogging generated in the linear motor 201B is the smallest, and the next X-direction cogging generated in the linear motor 201C is the smallest. It was.
It has been confirmed that the linear motors 201B and 201C can obtain the same operational effects as those of the linear motor 101 (101A) according to the first embodiment.

The various shapes and combinations of the constituent members shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

Although the case where the interval (separated distance) in the column direction between the first coil unit 105 and the second coil unit 106 is ¼ of the magnetic pole pitch P of the first magnet column 102A or the like (mechanical angle 90 °) has been described. Not limited to this. The interval may be between a mechanical angle of −30 ° and 90 °.

The case where the shift amount (shifted distance) in the column direction between the first coil unit 205 and the second coil unit 206 is ¼ of the magnetic pole pitch P of the first magnet column 202A (mechanical angle 90 °) has been described. However, it is not limited to this. The amount of deviation may be between a mechanical angle of −30 ° and 90 °.

The

first magnet rows

102A and 202A and the

second magnet rows

102B and 202B, the

first coil rows

103A and 203A, and the

second coil rows

103B and 203B are not limited to being arranged facing each other. Like the flat linear motor, the

first magnet arrays

102A and 202A and the

second magnet arrays

102B and 202B are arranged so as to face the same direction. And you may arrange | position so that 1st coil row | line |

column

103A, 203A and 2nd coil row | line |

column

103B, 203B may face (facing) with respect to 1st magnet row | line |

column

102A, 202A and 2nd magnet row | line |

column

102B, 202B.

Although the

linear motors

101 and 201 have been described as being three-phase induction motors, the present invention is not limited to this. The

linear motors

101 and 201 may be a two-phase induction motor or a multi-phase induction motor.
For example, when the

linear motors

101 and 201 are two-phase induction motors, the phase difference (electrical angle) between the input current to the

first coil arrays

103A and 203A and the input current to the

second coil arrays

103B and 203B is 180 °. Set to.
For example, when the

linear motors

101 and 201 are five-phase induction motors, the phase difference (electrical angle) between the input current to the

first coil arrays

103A and 203A and the input current to the

second coil arrays

103B and 203B is 72 °. Set to.

In the linear motor 201, the case where the first coil unit 105 and the second coil unit 106 are arranged to be shifted in the column direction has been described, but the present invention is not limited thereto.
The first magnet row 202A and the second magnet row 202B of the magnet unit 202 may be arranged so as to be shifted by a quarter of the magnetic pole pitch P (P / 4) in the row direction. In this case, the first coil part 105 and the second coil part 106 are arranged without being shifted in the column direction. Then, a three-phase alternating current having a phase difference of 120 ° is input to the first coil unit 105 (first coil group 203A) and the second coil unit 106 (second coil group 203B).

101 linear motor 102A first magnet array 102B second magnet array 103A first coil array 103B second coil array 103C first coil group 103D

second coil group

111, 112, 121, 122 magnet 131-136, 141-146 coil 151 156, 161 to 166 Teeth 151T to 156T, 161T to 166T Tooth tip surface 201 Linear motor 202A First magnet group 202B Second magnet group 203A First coil group 203B Second coil group 203C First coil group 203D

Second coil group

211, 212, 221, 222 Magnets 231 to 236, 241 to 246 Coils 251 to 256, 261 to 266 Teeth 251T to 256T, 261T to 266T Tooth tip surface P Magnetic pole pitch

Claims

A plurality of magnets forming a pair of magnet arrays arranged in parallel at the same magnetic pole pitch;
A plurality of coils forming a pair of coil arrays arranged in parallel corresponding to the pair of magnet arrays;
In the opposed linear motor comprising
The plurality of coils are linear motors that form a pair of coil groups in which the positional relationship and the phase arrangement in the column direction with respect to the magnetic poles of the pair of magnet rows are different from each other.
The linear motor according to claim 1, wherein the positional relationship between the pair of coil groups differs by ¼ of the magnetic pole pitch.
The linear motor according to claim 1, wherein the pair of coil groups have a phase difference of 120 ° in driving current to the equivalent coil.
Each of the pair of coil groups has a plurality of coils having the same number of phases and different phases for each of the pair of coil rows,
The linear motor according to any one of claims 1 to 3, wherein the pair of coil groups are spaced apart in the column direction.
Each of the pair of coil groups is one of the pair of coil rows,
The linear motor according to any one of claims 1 to 3, wherein the pair of coil rows or the pair of magnet rows are arranged to be shifted in a row direction.
Each of the plurality of coils is wound, and includes a plurality of teeth formed with tooth tip surfaces facing the magnetic poles,
The plurality of teeth are formed so that a pair of teeth arranged at both ends in a row direction out of the same number of teeth as different phases from each other are inclined so that the tooth tip surfaces face each other back. The linear motor according to any one of 1 to 5.
The linear motor according to any one of claims 1 to 6, wherein the pair of magnet rows are arranged so that magnetic poles facing each other are opposed to each other.