JP2005223997A - Linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lessen cogging torque, in a linear motor or a cylinder type linear motor which is constituted so that the overall length dimension in motional direction of the row of permanent magnets may be larger than the overall length dimension in motional direction of the row of slots wherein exciting coils are arranged and shorter than the overall length dimension in motional direction of the core. <P>SOLUTION: Each pole tooth face 23a of two end-side pole teeth 23A and 23G positioned at both ends of the seven pole teeth 23A-23G of the core 17 comprises a first incline part 23b which leans so that the interval dimension between the pole tooth face 23a and the row 9 of the permanent magnets may be larger gradually as it goes away from other pole teeth 23B and 23F adjoining each in its motional direction in such a state that it confronts the row 9 of permanent magnets, and a second incline part 23d which leans so that the interval dimension between the pole tooth face 23a and the rows 9-15 of permanent magnets may be smaller gradually as it goes away from the first incline part 23b. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a linear motor and a cylinder type linear motor.

Japanese Patent Laid-Open No. 2002-359962 (Patent Document 1) includes a mover that includes a permanent magnet array composed of a plurality of permanent magnets and reciprocates, and a stator that includes an armature having a core and an excitation winding. An included linear motor is shown. The core includes a plurality of pole teeth having pole tooth surfaces opposite to the permanent magnet row at the end, and a yoke that interconnects the plurality of pole teeth so that a slot is formed between two adjacent pole teeth. I have. The excitation winding plays a role of exciting a plurality of pole teeth. In this linear motor, the total length in the movement direction of the permanent magnet row is configured to be longer than the total length in the movement direction of the slot row where the windings are arranged, and shorter than the total length in the movement direction of the core. It has become a type.
Japanese Patent Laid-Open No. 2002-359962 (FIG. 6)

  However, in this type of linear motor, torque and thrust including pulsation (cogging force) are generated. Such cogging force hinders smooth reciprocation, and causes vibration and speed fluctuation. In the linear motor in which the total length dimension of the permanent magnet row in the moving direction is longer than the total length dimension in the core moving direction, the pole tooth surfaces of the two end side pole teeth positioned at both ends of the plurality of pole teeth are respectively The cogging force is reduced by inclining the gap dimension between the pole tooth surface and the permanent magnet array so as to gradually increase as the distance from other adjacent pole teeth increases. However, in a linear motor in which the total length in the movement direction of the permanent magnet row is not much longer than the total length in the movement direction of the slot row where the windings are arranged, the cogging force cannot be reduced only by such inclination.

  The purpose of the present invention is to provide a linear configuration in which the total length in the movement direction of the permanent magnet row is longer than the total length in the movement direction of the slot row where the windings are arranged, and shorter than the total length in the movement direction of the core. An object of the present invention is to provide a linear motor and a cylinder type linear motor that can reduce the cogging force in the motor and the cylinder type linear motor.

  The linear motor to be improved by the present invention is configured such that the mover reciprocates with respect to the stator. One of the stator and the mover has one or more permanent magnet rows configured such that a plurality of permanent magnets are arranged in a row in a moving direction in which the mover reciprocates. The other of the stator and the mover has a plurality of pole teeth such that a slot is formed between a plurality of pole teeth having a pole tooth surface facing the permanent magnet row at the end and two adjacent pole teeth. The armature includes a core having yokes that connect the two to each other, and an excitation winding that is provided to the core and excites a plurality of pole teeth. And the total length dimension in the movement direction of the permanent magnet row is configured to be longer than the total length dimension in the movement direction of the row of slots in which the excitation windings are arranged, and shorter than the total length dimension in the movement direction of the core, The shape of the pole tooth surfaces of the two end side pole teeth located at both ends in the movement direction among the plurality of pole teeth is determined so as to reduce the generation of cogging force. In the present invention, the pole tooth surfaces of the two end-side pole teeth are opposed to the permanent magnet row, and the gap between the pole tooth surface and the permanent magnet row is increased as the distance from the other adjacent pole teeth increases. A first inclined surface portion that inclines so that the size gradually increases, and a second inclined surface that inclines so that the gap size between the pole tooth surface and the permanent magnet row gradually decreases as the distance from the first inclined surface portion increases. And an inclined surface portion. If the pole tooth surfaces of the two end side pole teeth are formed as in the present invention, the cogging forces generated in the two end side pole teeth positioned at both ends are optimally canceled when the mover reciprocates. be able to.

  In the present invention, the permanent magnet row side may be a mover and the armature side may be a stator, or the permanent magnet row side may be a stator and the armature side may be a mover. Since the dimension is shorter than the overall length in the moving direction of the core, the weight of the mover can be reduced if the permanent magnet array side is a mover and the armature side is a stator.

  The first inclined surface portion and the second inclined surface portion may be formed continuously, or one or more surfaces may be formed between the first inclined surface portion and the second inclined surface portion. In the case where the first inclined surface portion and the second inclined surface portion are continuously formed, the boundary position between the first inclined surface portion and the second inclined surface portion and the position viewed from the boundary portion It is preferable that the length dimension between the end point position of one inclined surface is longer than the length dimension between the boundary position and the end point position of the second inclined surface viewed from the boundary part. In this way, cogging generated at both ends is offset in a balanced manner, and there is an advantage that the entire cogging force can be reduced.

  Each of the first inclined surface portion and the second inclined surface portion may be a flat surface or a curved surface. If the first inclined surface portion and the second inclined surface portion are curved so as to be convex toward the side where the permanent magnet row is located, the cogging force caused by the dimensional error of the permanent magnet row or armature There is an advantage that balance can be suppressed.

  If the first inclined surface portion and the second inclined surface portion are curved so as to be recessed toward the side where the permanent magnet row is located, the number of elements for determining the pole tooth surface dimension is reduced, and the design of the magnetic pole surface is reduced. Becomes easier.

  The pole tooth surfaces of the two end side pole teeth have an extended surface portion that extends outward in the movement direction beyond the end of the permanent magnet row when the mover is in a stop position determined at both ends in the movement direction. It is preferable. As described above, when the extended surface portion is provided, there is an advantage that the cogging force at the stop position where the movable element is determined at both ends in the movement direction can be reduced. In this case, the length dimension δ in the movement direction of the extended surface portion is preferably determined so that the relationship with the pitch τp for arranging the permanent magnets in the permanent magnet row is δ / τp ≧ 0.05. In this way, the cogging force can be reduced within the entire movable range.

  The extended surface portion may be configured by extending the second inclined surface portion as it is, or may be formed so as to be substantially parallel to the permanent magnet row. If the second inclined surface portion is extended as it is, there is an advantage that the core can be easily formed. If it is formed so as to be almost parallel to the permanent magnet row, the cogging force near the stop position where the mover is fixed at both ends in the direction of movement can be reduced, and the cogging force caused by the dimensional error of the permanent magnet row or armature can be reduced. There is an advantage that balance can be suppressed.

  Assuming a virtual horizontal line connecting the end point position of the first inclined surface part and the end point position of the second inclined surface part and a virtual vertical line orthogonal to the virtual horizontal line and passing through the boundary position, the virtual horizontal line and the virtual vertical line When the distance between the intersection point and the boundary position is h, the relationship between the pitch τp and the distance h for arranging the permanent magnets in the permanent magnet row is h / τp = 0.1 to 0.4. Thus, it is preferable that the first and second inclined surface portions are formed. In this way, the cogging force can be reduced optimally.

  The distance dimension LK between the boundary portion of one pole tooth surface of the two end side pole teeth and the boundary portion of the other pole tooth surface, the total length dimension LM in the movement direction of the permanent magnet row, and the permanent magnet row permanent The relationship with the pitch τp for arranging the magnets is preferably (LK−LM) /τp=0.25 to 1.25. In this way, the cogging force can be reduced optimally.

  The core is preferably configured by laminating a plurality of steel plates in a direction orthogonal to the movement direction. In this way, the manufacturing cost of the core can be reduced.

A cylinder type linear motor to be improved by the present invention includes a mover and a stator. The mover includes a linear motion shaft that reciprocates in the axial direction, a magnet mounting portion that is fixed to the linear motion shaft, and four permanent magnet rows that are fixed to the magnet mounting portion and arranged in the axial direction of the linear motion shaft. have. The stator is formed such that a slot is formed between a plurality of pole teeth having an end face facing a corresponding one of the four permanent magnet rows, and two adjacent pole teeth. The armature includes four cores including yokes that interconnect the plurality of pole teeth, and excitation windings that are attached to the four cores and that excite the plurality of pole teeth. And the total length dimension in the movement direction of the permanent magnet row is configured to be longer than the total length dimension in the movement direction of the row of slots in which the excitation windings are arranged, and shorter than the total length dimension in the movement direction of the core, Of the plurality of pole teeth included in the core, the shape of the pole tooth surfaces of the two end side pole teeth located at both ends in the movement direction is determined so as to reduce the generation of cogging force. In the present invention, the pole tooth surfaces of the two end side pole teeth are opposed to the permanent magnet row, and the distance between the pole tooth surface and the permanent magnet row increases as the distance from other pole teeth adjacent in the movement direction increases. Inclining so that the gap dimension between the pole tooth surface and the permanent magnet row gradually decreases as the distance from the first inclined surface part increases from the first inclined surface part. A second inclined surface portion. When the present invention is applied to such a cylinder type linear motor, in addition to reducing the cogging force, a coil end can be reduced by winding one winding so as to extend over four surfaces, and a low heat generating cylinder. A type linear motor can be obtained.

  According to the present invention, when the mover reciprocates, the cogging force generated in the two end side pole teeth located at both ends can be canceled out. Therefore, the cogging force can be reduced.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view of an example of an embodiment of a mover and a stator of a cylinder type linear motor of the present invention, and FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. As shown in both figures, the cylinder type linear motor of this example is composed of a mover 1 and a stator 3. The mover 1 is configured by attaching permanent magnet rows 9, 11, 13, and 15 to a structure in which a magnet mounting portion 7 is fixed to a linear motion shaft 5. The linear motion shaft 5 is made of iron, which is a magnetic material, and is supported by a pair of linear bearings (not shown) so as to be able to reciprocate. The magnet mounting portion 7 fixed to the linear motion shaft 5 has a quadrangular prism shape extending along the axial direction of the linear motion shaft 5, and its four side surfaces (four sides surrounding the linear motion shaft) 7a. , 7b, 7c, 7d are attached permanent magnet rows 9, 11, 13, 15 respectively. Each of the permanent magnet rows 9 to 15 is composed of nine plate-like permanent magnets (9a in FIG. 2) arranged in the axial direction. As shown in FIG. 1, the plate-like permanent magnets of the four permanent magnet rows 9 to 15 are attached in contact with other plate-like permanent magnet rows 9 to 15 adjacent in the circumferential direction. The circumferential lengths of the four flat permanent magnet rows 9 to 15 are longer than the circumferential length of the magnet mounting portion 7 by the thickness of the flat permanent magnet rows 9 to 15. Accordingly, projecting portions 9a, 11a, 13a, and 15a corresponding to the thickness of the plate-like permanent magnet rows 9 to 15 project from the end portions of the side surfaces 7a, 7b, 7c, and 7d of the magnet mounting portion 7, and this projecting portion 9a, 11a, 13a, and 15a are in contact with the end faces 11b, 13b, 15b, and 9b of the other flat permanent magnet rows 11, 13, 15, and 9, respectively.

  The stator 3 is composed of an armature having four cores 17 and six annular excitation windings 19A to 19F. The four cores 17 are arranged around the mover 1 and include seven pole teeth 23A to 23G and a yoke 21 that interconnects the seven pole teeth 23A to 23G as shown in FIG. ing. The seven pole teeth 23A to 23G have pole tooth surfaces 23a facing the corresponding one permanent magnet array (in the example shown in FIG. 2, the permanent magnet array 9) of the permanent magnet arrays 1 to 9 at the end. Yes. Further, as shown in FIG. 1, the four cores 17 are equally spaced in the circumferential direction so that the pole tooth surface 23a faces the permanent magnet rows 9 to 15 of the mover 1 (90 ° intervals in this example). It is arranged with a gap. A magnetic coupling body 25 that magnetically couples both cores 17 is disposed between two adjacent cores 17. On two surfaces of the magnetic coupling body 25, through holes 31 and 33 are formed side by side in the axial direction for fixing the two adjacent cores 17 by screwing with screw members 29. With this screw member 29, the magnetic coupling body 25 is firmly fixed between the adjacent cores 17.

  The four cores 17 are each configured by laminating a plurality of silicon steel plates in a direction orthogonal to the direction of movement of the mover 1 in a reciprocating motion. As shown in FIG. 2, six slots 26 formed between two adjacent pole teeth 23 of each core 17 have annular excitation windings 19A to 19F formed by winding a winding conductor in an annular shape. Part of each is fitted. In this example, the opposing surfaces 26a and 26a in the axial direction of the slot 26 extend in parallel so that the excitation windings 19A to 19F can be easily fitted.

  Of the seven pole teeth 23A to 23G of the core 17, the pole tooth surfaces 23a of the two end side pole teeth 23A and 23G located at both ends in the movement direction of the mover 1 are opposed to the permanent magnet rows 9 to 15. The first inclined surface portion 23b is inclined so that the gap dimension between the pole tooth surface 23a and the permanent magnet row 9 gradually increases as the distance from the other pole teeth 23B and 23F adjacent in the movement direction increases. And the first inclined surface portion 23b is formed continuously, and as the distance from the first inclined surface portion 23b increases, the gap between the pole tooth surface 23a and the permanent magnet rows 9 to 15 is inclined so as to gradually decrease. A second inclined surface portion 23d. Thereby, the recessed part 27 is each formed in the part by the side of the permanent magnet row | line | column 9 of the pole teeth 23A and 23G.

  The total length dimension LM in the movement direction of each of the permanent magnet rows 9 to 15 is longer than the total length dimension in the movement direction of the row of slots 26 in which the excitation windings 19A to 19F are arranged, and the total length dimension in the movement direction of the core 17. It is shorter than LE by about the end side pole teeth (23A or 23G). Further, the length dimension between the boundary position where the boundary portion 23c between the first inclined surface portion 23b and the second inclined surface portion 23d is located and the end point position of the first inclined surface 23b viewed from the boundary portion 23c. L1 is longer than the length dimension L2 between the boundary position and the end point position of the second inclined surface as viewed from the boundary portion 23c. Further, the pole tooth surfaces 23a of the two end-side pole teeth 23A and 23G are moved in the direction of motion beyond the ends of the permanent magnet rows 9 to 15 when the mover 1 is at a stop position determined at both ends of the direction of motion. It has the extended surface part 17a extended on the outer side. The extended surface portion 17a is formed so as to be substantially parallel to the permanent magnet rows 9-15. Thereby, the overall length LE in the motion direction of the core 17, the overall length LM in the motion direction of the permanent magnet rows 9 to 15, the stroke length S of the mover 1, and the length dimension δ in the motion direction of the extension surface portion 17a. The relationship is LE = LM + S + 2δ.

  Further, in the cylinder type linear motor of this example, the relationship between the length dimension δ in the movement direction of the extension surface portion 17a and the pitch τp for arranging the permanent magnets of the permanent magnet rows 9 to 15 is δ / τp ≧ 0. It is set to be 05. Further, assuming a virtual horizontal line LH connecting the end point position of the first inclined surface part 23b and the end point position of the second inclined surface part 23d and a virtual vertical line LP orthogonal to the virtual horizontal line LH and passing through the boundary position, the virtual line LH is assumed. When the distance between the intersection of the horizontal line LH and the virtual vertical line LP and the boundary position (the depth dimension of the recess 27) is h, the pitch τp for arranging the permanent magnets of the permanent magnet rows 9 to 15 is The first and second inclined surface portions 23b and 23d are formed so that the relationship with the depth dimension h of the recess 27 is h / τp = 0.1 to 0.4. Further, the first and second inclined surface portions 23b and 23d are formed between the boundary portion 23c of one pole tooth surface 23a of the two end side pole teeth 23A and 23G and the boundary portion 23c of the other pole tooth surface 23a. The relationship between the distance dimension (boundary distance dimension) LK, the total length dimension LM in the movement direction of the permanent magnet arrays 9 to 15 and the pitch τp for arranging the permanent magnets of the permanent magnet arrays 9 to 15 is (LK-LM). ) /Τp=0.25 to 1.25.

  In this example, the total length LM in the movement direction of each of the permanent magnet rows 9 to 15 is 144 mm, the total length in the movement direction of the core 17 is 180 mm, and the stroke length S is 32 mm. The length dimension δ in the movement direction of the extension surface portion 17a was 2 mm.

  The pitch τp for arranging the permanent magnets of the permanent magnet rows 9 to 15 is 16 mm, the depth dimension h of the recess 27 is 3.5 mm, and the pitch between the pole teeth is 18.7 mm. Yes, the boundary distance dimension LK was 152 mm.

Next, the cylinder type linear motor of this example was made with various dimensions and tested. First, three types of cylinder type linear motors XS1, XS2, and XS3 having stroke lengths S of 32 mm, 24 mm, and 16 mm, in which the first and second inclined surface portions 23b and 23d are formed (Example), The first and second inclined surface portions 23b and 23d are not formed, and the pole tooth surfaces of the two end side pole teeth are made flat (comparative example), and the first and second inclined surface portions 23b and 23d are formed. The cogging force of each cylinder type linear motor formed with the first and second inclined surface portions 23b and 23d when the cogging force of the cylinder type linear motor not formed is set to 100 was measured. Table 1 shows the measurement results.

  From Table 1, it can be seen that at any stroke length S, the cogging force can be greatly reduced by forming the first and second inclined surface portions 23b and 23d.

Next, the value (δ / τp) obtained by dividing the length dimension δ in the moving direction of the extension surface portion 17a by the pitch τp for arranging the permanent magnets is variously changed. The cogging force of each cylinder type linear motor was measured. In this test, the value of τp was kept constant, the value of δ was changed, and the value of δ / τp was changed variously. FIG. 3 shows the measurement results. It can be seen from FIG. 3 that the cogging force decreases when δ / τp ≧ 0.05.
Next, the value (h / τp) obtained by dividing the depth dimension h of the recess 27 by the pitch τp for arranging the permanent magnets of the permanent magnet array is variously changed. The cogging force of each cylinder type linear motor was measured. In this test, the value of pitch τp was made constant, and the value of depth dimension h was changed to change the value of (h / τp) variously. FIG. 4 shows the measurement results. FIG. 4 shows that the cogging force decreases when h / τp = 0.1 to 0.4.

  Next, in each of the three types of cylinder type linear motors XS1, XS2, and XS3 having different stroke lengths S, the boundary portion distance dimension LK and the total length dimension LM in the movement direction of the permanent magnet rows 9 to 15 and the permanent magnets. Cylinder linear motors similar to those in this example are made by changing the value of the relationship with the pitch τp for arranging the permanent magnets in the row to (LK-LM) / τp, and the others are the same as in this example. The cogging force was measured. In this test, the values of the total length dimension LM and the pitch τp were made constant, the value of the boundary portion distance dimension LK was changed, and the value of (LK−LM) / τp was changed variously. FIG. 5 shows the measurement results. From FIG. 5, it can be seen that at any stroke length S, the cogging force decreases when (LK−LM) /τp=0.25 to 1.25.

  The first and second inclined surface portions and the extended surface portion can be formed in various shapes. For example, as shown in FIG. 6, the first inclined surface portion and the second inclined surface portions 123 b and 123 d can be curved so as to be convex toward the side where the permanent magnet row 109 is located. In this way, there is an advantage that the balance of the cogging force due to the dimensional errors of the permanent magnet arrays 9 to 15 and the armature can be suppressed.

  Further, as shown in FIG. 7, the first inclined surface portion and the second inclined surface portions 223 b and 223 d can be respectively curved so as to be recessed toward the side where the permanent magnet row 209 is located. In this way, the elements that determine the pole tooth surface dimensions are reduced, and the design of the magnetic pole surface is facilitated. Further, the first inclined surface portion and the second inclined surface portion do not have to be formed continuously. For example, as shown in FIG. 8, the first inclined surface portion 323b and the second inclined surface portion 323d are formed. One or more surfaces 323e extending in parallel with the permanent magnet row 209 may be provided therebetween.

  In the above example, the extended surface portion is formed so as to be substantially parallel to the permanent magnet row. However, the extended surface portion may be configured by extending the second inclined surface portion as it is.

It is a schematic perspective view of an example of an embodiment of a mover and a stator of a cylinder type linear motor of the present invention. It is the schematic sectional drawing which cut | disconnected FIG. 1 by the II-II line. It is a figure which shows the relationship between the value (delta / taup) which divided | segmented the length dimension (delta) of the movement direction of the extended surface part by the pitch (tau) p for arrange | positioning a permanent magnet, and the cogging force of a cylinder type linear motor. It is a figure which shows the relationship between the value (h / τp) which divided the depth dimension h of the recessed part by the pitch (tau) p for arrange | positioning the permanent magnet of a permanent magnet row | line | column, and the cogging force of a cylinder type linear motor. The relationship between the boundary distance dimension LK, the total length dimension LM in the movement direction of the permanent magnet array, and the pitch τp for arranging the permanent magnets of the permanent magnet array is (LK−LM) / τp and the cylinder type linear motor It is a figure which shows the relationship with cogging force. It is the elements on larger scale of the cylinder type linear motor of other embodiment of this invention. It is the elements on larger scale of the cylinder type linear motor of other embodiment of this invention. It is the elements on larger scale of the cylinder type linear motor of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Movable element 3 Stator 9, 11, 13, 15 Permanent magnet row | line | column 17 Core 19A-19F Excitation winding 21 Yoke 23A-23G Polar tooth 26 Slot 23b 1st inclined surface part 23c Boundary part 23d 2nd inclined surface part

Claims (13)

The mover is configured to reciprocate with respect to the stator,
One of the stator and the mover has one or more permanent magnet rows configured such that a plurality of permanent magnets form a row in a moving direction in which the mover performs the reciprocating motion,
The other of the stator and the mover includes a plurality of pole teeth having pole tooth surfaces facing the permanent magnet row at the end, and a plurality of slots formed between the two adjacent pole teeth. An armature having a core including a yoke for connecting pole teeth to each other and an excitation winding provided to the core to excite the plurality of pole teeth;
The overall length dimension of the permanent magnet row in the movement direction is longer than the overall length dimension in the movement direction of the row of slots in which the excitation windings are arranged, and is shorter than the overall length dimension of the core in the movement direction. Configured as
The shape of the pole tooth surface of the two end side pole teeth located at both ends of the movement direction among the plurality of pole teeth is a linear motor that is determined so as to reduce the occurrence of cogging force,
The pole tooth surfaces of the two end-side pole teeth face each other between the pole tooth surface and the permanent magnet row as they move away from the other adjacent pole teeth in a state of facing the permanent magnet row. A first inclined surface portion that inclines so that a gap dimension of the first electrode gradually increases, and a gap size between the pole tooth surface and the permanent magnet row gradually decreases as the distance from the first inclined surface portion increases. The linear motor characterized by including the 2nd inclined surface part which inclines. The mover is configured to reciprocate with respect to the stator,
The mover has a plurality of permanent magnet rows configured such that a plurality of permanent magnets form a row in a moving direction in which the mover reciprocates.
In the stator, a plurality of pole teeth having pole tooth surfaces facing one of the corresponding permanent magnet rows among the plurality of permanent magnet rows at an end thereof and a slot formed between two adjacent pole teeth. An armature having a plurality of cores including yokes that interconnect the plurality of pole teeth, and an excitation winding that is attached to the plurality of cores and that excites the plurality of pole teeth. ,
The overall length in the movement direction of the permanent magnet row is longer than the overall length in the movement direction of the row of slots in which the excitation windings are arranged, and shorter than the overall length in the movement direction of the core. Configured as
The shape of the pole tooth surfaces of the two end side pole teeth located at both ends of the movement direction among the plurality of pole teeth included in the core is determined so as to reduce the occurrence of cogging force A motor,
The pole tooth surfaces of the two end side pole teeth are opposed to the permanent magnet row, and the pole tooth surfaces and the permanent magnets are separated from other pole teeth adjacent to the movement direction. The first sloping surface portion that inclines so that the gap size between the rows gradually increases, and the gap size between the pole tooth surface and the permanent magnet row gradually increases as the distance from the first sloping surface portion increases. A cylinder-type linear motor including a second inclined surface portion that is inclined so as to become smaller.   The linear motor according to claim 1, wherein the first inclined surface portion and the second inclined surface portion are continuously formed.   A length dimension between a boundary position where a boundary portion between the first inclined surface portion and the second inclined surface portion is located and an end point position of the first inclined surface viewed from the boundary portion is The linear motor according to claim 3, wherein the linear motor is longer than a length dimension between a boundary position and an end point position of the second inclined surface as viewed from the boundary portion.   3. The linear motor according to claim 1, wherein the first inclined surface portion and the second inclined surface portion are respectively curved so as to be convex toward the side where the permanent magnet row is located.   3. The linear motor according to claim 1, wherein the first inclined surface portion and the second inclined surface portion are respectively curved so as to be recessed toward the side where the permanent magnet row is located. The pole tooth surfaces of the two end side pole teeth extend beyond the end of the permanent magnet row beyond the end of the movement direction when the mover is at a stop position determined at both ends of the movement direction. It has an extended surface part that goes out,
The length dimension δ of the extension surface portion in the moving direction is determined so that the relationship with the pitch τp for arranging the permanent magnets in the permanent magnet row is δ / τp ≧ 0.05. The linear motor according to claim 3.   The linear motor according to claim 7, wherein the extended surface portion is configured by extending the second inclined surface portion as it is.   The linear motor according to claim 7, wherein the extension surface portion is formed to be substantially parallel to the permanent magnet row.   Assuming a virtual horizontal line connecting the end point position of the first inclined surface part and the end point position of the second inclined surface part, and a virtual vertical line orthogonal to the virtual horizontal line and passing through the boundary position, the virtual horizontal line When the distance between the intersection of the imaginary vertical line and the boundary position is h, the relationship between the pitch τp for arranging the permanent magnets of the permanent magnet row and the distance h is h / τp. The linear motor according to claim 3, wherein the first and second inclined surface portions are formed so as to be equal to 0.1 to 0.4.   The distance dimension LK between the boundary part of one pole tooth surface of the two end side pole teeth and the boundary part of the other pole tooth surface, and the total length dimension of the permanent magnet row in the movement direction The first and second inclined surface portions so that the relationship between LM and the pitch τp for arranging the permanent magnets in the permanent magnet row is (LK−LM) /τp=0.25 to 1.25. The linear motor according to claim 3, wherein the linear motor is formed.   The linear motor according to claim 1, wherein the core is configured by laminating a plurality of steel plates in a direction orthogonal to the movement direction. Four permanent magnet rows comprising a linear motion shaft that reciprocates in the axial direction, a magnet mounting portion fixed to the linear motion shaft, and a plurality of permanent magnets fixed to the magnet mounting portion and arranged in the axial direction of the linear motion shaft. A mover having,
A plurality of pole teeth having pole tooth surfaces facing one of the corresponding permanent magnet rows among the four permanent magnet rows, and slots formed between the two adjacent pole teeth. A stator including an armature having four cores having yokes for interconnecting a plurality of pole teeth, and an excitation winding attached to the four cores to excite the plurality of pole teeth; Equipped,
The overall length dimension of the permanent magnet row in the movement direction is longer than the overall length dimension in the movement direction of the row of slots in which the excitation windings are arranged, and is shorter than the overall length dimension of the core in the movement direction. Composed of
A cylinder in which the shape of the pole tooth surfaces of two end side pole teeth located at both ends in the movement direction among the plurality of pole teeth included in the core is determined so as to reduce the occurrence of cogging force. Type linear motor
The pole tooth surfaces of the two end side pole teeth are respectively opposed to the permanent magnet row, and the pole tooth surfaces and the permanent magnets are separated from the other pole teeth adjacent to the movement direction. The first sloping surface portion that inclines so that the gap size between the rows gradually increases, and the gap size between the pole tooth surface and the permanent magnet row gradually increases as the distance from the first sloping surface portion increases. A cylinder-type linear motor including a second inclined surface portion that is inclined so as to become smaller.

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