JPH11206100A - Linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cogging force and heat generation of a linear motor and improve the performance of the linear motor without increasing the cost. SOLUTION: A linear motor is composed of stators, which have respective permanent magnet rows facing each other and mover which runs between the stators. A mover 10 is constituted of main division cores 12, on which coils 11 are wound and auxiliary division cores 13 on which coils are not wound and the auxiliary division cores are formed of layered magnetic steel plates which have identical shapes or shapes similar to the layered magnetic steel plates of which the main division cores 12 are composed. The layering thicknesses of the auxiliary division cores 13 are successively reduced, the farther away they are from the main division cores 12. The shape of the magnetic steel plate is made into one of cross-shape, T-shape or I-shape. The sum of the lengths of the auxiliary division cores 13 satisfies the inequality: the sum <=(2 × pole pitch). If a solid core 53 is used for the auxiliary division core 13, the shape of the side view of the solid core 53 is a chevron shape pentagon which is made to satisfy the inequality: chevron height $(2 ×pole pitch). The number of the main division cores 12 is made a multiple of 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor used for feeding a machine tool table.

[0002]

2. Description of the Related Art Conventional linear motors are disclosed in Japanese Patent Application Nos. 9-82133 and 9-14 already filed by the present applicant.
As disclosed in Japanese Patent No. 3016, there is one in which two stators face each other and a mover moves between them. The structure of the mover of these linear motors is such that the coil is wound around the split core in advance and the split cores are connected to each other, so that the winding space factor in the slot is high and the heat generation is small. Is the feature. Another conventional linear motor is disclosed in Japanese Patent Application Laid-Open No. 64-47260, which has the effect of reducing the cogging force by diagonally cutting out the iron core of the armature as a mover. Has been obtained.

[0003]

However, these prior arts have the following problems. That is, Japanese Patent Application Nos. 9-82133 and 9-14 filed by the present applicant.
The linear motor described in No. 3016 has a problem that a large cogging force is generated when the mover tilts due to slight mishandling at the time of mounting the table and imbalance occurs in the left and right gaps. Further, the permeance differs greatly where the iron cores at both ends of the mover exist and where there is no iron core, and this also causes a problem that the cogging force is increased. Further, in the linear motor described in Japanese Patent Application Laid-Open No. 64-47260, when the iron core of the armature is formed by stacking magnetic steel plates, several types having different shapes must be prepared to reduce the cogging force. The stacking method became complicated and the cost was high. Further, in such an integrated armature core, the space factor of the winding in the slot is small, and when a large thrust is required, the heat generation becomes large.

[0004]

In order to solve the above-mentioned problems, the present invention according to claim 1 has a structure in which opposing permanent magnets are fixed inside two parallel back yokes, and the permanent magnets are moved in the moving direction. A plurality of stators respectively arranged on the two back yokes so as to be sequentially different in polarity along with a plurality of divided cores formed by stacking magnetic steel sheets and wound with coils are arranged in the moving direction and mechanically arranged. And a mover supported at the center of the stator such that the side surface of the split core faces the permanent magnet and supported so as to be movable in the moving direction. Consists of a plurality of main split cores around which coils are wound, and auxiliary split cores which are arranged at both ends of the main split core without winding the coils, and whether the auxiliary split cores are the same as the main split cores. Or similar Together are formed by laminating magnetic steel plates of shape, is characterized in that a product thickness of the complement split cores are successively smaller as the distance from the closer to the main split core. The invention according to claim 2 is characterized in that the shape of the magnetic steel sheet is any one of a cross shape, a T-shape, and an I-shape. And the number thereof is set so that the sum of the lengths of the complementary split cores ≤ (2 x pole pitch).

According to a fourth aspect of the present invention, an opposing permanent magnet is fixed inside two parallel back yokes,
A plurality of stators respectively arranged on the two back yokes such that the permanent magnets have different polarities sequentially along the moving direction; and a plurality of divided cores formed by stacking magnetic steel plates and winding coils. Are arranged in the center of the stator such that the side surfaces of the split core face the permanent magnets and are supported so as to be movable in the moving direction. In the linear motor, the mover is formed by laminating a cross-shaped magnetic steel plate and then winding a plurality of main divided cores, and the coil is not wound and disposed at both ends of the main divided core. Wherein the shape of the iron core viewed from the side is pentagonal and has a mountain shape. The invention according to claim 5 is characterized in that the pentagonal mountain shape has a peak height ≦ ( 2 x pole pitch) Characterized in that it is formed so as to be, the invention of claim 6 is characterized in that the number of primary split core is a multiple of 3. By each of the above means, the divided cores at both ends of the mover are arranged stepwise with respect to the permanent magnet, so that the cogging force can be reduced. As described above, when the cogging force is reduced by using the above-described means, it is only necessary to change the number (thickness) of magnetic steel sheets having the same shape when forming the split core, or to reduce the number of magnetic steel sheets having a small number of shapes. Since it is only necessary to change the number of sheets (thickness), the width in which the cogging force can be reduced can be freely selected without increasing the number of processing steps. In addition, instead of the split cores at both ends of the mover with laminated magnetic steel plates, by attaching a diagonally cut iron core, the cogging force generated at the pole pitch can be completely eliminated while reducing the number of processing steps. is there.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a drawing of a linear motor according to a first embodiment of the present invention, wherein FIG.
(B) is a diagram of the lateral end surface of the mover. FIG. 4A is a cross-sectional view of a main part taken along the line AA ′ in FIG. This linear motor has a basic configuration of 8 poles and 9 slots. In FIG. 1, reference numerals 4 and 5 denote back yokes on which a plurality of permanent magnets 3 are fixedly arranged so that magnetic poles are alternately arranged. The back yoke 4 to which the permanent magnet 3 is fixed forms the left stator 1, and the back yoke 5 to which the permanent magnet 3 is fixed forms the right stator 2, and the opposed permanent magnets 3 of the two stators
Are arranged to have the same polarity. Reference numeral 13 denotes a complementary cruciform split core formed by laminating cruciform magnetic steel sheets.
Is a main cruciform split core formed by laminating the same magnetic steel plates as the complementary cruciform split core 13 and then winding the coil 11. The nine main cruciform split cores 12 and the four complementary cruciform split cores are mechanically fixed by concave and convex portions that fit together, and the complementary cruciform split core 13 moves away from the main cruciform split core 12 as a magnetic steel sheet. Has become smaller. The main cruciform split core 12 and the complementary cruciform split core 13 are vertically sandwiched between an upper mover member 14 and a lower mover member 15, and are provided at the center of the main cruciform split core 12 and the complementary cruciform split core 13. The movable element 10 is rigidly fixed to each other with bolts 16 passing through the screw holes 17. A load (not shown) is fixed to the mover upper member 14, and the mover 10 is supported by a guide (not shown).
2 and the gap between the two lateral end surfaces of the complementary cross-shaped split core 13 and the permanent magnets 3 of the two stators 1 and 2 are kept constant, and the mover 10 is moved in the longitudinal direction with respect to the stators 1 and 2. It is possible to move to.

FIGS. 2A and 2B are drawings of a linear motor according to a second embodiment of the present invention, wherein FIG.
FIG. 4 is a view of a lateral end surface of the mover. FIG. 4B shows FIG.
It is a principal part sectional view of the AA 'side of (b). This linear motor also has a basic configuration of 8 poles and 9 slots. This embodiment differs from the first embodiment in that a main split core 12 and a complementary split core 13 are formed using a T-shaped magnetic steel plate, and a main T-shaped split core 22 and a complementary T-shaped split core. 2
3 and the method of winding the coil in accordance therewith, and the others are the same as in the first embodiment. FIG. 3 is a drawing of a linear motor according to a third embodiment of the present invention.
(A) is a sectional view of a main part viewed from above, and (b) is a view of a lateral end surface of the mover. FIG. 4C is a cross-sectional view of a main part taken along the line AA ′ in FIG. This linear motor also has a basic configuration of 8 poles and 9 slots. This embodiment is different from the first and second embodiments in that the main split cores 12, 22 and the auxiliary split cores 13, 23 of the mover 10 are formed by using a main I-shaped magnetic steel plate. The mold split core 32 and the complementary I-shaped split core 33 are replaced, and the opposed permanent magnets 3 of the two stators are arranged so as to have different polarities. The method of winding the coil is the same as that of the first and second embodiments.

FIG. 5 is a drawing of a linear motor according to a fourth embodiment of the present invention, wherein (a) is a cross-sectional view of a main part viewed from above, and (b).
FIG. 4 is a view of a lateral end surface of the mover. In this embodiment, the first
The difference from the embodiment is that the complementary cross-type split core 5 of the mover 10
3 is shorter in length than the main cross-shaped split core 52, and the other points are the same as in the first embodiment. In the above four embodiments, the main split cores 12, 22, 3
Complementary split cores 13, 23, 33 provided before and after 2, 42,
The length and the number of 43 are set so that the sum of the lengths of the sub-divided cores ≦ (2 × pole pitch). 6A and 6B are drawings of a linear motor according to a fifth embodiment of the present invention, wherein FIG. 6A is a cross-sectional view of a main part viewed from above, and FIG. 6B is a view of a lateral end surface of the mover. This embodiment differs from the first embodiment in that, instead of the complementary cruciform split core 13 of the mover 10, a diagonally notched iron core is provided, and the shape of the side surface is a pentagon having a mountain shape. is there. The pentagonal mountain is formed so as to satisfy the relationship of mountain height ≦ (2 × pole pitch). In the above several embodiments, the number of the main split cores is described as nine. However, the number of the main split cores may be a multiple of three, and is not limited to nine. According to each of the above embodiments, the complementary split cores at both ends in the longitudinal direction of the mover are arranged stepwise with respect to the permanent magnet, so that the cogging force can be reduced.
In the case of Examples 1 to 3, when forming the divided cores, the number of sheets (thickness) using magnetic steel sheets having the same shape as the main divided cores is used.
, The cogging force can be reduced without increasing the number of processing steps. In the case of the fourth embodiment, only one kind of auxiliary split core having a different shape prepared separately from the main split core may be used, and the auxiliary split core can be configured only by changing the number (thickness) of the auxiliary split core. The cogging force can be reduced without increasing it unnecessarily.
As described above, it is easy to obtain a required thickness according to the shape and arrangement of the divided cores, and the degree of freedom of design can be increased without increasing the number of steps.

[0009]

As described above, according to the present invention, near the both ends in the longitudinal direction of the mover 10, the area of the iron core facing the permanent magnet 3 decreases from the main split core toward both ends. Therefore, the cogging force of the linear motor is reduced. Further, when manufacturing the supplemental split cores at both ends of the mover 10, in Examples 1 to 3, it is only necessary to change the number (thickness) of magnetic steel plates having the same shape as the split core at the center of the mover. The cogging force can be reduced without increasing the cost, and the thickness can be freely set, so that the design can be easily changed. Further, in the embodiment in which the iron core of the mover is constituted by the split core, there is an advantage that the winding space factor in the slot is high and the heat generation is suppressed to a small value.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a linear motor according to a first embodiment of the present invention.

FIG. 2 is a structural diagram of a linear motor according to a second embodiment of the present invention.

FIG. 3 is a structural diagram of a linear motor according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a main part of the linear motor according to the first to third embodiments;

FIG. 5 is a structural diagram of a linear motor according to a fourth embodiment of the present invention.

FIG. 6 is a structural diagram of a linear motor according to a fifth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 left stator 2 right stator 3 permanent magnet 4, 5 back yoke 10, 20, 30, 50, 60 mover 11, 21, 31, 51, 61 coil 12, 52, 62 main cruciform split core 13, 53 Complementary cross-type split core 17, 27, 37, 57, 67 Screw hole 14, 24, 34 Upper mover 15, 25, 35 Lower mover 16, 26, 36 Bolt 22 Main T-shaped split core 23 Complement T D-shaped split core 32 Main I-shaped split core 33 Complementary I-shaped split core 63 Iron core cut diagonally

Claims (6)

[Claims] An opposing permanent magnet is fixed inside two parallel back yokes, and a plurality of the permanent magnets are arranged on the two back yokes such that the permanent magnets have different polarities sequentially in the moving direction. And a plurality of divided cores formed by stacking magnetic steel sheets and wound with coils are arranged side by side in the moving direction and mechanically coupled, and the side surfaces of the divided cores face the permanent magnets. A linear motor comprising: a movable element disposed at the center of the stator and movably supported in the moving direction; wherein the movable element includes a plurality of main divided cores having coils wound thereon, and coils wound thereon. And the auxiliary split core is formed by stacking magnetic steel sheets having the same or similar shape as the main split core, and the main split Ko Linear motor, characterized in that the lamination thickness of the complement split cores are successively smaller as the distance from near the. 2. The magnetic steel sheet has a cross shape, a T shape and an I shape.
2. The linear motor according to claim 1, wherein the linear motor is one of a letter shape. 3. The length and the number of the auxiliary split cores are set such that the sum of the lengths of the auxiliary split cores ≦ (2 × pole pitch).
Or the linear motor according to 2. 4. A permanent magnet opposed to the inside of two parallel back yokes is fixed, and a plurality of the permanent magnets are arranged on the two back yokes so as to sequentially have different poles in the moving direction. And a plurality of divided cores formed by stacking magnetic steel sheets and wound with coils are arranged side by side in the moving direction and mechanically coupled, and the side surfaces of the divided cores face the permanent magnets. A linear motor comprising: a movable member disposed at the center of the stator and supported to be movable in the moving direction, wherein the movable member is formed by laminating a cross-shaped magnetic steel sheet, and then winding a coil. It is composed of a plurality of main split cores and iron cores which are not wound around the coils and are arranged at both ends of the main split cores, and the shape of the iron core as viewed from the side surface is a pentagon and has a mountain shape. Linear motor. 5. The linear motor according to claim 4, wherein the pentagonal peaks are formed so as to satisfy the following relationship: peak height ≦ (2 × pole pitch). 6. The linear motor according to claim 1, wherein the number of the main split cores is a multiple of three.