JP2005057822A - Linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high efficiency, high performance linear motor applicable to a machine tool, a carrying unit between semiconductor equipments, a carrying position determining unit, and the like. <P>SOLUTION: This linear motor has a three-dimensional structure in which a moving member (22) having a claw-pole core (24) is provided reciprocally between yokes (21A, 21A) of a stator (21), a permanent magnet (23) projects from the inner surface (21Aa) of each yoke (21A, 21A), and the stator (21) and moving member (22) are formed of soft magnetic materials. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a linear motor, and in particular, by making each permanent magnet project from the inner surface of each yoke, the efficiency is improved, and a high-speed, high-precision control is required for a machine tool, a semiconductor manufacturing equipment transport unit, and transport. The present invention relates to a technique for improving performance so that it can be used in a positioning device or the like.
[0002]
[Prior art]
Conventionally, among linear motors that have been used, there is a configuration using only an armature coil as a mover (see Patent Document 1). However, a disadvantage is that the thickness increases in order to obtain high thrust. 3 to FIG. 5, the configuration filed by the present applicant (Japanese Patent Application No. 02-304844) can be mentioned.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-86726
3 to 5, the conventional linear motor includes a stator 21 having an embedded permanent magnet and a mover 22 having a claw pole type core.
Next, as shown in FIGS. 3 and 4, the stator 21 has a configuration in which a permanent magnet 23 is embedded in a pair of yokes 21A and 21A made of a soft magnetic material. The magnetization direction of the permanent magnet 23 is configured so that the same pole is opposed to the traveling direction of the mover 22. The magnetic pole pitch τ of the stator 21 is set to about 20 mm, for example. Further, the length lm and the width Wm of the permanent magnet may be set to about lm = 3 to 6 mm and Wm = 6 mm, for example. Note that the yoke 21A made of soft magnetic material is made of a conventional laminated steel plate and sintered powder magnetic material, or only made of sintered powder magnetic material, so that each stator 21 and mover can be made. It is possible to configure the 22 structures into a three-dimensional structure.
[0005]
As shown in FIGS. 4 and 5, the mover 22 is provided in the longitudinal gap 10 between the yokes 21 </ b> A and 21 </ b> A so as to be reciprocally movable, and is a claw pole type core 24 that is a claw pole type core. 3 is a three-phase integrated structure in which a winding 25 which is an armature coil is wound and shifted by 2/3 pitch τ as shown in FIG. The claw pole type core 24 includes a claw pole portion 24A that is located on the winding 25 and has the same width as that of the winding 25, and a core portion 24B that is configured by a portion other than the claw pole portion 24A. Has been. The claw pole portion 24A constitutes a claw pole type tooth portion of the claw pole type core 24, and is formed in a taper type tapering toward the tip in order to prevent cogging of the linear motor. Yes. This taper type claw pole portion 24A has a total of four sets (see FIG. 3, that is, four at the top and bottom) in total so that the magnetic poles are opposite to each other, and is configured to generate a magnetic flux according to the current phase. . The number N of windings 25 may be about N = 100, for example.
[0006]
[Problems to be solved by the invention]
Since the conventional linear motor is configured as described above, the following problems exist.
That is, since the permanent magnet is embedded in the stator yoke, the magnetic flux from the permanent magnet flows to the yoke portion of the stator yoke sandwiching the permanent magnet, and cannot be used efficiently, increasing the motor efficiency. It was difficult.
In addition, since the yoke portion is thin, it is difficult to increase its mechanical strength against the suction force of the stator yoke and the mover.
[0007]
The present invention has been made to solve the above-described problems. In particular, high efficiency and high speed and high precision control are required by projecting each permanent magnet from the inner surface of each yoke. It is an object of the present invention to provide a linear motor designed for high performance so that it can be used for a machine tool, a semiconductor manufacturing device transfer unit, a transfer positioning device, and the like.
[0008]
[Means for Solving the Problems]
A linear motor according to the present invention includes a pair of yokes arranged opposite to each other to constitute a stator, a plurality of permanent magnets arranged at predetermined intervals along the longitudinal direction on the inner surface of each yoke, and the pair of yokes. In the linear motor including a mover having a claw pole type core that is disposed so as to be reciprocally movable in the formed longitudinal gap and wound with a winding, each permanent magnet protrudes from the inner surface of each yoke. Further, the movable element is formed of a soft magnetic material and has a three-dimensional structure.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a linear motor according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated to a part the same as that of a prior art example, or an equivalent part.
In FIG. 1 and FIG. 2, what is indicated by a reference numeral 21 is a long-shaped stator. The stator 21 includes a pair of yokes 21A and 21A that are spaced apart from each other, and inner surfaces of the yokes 21A and 21A. 21Aa is composed of a plurality of permanent magnets 23 disposed at predetermined intervals along the longitudinal direction thereof, and each permanent magnet 23 is provided in a state of projecting inward from the inner surface 21Aa.
[0010]
In the longitudinal gap 10 between the yokes 21A and 21A, a known claw pole type movable element 22 is disposed so as to freely reciprocate. The movable element 22 is a laminated steel plate made of a soft magnetic material, sintered powder magnetic material. A claw pole type core 24 formed in a three-dimensional shape by any of the materials, claw pole portions 24A disposed on both sides of the claw pole type core 24, and windings provided on the claw pole type core 24 25.
The principle of applying the current to the winding 25 to drive the mover 22 is the same as that of the above-described conventional example, and is omitted here.
[0011]
【The invention's effect】
Since the linear motor according to the present invention is configured as described above, the following effects can be obtained.
That is, since the permanent magnet is formed so as to protrude from the inner surface of the yoke, the magnetic flux does not flow to the yoke yoke portion as in the conventional case, and high-efficiency driving can be performed.
Further, since the permanent magnet protrudes from the inner surface of the yoke, the magnetic flux in the permanent magnet gap between the yokes can be freely controlled, and the thrust ripple can be reduced and the speed and the like can be easily controlled.
Further, since the mover is a claw pole type core, only one coil is required for each phase, and the coil manufacturing process can be simplified.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a linear motor according to the present invention.
FIG. 2 is a perspective view showing the mover of FIG. 1;
FIG. 3 is a perspective view showing a conventional linear motor.
4 is a perspective view showing a main part of FIG. 1. FIG.
5 is an enlarged perspective view showing the mover of FIG. 4;
[Explanation of symbols]
10 Longitudinal gap 21 Stator 21A York 21Aa Inner surface 22 Movable element 23 Permanent magnet 24 Claw pole type core 25 Winding

Claims (2)

A pair of yokes (21A, 21A) which are arranged opposite to each other and constitute the stator (21), and a plurality of permanents arranged at predetermined intervals along the longitudinal direction on the inner surface (21Aa) of each yoke (21A, 21A). A claw pole type core (24) in which a winding (25) is wound around a magnet (23) and a longitudinal gap (10) formed between the pair of yokes (21A, 21A). In a linear motor comprising a mover (22) having
Each of the permanent magnets (23) is provided so as to protrude from the inner surface (21Aa) of each of the yokes (21A, 21A). The linear motor according to claim 1, wherein the mover is made of a soft magnetic material and has a three-dimensional structure.

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