JPS63198572A - Linear pulse motor - Google Patents

Abstract

PURPOSE:To enhance the reliability of a linear pulse motor by enclosing the pole of a primary core with a nonmagnetic material, and constructing to form it in the same plane as the pole teeth of the core. CONSTITUTION:The primary core 10 of a linear pulse motor is composed of 4 poles 11, and a permanent magnet 12, and the periphery is enclosed with a nonmagnetic material 13. The surfaces of the material 13 and the secondary core of the pole 11 are simultaneously polished in the same plane, and pole teeth responsive to a step pitch are formed at the pole 11. Since the secondary core is formed larger than the region formed with the material 13, as the secondary moves, the pole 11 of the primary core is not contacted with the atmosphere except the intermediary of an air gap between the primary core and the secondary core. Thus, dust particles larger than the air gap length can be prevented from invading to the interior at the air gap between the material 13 and the secondary core.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a linear pulse motor in which a primary core or a secondary core moves a predetermined distance in response to an input pulse.

(Prior Art) FIG. 2 shows a schematic diagram of a conventionally well-known linear pulse motor. The mover 20 has a permanent magnet 23 installed between U-shaped magnetic members 21 and 22, and the magnetic member 21
．． It is constructed by winding excitation coils 24 and 28 around 22. The permanent magnet 23 is magnetized as shown by a symbol 27 indicating the direction of magnetization. The stator 25 is formed with unevenness 26 corresponding to the step pitch.

FIGS. 3(a) to 3(d) are diagrams illustrating the operating principle of the linear pulse motor shown in FIG. 2. The excitation coil 24 wound around the magnetic material 21 is connected in series so that the magnetic poles (1) and (2) have opposite magnetism. Similarly, an excitation coil 28 is wound around the magnetic material 22 so that the magnetism of the magnetic poles (1) and (2) are opposite to each other. When the excitation coil 24 is excited by passing a current in the direction shown by the arrow, the magnetic field is strengthened at the magnetic pole (2), and the magnetic field of the permanent magnet and the magnetic field of the electromagnet cancel each other at the magnetic pole (2). It stops at the position shown in figure (a). At this time, no current is flowing through the coil 28 on the side of the magnetic material 22, so the magnetic force is balanced. When the zero-order coil 24 is demagnetized and a current is caused to flow through the coil 28 in the direction of the arrow, a magnetic field is generated at the magnetic pole ■. As a result, the mover moves in the direction of movement shown by the arrow in the figure, and as a result, the mover moves in the direction of movement shown by the arrow in the figure, and
The mover stops at the position shown in b). That is, the mover 20 has moved 174 pitches in the direction of movement indicated by the arrow. Thereafter, the movable element is linearly moved in the same manner.

(Problems to be Solved by the Invention) Linear pulse motors are normally driven in the atmosphere. Since a linear pulse motor generates suction force through the gap between the primary core and the secondary core, this gap length must be kept very small. As it becomes finer,
It is important to keep it small. Usually 30 to 40 μm, depending on mechanical processing accuracy or surface roughness, etc.
degree is used as the void length. However, there is a large amount of dust with a diameter of 30 μm or more in the atmosphere, and there is a good possibility that this dust will enter the gap of the linear pulse motor. When dust enters the void,
Linear pulse motors not only do not perform the intended function, but also may cause damage to the magnetic pole teeth.

In view of this point, an object of the present invention is to provide a highly reliable linear pulse motor.

(Means for Solving the Problems) The present invention provides a secondary core in which a plurality of magnetic pole teeth are formed in a magnetic material having low coercive force and high saturation magnetic flux density so as to correspond to the step pitch, and a secondary core having low coercive force and high saturation magnetic flux density. forming a plurality of magnetic pole teeth in a magnetic material having a high saturation magnetic flux density so as to closely oppose the surface having the magnetic pole teeth of the secondary core and to obtain a desired step pitch in combination with the magnetic pole teeth; A linear pulse motor comprising a primary core equipped with a permanent magnet so as to generate force through magnetic coupling with magnetic pole teeth of the secondary core, and an excitation coil wound around the primary core. The magnetic pole of the primary core is surrounded by a non-magnetic material, and the surface facing the secondary core is constructed to be flush with the magnetic pole teeth of the primary core.

(Function) Magnetic pole teeth are formed in the primary core and secondary core of the present invention to correspond to the step pitch, and permanent magnets are attached so that the magnetic pole teeth generate force through magnetic coupling. has been done.

Furthermore, the magnetic pole of the primary core is surrounded by a non-magnetic material, and the non-magnetic material is built horizontally so as to be flush with the magnetic pole teeth of the primary core. Therefore, in the linear pulse motor of the present invention, there is nothing in the gap between the magnetic pole teeth of the primary core and the secondary core other than the dust that passes through the gap between the non-magnetic material and the secondary core.
It is possible to prevent dust from being caught between the magnetic pole teeth of the primary core and the secondary core.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1(a) is a schematic diagram of the primary core of a linear pulse motor according to an embodiment of the present invention, and FIG. 1(b) is a schematic diagram of the primary core in a direction parallel to the traveling direction of the linear pulse motor. It shows a cross-sectional view.

The primary core 10 is composed of four magnetic poles 11 and a permanent magnet 12, and is further surrounded by a non-magnetic material 13. The non-magnetic material 13 is made of aluminum, for example. The nonmagnetic material 13 and the surface of the magnetic pole 11 facing the secondary core are simultaneously polished to form the same plane. The magnetic pole 11 is formed with magnetic pole teeth corresponding to the step pitch. Since the secondary core is formed larger than the area formed by the non-magnetic material 13, as the secondary core moves, the magnetic pole 11 of the primary core is never comes into contact with the atmosphere. For example, if dust in the atmosphere is smaller than the air gap length, there are cases where it passes through the air gap between the non-magnetic material 13 and the secondary core, but it may cause significant damage to the magnetic pole teeth formed on the magnetic pole 11. are very few. In addition, dust particles larger than the gap length can be prevented from entering the inside at the gap between the non-magnetic material 13 and the secondary core.

(Effects of the Invention) As described above, according to the present invention, it is possible to realize a highly reliable linear pulse motor even when driven in the atmosphere.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic diagram of the primary core of a linear pulse motor according to an embodiment of the present invention, and FIG. 1(b) is a cross-section of the primary core in a direction parallel to the traveling direction of the linear pulse motor. Figure 2 is a schematic diagram of a conventionally well-known linear pulse motor, and Figures 3 (a) to (d) are diagrams explaining the operating principle of the linear pulse motor shown in Figure 2. Each is shown below. 1... Primary core 11... Magnetic pole 12, 23... Permanent magnet 13... Non-magnetic material 20... Mover 21, 22... Magnetic material 24, 28... Exciting coil 25 ···stator

Claims (1)

[Claims] A secondary core in which a plurality of magnetic pole teeth are formed in a magnetic material having low coercive force and high saturation magnetic flux density so as to correspond to the step pitch; A plurality of magnetic pole teeth are formed so as to closely face the surface having magnetic pole teeth of the core and to obtain a desired step pitch by combination with the magnetic pole teeth, and by magnetic coupling with the magnetic pole teeth of the secondary core. In a linear pulse motor configured with a primary core equipped with a permanent magnet to generate force and an excitation coil wound around the primary core, the magnetic pole of the primary core is surrounded by a non-magnetic material. A linear pulse motor characterized in that a surface facing the secondary core is constructed on the same surface as magnetic pole teeth of the primary core.