JPH053659A - Linear step motor - Google Patents

Abstract

PURPOSE:To reduce eddy current loss of stator by employing a structure substantially same as the structure of thin steel boards, laminated through slits, in the thicknesswise direction of scale teeth where the flux concentrates to induce eddy current thereby shunting the eddy current into small loops. CONSTITUTION:A long stator 1 is formed integrally of a magnetic material and a large number of scale teeth 1a are provided interdigitally at a predetermined pitch in the longitudinal direction wherein each scale tooth 1a is provided with four slits 1b at a predetermined interval in the thicknesswise direction. A plurality of sheets of H-shaped thin steel boards are laminated to produce an H-shaped core 21 and then an exciting coil 22 is applied thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear step motor, and more particularly to the shape of scale teeth of a stator.

[0002]

2. Description of the Related Art Conventionally, a linear step motor shown in FIG. 4 has been known, and this linear step motor is composed of a stator 11 and a mover 12.

The stator 11 is formed of a magnetic material in the form of a long piece, and is provided with a large number of scale teeth 11a protruding in a comb shape at a predetermined pitch in the longitudinal direction.

The mover 12 has two protruding pieces 13a, which are formed by laminating a plurality of U-shaped thin steel plates which are insulated from each other.
Iron core 13 formed in a U shape having 13b and its protruding piece
It consists of an exciting coil 14 wound around each of 13a and 13b, and at the tip of each of the protruding pieces 13a and 13b, the comb teeth are formed at a predetermined pitch relative to the scale teeth 11a of the stator 11. Four slider teeth 12a are provided so as to project.

In the mover 12, thrust is applied between the scale teeth 11a and the slider teeth 12a by a magnetic flux generated by applying an alternating current to the exciting coil 14 at a predetermined timing, so that the length of the stator 11 increases. It is designed to proceed along the direction.

[0006]

In the above-described conventional linear step motor, the mover 12 has a U-shaped iron core 13 formed by stacking a plurality of U-shaped thin steel plates insulated from each other.
, The eddy current loss can be reduced, but the stator 11 is formed of a magnetic material in the shape of an integral body, and the magnetic flux is concentrated as shown by the one-dot chain line in FIG. In the scale teeth 11a, a particularly large eddy current flows and the eddy current loss also increases, so that the thrust of the motor is drastically reduced.

The eddy current loss can be reduced by laminating thin steel sheets insulated from each other such that the insulating surfaces are parallel to the direction of the magnetic field alternation, but the direction of the magnetic field alternation is the longitudinal direction. In the case of a certain stator 11, since it is difficult to stack long thin steel plates and accurately form all the pitches of a large number of scale teeth 11a, it is generally formed as a single piece. is there. Further, the thinner the thin steel plate is, the more the eddy current loss is suppressed.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a linear step motor capable of reducing the eddy current loss of the stator.

[0009]

In order to solve the above-mentioned problems, a linear stepping motor according to the present invention is provided with a stator provided with scale teeth in a comb shape, and a comb shape facing the scale teeth. A linear step motor having a mover provided with slider teeth on the scale tooth is provided with a plurality of slits.

[0010]

According to the linear stepping motor of the present invention, the scale teeth of the stator are provided with a plurality of slits. Therefore, the scale teeth, on which magnetic flux is concentrated and eddy currents are easily generated, are laminated thin steel plates. Since the eddy current is divided into small loops and flows, the eddy current loss is reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS.

Reference numeral 1 denotes a stator, which is made of a magnetic material and is formed in an elongated shape, and a plurality of scale teeth 1a projecting like comb teeth at a predetermined pitch in the longitudinal direction thereof. As shown in FIG. 1, the scale teeth 1a extend from the tip of the protruding portion to the root at equal intervals in the plate thickness direction.
Individual slits 1b are provided. And this stator
Two of them 1 are arranged in parallel at a predetermined interval so that both scale teeth 1a are opposed to each other and the pitches of the scale teeth 1a facing each other are not displaced.

Numeral 2 is a mover, which is formed by laminating a plurality of H-shaped thin steel plates insulated from each other to form four protruding pieces 21a,
It comprises an iron core 21 formed in an H shape having 21b, 21c, 21d, and an exciting coil 22 wound around each of the projecting pieces 21a, 21b, 21c, 21d. , 21b, 21c, 21d have comb-shaped teeth 4 at the same pitch as the pitch of the scale teeth 1a relative to the scale teeth 1a of the stator 1.
The individual slider teeth 2a are provided so as to project.

The scale teeth 1a of the stator 1 and the mover
The deviation of the pitch between the slider tooth 2a and the slider tooth 2a of 2 is 1/2 in the protruding piece 21b when 0 is set in the protruding piece 21a.
Pitch, 1/4 pitch in protruding piece 21c, protruding piece 21d
Is set to be -1/4 pitch.

In this embodiment, two movable elements 2 having the above-described structure are arranged in a row in the longitudinal direction of the stator 1.

In the mover 2, the magnetic flux generated by applying an alternating current to the exciting coil 22 at a predetermined timing produces a thrust between the scale teeth 1a and the slider teeth 2a, so that the longitudinal length of the stator 1 is increased. It is designed to proceed along the direction.

In such a linear step motor,
The stator 1 formed of a magnetic material in the shape of a single piece is
Since the scale teeth 1a are provided with four slits 1b at equal intervals in the plate thickness direction, magnetic flux is concentrated and eddy currents are easily generated. Since the structure is substantially the same as that described above, the eddy current is divided into small loops and flows as shown by the alternate long and short dash line in FIG. 3 to reduce the eddy current loss, thus reducing the thrust of the motor. Can be prevented.

In this embodiment, the scale tooth 1a is provided with four slits 1b. However, if the number of slits is increased as much as possible, the eddy current loss can be further reduced in proportion thereto. ..

[0019]

In the linear stepping motor of the present invention, since the scale teeth of the stator are provided with a plurality of slits, thin steel plates are laminated on the scale teeth where magnetic flux concentrates and eddy currents are easily generated. Since the eddy current is divided into small loops and flows, the eddy current loss is reduced, and thus the thrust of the motor can be prevented from decreasing.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a main part of an embodiment of the present invention.

FIG. 2 is a front view showing the overall structure of the above.

FIG. 3 is a partial perspective view showing the same scale tooth.

FIG. 4 is a front view showing the overall structure of a conventional example.

FIG. 5 is a partial perspective view showing the same scale tooth.

[Explanation of symbols]

 1 Stator 1a Scale tooth 1b Slit 2 Mover 2a Slider tooth

Claims (1)

Claim: What is claimed is: 1. A linear step having a stator provided with comb teeth and scale teeth, and a mover provided with comb teeth and slider teeth facing the scale teeth. In the motor, a linear step motor, wherein the scale teeth are provided with a plurality of slits.