JPH0222640B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a linear pulse motor, and particularly to core teeth of a stator and a mover thereof.

[Prior art]

1 to 3 are for explaining a conventional linear pulse motor.

A large number of stator teeth 2 are formed on the surface of the stator 1 at equal intervals, and a movable element 3 is movably arranged with respect to the stator 1 with a minute gap maintained therebetween. The movable element 3 is provided with a plurality of magnetic pole parts 5 having slider teeth 4 on the side facing the stator teeth 2 of the stator 1, and each magnetic pole part 5 is wound with an excitation coil 6, respectively. Each magnetic pole part 5 is relatively shifted with a predetermined phase difference, and the excitation coil 6
Current can be applied to each independently.

Depending on the correspondence state between the stator teeth 2 of the stator 1 and the slider teeth 4 of the movable element 3, a magnetic force is created between the stator 1 and the movable element 3 by sequentially selecting and applying current to the excitation coil 6. Creates a suction force. This magnetic attraction force causes the movable element 3 to move relative to the stator 1.

[Problem to be solved by the invention]

However, in the conventional linear pulse motor, the stator teeth 2 of the stator 1 and the slider teeth 4 of the movable element 3
Both are rectangular in shape. When magnetic flux flows between the stator teeth 2 and the slider teeth 4, the overlapping portion of the stator teeth 2 and slider teeth 4 is the shortest distance between the two magnetic poles, as shown in FIG. Magnetic flux is concentrated in the overlapping portion of the slider teeth 4, and the magnetic axis 7 of the magnetic flux is perpendicular to the reference plane 8 of the stator 1.

Since the magnetic flux flows vertically in this way, the vertical force A is large but the thrust force B is small. Note that the straight line C in the figure is the suction force. If the thrust of the motor is small in this way, the speed characteristics will be poor accordingly.

〔the purpose〕

An object of the present invention is to eliminate such drawbacks of the prior art and provide a linear pulse motor with good thrust characteristics and speed characteristics.

〔composition〕

In order to achieve this object, the present invention provides that the stator teeth of the stator and the slider teeth of the movable element, when cut along the moving direction of the movable element, have an arc-shaped cross-sectional shape on the protruding tip side, Both teeth face each other with a predetermined interval maintained, and the magnetic axis of the magnetic flux formed between the stator tooth and the slider tooth is always oblique to the reference plane of the stator at the stop position of the mover. It is characterized by

Embodiments of the present invention will be described below with reference to FIGS. 4 to 6.

As before, stator teeth 2 are provided on the stator 1 at equal intervals, while slider teeth 4 are provided on the mover 3.
A plurality of magnetic pole portions 5 having a predetermined phase are arranged in a row with a predetermined phase. An excitation coil 6 is wound around each magnetic pole portion 5, and the stator teeth 2 of the stator 1 and the slider teeth 4 of the movable element 3 face each other with a predetermined gap maintained therebetween.

The cross-sectional shape of the stator teeth 2 and slider teeth 4 cut along the moving direction of the movable element 3 is arc-shaped, unlike the conventional square shape, and there is no flat surface at the tips of the teeth. Therefore, the magnetic flux 9 formed between the stator teeth 2 and the slider teeth 4 is distributed in an almost oval shape as shown in FIG. 6, and the magnetic flux is particularly concentrated in the center. Magnetic axis 7 of magnetic flux 9
is inclined with respect to the reference plane 8 of the stator 1.

If the magnetic axis 7 of the magnetic flux is always made to be oblique at the stop position of the mover 3, the vertical force A will be smaller than the conventional one, as shown in Fig. 4, and instead the thrust force B will be increased. growing.

Assuming that the displacement amount of the mover 3 is X, the thrust is B, and the mass is M, the time T for the mover 3 to move by the displacement amount X is
The relationship with is as shown in the following equation (1).

X=1/2・B/M・T ² ………(1) And the predetermined time T is as shown in equation (2), Therefore, if the displacement X and mass M of the mover 3 are kept constant, if the thrust B is large, the mover 3 will change accordingly.
speed becomes faster. Therefore, since the linear pulse motor of the present invention has a larger thrust force B than the conventional motor, its speed characteristics are improved.

〔effect〕

FIGS. 7 and 8 are diagrams showing a comparison of the operating characteristics of a linear pulse motor according to the present invention and a conventional one. FIG. 7 shows the thrust characteristics, and FIG. 8 shows the self-starting frequency characteristics. Curve A in the figure shows the characteristics of the linear pulse motor of the present invention according to the above embodiment, and curve B shows the characteristics of the conventional linear pulse motor. It is a curve.

The present invention has the above-described configuration, and by making the cross-sectional shapes of the protruding tips of the stator teeth and the slider teeth arc-shaped when cut along the moving direction of the movable element, the shapes of both teeth are reduced. The magnetic axis of the magnetic flux generated between the two can be effectively and reliably tilted, increasing the thrust of the linear pulse motor, and as is clear from Figs. 7 and 8, the linear pulse motor has excellent operating characteristics. can be provided.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a conventional linear pulse motor, Fig. 2 is a perspective view of a stator in the linear pulse motor, Fig. 3 is an enlarged view of the main parts of Fig. 1, and Fig. 4
5 is a perspective view of a stator in the linear pulse motor, FIG. 6 is an enlarged view of the main part of FIG. 4, and FIG.
8 are a thrust characteristic diagram and a self-starting frequency characteristic diagram of a linear pulse motor. DESCRIPTION OF SYMBOLS 1... Stator, 2... Stator tooth, 3... Mover, 4... Slider tooth, 7... Magnetic axis, 8... Reference plane, 9... Magnetic flux.

Claims (1)

[Claims] 1. When cut along the moving direction of the mover, the protruding tip side cross-sectional shapes of the stator teeth of the stator and the slider teeth of the mover are arc-shaped, and both teeth maintain a predetermined interval. A linear pulse motor characterized in that a magnetic axis of magnetic flux formed between the stator teeth and the slider teeth that face each other is always oblique with respect to a reference plane of the stator at a stop position of the movable element.