JPH0191652A - Field structure of linear dc brushless motor - Google Patents

Abstract

PURPOSE:To make the arrangement of a field magnet correctly at a specific pole pitch and angle by making a hole in a polarity plate equivalent to the arrangement position of each field magnet, inserting a pin into the hole and adhering the field magnet in accordance with the position of the pin. CONSTITUTION:This field construction is constituted of a polarity table 1, a field magnet 2 and a spring pin 3, and the field magnet 2 is adhered on the polarity plate 1 consisting of permanent magnet at specific intervals. A hole 1a is made in the polarity poate 1 so that the field magnet 2 can be correctly positioned, and the spring pin 3 is inserted into the hole 1a. The height of this spring pin 3 is set shorter than the thickness of the field magnet 2. When a linear DC brushless motor constituted of such a constitution of field system and an armature not shown in the fig. is electrically charged, a thrust generates to operate this motor.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a field structure of a linear DC brushless motor,
In particular, it concerns the arrangement of field permanent magnets.

[Prior Art] There are increasing demands for servo control and precision positioning of linear actuators, and linear DC planless motors are attracting attention as near motors suitable for such applications.

Linear DC brushless motor (hereinafter abbreviated as LDM)
The principle and structure are a linear development of a normal DCC planless morph AC servo motor. This LDM consists of an armature side and a field side, and the field side consists of a magnetic plate 1 and a permanent magnet on which N-3 poles are alternately arranged at a predetermined pitch, as shown in Figure 3. It is composed of a plurality of field magnets 2. Further, the field magnet 2 is arranged obliquely as shown in this figure. This is because a skew effect is provided to reduce the detent thrust caused by the field magnet 2.

[Problems to be Solved by the Invention] In the field structure as described above, in order to sufficiently reduce the detent thrust and obtain stable running of the LDM, the arrangement and skew angle of the field magnets must be accurate. That is, the pole pitch of two adjacent field magnets must be a predetermined dimension, and the gap between these field magnets must be appropriate.

However, when field magnets are lined up and glued on a flat magnetic plate, there is an attractive force between the field magnets and an attractive force between the field magnet and the magnetic plate. It is very difficult to make the pole pitch, angle, gap between the magnets, etc. accurate.

The present invention was made to solve this problem, and aims to provide an LDM field structure in which field magnets can be arranged simply and accurately on a magnetic plate.

Means for Solving Problem E] Therefore, in the present invention, a hole is made in a magnetic plate in accordance with the arrangement position of each field magnet, a bottle is set upright in this hole, and the field magnet is placed in accordance with the position of the bottle. By gluing these field magnets together, the field magnets can be accurately aligned and the above-mentioned problem can be solved.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention, with FIG. 1 being a plan view and FIG. 2 being a cross-sectional view taken along the line AA in FIG. 1. In the figure, reference numeral 1 denotes a magnetic plate, on which field magnets 2 made of permanent magnets are adhered at predetermined intervals. Reference numeral 3 denotes a spring bin, which has a hole 1a formed in the magnetic plate 1 and stands upright in the hole 1a so that the plurality of field magnets 2 can be accurately positioned. Also, the height of this spring pin is
The thickness is set to be shorter than the thickness of the field magnet.

V- with this kind of configuration? , and an LDM consisting of a magnetic side and an armature (not shown), a thrust is generated by a known action, and this LDM operates.

Note that the spring pin may be replaced with another member as long as it can suppress leakage magnetic flux and can be easily installed upright.

[Effects of the Invention] As described above, according to the present invention, by providing spring pins on the magnetic plate, the field permanent magnets can be accurately arranged at a predetermined pole pitch and angle. Further, even if this mutual attraction force is generated between the permanent magnets, the presence of the spring pin prevents adjacent permanent magnets from coming into contact with each other. Furthermore, since it is a spring pin, precision in hole diameter is not required, and since it is not solid but hollow, leakage magnetic flux can be kept to a minimum. Therefore, there is an advantage that the detent thrust can be sufficiently reduced and the LDM can run stably.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the field structure of an LDM showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 3, and FIG. 3 shows the field structure of a conventional LDM. FIG. 1. Magnetic plate 2. Field permanent magnet 3. e-spring bin

Claims (1)

[Claims] In a field body of a linear DC brushless motor consisting of a magnetic plate and a plurality of field permanent magnets arranged on the magnetic plate at predetermined intervals, pins are erected on the magnetic plate at predetermined intervals to position the permanent magnets. The field structure of a linear DC brushless motor is characterized by: