JPH0545107Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention makes it possible to arrange the field structure of a linear DC brushless motor, especially the field permanent magnet, on a magnetic substrate at an accurate skew angle. ,
The sides of the magnetic substrate and the non-magnetic positioning plate placed on it, as well as the surface of the non-magnetic positioning plate itself and the field permanent magnet housed inside, are covered with non-magnetic covers to protect them from external sources such as dust. The present invention relates to a field structure capable of protecting a field part from contamination.

[Prior Art] The use of linear actuators for servo control and precision positioning is increasing, and linear DC brushless motors are attracting attention as a linear motor suitable for meeting such demands.

A linear DC brushless motor has a structure that is a linear version of a normal DC brushless motor, and the mover performs a linear motion of a finite length instead of the rotational motion of a normal DC brushless motor.

As shown in Fig. 2, the fixed part, that is, the field side, has a magnetic substrate 1 and a N pole and an S pole arranged at a predetermined pitch on top of the magnetic substrate 1.
It is composed of a plurality of field magnets 2 each consisting of a plurality of permanent magnets whose poles are arranged alternately and regularly.

Further, as shown in FIG. 2, these plurality of field magnets 2 are arranged on the magnetic plate 1 obliquely at a predetermined skew angle with respect to the longitudinal axis of the magnetic plate 1, and parallel to each other. Arranged in

The purpose is to exhibit a skew effect so as to reduce the detent thrust caused by the field magnet 2.

As a means for accurately and efficiently arranging a plurality of field magnets 2 at a predetermined skew angle with respect to the longitudinal axis of the magnetic plate 1, the inventor of the present invention installed a plurality of spring pins on the magnetic plate. We developed a field structure in which field magnets are erected at predetermined intervals and adhered using these pins as guides, and filed a patent application (Japanese Patent Application No. 1989-91652).

As shown in FIGS. 3 and 4, this field structure has a pair of holes 1a formed between two adjacent field magnets on a magnetic plate 1, and a spring pin 3 inserted into each hole 1a. This is a guide for arranging field magnets 2 in an upright position.

[Problem to be solved by the invention] This prior art improves the accuracy of the arrangement of magnetic plates,
We were able to achieve various effects such as preventing contact between the field magnets due to mutual attraction, reducing leakage magnetic flux, and reducing detent thrust.

However, this prior art requires the work of drilling a large number of holes 1a in the magnetic plate 1, erecting spring pins 3 in each of those holes 1a, and arranging field magnets using these as guides. The work is somewhat troublesome because magnetic attraction forces act between the field magnets and between the field magnets and the magnetic plate, and the narrow grooves formed between the field magnets prevent dust, especially iron. Foreign matter such as powder easily accumulates, and since the spring pin 3 is installed upright, it is difficult to clean and remove such foreign matter.
There was a problem that it was unsuitable for use in clean rooms and the like.

[Means for solving the problem] A non-magnetic positioning plate with the same length and width as the magnetic board is placed on the magnetic board, and only one field magnet is fitted into this positioning plate. A plurality of through holes are drilled in the size of the positioning plate and are arranged at a predetermined skew angle with respect to the longitudinal axis of the positioning plate.A field magnet is housed in each hole, and the field magnet is attached to the top surface of the magnetic substrate using adhesive. be done.

Furthermore, a non-magnetic cover is disposed as an uppermost layer thereon, covering at least the upper part of the longitudinal side surface of the magnetic substrate and the upper surface of the positioning plate containing the field magnet.

[Function] The through holes drilled in the positioning plate are of a size suitable for accommodating each field magnet, and the through holes are arranged at a predetermined skew angle with respect to the positioning plate, that is, with respect to the magnetic substrate. All of the field magnets are attached to the magnetic substrate at a predetermined skew angle by simply sliding the field magnets into their respective through holes.

Furthermore, since the non-magnetic cover placed as the top layer completely covers both longitudinal sides of the magnetic substrate and the top surface of the positioning plate containing the field magnet, dust, metal powder, etc. Foreign matter is prevented from entering.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings, and the same members as those described in relation to the prior art will be described using the same reference numerals.

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, in which reference numeral 1 is a magnetic substrate, 4 has the same length and width as the magnetic substrate 1, is made of a non-magnetic material, and is placed exactly on the magnetic substrate 1. The positioning plate is sized to
According to the number of field magnets 2 to be arranged, through holes 5 to accommodate them are opened while maintaining a predetermined skew angle.

Reference numeral 6 denotes a non-magnetic cover, which covers the side and top surfaces of the magnetic substrate 1 and the positioning non-magnetic plate placed thereon, as well as the top surface of the field magnet 2 housed in the through hole 5. This is a non-magnetic cover to protect the field part from the intrusion of foreign matter such as dust.

To assemble the field structure of this invention, the non-magnetic 4 for positioning is placed correctly on the magnetic substrate 1 and fixed by adhering with adhesive or the like.

The field permanent magnets 2 are fitted into each of the through holes 5 formed in the non-magnetic plate 4 for positioning so that their N and S poles are arranged alternately.

As a result, all the permanent magnets 2 maintain a predetermined skew angle, and the through holes 5 of the non-magnetic plate 4 for positioning
contained within. Further, a non-magnetic cover 6 is disposed so as to cover the side surface and top surface of the non-magnetic plate 4 from above or from the side thereof, and is bonded with an adhesive or the like as necessary.

[Effect] By simply fitting the field magnets 2 into each of the through holes 5 made in the positioning non-magnetic plate 4 and adhering them onto the magnetic substrate 1 with adhesive, the field magnets 2 can be attached to the magnetic substrate 1. In contrast, it is arranged at a predetermined skew angle.

Furthermore, by simply covering the entire field structure including the field magnet 2 with a non-magnetic cover of a simple structure, it is possible to prevent foreign matter from entering the field structure. Remarkable.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing the field structure of the present invention, Fig. 2 is a plan view showing the field magnets skewed in relation to the magnetic substrate, and Fig. 3 is the spring pins erected on the magnetic substrate. FIG. 4 is a partial plan view showing a conventional technique in which a field magnet is fixed using a guide as shown in FIG.
FIG. 4 is a side sectional view taken along line A-A in FIG. 3; Reference numerals in the drawings: 1...Magnetic substrate, 2...Field magnet, 4...Positioning plate, 5...Through hole for accommodating field magnet, 6...Cover.

Claims (1)

[Scope of utility model registration request] A magnetic substrate, a plurality of field permanent magnets disposed on the magnetic substrate, and a planar dimension that is substantially the same as that of the magnetic substrate, and the field permanent magnets can be exactly housed inside the magnetic substrate. a non-magnetic positioning plate having a plurality of through-holes with a certain number and dimensions and set to maintain a predetermined skew angle with respect to the magnetic substrate; With the field permanent magnet accommodated in the through-hole and placed on the magnetic substrate, the side surface of the magnetic substrate and the non-magnetic positioning plate thereon, and the field permanent magnet and the A field structure for a linear DC brushless motor, comprising: a top surface of a non-magnetic positioning plate containing a non-magnetic positioning plate; and a non-magnetic cover that covers the top surface of the non-magnetic positioning plate to prevent foreign matter such as dust from entering the inside thereof.