JPS61191259A - Linear pulse motor - Google Patents

Abstract

PURPOSE:To obtain thrust efficiently preventing a forcer (mover) from getting out of position laterally against the running direction, by a method wherein the cross section of a stator is formed in an almost circular shape, and wherein a plurality of strips of grooves in the running longitudinal direction are provided, and wherein a space for running between the forcer and the stator is retained via a spherical body. CONSTITUTION:A stator 1 is organized by providing the grooves 3 of semi-circular cross sections of a plurality of strips in the longitudinal direction of a circular rod, and magnetic pole teeth 4 in parallel with each other crossing the longitudinal direction. A forcer 2 is organized by providing a plurality of exciting units having field teeth confronting the inner wall of the hollow circular cylinder. A space between the stator 1 and the forcer 2 is retained by a spherical body 5 for moving into the grooves 3. A gap between the pitch of the magnetic pole teeth 4 and the pitch of the field teeth is provided, and exciting current according to pulse is conducted to the exciting units. The exciting units are organized with a coil wound up on a core, a permanent magnet, and back iron, and are fixed to the hollow cylinder with resin.

Description

[Detailed description of the invention] A. Industrial application field IJ allows for high-speed and high-precision predetermined displacement as a driving element.
Regarding the structure of a near pulse motor.

In a conventional linear pulse motor, a linear force forcer is stepped by a change in mutual magnetic flux between a forcer having field teeth and a stator having magnetic pole teeth.

Magnetic flux is generated at the tooth ends of the field teeth and the magnetic pole teeth, and these teeth are often formed to have a rectangular or trapezoidal cross section and a straight line.

Various methods are used to form the teeth, such as tool grinding, electron beam cutting, etching corrosion, adhesion of parallel wires, and stamping alloys, but all of them are straight. That is, the protrusions are simply provided on a flat surface, and the flat surfaces are used to face each other. As a drive element that moves in the XY direction with opposing surfaces, the Japanese Patent Publication No. 49-41602
The two-sided type is JP-A-58-19246.
There is number 2. The configuration of these linear pulse motors is that the facing surfaces are flat, and the gap between the facing surfaces is maintained by an air film using air, and by selecting the rolling position of a roller provided on a forcer.

C1 Problems that the invention aims to solve.

The conventional configuration had various drawbacks because it attempted to obtain a set thrust for stepping by placing the flat surfaces facing each other. First of all, the stroke of step movement becomes shorter. In order to obtain the same thrust force, it is sufficient if the performance and number of excitation units provided in the forcer are the same, but it is usual to arrange the excitation units in the walking direction. In particular, in the case of a one-sided type, they are arranged in one row, and in the case of a two-sided type, they are arranged in two rows, reducing the row length to about 1/2. If the four-sided type is used, the row length will be reduced to about 1/4, resulting in a shorter forcer length. However, a linear pulse motor having two or more opposing flat surfaces has not been put to practical use.

That is, the gap between the surfaces and the pitch between the teeth should be 10 to 50.
This is because, although accuracy as high as μ is required, it is not possible to absorb the amount of displacement due to processing/assembly errors and temperature expansion. In the case of two or more opposing surfaces, there are displacements due to the angle between the surfaces, waviness of each surface, and relief due to expansion, and at the same time, it is difficult to process each surface uniformly, resulting in loss of synchronization. occurs frequently. The second drawback is that the facing surface cannot be changed. The facing surface of single-sided and two-sided types can be vertical, inclined, or horizontal, and the originally determined surface cannot be changed. Therefore, it is difficult to apply it as a driving element, that is, to provide limited supply to users. That's all I could do.

As mentioned above, the thrust of a linear pulse motor is the same when the performance and number of excitation units are constant, but when the surface with field teeth and magnetic pole teeth is flat, or when there are multiple flat surfaces As a result, a device to prevent the forcer from shifting laterally or falling off becomes necessary, which increases the weight of the linear pulse motor, and also causes the multiple flat surfaces to be out of phase during processing and assembly, reducing the thrust efficiency. It has disadvantages such as increased size and greatly limited usability. The present invention has been achieved by improving the drawbacks of the items that were lacking in the prior art, and will be disclosed in detail and the technology thereof will be presented herein.

21 Means for Solving the Problems The present invention provides a stator with a plurality of grooves each having a semicircular arc cross section and parallel magnetic pole teeth crossing the longitudinal direction of a round bar, and the inner wall of a hollow cylinder. A plurality of excitation units having field teeth are provided toward the forcer to form a forcer, and the gap between the stator and forcer rolls in a groove.6.

It is characterized by being held in a spherical shape.

By creating a gap in the pitch of the field teeth relative to the pitch of the magnetic pole teeth,
A separate driver is provided to supply an excitation current according to the pulse to the excitation unit. The excitation unit consists of a coil wrapped around an iron core, a permanent magnet, and a back iron, and is fixed to the hollow cylinder with resin. The excitation units are provided in one row or in multiple rows in the circumferential direction facing the stator to match the set thrust of the forcer.

Several of the field teeth are grouped together, and each group has the same tooth profile and pitch as the magnetic pole teeth, and the deviation is provided for each group.

When the excitation current from the driver is applied to the coil of the excitation unit according to the set pulse, magnetic flux is generated in the coil winding part of the iron core, and this magnetic flux passes through the iron core legs and reaches the field teeth. . Since the cross-sectional area of the iron core leg and the cross-sectional area of the field tooth group are made the same, the current product, that is, the dissipation due to thermal energy generation does not occur and is effective.

The tip area of the field tooth is proportional to y, which faces the magnetic pole tooth, 4
.

A magnetic flux passes through the lap area 17, and the field teeth and the magnetic pole teeth are attracted by the magnetic force in the perpendicular direction within the magnetic flux. Although an electromagnetic effect is generated to try to shorten this gap due to attraction, this gap is limited by the sphere, and the mutual positions of the solid objects will not be displaced. However, when the lap area integral described above is changed, a component of the magnetic force in the perpendicular direction, that is, a horizontal force acting in the tooth pitch direction is generated.
This horizontal force becomes the thrust of the linear pulse motor. The lap area integral is determined by the mutual arrangement of many teeth, and the resolution is determined by the tooth width, pitch, □ deviation dimension, and processing accuracy. In this way, the magnetic force acting on the teeth is determined by the magnetic density of the permanent magnet. It simply switches the direction of the magnetic flux of the permanent magnet using the coil of the iron core leg.
This is because only the magnetic force of the permanent magnet acts on the teeth.

When the coils provided in each of the plurality of excited units are energized in accordance with sequential pulses, the units move by an amount outside the mutual gap between the teeth. The above-mentioned magnetic flux and magnetic force action between the teeth was an instantaneous phenomenon for one set of teeth, but when a large number of teeth are caused to generate magnetic force between each other in succession, the forcer moves smoothly.

The movement locus of the forcer is limited by the sphere rolling in the groove of the stator, and the forcer follows and moves due to the linearity and curvedness of the groove. Since the locus of the forcer is based on the displacement between the groove and the sphere, the forcer can move freely depending on the direction of the groove.

To, Example The configuration of the present invention will be explained in detail based on the drawings.

A plurality of grooves 3 are provided on the surface of the round bar, and recesses are provided in the direction across the grooves 6, and the protrusions on the surface are used as magnetic pole teeth 4 to form the stator 1.The cross section of the stator 1 is an arc, an ellipse, or an oval. A real shaft or a hollow shaft may be used, and this is appropriately selected depending on the thrust of the linear pulse motor, the volume depending on the application, and the external shape.

Six grooves 3 are provided in a straight line in the longitudinal direction of the round bar, and the intervals between the grooves are equal. On the other hand, the forcer 2 is fitted into the stator 1 through the sphere 5, and as shown in FIG. A sphere 5 is provided on an inner wall 9 of a frame 6. Although the foregoing is limited to three straight grooves based on FIGS. 1 and 2, a straight groove is provided in order for the forcer 2 to move in a straight line. In order to provide a curved step, that is, a slight rotational motion to the forcer 2, a curved groove is used.

However, the intervals between the grooves should be equally divided and the entire length should be parallel.Next, regarding the number of grooves, in the case of the present invention, it is effective as long as it is not one groove. Providing six contact points on the cross section of the stator 1 is the most stable and best way to maintain the distance between the field teeth and the tips of the magnetic pole teeth 4, but the line condition of the grooves on the stator 1 The number is selected depending on the thrust, operation of the forcer 2, required resolution, etc.

Next, the unit 7 will be explained based on FIG. unit 7
is composed of an iron core 30, a magnet 29, and a back iron 35, and terminals 69 are provided on a glass epoxy substrate 37 via an epoxy resin substrate stand 56.

The iron core 60 is provided with field teeth 42 at the tips of the legs 40,
.

layer. A plurality of non-oriented silicon steel plates are formed and fixed by pressure bonding with an adhesive having good permeability through an insulating layer so that the field teeth 42 in particular match. Iron heart! 10
Two of them are arranged in parallel, a spacer 52 is provided between them, and the coil 31 is wound around the spacer 32 around the space 41 formed by the legs 40 of the iron core 30 and fixed with a face. The wire ends 33 of the coils 510 are each joined to a terminal 39.

The front end surface 64 of the field tooth 42 is a curved surface drawn on the same axis as the axis of the stator 1. However, it is not always necessary to provide a curved surface on the surface 38 of the magnet 290. It suffices if the magnetic force is the same whether it is a flat plate or a curved plate. Only the tip surface 54 is required to be parallel to the outermost end 12 of the stator 1 (the tip surface of the magnetic pole tooth).

The configuration of the forcer 2 is shown in FIG. A resin is applied to a space 10 in which a unit 7 is provided in a frame 6, and a space wall 11 and the unit 7 are also filled with resin and fixed. The units 7 are arranged in rows in the direction of movement of the forcer 2, and the number of units in each row is determined as appropriate based on the thrust and resolution of the forcer 2.

, 8.

The opposing relationship between the forcer 2 and the stator 1 is as shown in FIG. Fill everything with resin.

The running distance 16 between the outermost end 12 and the tip surface 34 is 10 to
Provided at 50μ. The tooth width and pitch of the field tooth groups of the iron core legs 28A and 28B are each the same as the magnetic pole teeth 4 of the stator 1, but the relative pitch is different.For example, if there are 64 field teeth 42, 16 pieces without pitch deviation,
If there are 16 1/4 deviations, 16 1/2 deviations, and 16 5/4 deviations, one step taken in response to a pulse will be 1/4 of the pitch. Similarly, 8 pieces with 1/8 deviation, 1/4
If there are 8 deviations, one step is 1A.

That is, the smaller the tooth width and pitch are, and the larger the number of equal deviations in pitch, the smaller the amount of one step. This is the reason for increasing the resolution.

The sphere 5 is housed in the frame 6 by providing a concave portion 17 with the same window, so that the sphere 5 is housed in the groove 6 as well. A very thin oil film is provided in the recess 17, or it is hardened together with the #3 surface. Since the running distance 16 is maintained by point contact by the spheres 5, bearing steel is used as a material that can withstand surface pressure, wear, and corrosion. Ceramic grooves, spheres, and recesses are rare.

Effects of the Invention Since the linear pulse smoke constructed in this way uses the entire circumference of the stator as a running element, there is essentially no lateral deviation in the direction of movement of the forcer, and the processing is circular with a single reference center. Not only is it easier to assemble, it expands and contracts radially even when the temperature of the unit increases, making it possible to maintain a constant travel interval. The distortion caused by displacement due to undulation of a flat surface has been eliminated. Sarahi allows the forcer to go straight or turn, and since the forcer can be inserted and replaced, it can be used as a driving element for multi-purpose and one-touch changes.

[Brief explanation of drawings]

1. FIG. 1 is a conceptual diagram of the present invention, FIG. 2 is a cross section taken along line A-A in FIG. 1, FIG. 3 is a detailed view of the unit 7 in FIG. 2, and FIG. B section, FIG. 5 is a detailed view showing section D in FIG. 4, and FIG. 6 is a detailed view showing section 0 in FIG. 4. 1: Stator 2: Forcer 3: #45: Sphere
Body 7: Unit 15: Magnetic pole tooth 42: Magnetizing tooth 3rd Figure 1-Ikkakushin special opening 111iG1-191259 (5) Article 4 Figure 6 =:=2-

Claims (2)

[Claims] 1. In a linear pulse motor in which a forcer is fitted into the stator and the forcer steps, the stator has a substantially circular cross section and a plurality of grooves are provided in the longitudinal direction of the step so that the distance between the forcer and the forcer is maintained through a sphere. A linear pulse motor featuring 2. 2. The linear pulse motor according to claim 1, wherein the groove is linear or curved so that the sphere is accommodated, and the sphere is accommodated in a recess provided in the forcer so that the forcer can move straight or in a curved direction.