JPH0135592B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a permanent magnet type linear stepping motor in which the armature is an inductor and the field is a multi-pole magnetized permanent magnet.

[Conventional technology]

Conventionally, a linear stepping motor has been developed as a linear stepping motor in which a gap is provided in the same plane in which permanent magnet magnetic poles of equal pitch and an armature with a field coil wound around the core are opposed to each other with a gap between them. As disclosed in Publication No. 74080, permanent magnets magnetized with multiple poles in the direction of movement are used as stator rails, so the longer the rails, the higher the cost, and the need to avoid attracting surrounding iron powder. This required a protective cover to prevent this, which was inconvenient for maintenance.

In addition, as for a device in which air gaps are provided on the same line, Japanese Utility Model Application No. 56-118588 and Japanese Patent Application No. 57-48737 (permanent magnet type linear stepping motor) proposed earlier by the present applicant address this point. In order to solve this problem, we used a mover structure in which a rail consisting only of inductor teeth was sandwiched between an armature electromagnet and a multipolar magnetized permanent magnet.

A front cross-sectional view of this prior art device is shown in FIG. 5, and FIG. 6 shows cross-sectional views along A-A' and B-B'.

1 is a coil wound around both sides of the yoke 2, 3 is a mover made of a magnetic material with inductor teeth, and 4 is fixed to the yoke 2 with a tape facing the mover 3 through an air gap. The permanent magnet 5 is a non-magnetic material that is fixed to the movable element 3 and supports the industrial machine 6.

Due to the repulsion and attraction between the magnetic poles of the inductor teeth formed on the movable element 3 and the magnetic poles of the permanent magnet 4, which are induced by the coil 1, the direction perpendicular to the paper plane of FIG. 5, that is, the direction of FIG. The movable element 3 moves in the vertical direction.

[Problem to be solved by the invention]

However, there are two voids, making the structure complicated.
It had drawbacks such as requiring high machining accuracy to maintain the air gap value.

SUMMARY OF THE INVENTION An object of the present invention is to provide a permanent magnet type linear stepping motor that is easy to work with and is inexpensive, solving the problems of the conventional and prior art techniques.

[Means to solve the problem]

The present invention is a permanent magnet in which a stator made of a ferromagnetic material with teeth cut at equal pitches and a mover in which a concentrated armature winding is wound around an E-shaped core equipped with a permanent magnet are opposed to each other through an air gap. In a magnet-type linear stepping motor, a large number of permanent magnet strips with the same width as the tooth width of the stator are placed on the plane of the central leg of the E-shaped core facing the stator, perpendicular to the direction of movement, at the same pitch as the tooth pitch of the stator. Adjacent permanent magnet strips are pasted so that the NS of the magnetic poles are alternate, and permanent magnet strips with the same width as the tooth width of the stator are attached to the left and right legs of the E-shaped core on the plane facing the stator. of,
A large number of permanent magnet strips are attached at right angles to the traveling direction and on the same pitch line so that the magnetism is opposite to that of the permanent magnet strips attached to the center leg, and the magnetic field produced by the permanent magnet strips is superimposed on the magnetic field produced by the armature winding. The electromagnetic unit is made into a mover electronic unit for one phase by generating a wavy magnetic field of equal pitch and serving as a simulated mover magnetic pole, and this electromagnetic unit is set at a constant phase difference angle with the tooth pitch of the stator, which is geared by several phases. It was arranged like an eggplant.

It is a permanent weak type linear stepping motor.

[Effect]

The magnetic field generated by the permanent magnet strips is superimposed on the magnetic field generated by the armature winding to generate an evenly pitched wavy magnetic field, resulting in the shortest effective magnetic path length, high utilization rate of permanent magnets, and a strong Thrust is generated.

〔Example〕

FIG. 1 shows a perspective view of an embodiment of the present invention.

In all figures, the same reference numerals represent the same or corresponding parts.

Although only one phase of the mover electromagnet unit 20 is shown, several phases are arranged in series or in parallel in the direction of the moving axis Z-Z' and connected together to form a mover.

By the way, in FIG. 1, the Z-Z' axis direction of the movable electromagnetic unit (for one phase) 20 is short and the direction perpendicular to it is long, but in reality, the straight part of the armature winding 1 is formed long and the Z- The side in the Z'-axis direction is longer than the side in the perpendicular direction.

The stator rail 30 is a laminated iron core in which teeth 31 (grooves are 32) are provided at equal pitches at right angles to the movement axis Z-Z' direction. However, if it is used at low speeds, a solid iron core may be sufficient.

Figure 2 is centered around the X-X' axis in Figure 1.
The magnetization pattern of the permanent magnet 4 is observed when the movable electromagnetic unit 20 is rotated 180 degrees in the θ direction and turned over.

On the gap surface of the movable yoke 2 facing the stator rail 30, a permanent magnet 4 in the shape of a thin strip having the same width as the teeth 31 is placed on the leg plane of the yoke 2, and the stator rail 30
The central leg part (A part) of the E-shaped core surrounded by the armature winding 1 is parallel to the inductor teeth 31 of the
The left and right legs (section B) of the shaped core are magnetized so that the polarities of the magnetic poles are opposite.

Its operation is as follows.

At the position where the N pole of part A of the mover 20 matches the inductor teeth 31 of the stator rail 30, the armature winding 1 has the following: part A (N) → gap → tooth part 31 → right gap → Right part B (S) → Left gap → Right part B (S) → Yoke 2 → Part A (N) The rotating magnetic flux φ interlinks.

When the movable element 20 moves by 1/2 tooth pitch, the S pole of the part A coincides with the inductor tooth 31, so the interlinkage magnetic flux is reversed and becomes -φ.

In this way, when the mover 20 moves by one tooth pitch, the interlinkage magnetic flux changes by one cycle. If the mover 20 continues to move at a constant speed, the armature winding 1
A single-phase AC voltage of √2πNφ·v/τ _t is generated. (Here, N is the winding, v is the speed, τ _t is the tooth pitch, and φ is the magnetic flux. However, it is assumed that this magnetic flux φ changes in a sinusoidal manner.) To operate this as a motor A current is passed through the armature winding 1. The magnetomotive force generated by the winding 1 is set below a value that does not irreversibly demagnetize the permanent magnet 4.

If the winding magnetomotive force has a polarity that makes part A the north pole, the north pole part of the strip permanent magnet 4 in part A will be strengthened, and the south pole part will be weakened. Part B strip permanent magnet 4
The S-pole portion of the coil is strengthened and the N-pole portion is weakened, producing a wavy magnetic field based on the winding magnetomotive force.

Therefore, the movable element 20 is attracted and moves in a direction in which the N pole part of the part A of the permanent magnet 4 and the S pole part of the part B coincide with the inductor teeth 31. When the winding magnetomotive force is reversed, the S pole of section A and the N pole of section B are attracted in the direction that coincides with the inductor teeth 31, and the machine operates as a single-phase synchronous machine.

Therefore, if several phases of the mover electromagnet units 20 are arranged in series or in parallel in the direction of the moving axis Z-Z' so that the relative positions of the magnetic poles of the permanent magnets 4 with respect to the teeth 31 of the stator have a constant phase difference, A polyphase synchronous machine is constructed.

The above structure and operating principle have been explained using a so-called right-angled inductor in which the linear portion of the armature winding 1 and the cutting direction of the inductor teeth 31 are perpendicular to each other.

FIG. 3 is a perspective view of another embodiment of the present invention, and FIG. 4 shows the movable electromagnet unit 20 shown in FIG.
It is a diagram showing the relationship between the magnetization pattern of the permanent magnet 4 and the inductor teeth 31 when the permanent magnet 4 is rotated 180 degrees in the θ direction around the Y' axis and viewed upside down.

In this other embodiment, the structure of the present invention is applied to an inductor in which the straight portion of the armature winding 1 and the cutting direction of the inductor teeth 31 are parallel (parallel inductor). In FIG. 3, the direction of the straight part of the armature winding 1 (direction perpendicular to the direction of movement Z-Z') is shown as short, but in reality it is made long in order to improve efficiency.

〔effect〕

Thus, according to the present invention, the following many remarkable effects are recognized.

Since the bias permanent magnet strips also serve as the magnetic poles of the mover, there is no need for gear cutting or fine salient poles on the mover, and the E-shaped core can be used as is, making it easy to manufacture, and the utilization rate of permanent magnets is high. Cost is lower.

Since the mover electromagnet unit 20 is made into a unit for each phase, there is a high degree of freedom in configuration, such as arranging them in series or parallel to the moving axis Z-Z'. Can be installed according to machine requirements.

Compared to the hybrid type and variable reactance (VR) type, it has a higher power factor and larger peak torque, so the power supply capacity is smaller and control is easier.

[Brief explanation of drawings]

Figure 1 is a perspective view of one embodiment of the present invention, and Figure 2 is a view of the movable electromagnetic unit rotated 180 degrees in the θ direction and turned over around the X-X' axis in Figure 1. Relationship diagram between permanent magnet magnetization pattern and inductor teeth, 3rd
Figure 4 is a perspective view of another embodiment of the present invention, Figure 4 is a diagram showing the relationship between the magnetization pattern of the permanent magnet of the movable electromagnet unit and the inductor teeth, and Figure 5 is a front sectional view of the previously proposed device. , Figure 6 shows the A-A' and B-
B′ cross-sectional view. 1... Armature winding, 2... Yoke, 3... Mover, 4...
Permanent magnet, 5... Non-magnetic material, 6... Industrial machine, 20...
Mover electromagnet unit (for one phase), 30... Stator rail, 31... Inductor tooth, 32... Groove.

Claims (1)

[Claims] 1. A stator made of a ferromagnetic material with equally pitched gears and a mover in which a concentrated armature winding is wound around an E-shaped core equipped with a permanent magnet are opposed to each other with an air gap interposed therebetween. In a permanent magnet type linear stepping motor, an E-shaped core on the gap surface facing the stator of the mover,
On the central leg plane, a large number of permanent magnet strips with the same width as the stator tooth width are affixed perpendicular to the traveling direction so that the NS poles alternate, and on the left and right leg planes, a large number of permanent magnets are attached. The strips are attached to the center leg so that the polarity is opposite to that of the permanent magnet strips to form a mover electromagnetic unit for one phase, and this mover electromagnetic unit is connected to several phases of the stator tooth pitch. A linear stepping motor is characterized in that it is arranged so as to form a constant phase difference angle.