JPH02131349A - Pulse motor - Google Patents

Abstract

PURPOSE:To obtain a series mount pulse motor having reduced torque ripple by determining the positional relation between stators such that the electrical angular phases of respective stators are in a predetermined relation through a guide means then fixing the positional relation through a fixing means. CONSTITUTION:First and second pulse motors 18, 19 share a rotary shaft 15 and the second pulse motor 19 is rotatable with respect to the first pulse motor 18. Rotary amount of the second pulse motor 19 is regulated by guiding a guide pin 25 along a guide groove 24. Rotary position of the second pulse motor 19 is fixed by fixing a lock click 27 into a lock groove 26. Three lock grooves 26 are positioned such that when they fit to the lock click 27 the electrical angle between the first and second pulse motors 18, 19 will be 0 deg., 22.5 deg. and 45 deg., respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a multiple valsmotor in which a plurality of stators are arranged around one rotor as the same rotation axis.

[Conventional technology]

FIG. 4 is an exploded perspective view showing the basic structure of the balsmower.

In the figure, reference numeral 1 consists of a permanent magnet whose outer peripheral surface is magnetized in sections in the circumferential direction by a rotor, and a rotor shaft 2 located at the center thereof.

3.4 is an outer stator, and 5.6 is an inner stator. The outer stator 3.4 and the inner stator 5.6 each have n/4 magnetic poles 7 (n is the number of steps) on their inner circumferences.
, each of which is bent inward and arranged alternately.

The total number n of these magnetic poles 7 is the number of rotation steps of the rotor 1.

In the inner stators 5 and 6, the phases of the respective magnetic poles 7 are 90@
They are joined in a misaligned manner.

Further, the magnetic poles 7 of the outer stator 4 face the magnetic poles 7 of the inner stator 6 with a phase shift of 180'', and the relationship is the same for the outer stator 3 and the inner stator 5. 8.9 is a drive coil; 10.11 is a bobbin that fixes the drive coil 8.9.

12 is a mounting plate fixed to the bottom of the outer stator 4 by spot welding or the like, and 13 is a flange fixed to the top of the outer stator 3 by spot welding or the like.

Bearings 14 are fitted into the central portions of the mounting plate 12 and the flange 13, respectively, and these bearings 14 rotatably support the rotor shaft 2.

The valsmotor configured as described above has the drive coil 8.
When a drive current flows through the drive coil 8, the magnetic flux generated by the drive coil 8 is directed radially outward by the magnetic poles 7 of the inner stator 5 so as to surround the drive coil 8, passes through the side surface of the outer stator 3, heads toward the center of the circle, and is directed outward. A path is formed that passes through the unillustrated magnetism of the stator 3, enters the rotor 1 through the air gap, and returns again to the +11 digit 7 of the inner stator 5 through the air gap.

A force is generated so that the magnetic path passing through the gap between the magnetic poles 7 of the outer stator 3 and the inner stator 5 and the rotor 1 becomes shorter, and the rotor 1 obtains rotational force.

By performing the above operation and continuously flowing alternating currents with a phase difference of 90° to the drive coils 8 and 9, the rotor 1 rotates by obtaining continuous rotational force at a rate of 4 steps per cycle of the alternating current. .

In order to increase the resolution, for example, 1-2 phase excitation operation is performed. The above is the basic structure of a pulse motor and its operation.

By the way, depending on the equipment used, higher output than the pulse motor of the above structure may be required. In this case, if the radial outer diameter of the pulse motor is increased, high output can be obtained, but it is not desirable to increase the radial outer diameter of the pulse motor due to the size of the casing and the space for installing the motor within the casing. There are cases. In order to solve this problem, there has conventionally been a multiple pulse motor in which a plurality of stators are arranged around one rotor as the same rotation axis.

FIG. 5 is a perspective view showing a conventional example of this type of multi-unit pulse motor, and here a two-unit type is shown. In the figure, 15 is a rotating shaft, 16 is a first pulse motor, l7 is a second pulse motor with the same output as the first pulse motor 16, and these first pulse motor l6 and second pulse motor 17 The rotating shaft 15 is common, and the electrical angles of the respective stators are also common.

The operating principle is the same as that of the pulse motor shown in FIG.

[Problem to be solved by the invention]

However, when the conventional technology having the above-mentioned configuration is used as a drive source for a mechanism that performs high-precision positioning, such as a carriage on which a print head is mounted, the following problems occur.

FIG. 6 shows the torque characteristics of the conventional example shown in FIG.

As shown in the figure, when 2-phase excitation operation is performed, a nearly average resultant torque curve is drawn, but when 1-2 phase excitation operation is performed to further improve resolution, a large torque ripple is drawn. This causes the problem that rotation becomes unstable.

In view of the above-mentioned problems, the present invention provides a configuration in which torque ripple does not occur even when the resolution is increased, and a multiple valsmotor that reduces torque ripple even when used as a drive source for a mechanism that performs high precision positioning. The purpose is to obtain evening light.

[Means to solve the problem]

In order to achieve the above object, the present invention makes the electrical angle phase of the stator of each pulse motor variable in accordance with the resolution.

In other words, the present invention provides a multiple pulse motor in which a plurality of stators are arranged around one rotor as the same rotation axis, in which the plurality of stators are each independently rotated with respect to the rotor, which is one rotation axis. so that the electrical angle phase of each stator becomes a predetermined phase.
The present invention is characterized in that it includes a guide means for determining the positional relationship between the stators, and a fixing means for fixing the positional relationship between the stators guided by the guide means.

[For production]

With the above configuration, the present invention determines the positional relationship between the stators so that the electrical angle phase of each stator becomes a predetermined phase by the guide means according to the required resolution, and fixes this positional relationship by the fixing means. can do.

〔Example〕

Examples will be described below according to the drawings.

FIG. 1 is an exploded perspective view showing one embodiment of the present invention, and FIG. 2 is an external perspective view of the same embodiment, in which two sets are shown.

In the figure, l5 is a rotating shaft, 18 is a first pulse motor, 19 is a second pulse motor with the same output as the first pulse motor 18, and these first pulse motor 18 and second pulse motor 19 are The rotation axis 15 is common, and the second
The pulse motor 19 is rotatable relative to the first pulse motor 18.

The internal configuration of each pulse motor is similar to that shown in Fig. 4. 20.21 is the outer stator of the first pulse motor 18;
2.23 is the outer stator of the second pulse motor 19; 24 is a guide groove provided on the outer stator 22 of the second pulse motor 19; and 25 is a guide pin provided on the outer stator 21 of the first pulse motor 18. By guiding the guide pin 25 with the guide groove 24, the second pulse motor 19
The amount of rotation is regulated.

26 is three lock grooves (guide means) provided on the outer stator 22 of the second pulse motor 19; 27 is a rotor claw (fixing means) provided on the outer stator 21 of the first pulse motor 18; By fixing the lock pawl 27 to 26, the rotational position of the second pulse motor 19 is fixed.

In this embodiment, the lock claw 27 and guide bin 25 are provided by bending a part of a flange 28 that is separate from the outer stator 21, and the flange 28 is spot welded to the outer stator 21. It was installed by fixing it.

When the three lock grooves 26 are respectively fitted with the lock claws 27, the electrical angle phases of the stators of the first pulse motor 18 and the second pulse motor 19 are O', 22.
．． The positions are set so that the angles are 5° and 45°.

The operation of this embodiment with the above configuration will be explained.

FIG. 3 is a graph showing the torque characteristics in this example, where (a) shows the electrical angle phase of two pulse motors set to 0° and two-phase excitation, and (b) shows the electrical angle of two pulse motors. 1-2 phase excitation with the phase of 22.5°,
(C) shows two-phase excitation with the electrical angle phase of the two pulse motors set to 45''.

As shown in the figure, when the electrical angle phase of the two valsmotors is set to 0'', the generated torque is 4-phase high torque, 2-phase high torque, and 2-phase high torque.
If the angle is set to 2.5 degrees, the generated torque will be 16 phases with high resolution, and if it is set to 45 degrees, the generated torque will be 8 phases with medium resolution and medium torque without torque ripple.

Therefore, by selectively fitting the lock claws 27 into the three lock grooves 26 to fix the position of the second pulse motor 19 with respect to the first pulse motor 18, it can be used as a motor having the characteristics shown in the table below. It becomes possible.

Note that although this embodiment describes a configuration in which the electrical angle phase is set manually, the configuration is not limited to this, and it may be operated mechanically using other motors, solenoids, etc. .

〔Effect of the invention〕

As explained in detail above, according to the present invention, in a multiple pulse motor in which a plurality of stators are arranged with one rotor as the same rotation axis, a plurality of stators are A guide means for determining the positional relationship between the stators so that the stators are each independently arranged to encompass the rotational axis and the electrical angle phase of each stator becomes a predetermined phase; Since the fixing means for fixing the positional relationship between the stators is provided, the electrical angle phase of the stator of each pulse motor can be made variable according to the resolution.

This makes it possible to prevent torque ripple from occurring even when the resolution is increased, and to obtain a multiple pulse motor with reduced torque ripple even when used as a drive source for a mechanism that performs high-precision positioning. effective.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing one embodiment of the present invention, Fig. 2 is an external perspective view of the same embodiment, and Figs. 3 (a), (b), (C
) is a graph showing the operation of the same embodiment, Fig. 4 is an exploded perspective view showing the basic structure of the pulse motor, Fig. 5 is a perspective view of the conventional example, and Fig. 6 is a graph showing the torque characteristics of the conventional example. . 20, 24 ・ 25 ・ 26 ・ 27 ・ 1, 22. 23 ・・Guide groove・Guide pin・Lock groove・Lock pawl・Outer stator

Claims (1)

[Claims] 1. In a multiple pulse motor in which a plurality of stators are arranged around one rotor as the same rotation axis, each of the plurality of stators is independently rotated with respect to the rotor, which is one rotation axis. a guide means that determines the positional relationship between the stators so that the electrical angle phase of each stator becomes a predetermined phase; and a guide means that determines the positional relationship between the stators guided by the guide means. A pulse motor characterized in that it is provided with a fixing means for fixing the motor.