JPS63316662A - Motor - Google Patents

Abstract

PURPOSE:To miniaturize a motor under high-speed control, by providing feeding slip rings on the rotating shaft of a rotor, and by step-driving the rotor. CONSTITUTION:Inside the magnetic field generated by a stator 1 composed of permanent magnets, a motor arranges a rotor 4 which is constituted by winding armature windings 3a-3c in delta connection around field poles 2a-2c of an armature core 2. An insulator 5 is wound around a rotating shaft 4a, over which three slip rings 6-8 are provided at intervals. These slip rings 6-8 are electrically connected to contacts A-C of armature windings 3a-3c respectively in delta connection through communicating members 9a-9c. Brushes 10a-10c are respectively provided in keeping in contact with each slip ring. The rotating speed of the rotor 4 can thereby be adjusted by changing the cycle of driving voltage to feed the current from brushes 10a-10c by slip rings. The rotating direction can be then changed by changing the phase.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a motor that drives a rotor in steps using the same torque generation mechanism as a DC motor.

(Prior Art) In recent years, there has been a trend for all products and parts to become lighter, thinner, shorter, and smaller, but it is well known that cameras have long been required to be made more compact, and the results are steadily coming true. In parallel with the miniaturization of cameras, electronic and automated functions such as automatic focusing, automatic film winding and rewinding, and automatic focus switching are progressing. Motors are widely used.

A micromotor is a DC motor that obtains torque by placing an armature as a rotor in a magnetic field created by a permanent magnet as a stator and passing current through the armature conductor. It also contributes to the generation of torque, and since the field is a permanent magnet, there is no excitation loss, so it is efficient, and it is used as a camera lens due to its features such as small size, low cost, low voltage drive, and large starting torque. It is widely used for drive, shutter drive, film winding drive, etc.

In this way, DC motors can be miniaturized and have a large torque, so are they suitable for camera applications?
When used to drive a lens, it is not enough to cut off the current to the armature conductor in order to accurately stop the lens at a predetermined position, so it is necessary to use an auxiliary stopping mechanism such as a pawl that uses spring force. Some means will be needed. Furthermore, the torque characteristics of a micromotor are subtly affected by external temperature and fluctuations in the voltage of the battery, which is the power source.

Therefore, if a stepping motor whose rotation is controlled by the number of pulses supplied is used, the lens can be accurately stopped at a predetermined position and held at that position by continuing to supply electricity, so it is possible to use an auxiliary motor such as the stopping mechanism described above. This eliminates the need for technical means and simplifies the structure.

However, currently available stepping motors are flat or have large diameters, making it difficult to incorporate them into cameras, making them unsuitable for making cameras more compact. Furthermore, stepping motors have the disadvantage that their torque per unit volume is smaller than that of DC motors, they cannot be controlled at high speeds, and they require advanced technology to manufacture.

(Objects and Structure of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to drive a rotor in a step manner while maintaining the torque generation principle of a DC motor and retaining the advantages of a DC motor. To achieve this purpose, a power supply slip ring is installed instead of a commutator on the rotating shaft of a motor consisting of a stator made of magnets and a rotor that can rotate inside the magnetic field generated by the stator. By providing this, the rotor is configured to be driven in steps.

(Example) The present invention will be explained below based on the drawings.

FIG. 1 shows the appearance of an embodiment of a motor according to the present invention.

The motor according to the present invention has field poles 2a, 2b of an armature core 2 made of laminated thin steel plates inside a magnetic field generated by a stator 1 made of a permanent magnet.

A rotor 4 configured by winding armature windings 3a, 3b, and 3c in a delta connection is rotatably arranged around the rotating shaft 4a.
is wrapped with an insulating material 5, and three slip rings 7.8 are provided spaced apart from each other in the axial direction.

FIG. 2 shows an enlarged view of the power feeding end side of the motor.

The slip rings 6.7.8 connect the connection points A, B, C (second
Only connection points A and B are shown in the figure. ) conductive members 9a, 9b.

9c, and each slip ring has a brush 10a, 10b, respectively.

10c are provided in contact with each other.

Next, the operation of the motor having the above configuration will be explained with reference to FIGS. 3 to 5.

FIG. 3 schematically shows the power supply section of the motor, and FIG. 4 shows the waveform of the driving voltage.

The fourth terminal is attached to the terminals of brushes 10a, 10b, and 10c, E and F.
The operation of the rotor when the driving voltages shown in Figures (a), (b), and (c) are applied is shown in the driving voltage period T1 to T6.
I will explain it separately.

Assuming that the rotor 4 is in the state shown in FIG.
When V) is applied, a current flows from the armature winding connection point B to A, and from connection point B to A through connection point C, and the voltage V at terminal E flows.
/2(v) appears, and an S pole is generated at the field pole 2a, and an N pole is generated at the field poles 2b and 2c. As a result, the field pole 2a (S pole) is attracted to the N pole of stator 1, the field pole 2b (N pole) is repelled by the N pole of stator l, and the field pole 2c (N pole) is attracted to the N pole of stator 1. Attracted to the south pole, the rotor 4 as a whole rotates in the direction of the arrow and stops at the position shown in FIG. 5(b). In the next period T2, the terminal is O(
When V (v) is applied to terminal E, current flows from connection point C to A, and from connection point C to A via B, so that S is applied to field poles 2a and 2b. A north pole is generated at the field pole 2C. As a result, the rotor 4 rotates in the direction of the arrow and stops at the position shown in FIG. 5(c) due to attraction and repulsion between each field pole and the magnetic pole of the stator. In the next period T3, V(v) is applied to the terminal E and 0(v) to the terminal F. As a result, current flows from the connection point C to B, and from the connection point C to B via A, so the field pole 2a
A north pole is generated at the field pole 2c, and an south pole is generated at the field pole 2b. Field pole 2a (N pole) is repelled by the N pole of stator l, field pole 2c (N pole) is repelled by the S pole of stator 1, but field pole 2b is strongly repelled by the N pole of stator 1. As it is attracted, the rotor 4 further rotates in the direction of the arrow as shown in Fig. 5 (
d) will occur. Thereafter, in the same manner, during period T4, V(v) is applied to the terminal and O(v) is applied to the terminal F, and in period T5, V(v) is applied to the terminal and 0 (V) is applied to the terminal E, and then during the period T
6, when V (v) is applied to terminal F and 0 (v) is applied to terminal E, each field pole of rotor 4 has a polarity as shown in FIG. Rotate in the direction (E), (E), and return to the initial position (A).

When the period T□ to T6 has elapsed in this way, the rotor 4 has made one revolution. After that, the waveform of the driving voltage is for a period T,
~Repeat the above operation to repeat T6,
The rotor 4 continues to rotate.

As can be seen from the above, the rotor 4 changes the polarity generated in the field pole every period of the drive voltage (T, T2, T3, T4, T5, T6), and the polarity generated in the field pole is changed between the magnetic poles of the stator. The rotation continues due to the attraction and repulsion between the
Just perform a stepping motion. Moreover, at the end of each period, the rotor maintains its relative position with respect to the stator. The rotation speed of the rotor can be adjusted by changing the period of the drive voltage, and the rotation direction can be changed by changing the phase of the drive voltage.

FIG. 6 shows another structure of the power supply section of the motor according to the present invention.

This is an example in which a stepped portion is formed by changing the diameter of the rotating shaft 4a in the axial direction, and slip rings 6, 7, and 8 are provided for each column diameter. Each slip ring and the armature winding are electrically connected by a conductor passing through an insulating material 5 wound around the rotating shaft 4a.

FIG. 7 shows the main parts of another embodiment of the motor according to the present invention, and in the figure, the same reference numerals as in FIG. 2 indicate the same components.

This embodiment differs from the above embodiments in that instead of using three slip rings, two slip rings 6.7 and brushes 10a and 10b that contact each of them are provided, and each slip ring 6 and 7 is connected to a conductive member 9a. and electrically connected to connection points A and B via 9b, respectively,
The rotating shaft 4a is used instead of a slip ring so that the bearing acts as a brush.In this way, two slip rings can be installed on the rotating shaft, which is advantageous in terms of manufacturing and cost. big.

The normal rotational operation of the motor in this embodiment and the generation of the rotor holding function during stoppage are exactly the same as in the embodiment shown in FIG. 1, so a description thereof will be omitted.

In each of the above embodiments, a motor having a torque generation mechanism similar to a three-pole DC motor was exemplified, but the present invention can of course be applied to other multi-pole motors of the same type, and basically the motor The same number of slip rings and brushes as the number of poles are used, but as in the second embodiment above,
A rotating shaft may be used instead of one of the slip rings. It goes without saying that the motor may be connected by star connection in addition to the exemplified delta connection.

Furthermore, although the above embodiments have exemplified a motor using a permanent magnet in the stator, the present invention can also be applied to a DC motor having a stator using an electromagnet, and an AC commutator motor ( It can also be applied to a motor that performs step drive using the torque generation mechanism of a universal motor (also called a universal motor).

(Effects of the Invention) As explained above, the present invention provides a motor that includes a stator made of magnets and a rotor that can rotate within a magnetic field generated by the stator, in which power is supplied to the rotating shaft of the rotor. Since the rotor is configured to be driven in steps by providing a slip ring, it is possible to realize a motor that has the advantages of both a DC motor and a Stellar Pink motor. In other words, the torque generating mechanism has a simple structure similar to that of a DC motor, and a relatively large torque can be obtained.Moreover, since it is a step drive, it is easy to manufacture, and it also has high speed control, miniaturization, and accurate position control. It becomes possible. Therefore, when the motor of the present invention is used to control, for example, a camera lens or shutter, an auxiliary means such as a stop mechanism is not required, and highly accurate control can be achieved with a simple structure and a small space. Generally, the number of poles of a DC motor must be odd, but the number of poles of the rotor of the motor according to the present invention may be odd or even, increasing the degree of freedom in design.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the appearance of a motor according to the present invention, and FIG.
The figure is an enlarged perspective view of the power supply section of the motor shown in Figure 1.
The figure is a schematic diagram of the power supply part of the motor according to the present invention, FIG. 4 is a waveform diagram of the driving voltage, FIGS. FIG. 6 is a perspective view showing another example of the structure of the power supply section of the motor according to the present invention, and FIG. 7 is a perspective view of essential parts of another embodiment of the motor according to the present invention. 1... Stator, 2... Armature core, 3a, 3b. 3C... Armature winding, 4... Rotor, 4a... Rotating shaft, 5... Insulating material, 6.7.8... Slip ring, 10a, 10b, 10c-brush Patent applicant: Konishiroku Photo Industry Co., Ltd. Agent: Patent attorney: Hiroo Suzuki, 12

Claims (3)

[Claims] (1) A motor comprising a stator made of a magnet and a rotor rotatable within a magnetic field generated by the stator, and characterized in that a power supply slip ring is provided on the rotating shaft of the rotor. (2) The motor according to claim 1, wherein the number of slip rings is equal to the number of poles of the rotor. (3) The motor according to claim 1, wherein the number of slip rings is one less than the number of poles of the rotor, and power is supplied via the slip rings and the rotating shaft.