JPH01303039A - Complex motor - Google Patents

Abstract

PURPOSE:To reduce fluctuation of speed over a wide range, by constructing a DC motor having excellent high speed performance and a VR(Variable Reluctance) motor having excellent low speed performance integrally on a single rotary shaft. CONSTITUTION:The rotor at a facing surface type brushless motor section 10, the rotor at a VR type step motor section 20 and the rotary encoder disc 31 at a detecting section 30 are secured to a rotary shaft 2 arranged in the center of a case 1 through bearings 3, 4. Torque to be produced from the brushless motor section 10 has periodicity of about 20 cycle/rotation, but it is damped through inertia because it is employed for high speed operation. Torque to be produced from a low speed VR step motor has periodicity of 100 cycle/rotation and high frequency is maintained even during low speed operation, but the torque is damped through inertia.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to motors such as permanent magnet excitation motors (DC motors) and step motors used to drive optical system scanners of copying machines.

[Prior art]

The optical system scanner of a copying machine and the scanner drive of an image scanner have a wide range from low speed to high speed (several 10 to several 10100).
Orp speed control is required. Conventionally, direct current motors or step motors have been frequently used to drive these scanners.

Here, we will briefly describe the configurations of a permanent magnet excitation motor (DC motor) and a step motor, and clarify the problems.

First of all, in a permanent magnet excitation motor, a coil is placed in the magnetic field of a permanent magnet, and when a current is passed through this coil, the rotor (for rotating magnetic field type: magnet, for rotating armature type: coil)
It has a rotating structure. A permanent magnet excitation motor with this structure is driven by a DC power source, but the generated 1-lux fluctuates due to non-uniform magnetic fields from the permanent magnets, excitation switching due to rectification, etc. The variation in this generated torque is due to the magnetic number and phase number.

It occurs in relation to the number of coils, and has a periodicity of around 20 cycles/rotation in the case of small motors used in copying machines, image scanners, etc. When the motor is operated at high speed, this fluctuation in the generated torque is attenuated by the rotor of the motor and the load inertia effect, and the speed unevenness is small, but when the motor is operated at low speed, the fluctuation in the generated torque increases the speed unevenness.

Therefore, when using a permanent magnet excitation motor to drive the optical system scanner of a copying machine or the scanner of an image scanner,
Although it is possible to control the speed over a wide range from low to high speeds, it has the disadvantage that speed unevenness occurs during low speed rotation, causing image blur.

On the other hand, some step motors use permanent magnets (PM
(type HB, type HB), and one that uses an electromagnet (type VR). −
For boat fishing, use a pulse-driven type with a pulse rotation angle of several degrees. Therefore, the generated I-lux fluctuation during one rotation of the motor has a periodicity of several hundred cycles/rotation. This generated torque fluctuation occurs at the frequency (T) even when the motor is running at low speed.
-1y, = ], /S) is high, is attenuated by the effects of the motor rotor and load inertia, and has little speed unevenness.

However, as mentioned above, this type of motor has 1
The rotation angle with a pulse is several degrees, and this motor has a rotation angle of several 110 degrees.
It is very popular to rotate at a high speed of 00 rpm.

The reason for this is that while it is necessary to rise and fall the magnetic flux at a high frequency of several 1000 Hz, the magnetic flux rises and falls at a high frequency due to the transient response of the current during excitation switching, the hysteresis of the magnetic circuit, etc. However, the nationality (
This is because. In this way, for a step motor,
It is not suitable for image scanners in optical systems of copying machines that require high-speed control over a wide range from low to high speeds.

Rather, it is suitable for scanner drives that require a low speed range.

As explained above, when driven by a permanent sand and stone magnetic motor (DC sarpo motor), it is possible to control from low to high speeds, but speed unevenness occurs during low speed rotation, causing image jitter. Also, when driving with a step motor,
It is extremely difficult to drive over a wide range from low to high speeds. In particular, high-speed driving is impossible.

〔the purpose〕

The present invention was developed against this background, and enables speed control over a high range from ultra-low speed to high speed.
The object of the present invention is to provide a composite motor that reduces speed unevenness at low speeds, which is a problem especially with DC sarpo motors.

〔composition〕

In order to achieve this object, the present invention is capable of individually controlling the drive and has no pulsation between 1 and 2 rotations in a non-excited state.
It is characterized in that the rotors of two motors are integrally installed on the same rotating shaft.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The figure is a vertical cross-sectional view of a compound motor according to one embodiment,
2 is a rotating shaft, 3 and 4 are bearings, and 5 is a flange. The rotating shaft 2 has a rotor with a G: 1, flat surface-to-plane flush smoked part] 0, and a VR (Variable ・Re
The rotor of the step motor section 200 and the encoder disk 31 of the detection section 30 (rotary encoder in this embodiment) are fixed and rotatable together with the rotating shaft 2.

The rotor of the flashless smoke section 10 is composed of a multipolar ring-shaped magnet 1] and a rotor yoke 12, and the ring-shaped magnet 11 and the rotor yoke 12 are fixed by adhesive or other means. The armature 13 facing the ring-shaped saltpeter 11 with a gap therebetween is a multi-phase plurality of coils, and is arranged and fixed on the flat surface of the iron flange 14 of the compound motor according to this embodiment. The generation of 1 to 1 to 1 hr during operation of this flashless smoke section 10 has a periodicity of around 20 cycles/rotation, which is related to the number of poles of the magnet and the number of coil phases, but since it is used for high-speed operation, the effect of rotor and load inertia It is possible to achieve velocity unevenness that does not affect the image. Also, since the armature 13 is a coil arranged on a flat plate, a state in which no current flows through the armature 13 (non-excited state)
In this case, no cogging torque is generated. Therefore, V
No disturbance torque is generated when the R-type step motor section 20 is operated.

The VR type step motor section 20 of the embodiment has two phases, and there are two rotors made of soft magnetic material corresponding to each phase. Each rotor 21. ．． 24 has a structure in which two rows of many tooth grooves are provided. Rotor 21. ．． 24, the rotor 22.
23, each rotor 21.24 has two rows of many tooth grooves on its surface facing the tooth grooves, and a solenoid coil 25.26 is installed in the center thereof. Rotor 2
1° 24 and the number of tooth spaces provided on the stator 22 and 23 are: ■ Step angle per pulse and solenoid coil 25
．． In this embodiment, approximately 50 tooth spaces are provided. Therefore, in the case of this embodiment, the step angle is several orders of magnitude per pulse. The torque generated during operation of the VR type step motor section 20 has a periodicity of around 100 cycles/rotation, but because the period is short, it is attenuated by the rotor and load inertia effect even during low speed operation, which does not affect the image. It is possible to suppress speed unevenness to a minimum level. Further, the step morph of this embodiment is of the VR type and does not have a permanent magnet. For this reason, the solenoid coil 25.2 provided on the stator 22.23
When no current is applied to the detent 6 (non-excited state), the detent 1-lux is not generated. Therefore, when the brushless morph section 10 described above is operated, no disturbance torque is generated.

The encoder disk 31 of the detection unit 30 is a thin disk with a plurality of slits provided on its outer circumference, and is fixed to the rotating shaft 2 by two support plates 33 . An optical detector 32 is provided on the outer diameter of the encoder disk 31, and detects the rotation angle when the rotation 1llll12 rotates. When the brushless morph unit 10 is operated, the signal from the detector 32 switches the current flowing through the coil of the armature 13 to rotate the rotor and is used as a feedback signal for constant speed control of the brushless morph unit 10.

As described above, the brushless morph section 10 is used to drive the optical system scanner or image scanner of a copying machine at high speed, and the step motor section 20 is used to drive it at low speed. Therefore, each motor section is operated independently, and when one motor section is in an operating state, the other motor section is in a non-excited state, and there is no disturbance to the motor section that is in an operating state. (Daytent 1-
Luk.

Cogging (1-lux) must not occur, but in the case of this embodiment, the slotless type brushless morph section 10 and V
Since it is constituted by an R-shaped step motor section 20, the motor sections do not generate torque that would cause disturbance to each other. In addition, the flange 14.5 holds the bearings 3 and 4 of the compound motor of this embodiment, and is arranged so that the rotating shaft 2 supported by the bearings 3 and 4 is kept coaxial with the case 1 so that it rotates smoothly. is fixed. Furthermore, the stator 23, 26 of the step motor section 20 and the detector 32 of the sensor section 30 are similarly fixed to the case 1.

[Effects] Second, the composite motor of the present invention combines a DC motor with excellent high-speed performance and a VR type motor with excellent low-speed rotation into one.
Since it is integrally constructed on two rotational axes, it can be used in optical system scanners and image scanners of copying machines to reduce speed unevenness in a wide range of speeds from low to high speeds.

[Brief explanation of the drawing]

The figure is a longitudinal cross-sectional view of a composite morph according to one embodiment. 2... Rotation axis, 10... Brushless morph section, 20
...Step motor section.

Claims (1)

[Claims] A compound motor characterized in that two motor rotors which can be individually controlled and whose rotational torque does not pulsate in a non-excited state are integrally provided on the same rotating shaft.