JPH06284635A - Driving device and copier having motor and power transmission mechanism - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a drive device having a simple structure and a structure for adjusting the backlash of a transmission gear. [Structure] A part 2a of a base member 2 is formed in a motor housing member, and the motor drive mechanism 1 is formed in the housing member.
4, 16 and a power transmission mechanism 4 having a transmission gear 7 in which a gear shaft 7a is fixed to the base member 2 is provided on the surface of the base member on the opposite side of the motor drive mechanisms 14, 16. The motor rotating shaft 5 is rotatably supported by the housing member via the shaft, the end of the rotating shaft 5 is connected to the power transmission mechanism 4, and at least one bearing of the bearing pair is the slide bearing 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive unit having a motor and a transmission gear, which is incorporated in, for example, a copying machine, and particularly has a simple structure and a drive unit having a structure for adjusting the backlash of the transmission gear. The present invention relates to a copying machine using a driving device.

[0002]

2. Description of the Related Art Generally, a driving device for a copying machine has a motor mounted on a base member, the output end of a motor rotating shaft is projected to the opposite side of the base member, and the motor is driven by a power transmission mechanism such as a gear or timing belt. It has a structure to take out the rotational power of.

FIG. 5 shows the structure of a conventional drive device. This conventional drive device 31 includes a base member 32 having a flange portion to be attached to a copying machine, and a drive source motor 33.
And a transmission mechanism 34 for transmitting the power of the motor.

The rotating shaft 35 of the motor 33 is mounted on the base member 32.
Through the first stage pinion gear 36 at the lower end of the rotary shaft 35.
Is equipped with. The first-stage pinion gear 36 has a gear shaft 37 a meshed with a rotatable first-stage transmission gear 37 integrally formed with the base member 32. First stage transmission gear 37
Is configured to be capable of transmitting power to the next stage transmission gear 39 via the timing belt 38. The next stage transmission gear 39 is
It meshes with the gears of a driven machine 40, such as the drum of a copier.

A motor 33 is provided on the motor side of the base member 32.
A circuit board 41 for controlling the rotation of is attached.
The circuit board 41 is connected via a lead wire 42 to a circuit board heat dissipation portion 43 having a heat generating electronic element. The circuit board heat dissipation portion 43 is held by a screw 44 while being separated from the base member 32.

FIG. 6 shows the structure of the motor 33. The motor 33 has a housing member 46 having a cylindrical portion 46a and a flange portion 46b. The housing member 46 is screwed to the base member 32 by a plurality of screws 47 at the flange portion 46b. The ball bearings 4 are provided on the upper and lower portions of the cylindrical portion 46a of the housing member.
8,49 are provided. The rotating shaft 35 is rotatably supported by ball bearings 48 and 49. A substantially bowl-shaped rotor yoke 50 is fixed to the upper end of the rotary shaft 5. A magnet 51 is fixed to the inner peripheral surface of the cylindrical portion of the rotor yoke 50.

On the other hand, a stator core 52 is fixed to the outer periphery of the housing member cylindrical portion 46a. A coil 53 is wound around the stator core 52.

With the above structure, when the coil 53 is energized, the stator core 52 is excited, and the rotating shaft 35 is rotated by the action of the magnetic force. The rotation of the rotary shaft 35 is transmitted to the machine 40 driven by the power transmission mechanism 34 of FIG.

The current flowing through the coil 53 is controlled by the circuit board 41, and the heat generating electronic elements on the circuit board are diverged by the heat radiating plate 45.

[0010]

However, in the above-mentioned conventional drive unit, since the housing member of the motor is a separate component from the base member of the drive unit, the base member and the housing member are manufactured separately, and the entire drive unit is manufactured. The housing member was fixed to the base member with screws or the like when assembling. As a result, the number of parts and the number of assembling steps are increased, and a drive device having a structure as simple as possible has been demanded.

Further, since the ball bearing generally has a small play, the rotary shaft of the motor is supported by the pair of ball bearings as in the above-mentioned conventional drive unit, and the gear shaft of the first stage transmission gear is formed integrally with the base member. In such a case, the first-stage pinion gear and the first-stage transmission gear may not be properly meshed with each other due to an error in assembling / manufacturing, which may cause large noise and vibration, or the transmission gear may be abnormally worn.

In the drive device having such inconvenience,
There was a problem because a problem occurred after the assembly was completed and it could not be corrected by a simple correction work.

The backlash of the transmission gear may be further increased due to a mounting error when the motor / housing member is mounted on the base member and an inclination of the rotating shaft, so that an inappropriate backlash is totally prevented. There has been a demand for a drive device having such a structure.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional drive device and to provide a drive device having a simple structure and a structure for adjusting the backlash of the transmission gear.

[0015]

In order to achieve the above object, in a drive device having a motor and a transmission gear according to the present invention, a motor is provided on one side of a base member, and the rotation shaft of the motor is the base member. In a drive device in which a power transmission mechanism is provided on the protruding portion of the rotary shaft, the base member is partially formed in a motor housing member, and the motor drive mechanism is installed in the housing member. A power transmission mechanism having a transmission gear in which a gear shaft is fixed to the base member is provided on the surface of the base member opposite to the motor drive mechanism, and the housing member of the motor is provided via a pair of bearings. The rotary shaft is rotatably supported, the end of the rotary shaft is connected to the power transmission mechanism, and at least one of the pair of bearings is a slide bearing.

Further, in the drive device having the motor and the transmission gear of the present invention, a circuit board for controlling motor rotation and having a heat dissipation plate is provided on the side of the motor drive mechanism of the base member, and the heat dissipation plate of this circuit board is provided. It is characterized by being connected to the base member.

[0017]

According to the driving apparatus for a copying machine or the like having the motor and the transmission gear according to the present invention, a part of the base member is formed in the housing member of the motor and the motor driving mechanism is provided in the housing member. It is possible to obtain a drive device having a simple structure and easy manufacture by reducing the number of components.

Further, in the drive unit of the present invention, the gear shaft of the first stage transmission gear is fixed to the base member, but at least one of the bearings of the motor rotating shaft is a slide bearing having a relatively large play, so that When the backlash between the first-stage pinion gear and the first-stage transmission gear is too small due to manufacturing error, the motor rotation shaft is slightly inclined due to the play of the sliding bearing, and abnormal wear of the transmission gear and large noise and vibration can be prevented.

Further, in the driving device of the present invention, since the heat dissipation plate of the circuit board is connected to the base member, the heat of the heat-generating electronic element of the circuit board is transmitted to the base member via the heat dissipation plate, Since heat is dissipated from the entire base member, high heat dissipation efficiency can be obtained.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows the structure of the entire drive device of the present invention. As shown in FIG. 1, the drive device 1 mainly includes a base member 2, a drive source motor 3, and a power transmission mechanism 4 including a gear.

The tip of the rotary shaft 5 of the motor 3 projects below the base member 2. The first stage pinion gear 6 is fixed to the tip of the rotary shaft 5. The first-stage pinion gear 6 has a gear shaft 7a meshed with a rotatable first-stage transmission gear 7 integrally formed with the base member 2. The first-stage transmission gear 7 is configured to be capable of transmitting power to the next-stage transmission gear 9 via the timing belt 8. The next-stage transmission gear 9 is meshed with a gear of a driven machine (not shown), thereby taking out the power of the motor 3 to the outside.

A circuit board 10 for controlling the rotation of the motor 3 is attached to the motor side of the base member 2. A heat dissipation plate 11 of an electronic element is attached to a part of the circuit board 10. The base end side of the heat dissipation plate 11 is connected to the base member 2.

FIG. 2 shows the structure of the motor 3.
In FIG. 2, a part of the base member 2 is formed in a cylindrical portion 2a that supports the rotary shaft 5. A slide bearing 12 is attached to the inside of the lower portion of the cylindrical portion 2a. On the other hand, a ball bearing 13 is attached to the upper end of the cylindrical portion 2a. The rotary shaft 5 is rotatably supported by the slide bearing 12 and the ball bearing 13. A substantially bowl-shaped rotor yoke 14 is fixed to the upper end of the rotary shaft 5.
A magnet 15 is provided inside the cylindrical portion of the rotor yoke 14.
Are arranged in the circumferential direction.

A stator core 16 is fixed to the outer periphery of the cylindrical portion 2a of the base member 2. A coil 17 is wound around the stator core 16. The outer circumference of the stator and the inner circumference of the magnet 15 of the rotor are opposed to each other with a slight distance.

The operation of the driving device 1 of the present invention based on the above structure will be described below.

The drive unit 1 of the present embodiment has the above structure,
The cylindrical portion 2a of the base member constitutes a housing member of the motor 3. As a result, the assembly work of the motor is simplified without manufacturing the housing member of the motor as a separate part.

Further, since the plain bearing generally has a relatively large clearance between the plain bearing and the rotary shaft, the rotary shaft 5 of the motor of this embodiment allows a slight inclination due to the plain bearing 12 at the output end. To do. As a result, when the motor is assembled as shown in FIG. 1 and the backlash of the first-stage pinion gear 6 and the first-stage transmission gear 7 is slightly smaller than the predetermined value range, the backlash of the both gears is automatically eliminated by the escape of the sliding bearing 12. It can be adjusted to

Further, in the drive unit 1 of this embodiment, since the base end side of the heat dissipation plate 11 is connected to the base member 2, the heat of the electronic element of the circuit board 10 is transferred through the heat dissipation plate 11 to the base member. 2 and can be efficiently radiated using the entire base member 2.

In the above embodiment, the slide bearing 12 is provided on the output end side of the rotary shaft 5, but by using the slide bearing for either one of the rotary shafts, the self-centering action of the gear can be achieved. Obtainable.

FIG. 3 shows a motor in which a slide bearing is provided at the end of the rotary shaft opposite to the output side. Motor 1 of this embodiment
8 is used in a drive device that is exactly the same as the drive device in FIG. In FIG. 3, for easy understanding, the same reference numerals are given to the same portions and the description thereof is omitted.

The motor 18 of FIG. 3 is provided with a ball bearing 19 on the output end side of the rotary shaft 5, that is, on the lower portion of the cylindrical portion 2a of the base member, and slides on the opposite side of the ball bearing 19, that is, on the upper portion of the cylindrical portion 2a. A bearing 20 is provided.

As a result, the rotary shaft 5 allows a slight inclination, and thereby the backlash of the transmission gear can be adjusted, which is exactly the same as in the drive device 1 of FIG.

FIG. 4 shows a motor using sliding bearings for both of the two bearings of the rotary shaft. Since the rotary shaft 5 of the motor 21 is supported by the slide bearings 22 and 23, a larger inclination angle can be allowed and a larger gear backlash error can be accommodated.

[0034]

As is apparent from the above description, in the drive device of the copying machine having the motor and the power transmission mechanism according to the present invention, a part of the base member for fixing the motor is formed in the housing member of the motor. Therefore, it is possible to obtain a drive device having a simple structure and easy to assemble.

Further, since at least one of the pair of bearings supporting the rotary shaft is a slide bearing having a relatively large play,
When the backlash between the first-stage pinion gear and the first-stage transmission gear of the power transmission mechanism is too small, the rotary shaft is slightly inclined due to the play of the slide bearing, and the interference of the transmission gear can be automatically reduced.

Further, by connecting the heat dissipation plate of the circuit board to the base member, it is possible to obtain a driving device having high heat dissipation efficiency.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing the overall structure of a drive device including a motor and a power transmission mechanism according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of a motor of the driving device of the present invention.

FIG. 3 is a sectional view of a motor according to another embodiment of the present invention.

FIG. 4 is a sectional view of a motor according to still another embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing the structure of a conventional driving device such as a copying machine.

FIG. 6 is a sectional view showing a structure of a motor of a conventional drive device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive device 2 Base member 3 Motor 4 Power transmission mechanism 5 Rotating shaft 6 First stage pinion gear 7 First stage transmission gear 7a Gear shaft 10 Circuit board 10 11 Heat sink 11 12 Sliding bearing 13 Ball bearing

Claims (3)

[Claims] 1. A drive device in which a motor is provided on one side of a base member, a rotary shaft of the motor is projected to the other side of the base member, and a power transmission mechanism is provided on a protruding portion of the rotary shaft. A part of the base member is formed in a motor housing member, a motor drive mechanism is provided in the housing member, and a gear shaft is fixed to the base member on the base member surface opposite to the motor drive mechanism. A power transmission mechanism having a transmission gear is provided, the rotation shaft of the motor is rotatably supported by the housing member via a pair of bearings, and an end portion of the rotation shaft is connected to the power transmission mechanism. A drive device including a motor and a transmission mechanism, characterized in that at least one of the bearings is a sliding bearing. 2. A circuit board for controlling motor rotation and having a heat radiating plate is provided on the motor drive mechanism side of the base member, and the heat radiating plate of the circuit board is connected to the base member. A drive device comprising the motor according to claim 1 and a transmission mechanism. 3. A copying machine comprising the drive device according to claim 1.