JP2000193047A - Gear transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely mount a motor in a prescribed position by providing a circular mount hole formed with an intermediate point of a line connecting axial cores of both gear set to a center and a guide groove crossing at right angles with a line connecting the axial cores and formed continuously with the mount hole in a mounting plate journaling two driven gears. SOLUTION: This gear transmission device for transmitting a drive force of an electric motor to a photoreceptor drum and a roller of an image formation device is formed by rotatably journaling a first and a second driven gear 602, 603 to a mounting plate 601 at some intervals apart from each other. An electric motor is mounted from the rear face for driving the driven motors 602, 603 and the respective gears 602, 603 are engaged with a pinion 72 on the drive shaft of the electric motor. In this case, a circular mount hole 616 formed with an intermediate point on a line connecting the axial cores of the both gears 602, 603 set to the center and a guide groove 615 crossing at right angles with the line connecting the axial cores and formed continuously with the guide groove 615 are formed in the mounting plate 601 so that the mounting of the electric motor can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear transmission in which a pinion provided on a drive shaft of a motor is meshed with two driven gears rotatably supported at predetermined intervals. About.

[0002]

2. Description of the Related Art In an image forming machine such as a printer or a copying machine, a photosensitive drum, a developing roller of a developing unit, a conveying roller for conveying a transfer sheet, a fixing roller of a fixing device, and the like are driven to rotate. These photosensitive drums, rollers, and the like are generally configured to be driven by a driving force of an electric motor via a gear transmission. In such a gear transmission, while balancing the reaction force when driving the driven gear by the pinion provided on the drive shaft of the electric motor, the gear train to the driven member is reduced to reduce the driving load. In order to alleviate this, a configuration in which a pinion is meshed with two driven gears and each of the two driven gears drives a gear train has been generally put into practical use.

In the gear transmission described above, the electric motor is mounted on a mounting substrate after the gear mechanism including the two driven gears is rotatably supported on the substrate for ease of assembly. At the time of mounting, the pinion provided on the drive shaft of the electric motor is engaged with the two driven gears while being inserted through the positioning mounting holes provided on the mounting board.

[0004]

In the above-described conventional gear transmission, when the electric motor is mounted, the pinion provided on the drive shaft is disposed on the mounting board at a predetermined interval. The driven gears are pryed in from the side surfaces of the driven gears, causing damage to the driven gears, such as scratching.

The present invention has been made in view of the above-mentioned circumstances, and a main technical problem thereof is to engage a pinion provided on a drive shaft of a motor without damaging two driven gears. It is another object of the present invention to provide a gear transmission capable of securely mounting a motor at a predetermined position.

[0006]

According to the present invention, there is provided, in accordance with the present invention, a mounting substrate and two driven members rotatably supported at a predetermined interval on the mounting substrate. In a gear transmission including a gear and a motor having a drive shaft having a pinion meshing with each of the two driven gears, the mounting substrate has a line on the line connecting the axes of the two driven gears. And a circular mounting hole formed around an intermediate point between the two driven gears, and a line formed orthogonal to a line connecting the axes of the two driven gears and formed continuously with the mounting hole. A guide groove having a width smaller than the diameter of the mounting hole and larger than the diameter of the pinion is provided, and the motor has a diameter corresponding to the mounting hole on an end face on the drive shaft side, and is fitted in the mounting hole. Teeth provided with matching positioning portions Transmission apparatus is provided.

Preferably, the guide groove is formed around a line passing through the intermediate point and orthogonal to a line connecting the axis centers of the two driven gears. It is preferable that a guided portion having a diameter corresponding to the guide groove and fitted in the guide groove is provided at the front end.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gear transmission constructed in accordance with the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view of a laser beam printer equipped with a gear transmission constructed according to the present invention. The illustrated laser beam printer includes a rectangular parallelepiped housing 2 formed of a synthetic resin. A substantially central portion of the housing 2 is located between the front and rear side plates made of a metal plate (not shown) arranged at a predetermined interval in the front-rear direction (a direction perpendicular to the plane of FIG. 1) in the housing 2. The photosensitive drum 4 is rotatably provided. The photosensitive drum 4 is driven to rotate in a direction indicated by an arrow 4a by a gear transmission described later. Around the photosensitive drum 4 rotated in the direction indicated by the arrow 4a, a charging corona discharger 6, a developing device 8, a transfer roller 10, a peeling corona discharger 12, and a cleaning device 14 are sequentially seen in the direction of the arrow 4a. And a static elimination lamp 16. In the illustrated embodiment, the photosensitive drum 4, the charging corona discharger 6, the cleaning device 14, and the neutralization lamp 16 are mounted on one unit frame to constitute a photosensitive unit.

The charging corona discharger 6 charges the photosensitive layer mounted on the peripheral surface of the photosensitive drum 4 to a specific polarity. In the illustrated embodiment, the developing device 8 includes a developing housing 81 that stores a developer composed of a one-component toner.
And a developing roller 82, a stirring means 83, and the like provided in the developing housing 81. The electrostatic latent image formed on the peripheral surface of the photosensitive drum 4 is developed into a toner image as described later. A toner cartridge 18 containing replenished toner is detachably mounted above the developing housing 81, and is replenished sequentially when a predetermined amount of toner in the developing housing 81 is consumed. The transfer roller 10 is formed of, for example, conductive urethane foam, is rotatably supported by the front and rear side plates, and is driven to rotate in a direction indicated by an arrow by a gear transmission described later. Note that a constant current of, for example, about 10 μA is applied to the transfer roller 10. The peeling corona discharger 12 performs a corona discharge on the back surface of the recording paper after the transfer. Cleaning device 14
Includes a cleaning housing 141, a cleaning fur brush 142, a cleaning blade 143, a toner conveying member 144, and the like provided in the cleaning housing 141, and removes toner remaining on the surface of the photosensitive drum 4.

A laser unit 20 is disposed above the housing 2, that is, above the photosensitive unit. The illustrated laser unit 20 includes a box-shaped unit housing 201, in which a laser light source (not shown), a rotating polygon mirror 202 rotated in a predetermined direction, and a first imaging lens 203, a second imaging lens 204, a first reflecting mirror 205, a second reflecting mirror 20
6, a third reflecting mirror 207 and a cylindrical lens 208 are provided. A laser light source (not shown) irradiates a laser beam based on image information output from a computer, for example, to the rotary polygon mirror 202. The laser light reflected from the rotary polygon mirror 202 passes through a first imaging lens 203 and a second imaging lens 204 and reaches a first reflecting mirror 205 as shown by a broken line in FIG. Reflector 20
5, after being reflected by the second reflecting mirror 206 and the third reflecting mirror 207, further pass through the cylindrical lens 208, and in a projection area formed between the charging corona discharger 6 and the developing device 8, It is projected on the peripheral surface of the drum 4.

In the housing 2, a recording paper transport mechanism indicated by numeral 22 is arranged from the lower part to the upper left. The recording paper transport mechanism 22 shown in FIG.
4, guide plate 26, registration roller pair 28, guide plate 30,
Guide plate 32, fixing roller pair 34 constituting the fixing device, guide plate 36, transport roller pair 38, guide claw 40, guide plate 4
2, a transport roller pair 44, a guide plate 46, and a discharge roller pair 48 are provided. The recording paper cassettes 50 are connected to the lower side of the housing 2. The recording paper cassette 50 includes a paper feeding unit (not shown), and the paper feeding roller pair 24
The recording paper is fed toward. on the other hand,
The recording paper sent out by the action of the discharge roller pair 48 is discharged to a receiving portion 2 a defined on the upper surface of the housing 2.

In the illustrated laser beam printer, a reversing unit 52 indicated by a two-dot chain line in FIG. The reversing unit 52 is used for recording on both sides of a recording sheet. That is, when recording is performed on both sides of the recording paper, when the image is recorded on the surface of the recording paper, the guide claw 40 is positioned at the position indicated by the two-dot chain line, and the recording paper on which the image is recorded on the surface is recorded. The reversing unit 5
It leads to 2. The recording paper introduced into the reversing unit 52 is turned upside down here and is conveyed toward the guide plate 26.

Here, the operation of the above-described laser beam printer will be briefly described. The photosensitive drum 4 is an arrow 4
During the rotation in the direction indicated by a, the charging corona discharger 6 charges the photosensitive layer of the photosensitive drum 4 to a specific polarity. Next, laser light from a laser light source (not shown) of the laser unit 20 is projected onto the photosensitive drum 4 in the projection area, and an electrostatic latent image corresponding to image information is formed on the peripheral surface of the photosensitive drum 4. You. Thereafter, the developing roller 82 of the developing device 8 causes the toner to act on the electrostatic latent image on the photosensitive drum 4 to develop the electrostatic latent image into a toner image. On the other hand, the recording paper is fed by paper feeding means (not shown) of the recording paper cassette 50. The recording paper is conveyed by the paper feed roller 24 and temporarily stopped by the pair of registration rollers 28, and is conveyed to the transfer area where the photoconductor drum 4 and the transfer roller 10 face each other at the timing of the photoconductor drum 4. The toner image formed on the peripheral surface of the photosensitive drum 4 is transferred to the recording paper conveyed to the transfer area by the action of the transfer roller 10. The recording paper to which the toner image has been transferred is separated from the photosensitive drum 4 by the action of the separating corona discharger 12 and then conveyed to the fixing roller pair 34, where the toner image is transferred to the surface of the recording paper by the action of the fixing roller pair 34. Is established. The recording paper on which the toner image has been fixed is transported by the transport roller pairs 38 and 44, and is discharged to the receiving portion 2a on the housing 2 via the discharge roller pair 48. On the other hand, the photosensitive drum 4 further continues to rotate, the residual toner is removed from the surface of the photosensitive drum 4 by the operation of the cleaning device 14, and the photosensitive layer of the photosensitive drum 4 is neutralized by the operation of the neutralization lamp 16.

Next, a gear transmission for rotating the photosensitive drum 4 and each roller will be described with reference to FIGS.
This will be described with reference to FIG. The gear transmission 60 in the illustrated embodiment is mounted on the back surface of the above-mentioned rear side plate (not shown). The gear transmission 60 includes a mounting board 601. A first driven gear 602 and a second driven gear 603 having an electromagnetic clutch are rotatably supported on the mounting board 601 at predetermined intervals. Further, on the mounting board 601, each gear for transmitting a driving force of an electric motor described later via the first driven gear 602 and the second driven gear 603 is rotatably supported, respectively. . The respective gears will be described according to the power transmission path from the first driven gear 602 and the second driven gear 603.

The first driven gear 602 meshes with the intermediate gear 605 via the intermediate gear 604 and an electromagnetic clutch. One intermediate gear 604 meshing with the first driven gear 602 is mounted on the rotation shaft of the transfer roller 10 and drives the transfer roller 10 to rotate. The intermediate gear 604 is an intermediate gear 606 meshing with a drum gear (not shown) mounted on the photosensitive drum 4.
Are engaged with each other via an electromagnetic clutch.

The other intermediate gear 605 meshing with the first driven gear 602 is a two-stage gear, and
07. The intermediate gear 607 meshes with an intermediate gear 608 that meshes with a developing gear (not shown) that transmits power to the developing roller 82 and the stirring means 83 of the developing device 8. Also, the intermediate gear 607 is
It is in mesh with a registration gear 609 for rotationally driving the registration roller pair 28 via a one-way clutch (not shown). Further, the intermediate gear 607 meshes with a paper feed gear 610 for driving the paper feed roller pair 24 via an electromagnetic clutch (not shown).

The second driven gear 603 meshes with an intermediate gear 611 constituted by a two-stage gear, and the fixing roller pair 34, the transport roller pairs 38 and 44, via the intermediate gear 612 and the intermediate gear 613. It is operatively connected to a gear train (not shown) for driving the discharge roller pair 48.

An electric motor 70 for driving the first driven gear 602 and the second driven gear 603 is mounted on the mounting board 601 from the back. The electric motor 70 includes a pinion 72 provided on a drive shaft 71.
Are mounted so as to mesh with the first driven gear 602 and the second driven gear 603, respectively. When attaching the electric motor 70 to the mounting board 601,
In order to facilitate meshing of the pinion 72 with the first driven gear 602 and the second driven gear 603, a mounting hole 616 and a guide groove 615 are formed in the mounting substrate 601 as shown in FIG. I have. The mounting hole 616 is formed in a circular shape around a middle point P between the first driven gear 602 and the second driven gear 603 on a straight line 617 connecting the axes of the two driven gears. The guide groove 615 is perpendicular to a straight line 617 connecting the axes of the two gears, and
16 and are formed continuously. This guide groove 615 is
A line 618 orthogonal to the straight line 617 passing through the intermediate point P
, The width (B) of which is smaller than the diameter (D) of the mounting hole 616 and the diameter (d1) of the pinion 72.
It is configured to be larger.

On the other hand, the electric motor 70 mounted on the mounting board 601 is provided with a positioning portion 73 formed to protrude from an end surface of the case 700 on the drive shaft 71 side. The positioning portion 73 is formed in a cylindrical shape around the axis of the drive shaft 71 and has a diameter (d2) corresponding to the mounting hole 616. Is positioned at the mounting position. On the front end face of the positioning portion 73, a guided portion 74 formed to protrude is provided. The guided portion 74 is formed in a cylindrical shape around the axis of the drive shaft 71 and is formed in a cylindrical shape.
It has a diameter (d3) corresponding to a width (B) of 15;
It can move while being fitted into the guide groove 615 and being guided along the guide groove 615. A mounting plate 80 for mounting on the mounting board 601 is fixed to the case 700 of the electric motor 70 on the drive shaft 71 side. The mounting plate 80 is provided with four mounting holes 81.

Next, the electric motor 70 is mounted on the mounting board 6.
The procedure for mounting the camera on the 01 will be described. First, the pinion 72 provided on the drive shaft 71 of the electric motor 70 is inserted from the back side of the mounting board 601 through the guide groove 615,
When the guided portion 74 is fitted into the guide groove 615, the positioning portion 73 comes into contact with the back surface of the mounting board 601. Next, when the electric motor 70 is moved toward the mounting hole 616, the guided portion 74 moves along the guide groove 615. This guide groove 6
15 is centered on the line 618 orthogonal to the straight line 617 passing through the intermediate point P between the two gears on the straight line 617 connecting the axes of the first driven gear 602 and the second driven gear 603 as described above. As a result, the pinion 72 moves the first driven gear 602 and the second driven gear 6 by the above-described movement of the electric motor 70 toward the mounting hole 616.
Move toward 03. Accordingly, the pinion 72 can enter between the first driven gear 602 and the second driven gear 603 and easily and reliably mesh with both gears. At this time, since the first driven gear 602 and the second driven gear 603 are rotatably supported on the shaft, if the meshing phase with the pinion 72 is shifted, the first driven gear 602 is rotated to correct the phase difference. Interlocks easily. In this manner, when the pinion 72 reaches a position where the first driven gear 602 and the second driven gear 603 mesh with each other, the positioning portion 73 is fitted into the mounting hole 616, and the electric motor 70 is mounted in the predetermined mounting position. Positioned in position. When the electric motor 70 is positioned at a predetermined mounting position, a screw 90 is inserted through the mounting hole 81 and screwed into a screw hole 620 formed in the mounting substrate 601 to thereby attach the electric motor 70 to the mounting substrate 60.
1 can be attached.

As described above, the gear transmission configured according to the present invention has been described based on the embodiment in which the gear transmission is applied to a laser beam printer. However, the present invention is not limited to the embodiment, and is installed in various machines. It can be applied to a gear transmission.

[0023]

According to the present invention, at predetermined intervals, two
The mounting board on which the driven gears are rotatably supported,
A circular mounting hole formed around a midpoint between the two driven gears on a line connecting the axes of the two driven gears,
Since a guide groove is formed orthogonal to the line connecting the shaft cores and formed continuously with the mounting hole, when mounting the motor on the mounting board, the pinion provided on the drive shaft of the motor passes through the guide groove. By inserting and moving along the guide groove toward the mounting hole, the pinion can enter between the two driven gears and easily and reliably mesh with both gears. Then, by positioning the positioning portion provided on the motor into the mounting hole, the motor can be positioned at a predetermined mounting position.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a laser beam printer equipped with a gear transmission configured according to the present invention.

FIG. 2 is a front view of a gear transmission configured according to the present invention.

FIG. 3 is a rear view of the gear transmission shown in FIG. 1;

[Explanation of symbols]

 2: Housing 4: Photoconductor drum 6: Corona discharger for charging 8: Developing device 10: Transfer roller 12: Corona discharger for peeling 14: Cleaning device 16: Static elimination lamp 20: Laser unit 22: Recording paper transport mechanism 24: Paper feed roller pair 28: Registration roller pair 34: Fixing roller pair 60: Gear transmission device 601: Mounting substrate 602: First driven gear 603: Second driven gear 616: Mounting hole 617: Guide groove 70: Electric Motor 71: Drive shaft 72: Pinion 73: Positioning part 74: Guided part 80: Mounting plate

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[Procedure amendment]

[Submission Date] May 13, 1999 (1999.5.1
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a laser beam printer equipped with a gear transmission configured according to the present invention.

FIG. 2 is a front view of a gear transmission configured according to the present invention.

FIG. 3 is a rear view of the gear transmission shown in FIG. 2;

FIG. 4 is a perspective view of an electric motor included in the gear transmission shown in FIG. 2;

[Explanation of Signs] 2: Housing 4: Photoconductor drum 6: Corona discharger for charging 8: Developing device 10: Transfer roller 12: Corona discharger for peeling 14: Cleaning device 16: Static elimination lamp 20: Laser unit 22: Recording Paper transport mechanism 24: Paper feed roller pair 28: Registration roller pair 34: Fixing roller pair 60: Gear transmission 601: Mounting substrate 602: First driven gear 603: Second driven gear 616: Mounting hole 617: Guide groove 70: Electric motor 71: Drive shaft 72: Pinion 73: Positioning part 74: Guided part 80: Mounting plate

Claims (3)

[Claims] 1. A mounting board, two driven gears rotatably supported at a predetermined interval on the mounting board, and
A motor having a drive shaft provided with a pinion meshing with each of the two driven gears, wherein the mounting board has a line on the line connecting the axes of the two driven gears. A circular mounting hole formed around an intermediate point between the two driven gears, and a circular mounting hole formed at right angles to a line connecting the axes of the two driven gears and continuous with the mounting hole. A guide groove having a width smaller than the diameter and larger than the diameter of the pinion is provided, and the motor has an end surface on the drive shaft side having a diameter corresponding to the mounting hole and a positioning fitting into the mounting hole. A gear transmission, comprising a part. 2. The gear transmission according to claim 1, wherein the guide groove is formed around a line passing through the intermediate point and orthogonal to a line connecting the shaft centers of the two driven gears. 3. The gear according to claim 1, wherein the motor is provided with a guided portion having a diameter corresponding to the guide groove at a front end of the positioning portion and fitted in the guide groove. Gearing.