Driving Force Transmission Mechanism, Image Forming Apparatus and Assembling Method Thereof

• US 20080303364A1
• Filed: 06/05/2008
• Published: 12/11/2008
• Est. Priority Date: 06/06/2007
• Status: Active Grant

• Current Assignee: Brother Kogyo Kabushiki Kaisha
• Original Assignee: Brother Kogyo Kabushiki Kaisha
• Inventors: OGAWA, Daisuke
• Granted Patent: US 8,159,101 B2
• Time in Patent Office: Days
• US Class Current: 310/80
• CPC Class Codes: H02K 5/00 Casings; Enclosures; Supports
• CPC Class Codes: H02K 7/116 with gears

Abstract

To provide a driving force transmission mechanism in which the thickness can be reduced as well as the positioning between a driven shaft and driven, and a motor shaft of a motor is easy. The driving force transmission mechanism of the invention comprises a plate through which a reference hole is pierced, a driven shaft vertically standing with respect to an inner surface on the side of the inner surface of the plate, a driven gear pivotally provided around the driven shaft, a bracket fixed to the plate so as to cover the reference hole on the side of the inner surface of the plate, and a stepping motor protruding a motor shaft toward the reference hole, being fixed to the bracket. The motor shaft is positioned through the reference hole with driving tooth formed at the motor shaft to be directly engaged with the driven gear.

Claims

1. A driving force transmission mechanism, comprising:

a plate through which a reference hole is pierced;

a driven shaft vertically standing with respect to one surface on the one surface side of the plate;

a driven pivotally provided around the driven shaft;

a bracket fixed to the plate so as to cover the reference hole on the one surface side of the plate; and

a motor protruding a motor shaft toward the reference hole, being fixed to the bracket,

wherein the motor shaft is positioned through the reference hole with driving tooth formed at the motor shaft to be directly engaged with the driven, or with a driving gear fixed coaxially to the motor shaft to be indirectly engaged with the driven.

2. The driving force transmission mechanism according to claim 1,

wherein the bracket includes a leg portion vertically standing from the one surface of the plate, being fixed to the plate so that the position can be adjusted, and a pedestal portion integrally formed with the leg portion, extending in parallel with the one surface to fix the motor, and

wherein the height of the driven shaft or the driven from the one surface is higher than the height from the one surface to the pedestal portion.

3. The driving force transmission mechanism according to claim 2,

wherein the driven includes a cylindrical shaft portion extending in the axial direction,

first tooth formed large in diameter on one end side of the shaft portion with respect to the plate, receiving driving force and

second tooth formed small in diameter on the other end side of the shaft portion which is apart from the first tooth, transmitting driving force.

4. The driving force transmission mechanism according to claim 1,

wherein the motor shaft has a positioning portion for performing positioning through the reference hole formed at a tip thereof.

5. The driving force transmission mechanism according to claim 4,

wherein the reference hole includes a cylindrical guide surface which is perpendicular to the one surface, and

wherein the positioning portion has a cylindrical guided surface extending coaxially with the guide surface.

6. The driving force transmission mechanism according to claim 4,

wherein the motor shaft has the driving tooth formed to be engaged with the driven.

7. The driving force transmission mechanism according to claim 6,

wherein the driving tooth are formed on the side of a base end with respect to the positioning portion.

8. The driving force transmission mechanism according to claim 1,

wherein the reference hole has an inside diameter larger than an outside diameter of the motor shaft, and

wherein the motor shaft extends into the reference hole.

9. The driving force transmission mechanism according to claim 2,

wherein the bracket includes the leg portions positioned at two regions which are 180 degrees opposite to each other with respect to the motor shaft in plan view, and

wherein the respective leg portions are screwed in the plate.

10. The driving force transmission mechanism according to claim 9,

wherein temporary locking means for locking the plate and the bracket temporarily at the plate and the bracket.

11. The driving force transmission mechanism according to claim 10,

wherein screw holes in which respective screws are screwed as well as a locking hole are formed in the plate,

wherein screw holes having larger diameter than the screws as well as a protrusion to be engaged with the locking hole are formed in the bracket;

and

wherein the temporary locking means are the locking hole and the protrusion.

12. An image forming apparatus, comprising:

a paper feeding means;

an image forming means for forming images on papers fed by the paper feeding means; and

a driving means for driving the image forming means,

wherein the paper feeding means or the driving means includes a driving force transmission mechanism,

wherein the driving force transmission mechanism comprises a plate through which a reference hole is pierced, a driven shaft vertically standing with respect to one surface on the one surface side-of the plate, a driven pivotally provided around the driven shaft, a bracket fixed to the plate so as to cover the reference hole on the one surface side of the plate, and a motor protruding a motor shaft toward the reference hole, being fixed to the bracket, in which the motor shaft is positioned through the reference hole with driving tooth formed at the motor shaft to be directly engaged with the driven, or with a driving gear fixed coaxially to the motor shaft to be indirectly engaged with the driven, and

wherein the motor is arranged so as to be arranged on the side of the image forming means with respect to the plate.

13. A method of assembling an image forming apparatus, comprising:

a first step of preparing a plate through which a reference hole is pierced and a driven shaft which is perpendicular to one surface of the plate stands on the one surface side, a bracket on which a motor protruding a motor shaft is fixed and a positioning jig positioned with respect to the plate by the reference hole, allowing the motor shaft to be positioned with the driven shaft in a constant relationship;

a second step of providing the positioning jig at the reference hole after the first step;

a third step of positioning the motor shaft by the positioning jig after the second step;

a forth step of fixing the bracket on the plate after the third step; and

a fifth step of removing the positioning jig from the reference hole after the fourth step.