JPH0318241A - Driving motor for polygon mirror - Google Patents

Abstract

PURPOSE:To make a remaining unbalance amount minimum by fixing a motor to a balancing machine (dynamic balancing testing machine) in a state of a polygonal mirror having been mounted, rotating it at a rated speed, and making an adjustment by fitting balance weights to the grooves of two faces of a disk and of the polygonal mirror or a fixture. CONSTITUTION:At first, balancing of a rotor 4 is independently made and corrected at a low speed. Then, it is put on a balancing machine in a state of a polygonal mirror 11 without a cover 22 being mounted, and dynamic balancing is made rotating it at a high speed. The dynamic balancing is made by correcting remaining unbalance at two faces of disks on the mirror side and on the antimirror side, with unbalance-correcting balance weights 23 fitted in to the unbalance-correcting groove 12 on a side surface of the polygonal mirror 11 and into the unbalance-correcting groove 12a of a disk 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a technique for accurately taking the tolerance of a laser beam scanning inner rotor type motor for driving a polygon mirror (polygon mirror) rotating at 2000 rpm, for example.

(1) [Prior art] Fig. 2 is a sectional view of a conventional example, in which the driving side bracket 1
A rotor 4 is disposed with a gap inside a stator 3 inside a frame 2 which is integrally formed with a rotor 4, and this rotor 4 is supported by bearings 6 and 7 mounted on brackets 1 and 5. Mounting tool 1 that is fixed to the shaft 8 and attached to the shaft end with a screw 9
Attach the polygon mirror 11 via 0a and 10b.

In such an inner rotor type motor for driving a polygon mirror, residual unbalance is corrected by the groove 12 of the polygon ξ roller 11 and the rotor 4 in order to reduce vibration of the rotating part.

[Problem to be solved by the invention]

In this kind of residual unbalance correction, after the balance of the rotor itself is corrected, the balance is corrected only by the polygon ξ roller 11, so the balance on the polygon mirror side cannot be balanced dynamically during high speed rotation, and vibrations are large. 《This will worsen the surface inclination of the ξ roller and cause noise. Furthermore, when performing eight-lance corrections on a single rotor, the rotor cannot be rotated at high speed due to the limitations of the testing machine (2), and is tested at, for example, 1800 rpm, so a slight imbalance remains in the rotor alone.

[Means to solve the problem]

The polygon mirror drive motor of the present invention has a rotor disposed inside a stator attached to the inside of a frame with a gap in between, and this rotor is supported by bearings attached to brackets that cover both end surfaces of the frame. The polygon mirror is fixed to a shaft, and one end of the shaft is passed through one of the brackets to mount the polygon mirror via a fixture, the other end of the shaft is passed through the other end of the bracket and a disk is mounted; Dynamic balance is maintained on two surfaces: this disk and the polygon mirror or the fixture.

[Operation] With the polygon mirror fully mounted, attach the motor to a balancing machine (dynamic balance tester), rotate it at the rated speed, and insert the balance weight into the grooves on the two sides of the disc and polygon mirror or fixture. By attaching (3) and adjusting, the amount of residual unbalance can be easily minimized.

〔Example〕

FIG. 1 shows a sectional view of the embodiment, and the same reference numerals as in the conventional example have the same functions. That is, as a characteristic structure of the embodiment, a disk 21 having a groove 12a is attached to the other end of the shaft 8, passing through the bracket 5 on the non-driving side. Disk 2
1 is protected by a cover 22.

It is best to first correct the balance by rotating the rotor 4 alone at low speed. The fully mounted polygon mirror 11 without the cover 22 is placed on a balancing machine and rotated at high speed to achieve dynamic balance.

Balance weights 23 for correcting unbalance are attached to the groove 12 for correcting residual unbalance on the side circumference of the polygon mirror 1l and the groove 12a for correcting unbalance of the disk 21, and the balance weights 23 are attached to the mirror side and the opposite side. Correct the residual unbalance on two sides with the disk and balance Dyna ≧ Sok.

In addition, if the polygon mirror is not provided with the groove 12 (4) A groove may be provided in the fitting 10a.

The balance weight 23 is made of thermosetting adhesive that can be firmly bonded to the polygon roller 11 and the disc 21 by heating, and is mixed with iron powder, lead powder, or the like.

〔Effect of the invention〕

In this invention, a rotor is arranged inside a stator attached to the inside of a frame through a gap, and this rotor is fixed to a shaft supported by bearings attached to brackets that cover both end surfaces of the frame. In the case where one end of the shaft is passed through one of the brackets and the polygon mirror is mounted via a fixture, the other end of the shaft is passed through the other end of the bracket and a disc is mounted, and the disc and the polygon mirror are attached. Since the dynamic balance is achieved on two sides with the rotor and the above-mentioned fixture, a) residual unbalance in the rotor alone is no longer essential, so the adhesive curing process for the balance weight alone can be eliminated.

b) The dyna that corrects the residual balance (5) on two surfaces, the ξ mirror side and the anti-mirror side, is also a sock balancer, and moreover, it can be mounted on a balancing machine with the motor in full power and operated under high-speed rotation. Since the balance is maintained accurately, the dynamic balance is maintained accurately, the balance is good at high speeds during use, and vibrations are extremely reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the embodiment, and FIG. 2 is a sectional view of the conventional example. 1, 5...Bracket, 2...Frame, 3...
Stator, 4... Rotor, 6, 7... Bearing, 8...
Shaft, 10a, 10b... Fixture, 11... Polygon mirror, 12.12a... Groove, 21... Disc, 23
...Balance weight.

Claims (1)

[Claims] 1) A shaft in which a rotor is disposed with a gap inside a stator attached to the inside of a frame, and this rotor is supported by bearings attached to brackets that cover both end surfaces of the frame. in which a polygon mirror is attached via a fixture by passing one end of the shaft through one of the brackets, the other end of the shaft passing through the other side of the bracket and attaching a disc, and the circular A motor for driving a polygon mirror, characterized in that dynamic balance is maintained on two surfaces: a plate and the polygon mirror or the mounting fixture.