JP4080232B2 - Rotation axis tilt correction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotation axis inclination correction method for correcting an inclination of a rotation axis so that a rotation axis fixed in an insertion hole of the rotation base stands in a vertical direction with respect to the rotation base.
[0002]
[Prior art]
The rotating shaft is a mechanical element that is widely used in various devices such as motors. However, in recent years, there has been a request regarding the right angle accuracy of the rotating shaft, that is, the rotating shaft extending at right angles to the rotating surface. Is getting stronger. For example, in motors, various proposals have been made to rotate and support a rotating body such as a polygon mirror, a magnetic disk, and an optical disk at high speed, and accordingly, the rotational accuracy of the rotating shaft is becoming higher. is there. A polygon motor will be described with reference to FIG. 5 as an example of this type of motor.
[0003]
In FIG. 5, the polygon motor is schematically composed of a stator portion 10 and a rotor portion 20. The stator portion 10 is fixed to a radial bearing 12 held on the inner peripheral side of a cylindrical bearing holder 11, a thrust bearing 13 fixed to one opening of the bearing holder 11, and an outer peripheral side of the bearing holder 11. And a stator core 16 around which an armature coil 15 is wound.
[0004]
On the other hand, the rotor portion 20 is inserted into the radial bearing 12 and has one end supported by the thrust bearing 13, a hub 22 fitted and fixed to the other end of the rotation shaft 21, and a mirror of the hub 22. A polygon mirror 26 that is fixedly mounted on the mounting portion 23 by a spring member 24 and a fixing screw 25, and a rotor yoke 28 that is fixed to the lower portion of the hub 22 and that has a plurality of magnetic poles mounted on the inner periphery thereof. ing. The inner peripheral surface of the drive magnet 27 is opposed to the outer peripheral surface of the stator core 16 via a gap. When a predetermined current is passed through the armature coil 15, the rotor portion 20 is caused by the electromagnetic action 27 of the stator core 16 and the drive magnet. Rotates.
[0005]
[Problems to be solved by the invention]
In the polygon motor having such a configuration, in order to ensure the tilt accuracy of the polygon mirror 26, that is, the parallelism of the mirror surface (anti-slope) 26a with respect to the rotation axis direction with high accuracy, the processing accuracy and assembly accuracy of each component are strictly limited. There is a need to. This is because if a motor with a large tilt or shake of the polygon mirror 26 is used in a printer as it is, the deviation of the laser beam greatly affects the unevenness of the latent image on the photosensitive drum due to the tilt of the mirror surface 26a, and the output image quality deteriorates. Because it does. Therefore, prevention of the inclination of the polygon mirror 26 as the rotated body is an important management item in manufacturing the polygon motor.
[0006]
The parallelism of the mirror surface 26a with respect to the rotation axis direction is such that the rotation shaft 21 is set in a predetermined direction, that is, a direction perpendicular to the mounting surface 23a of the mirror mounting portion 23 of the hub 22 on which the polygon mirror 26 is mounted. It depends greatly on how it is fixed. In order to maintain an error with respect to a predetermined direction set in advance such as the squareness within a desired range, the processing accuracy of the rotating shaft 21 and the hub 22 and the assembly accuracy of both have been improved conventionally. However, in order to ensure these precisions, there is a problem that processing costs and assembly costs increase.
[0007]
Further, in the inspection process after the rotary shaft 21 and the hub 22 are once assembled, when it is found that the parallelism of the mirror surface 26a is poor and so-called surface tilt has occurred, in general, the rotary shaft 21 and the hub 22 The mirror mounting surface 23a of the hub 22 is processed in a state of assembling, and the perpendicularity between the rotating shaft 21 and the mirror mounting surface 23a is ensured. However, there is a problem that assembly cost increases due to the addition of such assembly processing. There is also.
[0008]
Note that the above-mentioned problem regarding the accuracy with respect to a prescribed direction such as the perpendicularity between the rotating shaft 21 and the rotating base (hub 22 or the like) is not limited to the polygon motor, but a rotating body such as a magnetic disk or an optical disk is used. The same problem occurs in various motors for rotational driving.
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for correcting the tilt of a rotating shaft that can secure the perpendicularity between the rotating shaft and the rotating base at a low cost.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, there is provided a method for correcting a tilt of a rotary shaft, wherein the rotary shaft is fixed to the rotary base after the rotary shaft is fixed in the insertion hole of the rotary base. In correcting the tilt of the rotary shaft so that the rotary shaft stands or tilts in the direction, it is in the vicinity of the fitting hole on the surface of the rotary base from which the rotary shaft protrudes, and is opposite to the direction in which the rotary shaft should be tilted. Correcting the inclination of the rotating shaft by crushing the portion on the side, and erecting or tilting the rotating shaft in the predetermined direction with respect to the rotating base to eliminate errors due to fixing of the rotating shaft It was made to let it be made to do.
[0011]
According to the tilt correction method of the rotating shaft according to the first aspect, it is not always necessary to sufficiently manage the processing accuracy and assembly accuracy of the rotating shaft and the rotating base, and the rotating shaft and the rotating base are rotated after being fixed. The inclination of the axis can be easily corrected.
[0012]
According to a second aspect of the present invention, in addition to the first aspect, when the rotation center of the rotating base and the center of the rotating shaft do not coincide with each other, It is characterized by crushing the part on the extended line connecting the center.
[0013]
According to the method for correcting the tilt of the rotating shaft according to the second aspect, the tilt of the rotating shaft is most effectively reduced by crushing the portion on the extended line connecting the rotation center of the rotating base and the center of the rotating shaft. It can be corrected.
[0014]
According to a third aspect of the present invention, in addition to the first or second aspect, the rotating shaft tilt correction method is characterized in that the rotating base is crushed in a state where the rotating body is mounted on the rotating base.
[0015]
According to such a method of correcting the tilt of the rotating shaft according to the third aspect, since the perpendicularity between the rotating body and the rotating shaft is directly corrected, the rotating body can be rotated with high accuracy.
[0016]
According to a fourth aspect of the present invention, there is provided a tilt correction method for a rotating shaft according to any one of the first to third aspects, wherein the distance from the rotation center of the rotating base to the crushing point or the crushing depth is changed. It is characterized by adjusting the inclination.
[0017]
According to the tilt correcting method of the rotating shaft according to the fourth aspect, the rotating shaft is adjusted by adjusting the tilt of the rotating shaft by changing the distance from the rotation center of the rotating base to the crushing point or the crushing depth. Since the inclination of the rotation axis can be finely adjusted, the perpendicularity of the rotation axis with respect to the rotation base can be accurately obtained.
[0018]
Further, in the tilt correction method of the rotating shaft according to the fifth aspect, the rotating shaft according to the first aspect is composed of a motor shaft, and in particular, a good result is obtained on the rotating shaft of the motor.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a method for correcting the tilt of a rotating shaft according to the present invention will be described with reference to FIGS. 1 to 4. Prior to that, an example of the structure of a polygon motor to which the present invention is applied will be described.
[0020]
FIG. 1 is a cross-sectional view showing an embodiment of a polygon motor in which the tilt of the rotating shaft 21 is corrected by applying the present invention. The configuration having the same function as that of the polygon motor shown in FIG. A description will be given with reference numerals. In FIG. 1, the polygon motor is schematically composed of a stator portion 10 and a rotor portion 20. The stator portion 10 includes a radial bearing 12 made of a sintered oil-impregnated alloy or the like held on the inner peripheral side of a cylindrical bearing holder 11, a thrust bearing fixed to one opening of the bearing holder 11, and a bearing holder. A stator substrate 13 fixed to the outer peripheral side and a stator core 16 around which the armature coil 11 is wound are provided. Note that circuit components (not shown) are mounted on the stator substrate 13.
[0021]
On the other hand, the rotor portion 20 is inserted into the radial bearing 12 and has one end supported by the thrust bearing 13 and a hub 22 as a rotating base fitted and fixed to the other end of the rotating shaft 21. A polygon mirror 26 fixedly mounted on the mirror mounting portion 23 of the hub 22 by a spring member 24 and a fixing screw 25 and a drive magnet 27 fixed to the lower part of the hub 22 and having a plurality of magnetic poles are mounted on the inner periphery. And a rotor yoke 28. The inner peripheral surface of the drive magnet 27 is opposed to the outer peripheral surface of the stator core 16 via a gap. When a predetermined current is passed through the armature coil 15, the rotor portion is caused by the electromagnetic action of the stator core 16 and the drive magnet 27. Rotates.
[0022]
In such a polygon motor, the rotating shaft 21 is fitted and fixed in a fitting insertion hole 22 a provided in the center of the hub 22, and the rotating shaft 21 stands substantially perpendicular to the mirror mounting surface 23 a of the hub 22. Yes. In order to raise the rotating shaft 21 vertically, a correction method described later is used. As a result of the correction, a crush mark 22b is formed in the vicinity of the fitting insertion hole 22a of the hub 22. The crush mark 22b is a concave portion that is recessed in a conical shape at a depth of several millimeters at a position several millimeters away from the insertion hole 22a. Since the crush marks 22b are provided on the back side of the hub 22, that is, inside the motor, there is no problem in appearance.
[0023]
Next, the manufacturing process of the polygon motor according to the above embodiment and the tilt correction method of the rotating shaft according to the present invention will be described with reference to FIGS.
[0024]
First, after the rotor yoke 28 having the drive magnet 27 fixed to the inner peripheral surface is fixed to the lower surface side of the hub 22 by means of caulking or the like, one end side of the rotary shaft 21 is press-fitted or shrink-fitted into the fitting insertion hole 22a of the hub 22. It is fixed by various fixing means. Next, the polygon mirror 26 is mounted on the mirror mounting portion 23 of the hub 22, and the polygon mirror 26 is mounted in a stationary state by the spring member 24 and the fixing screw 25. The rotor part 20 is once completed by the process so far.
[0025]
Next, the free end side of the rotating shaft 21 is inserted into the radial bearing 12 constituting the stator portion 20 (the assembly procedure is omitted) that has been assembled in advance. When fully inserted, the tip of the rotating shaft 21 comes into contact with the thrust bearing 13, and the polygon motor is completed at this stage.
[0026]
Thereafter, various inspections are performed in order to check the performance characteristics of the polygon motor. One of the most important inspection items is the inclination accuracy of the polygon mirror 26, that is, the parallelism of the mirror surface 26a with respect to the rotation axis direction. Inspection (inclination inspection) is performed. This inspection is to irradiate the mirror surface 26a of the polygon mirror 26 while rotating the rotor portion 20 and monitor the reflected light to check whether it is within an appropriate numerical value.
[0027]
As shown in FIG. 2, the products that have passed various inspections including the parallelism inspection of the mirror surface 26a will be packaged and shipped as non-defective products, but those that have failed the parallelism inspection. The tilt correction operation of the rotating shaft 21 is performed in the following procedure.
[0028]
First, when monitoring the reflected light in the parallelism inspection, it is measured how much the mirror surface 26a is tilted in which direction with respect to the axial direction, and the rotation axis C2 is determined based on the data. The degree of deviation from the center of rotation C1, that is, a predetermined direction set in advance, is derived.
[0029]
Next, the rotor portion 20 of the motor that requires correction of the rotation shaft 22 is extracted from the stator 10 portion, and the rotation shaft 21 should be tilted in the vicinity of the fitting insertion hole 22a of the hub 22 as shown in FIG. The tip of the punch 30 is crushed in a portion opposite to the direction (D direction). Thereby, the inclination of the rotating shaft 21 can be corrected in a predetermined direction, and the rotating shaft 21 is set to a predetermined direction set in advance with respect to the mirror mounting surface 23a of the hub 22, that is, the mirror mounting surface 23a. Can be erected in a perpendicular direction.
[0030]
The location where the tip of the punch 30 is crushed is an extension of a line connecting the rotation center C1 of the hub 22, that is, the center of the insertion hole 22a, and the center C2 of the inclined rotation shaft 21, and the rotation of the hub 22 The portion outside the rotary shaft 21 on the side where the center C2 of the rotary shaft 21 is shifted from the center C1 is crushed. That is, when the upper left side indicated by the arrow in FIG. 4 is the direction in which the rotation shaft 21 should be tilted (D direction), the rotation shaft 21 on which the rotation shaft 21 from which the fixing error is desired to protrude protrudes from the rotation center C1 on the upper surface of the hub 22 shown in FIG. The position indicated by reference numeral 22b located on the straight line on the lower right side (broken line) is crushed.
[0031]
In this manner, by crushing the vicinity of the fitting insertion hole 22a of the hub 22, plastic deformation is performed so that the root portion of the rotating shaft 21 is bent as indicated by an arrow in the portion where the punch 30 is driven as shown in FIG. Then, the rotary shaft 21 moves so that the portion of the hub 22 protruding from the upper surface in the figure stands upright while maintaining a straight shape. That is, the rotating shaft 21 is inclined to the side opposite to the side where the punch 30 is driven, and as a result, the rotating shaft 21 is inclined in the direction to be inclined (D direction), and thus the rotating shaft 21 is perpendicular to the hub 22. It can be corrected to stand up in the direction.
[0032]
In this case, if the rotation shaft 21 protrudes from the upper surface of the hub 22 in the direction to be corrected while being chucked and held by an appropriate jig, the rotation shaft becomes curved. The linearity of the rotating shaft may be hindered. However, according to the above-described embodiment of the present invention, the linearity at the portion where the rotating shaft 21 protrudes from the illustrated upper surface of the hub 22 is maintained well. The Rukoto.
[0033]
When the punch 30 is driven, the inclination of the rotating shaft 21 can be finely adjusted by appropriately changing the distance from the rotation center C1 of the hub 22 to the crushing point or the crushing depth. However, it is preferable that the depth at which the punch 30 is driven, that is, the depth of the crush mark 26b, is not deeper than the mirror mounting surface 23a. This is because when the punch 30 is driven deeper than the mirror mounting surface 23a, stress distortion is exerted on the outer peripheral surface of the hub 22 that is in close contact with the inner peripheral surface of the polygon mirror 26, and the polygon mirror 26 is displaced in the radial direction. Because there is a possibility of waking.
[0034]
Further, the number of places where the punch 30 is driven is not limited to one, and the crushing marks 22b may be formed by driving a plurality of places. The tip 30 has a conical shape (circular cross section) as shown in FIG. However, the inclination of the rotating shaft 21 can be similarly corrected even when the punch 30 is crushed with various shapes such as a polygon, an ellipse, and an arc.
[0035]
Further, the portion where the punch 30 is crushed does not necessarily have to be a portion on the extension line connecting the rotation center C1 of the hub and the center C2 of the inclined rotation shaft 21, and the direction in which the inclination of the rotation shaft 21 should be corrected ( It suffices if it is a portion on the opposite side to (D direction).
[0036]
Further, in the present embodiment, the correction operation is performed in the state where the rotor unit 20 is removed from the stator unit 10 and the polygon mirror 26 is mounted on the hub 22, but the rotating shaft 21 is inserted into the hub 22. Immediately after that, the perpendicularity inspection of the hub 22 and the rotating shaft 21 may be performed, and the above correction work may be performed on the case where the positional deviation between the rotating shaft core C2 and the rotating center C1 is out of the allowable range.
[0037]
According to the tilt correction method of the rotating shaft 21 as described above, it is not always necessary to sufficiently manage the processing accuracy and the assembly accuracy of the rotating shaft 21 and the hub 22, and the rotating shaft 21 and the hub 22 are rotated after being fixed. The inclination of the shaft 21 can be easily corrected.
[0038]
As mentioned above, although the embodiment of the invention made by the present inventor has been specifically described, it is needless to say that the present invention is not limited to the above embodiment and can be variously modified without departing from the gist thereof. .
[0039]
For example, in the above-described embodiment, the rotational axis correction method according to the present invention is applied in the manufacturing process of the polygon motor. However, the present invention is not limited to this, and a hard disk, an optical disk, a DVD, etc. The present invention can be similarly applied to a motor for driving such various rotating bodies, a variety of other motor manufacturing processes, and a rotating shaft used in a device other than the motor.
[0040]
Moreover, in the said embodiment, although the structural example using a sintered oil-impregnated bearing was shown as a radial bearing, it may replace with a sintered oil-impregnated bearing and may use a ball bearing, a fluid dynamic pressure bearing, etc.
[0041]
【The invention's effect】
As described above, according to the tilt correction method of the rotating shaft according to claim 1 of the present invention, it is not always necessary to sufficiently manage the processing accuracy and the assembly accuracy of the rotating shaft and the rotating base, and the rotating shaft and the rotating shaft are rotated. The inclination of the rotating shaft can be easily corrected after fixing the base.
[0042]
According to the method for correcting the tilt of the rotating shaft according to claim 2, the tilt of the rotating shaft is most effectively corrected by crushing the portion on the extension line connecting the rotation center of the rotating base and the center of the rotating shaft. can do.
[0043]
Furthermore, according to the rotation axis inclination correction method of the third aspect, the perpendicularity between the rotated body and the rotating shaft is directly corrected, and therefore the rotated body can be rotated with high accuracy.
[0044]
Furthermore, according to the tilt correction method of the rotating shaft according to claim 4, the rotating shaft is adjusted by adjusting the tilt of the rotating shaft by changing the distance from the rotation center of the rotating base to the crushing point or the crushing depth. Since the inclination of the rotation axis can be finely adjusted, the perpendicularity of the rotation axis with respect to the rotation base can be accurately obtained.
[0045]
In addition, since the rotation axis inclination correction method according to claim 5 is the one in which the rotation axis in claim 1 is composed of a motor shaft, the above-described effects can be obtained particularly well in the motor rotation shaft. it can.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a polygon motor manufactured by applying the present invention.
FIG. 2 is a process diagram showing a manufacturing process of the polygon motor of the embodiment.
FIG. 3 is a cross-sectional view showing an intermediate process of a tilt correction method for a rotating shaft according to the present invention.
FIG. 4 is a plan view showing an intermediate process of a rotation axis inclination correcting method according to the present invention.
FIG. 5 is a longitudinal sectional view showing an example of the structure of a conventional polygon motor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Stator part 12 Radial bearing 20 Rotor part 21 Rotating shaft 22 Hub (rotary base | substrate)
22a Insertion hole 22b Crush mark 23 Mirror mounting part 26 Polygon mirror C1 Rotation center C2 Rotation axis center D Direction in which the rotation axis should be inclined

Claims (5)

After fixing the rotating shaft to the insertion hole of the rotating base, when correcting the tilt of the rotating shaft so that the rotating shaft stands or tilts in a predetermined direction with respect to the rotating base,
Correcting the inclination of the rotating shaft by crushing a portion on the opposite side of the direction in which the rotating shaft should be inclined, in the vicinity of the insertion hole in the surface of the rotating base from which the rotating shaft protrudes,
A method of correcting a tilt of a rotating shaft, wherein the rotating shaft is raised or tilted in a predetermined direction set in advance to eliminate an error caused by the fixing of the rotating shaft. The portion on an extension line connecting the rotation center of the rotating base and the center of the rotating shaft is crushed when the rotation center of the rotating base does not coincide with the center of the rotating shaft. To correct the tilt of the rotation axis. The rotation axis inclination correction method according to claim 1 or 2, wherein the rotating base is crushed in a state where a rotating body is mounted on the rotating base. The inclination correction of the rotating shaft according to any one of claims 1 to 3, wherein the inclination of the rotating shaft is adjusted by changing a distance from a rotation center of the rotating base to a crushing point or a crushing depth. Method. The method of claim 1, wherein the rotation shaft is a motor shaft.

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