JPH0663542B2 - Spindle unit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle unit used for an optical deflector for a laser beam printer or the like, and particularly to prevent free movement of a rotary sleeve when the apparatus is not used. This is an improved mechanism.

[Conventional technology]

As a conventional spindle unit of this type, for example,
A structure shown in Fig. 10 is known.

A housing 10 of this optical deflector is sealed with a gas such as clean air, and a side wall is provided with a laser beam transmission window 11. The lower end of the fixed shaft 20 in the axial direction is fixed to the base 10a of the housing 10 by press fitting, and a groove 21 for generating dynamic pressure is formed on the outer peripheral surface of the fixed shaft 20.

A rotary sleeve 30 having a polyhedral light deflecting mirror 31 attached thereto is rotatably fitted around the fixed shaft 20 through a bearing gap 22, and an outer peripheral surface of the fixed shaft 20 and an inner peripheral surface of the rotary sleeve 30. A dynamic pressure type radial gas bearing is formed between the surface and the surface.

The lower end of the rotary sleeve 30 in the axial direction is an open end, but a thrust bearing 32 through which an exhaust hole 33 for adjusting the thrust pressure penetrates in the axial direction is attached by a retaining ring 35 to the inner surface (thrust). (Receiving surface) 34 is the upper end surface 24 of the fixed shaft 20 in the axial direction.
Is facing.

The rotor 26 of the drive motor is attached to the outer peripheral surface of the rotating sleeve 30, and the rotor 27 is attached to the side wall of the housing 10 with the stator 27 facing the outer peripheral side of the rotor 26 so that the rotating sleeve 30 is driven to rotate. There is.

When the rotary sleeve 30 is rotated during use of the above-mentioned optical deflector, dynamic pressure is generated by the pumping action of the groove 21 of the fixed shaft 20, and the gap between the open end of the lower end of the rotary sleeve 30 and the fixed shaft 20 is generated. A gas film having a high pressure is formed by the gas flowing into the bearing clearance 22, and the rotating sleeve 30 is supported in the radial direction by the gas film, and rotates around the fixed shaft 20 in a non-contact state.

Further, the discharge amount of the gas flowing into the bearing gap 22 is adjusted by the exhaust hole 33 of the thrust receiver 32 of the rotating sleeve 30,
A gas of a predetermined pressure presses the inner surface 34 of the thrust receiver 32, and the rotary sleeve 30 is levitated from the upper end surface 24 in the axial direction of the fixed shaft 20 with an appropriate gap, so that the axial direction of the fixed shaft 20 is reduced. Even if the non-contact state is maintained.

In this way, the light deflection mirror 31 attached to the rotary sleeve 30 rotates, the laser light incident from a light source (not shown) hits the light deflection mirror 31, and the reflected laser light passes through the transmission window 11 of the housing 10 to the outside. The photoconductor (not shown) is irradiated.

As described above, when the rotary sleeve 30 is rotated, the thrust receiver 32 and the fixed shaft 20 are in a non-contact state, but when the rotary sleeve 30 is stopped, the force that restricts the axial position is lost. The thrust receiver 32 comes into contact with the fixed shaft 20 due to its own weight, and the rotating sleeve 30 can move freely in this state.

Therefore, when the optical deflector is not used, for example, when the rotating sleeve 30 is subjected to external vibration or impact when the place of use is moved to another place or the product is transported to the destination, the axial direction is Since the thrust receiver 32 and the fixed shaft 20 are repeatedly brought into contact with each other, the contact surface is worn and the groove 21 of the fixed shaft 20 is damaged by the free movement of the rotary sleeve 30.

Therefore, in the conventional spindle unit of this type, as shown in FIG.
Screw a bolt 37 as a thrust receiving member to b,
When the device is not used, the bolt 37 is rotated in the tightening direction to press and fix the rotary sleeve 30 to the fixed shaft 20, and when the device is not used, the bolt 37 is pulled up in the loosening direction so that the rotary sleeve 30 can freely rotate. I am trying. This bolt
The rotation operation of 37 can be performed from the outside of the housing 10 to prevent foreign matter from entering the inside of the housing 10.

[Problems to be solved by the invention]

Since the thrust receiving member attached to the conventional spindle unit has a structure in which the thrust receiving member 32 of the rotary sleeve 30 is pressed against the fixed shaft 20 by the bolt 37 as described above, the tightening force of the bolt 37 is strong. If it is excessive, not only will the inner surface 34 of the thrust receiver 32 be deformed or damaged, but the fixed shaft 20 that is press-fitted into the base 10a of the housing 10 will also move in the axial direction.In extreme cases, the press-fitted state will become loose. There is a problem that it may fall out.

An object of the present invention is to solve the above problems and to provide a spindle unit having a mechanism for fixing a rotary sleeve without applying an excessive pressing force to the thrust receiver of the rotary sleeve.

[Means for solving problems]

In the spindle unit according to the present invention, the thrust receiving / holding member is fitted in the insertion hole provided in the cover of the housing on the side opposite to the thrust receiving of the rotary sleeve so as to be axially movable and rotatable.

The thrust receiving member is composed of a head, a body, and an elastic body attached to the shaft end of the body, with the head on the outer surface side of the housing cover and the elastic body on the inner surface side of the housing cover. The body is fitted into the insertion hole of the cover of the housing via the seal member, and the elastic body is opposed to the axially outer end surface of the thrust receiver of the rotary sleeve.

A recess is formed on either one of the outer surface of the cover of the housing and the inner end surface of the head of the thrust receiving member, and the other surface is formed with a protrusion that can be fitted into the recess.

The thrust receiving member is attached to the housing cover at the rotation stop position when the convex portion or the concave portion formed on the head portion of the thrust receiving member and the concave portion or the convex portion formed on the housing cover are fitted and not fitted. A member for fixing is provided.

[Action]

The spindle unit of the present invention, when in use,
Pull the thrust receiving member upward in the axial direction and rotate it so that the lower end surface of the convex portion of the head portion of the thrust receiving member contacts the outer surface of the cover of the housing or the head portion of the thrust receiving member. The inner end surface is brought into contact with the upper end surface of the convex portion of the cover of the housing so that the convex portion and the concave portion are in a non-fitting state, and the elastic body of the thrust receiving member is pushed from the axial outer end surface of the thrust receiving portion of the rotary sleeve. Separated, the thrust receiving member is fixed to the cover of the housing in this state.

When the spindle unit is not in use, after releasing the fixing state of the thrust receiving / holding member to the housing cover, rotate the thrust receiving / holding member so that the convex portion of the head of the thrust receiving / holding member is recessed in the housing cover. Or the convex portion of the housing cover is fitted into the concave portion of the head portion of the thrust receiving and pressing member, and the thrust receiving and pressing member is fixed to the cover of the housing with the convex portion and the concave portion fitted.

As a result, the elastic body of the thrust receiving member comes into contact with the axially outer end surface of the thrust receiving portion of the rotary sleeve, and the free movement of the rotary sleeve is blocked.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to the spindle unit of the optical deflector described in FIG.

The cover 10b, which is a member on the upper side of the housing 10, is provided with a step portion 12 at a predetermined height on the outer surface of the central portion thereof, and the step portion 12 has a substantially axial center line of the rotary sleeve 30. On the same extension line, an insertion hole 13 for mounting a thrust receiving / holding member 40 described later is provided so as to penetrate therethrough.

Further, as shown in FIGS. 2 and 3, the upper end surface of the stepped portion 12 is cut out between the inner peripheral surface of the insertion hole 13 and the outer peripheral surface of the stepped portion 12 to form a cross-shaped concave portion 14. And two screw holes 16 are provided at symmetrical positions with respect to the insertion hole 13.

As shown in FIGS. 4 and 5, the thrust receiving / holding member 40 includes a head 41 and a body 42 which are integrally formed, and a body 42.
And an elastic body 45 such as a rubber or a synthetic resin attached to the shaft end by adhesion.

The head 41 of the thrust receiving member 40 is disc-shaped,
On its inner end surface, a convex portion extending in a cross shape from the peripheral surface of the body portion 42.
44 are formed. The width and height of the convex portion 44 are slightly smaller than the width and depth of the concave portion 14 provided in the cover 10b of the housing 10. Further, between the adjacent convex portions 44 of the head portion 41, substantially elliptical hole portions 46 are provided at two symmetrical positions from the center. The body 42 has a cylindrical shape with a diameter smaller than that of the head 41, and an annular groove is formed on the peripheral surface thereof.
There are 48. The elastic body 45 has a disk shape having the same diameter as the body portion 42, and is adhered to the body portion 42 with an appropriate adhesive.

The thrust receiving member 40 is, as shown in FIG.
A sealing member 49 is fitted in the annular groove 48 of the body portion 42 to form a housing.
It is slidably fitted in the insertion hole 13 of the cover 10b of 10 so that it can be moved up and down in the axial direction and rotated about the axis.

The material of the head portion 41 and the body portion 42 of the thrust receiving member 40 may be processed by using a metal agent, but it is preferably molded by synthetic resin. Further, as the material of the elastic body 45, it is preferable to use rubber having excellent wear resistance and elasticity, for example, silicon rubber, or a synthetic resin having characteristics equivalent thereto.

The thrust receiving / holding member 40 fitted in the insertion hole 13 of the stepped portion 12 of the cover 10b of the housing 10 is fixed by a set screw 50 that defines a rotation stop position during operation and during non-operation. .

This set screw 50, as shown in FIGS. 6 and 7,
The thrust receiving and pressing member 40 is inserted into a hole portion 46 provided in a head portion 41 and screwed into a screw hole 16 provided in a step portion 12 of a cover 10b of the housing 10.

In this embodiment, ring members 28a and 28b for fixing the rotor 26 and the light deflection mirror 31 to the rotary sleeve 30 are provided with annular recesses 29a and 29b, respectively. An appropriate amount of adhesive or the like is applied to predetermined portions of the recesses 29a and 29b so as to correct the imbalance of the radial mass of the rotary sleeve 30.

Since the configuration other than the above is the same as that of FIG. 10, the same parts are denoted by the same reference numerals, and the repeated description will be omitted.

When the spindle unit is in use (when the thrust receiving / holding member 40 is not operating), the thrust receiving / holding member 40 is in the first position.
As shown in the figure, the elastic body 45 is pulled up in the axial direction so as to be separated from the thrust receiver 32 of the rotary sleeve 30, and is fixed by the set screw 50 in this state.

When the thrust receiving / holding member 40 is fixed at the non-operating position, as shown in FIG. 6, the convex portion 44 formed on the head 41 of the pulled up thrust receiving / holding member 40 has the housing cover 10b. It rotates so as to be positioned at an intermediate position between the adjacent concave portions 14 formed in the step portion 12, and at this rotation stop position, the lower end surface of the convex portion 44 of the head 41 of the thrust receiving member 40 is
It is brought into contact with the upper end surface of the stepped portion 12 of the cover 10b of the housing, and the set screw 50 is tightened and fixed. At the rotation stop position when not operating, the head portion of the thrust receiving member 40 is
The convex portion 44 formed on 41 and the concave portion 14 formed on the stepped portion 12 of the cover 10b of the housing are not fitted.

When the thrust receiving member 40 is operated when the spindle unit is not used, after loosening the set screw 50,
As shown in FIG. 7, the thrust receiving member 40 is rotated clockwise by about 30 degrees in the clockwise direction in FIG. 7 to form the convex portion 44 formed on the head portion 41 on the step portion 12 of the housing cover 10b. It is inserted into the recess 14 and pushed down, and the set screw 50 is tightened and fixed at the rotation stop position at the time of this insertion.

By switching the thrust receiving and pressing member 40 from the non-operating position to the operating position, the thrust receiving member 40 is pushed downward in the axial direction by the height of the convex portion 44 formed on the head 41, and the elastic body 45. Comes into contact with the axially outer end surface of the thrust receiver 32 of the rotary sleeve 30, and the rotary sleeve 30 is restrained from moving in the axial direction, so that free movement is blocked.

Regarding the arrangement positions of the convex portion 44 formed on the head 41 of the thrust receiving member 40 and the concave portion 14 formed on the step portion 12 of the cover 10b of the housing 10, it is not always necessary to form a cross shape as in this embodiment. Instead, they can be distributed at an appropriate arrangement angle as needed.

As shown in FIGS. 6 and 7, when the rotation stop position of the thrust receiving member 40 is switched to match the operating position and the non-operating position, the position of the hole 46 provided in the head 41 and its position Select the length in the major axis direction as appropriate and set screw 50 in the hole
It is preferable to set to rotate from the position of contacting one end of 46 to the contact of the other end. In this case, the rotation angle at the time of switching the alignment becomes small, and the alignment operation becomes simple.

It should be noted that if an identification mark for operating and non-operating is displayed between the head 41 of the thrust receiving member 40 and the cover 10b of the housing as shown in FIGS. 6 and 7, It is possible to surely prevent a malfunction when aligning.

When aligning the thrust receiving member 40,
42 rotates while sliding in the insertion hole 13 of the cover 10b of the housing, but since the seal member 49 is fitted in the annular groove 48 of the body portion 42, the gas sealed inside the housing 10 is exposed to the outside. There is no leakage, and the airtight state can be reliably maintained. This seal member 49 may be provided with an annular groove in the insertion hole 13 of the cover 10b of the housing and fitted into this annular groove.

FIG. 8 and FIG. 9 show the essential parts of another embodiment of the present invention in the positions when the thrust receiving and pressing member is inactive and in operation.

In this embodiment, the step 1 of the housing cover 10b
A recess 14 is formed at one location on the upper end surface of 2, and only one screw hole (not shown) is provided on the upper end surface opposite to the recess 14.

Similarly, the thrust receiving member 40 is also provided on the inner end surface of the head 41.
The convex portion 44 is formed at a portion, and the hole portion 46 is formed in a portion other than the convex portion 44.
They are provided at two symmetrical positions from the center.

The thrust receiving / holding member 40 of this embodiment, when not in operation, has a convex portion 44 formed on the head 41 as shown in FIG.
Is the recess 1 formed in the step 12 of the cover 10b of the housing.
Rotate so as to be located on the side opposite to 4, and fix with one set screw 50.

When operating the thrust receiving member 40, set screw 50
After loosening and removing, as shown in FIG. 9, rotate about 180 degrees to fit the convex portion 44 formed on the head portion 41 into the concave portion 14 formed on the step portion 12 of the housing cover 10b. In this state, fix with the set screw 50.

In each of the above-mentioned embodiments, the case where the concave portion is formed on the housing side and the convex portion is formed on the thrust receiving member side has been described, but on the contrary, the convex portion is formed on the housing side and the thrust receiving member side is formed. A configuration may be used in which a concave portion is formed, and even in such a configuration, the same operational effect as that of the above-described embodiment can be obtained.

Further, as the set screw for fixing the thrust receiving / holding member at the rotation stop positions in the operating state and the non-operating state, another fixing member having a function equivalent to this can be used.

In addition, a part of the housing 10 is opened without attaching the transparent window 11 or the like to the housing 10, and a case is attached to the housing 10 to cover the opening of the housing 10 and the like. A clean gas may be enclosed and sealed. Even in this way, the light deflecting mirror 31 can be prevented from becoming dirty.

In addition, in the above-described embodiment, the case where the rotary sleeve is supported in the radial direction by the dynamic pressure type radial gas bearing has been described, but the spindle unit of the present invention is not limited to the above-described embodiment, and the lubricating oil or the like is provided in the housing. It can also be applied to equipment used as a dynamic pressure type radial fluid bearing by enclosing the liquid.

Further, in the above-mentioned embodiment, the groove for generating the dynamic pressure is formed on the outer peripheral surface of the fixed shaft, but this groove may be formed on the inner peripheral surface of the rotary sleeve. It may be formed on both the inner peripheral surface of the rotary sleeve.

〔The invention's effect〕

As described above, the spindle unit of the present invention is configured such that the thrust receiving / holding member mounted on the cover of the housing is rotated by a predetermined angle and moved up and down in the axial direction, so that the concave or convex portion formed on the cover of the housing is formed. On the other hand, since it is configured to be able to switch between the non-fitted state and the fitted state, when the spindle is not used, by fitting the convex portion and the concave portion, the elastic body of the thrust receiving / pressing member is thrust to the thrust of the rotary sleeve. It can be brought into contact with the bridge to prevent free movement of the rotary sleeve.

Therefore, according to the present invention, the excessive tightening force of the conventional bolt type thrust receiving and pressing member is not applied to the thrust receiving portion of the rotary sleeve, and the inner surface of the thrust receiving portion is not deformed or damaged. In addition, the situation where the fixed end of the fixed shaft falls out of the housing is eliminated, and a spindle unit with excellent durability can be obtained.

Further, according to the present invention, even when the spindle unit is used, it is possible to easily confirm the rotation stop position when the thrust receiving and pressing member is deactivated, and therefore, compared with the conventional bolt type thrust receiving and pressing member. You can switch with certainty and simple operation.

Further, in the thrust receiving member of the present invention, since the body is slidably fitted to the cover of the housing through the seal member, leakage of the enclosed fluid inside the housing is completely prevented to ensure a reliable operation. It can be used while maintaining a tightly sealed state.

[Brief description of drawings]

1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a plan view of a step portion of a cover of a housing, and FIG. 3 is A of FIG.
-A line sectional view, FIG. 4 is a side view of the thrust receiving member,
5 is a bottom view thereof, FIG. 6 is a plan view showing a rotation stop position of the thrust receiving / holding member when it is not operated, and FIG. 7 is a plan view showing a rotation stop position of the thrust receiving / holding member when it is operating. 8
FIG. 9 and FIG. 9 are main parts of another embodiment of the present invention respectively. FIG. 8 is a sectional view showing a non-actuated position of the thrust receiving / holding member, and FIG. 9 shows an operating position of the thrust receiving / holding member. FIG. 10 is a vertical sectional view showing an example of a conventional spindle unit. In the figure, 10 is a housing, 10b is a cover of the housing, 13
Is an insertion hole, 14 is a recess, 20 is a fixed shaft, 30 is a rotating sleeve,
32 is a thrust receiving member, 40 is a thrust receiving member, 41 is a head,
42 is a trunk portion, 44 is a convex portion, 45 is an elastic body, 49 is a sealing member, 50
Is a set screw.

Claims (1)

[Claims] 1. An axial end of a fixed shaft is fixed to a housing, and a rotary sleeve having an open end on the fixed end side of the fixed shaft is rotatable around the fixed shaft via a dynamic pressure type radial fluid bearing. In the spindle unit, which is fitted to the rotary sleeve and has a thrust receiver attached to the axial end opposite to the opening end of the rotary sleeve, an insertion hole is opened in the cover of the housing on the side facing the thrust receiver of the rotary sleeve. Then, the head of the thrust receiving member consisting of the head, the body, and the elastic body attached to the shaft end of the body is the outer surface side of the cover of the housing, and the body is fitted into the insertion hole via the seal member. And an elastic body that is movable and rotatable in the axial direction and faces the axially outer end surface of the thrust receiving portion of the rotary sleeve, and is either the outer surface of the housing cover or the inner end surface of the head portion of the thrust receiving and pressing member. A concave portion is formed on one surface and a convex portion that can be fitted into the concave portion is formed on the other surface, and the convex portion or concave portion formed on the head of the thrust receiving member is formed on the cover of the housing. Alternatively, the spindle unit is characterized in that a member for fixing the thrust receiving member to the cover of the housing is provided at the rotation stop positions in the non-fitting state and the fitting state with respect to the convex portion.