JPH0560564B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating unit used in a rotating polygonal mirror light polarizer for a laser beam printer, etc., and particularly to a means for preventing the rotating sleeve from moving freely except when in use. This is related to the improvement of.

For example, in a conventional rotating unit for a laser beam printer (the technology used in the development process of the present invention), as shown in FIG. It has a structure in which it is supported by a so-called dynamic pressure fluid bearing that works together with a fixed shaft 1 having a fixed dynamic pressure generating groove to generate dynamic pressure between both members. In order to avoid damage caused by external vibration during transportation, the cover 6 of the housing 6 is closed when not in use.
The rotary sleeve 2 is pressed against the fixed shaft 1 using a bolt 7 from the outside of the cover and fixed, and when in use, the rotary sleeve 2 can be freely rotated by loosening the bolt from the outside of the cover. In this case, the hydrodynamic bearing is sealed by a housing 6 to prevent foreign matter such as dust from entering, so that the rotary sleeve 2 can be fixed and released from the outside via bolts 7. . To explain the hydrodynamic bearing used here, the radial bearing surface of the fixed shaft has a groove 11 for generating dynamic pressure, and the thrust bearing surface has a groove 11 facing the thrust bearing surface 12 of the fixed shaft. A shaft hole 22 for thrust pressure adjustment is bored in a thrust bearing surface 211 of a plate 21 fixed to the rotating sleeve with a spring 23. Further, the rotating sleeve 2 is equipped with a rotor 4 of a drive motor, and the housing 6 is equipped with a stator 5 and a glass window 64.

However, in the above structure, the rotating sleeve is fixed by being pressed toward the fixed shaft by the bolt, so if the bolt is tightened too strongly, the plate 21 may be deformed or damaged in some cases. Furthermore, there was a fear that the fixed shaft 1, which is press-fitted into the base of the housing 6, would move in the axial direction or even fall out.

The present invention aims to obviate the above-mentioned drawbacks. Next, an embodiment of the present invention will be described with reference to FIG. (Members common to those in FIG. 1 are given the same reference numerals as in FIG. 1). In the same figure,
A recess 631 is provided in the center of the cover 63, into which a bolt 7 and a stopper 8 are screwed as operating members inserted from the outside of the cover, and between a collar 81 provided on the stopper and the cover. A spring member 9 is interposed therebetween.

The configuration other than the above is the same as that in Figure 1, so the explanation will be omitted, but when in use, the bolt pulls the stopper toward the cover, and the bolt and stopper clamp the cover. However, by loosening the bolt when not in use, the elasticity of the spring member presses against the rotary sleeve so that the rotary sleeve does not move freely.

According to this invention, the pressing force of the spring member is used to press the rotary sleeve toward the fixed shaft so that it does not move freely when not in use. In addition to preventing damage, it is possible to provide a rotating unit with no worries about the fixed shaft falling off. Also, during use, the pressing force can be released by simply tightening the bolt 7 until the stopper 8 contacts the cover 63.
There is no need to worry about the degree of loosening of bolts as in the past, and there is an advantage that it can be set easily and reliably.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional rotating unit for a laser beam printer, and FIG. 2 is a sectional view showing an embodiment of the present invention. Explanation of symbols: 1...Fixed shaft 2...Rotating sleeve 6...Housing 61...Base 63...
Cover 7...Bolt 8...Stopper 9...
...Spring member.

Claims (1)

[Scope of Claims] 1. A rotating unit comprising: a fixed shaft having one end fixed to a housing; and a rotating sleeve surrounding the fixed shaft and cooperating with the fixed shaft to constitute a bearing. a spring member that constantly applies a pressing force to the fixed shaft on the opposite side of the fixed shaft so that the rotating sleeve does not move freely except when in use;
A rotating unit comprising an operating member capable of releasing the pressing force of the spring member from the outside of the housing when in use. 2. The rotating unit according to claim 1, wherein the bearing is a hydrodynamic bearing.