JPH02202341A - Deflection-scanning motor having built-in dynamic pressure fluid bearing - Google Patents

Abstract

PURPOSE:To improve the assembling accuracy of an apparatus by providing a sleeve and a thrust plate for supporting a shaft via dynamic pressure- generating grooves in the radial W and axial directions and by fitting a fixed plate having a diameter larger than the outside diameter of said sleeve with said thrust plate. CONSTITUTION:A shaft 3 fitted with a polygon rotating mirror 1 is rotatably held by a sleeve 10 in the radial direction. Also, an axial thrust is received by a thrust plate 11. Dynamic pressure-generating grooves 4 and 15 are formed in a part of the outer periphery of said shaft 3 and at the end thereof. Said thrust plate 11 is fitted to a thrust support plate 13 having a diameter larger than the outside diameter of said sleeve 10. The sleeve 10 is supported by a motor case 12 and said thrust support plate 13 in the manner of being put between them. Thus, it is possible to assemble an apparatus easily, to improve the accuracy of said assembling, and to prevent mixing of dust and oil spillage at the time of assembling.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a deflection scanning motor using a hydrodynamic bearing, and in particular, to a deflection scanning motor using a hydrodynamic bearing, in particular, a sleeve, which is a radial bearing, is sandwiched between a fixed plate and a case of the motor. The present invention relates to a deflection scanning motor with a built-in dynamic pressure flow pair bearing, which facilitates the assembly process, improves assembly accuracy, and prevents deterioration of bearing performance by having a fixed configuration.

(Prior Art) Conventionally, a deflection scanning motor that rotationally drives a rotating polygon mirror using a hydrodynamic bearing has a configuration as shown in FIG. In the figure, 1 is a rotating polygon mirror, 2 is a rotor, and these are fixed to a mirror mounting flange 5. The rotor 2 is provided with a drive magnet 6 and an FG magnet 7, and a stator coil 8 and a printed circuit board 9 on which an FG pattern is printed are arranged opposite to each other. The mirror mounting flange 5 is fixed to the shaft 3 by press fit or shrink fit, and a dynamic pressure generating groove 4 is formed on the outer peripheral surface of the shaft 3. Reference numeral 12 denotes a motor case, into which a sleeve 1o that supports the shaft 3 is fitted and fixed from below. A thrust plate 11 provided with a shallow groove 15 for generating thrust pressure is fixed to the bottom of the sleeve 1o by press-fitting or the like.

[Problem to be solved by the invention]

However, the above conventional example has the following drawbacks.

(1) Since the thrust plate 11 is fixed to the sleeve 10 by direct press-fitting or the like, it is difficult to manage or adjust the right angle between the pressure generating portion of the thrust plate 11 and the inner surface of the sleeve 1o.

(2) After the sleeve 10 is fixed to the motor case 12 from below, the shaft 3 to which the rotor 2 and the rotor 2 are fixed is fitted to the sleeve 10 from above the motor case 12, which facilitates assembly automation. difficult, and the assembly cost increases. In addition, the bearing unit (sleeve 10 and shaft 3) must be separated and assembled at the end.
This can cause deterioration of bearing performance due to contamination with dust, etc.

(3) Oil leakage may occur from the fixed portion of the sleeve 10 and thrust plate 11.

(Means for Solving the Problem) In order to achieve the above object, the present invention includes a shaft, a sleeve that rotatably fits onto the shaft and supports the shaft in the radial direction, and a shaft that supports the shaft in the thrust direction at one end surface thereof. A case is provided to which a thrust plate and a sleeve are fixed, a groove is formed in at least one of the shaft or the sleeve to generate dynamic pressure in the radial direction, and dynamic pressure in the thrust direction is generated in either the shaft or the thrust plate. In a deflection scanning motor with a built-in dynamic pressure fluid bearing, which has a groove formed for the purpose of It is fixed by being sandwiched between the two.

The space between the sleeve and the fixed plate is sealed with a mechanical seal.
It is preferred to further prevent oil leakage.

The thrust plate is made of, for example, a resin material, and is fixed to the fixed plate by press fitting or locking means.

Further, the fixed plate may also serve as a thrust plate.

[Function] In the present invention, the thrust plate is attached to the fixed plate whose outer diameter is smaller than the outer diameter of the sleeve, and the sleeve is sandwiched and fixed between the fixed plate and the motor case. By assembling based on the standard, assembly can be easily automated and performed at low cost. At that time, compared to the conventional technology in which the thrust plate is fixed by press-fitting it into the sleeve, it is easier to install the thrust plate with accuracy by fixing the thrust plate to the fixed plate and then attaching it to the case.
Moreover, since it is easy to remove when adjustment is required, it can be easily assembled with high precision. Furthermore, oil leakage can be easily prevented by sealing between the sleeve and the fixed plate.

(Example〕 Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a sectional view of a deflection scanning motor according to an embodiment of the present invention, and is a drawing that best represents the features of the present invention.

Hereinafter, the same members as in FIG. 4 are given the same numbers. In FIG. 1, reference numeral 3 denotes a shaft, to which a mirror mounting flange 5 is fixed by press fit or shrink fit, and a dynamic pressure generating groove 4 is formed on the outer periphery of the shaft 3. Further, a rotating polygon mirror 1 and a rotor 2 are attached to the mirror mounting flange 5, and a driving magnet 6 and an FG magnet 7 are provided on the rotor 2, and a stator coil 8 and a stator coil 8 are arranged opposite to each other. Board 9 with FG pattern printed on it
is mounted on top of the motor case. 13 is a fixed plate, and on the other hand, there is a shallow groove 15 for generating thrust pressure.
A thrust plate 11 provided with is fixed by press-fitting or the like.

The fixed plate 13 has an outer diameter larger than the outer diameter of the sleeve 10, and is fixed to the motor case 12 so as to sandwich the sleeve 10 therebetween. Therefore, when the thrust plate 11 is press-fitted into the fixed plate 13, the parallelism between the pressure generating surface of the thrust plate 11 and the mounting surface of the fixed plate 13 to the motor case 12 is easily ensured, and furthermore, the inner diameter of the sleeve 10 and the thrust plate The perpendicularity with the pressure generating part of 11 is also the same as that of sleeve 10.
It is easy to achieve accuracy because it is determined by the processing accuracy and the parallelism. In addition, the assembly procedure includes press-fitting the thrust plate 11 into the fixed plate 13, and then attaching the mechanical seal member 14 and the sleeve 1.
0, the motor case 12 is attached, and the rotating members such as the shaft 3 are inserted, making it possible to assemble from one side. Therefore, automation of assembly becomes easy and assembly costs can be reduced. Furthermore, if adjustment is required during assembly, it can be easily disassembled, so adjustment can be made easily. Furthermore, by providing a mechanical seal member 14 between the fixed plate 13 and the sleeve 10, it is possible to prevent lubricating oil from getting wet.

FIG. 2 is a sectional view of a portion of a thrust receiver of a deflection scanning motor according to another embodiment of the present invention. In the same figure, lla
A thrust plate is provided with a shallow groove 15 for generating thrust pressure, and is made of a resin material manufactured by molding. By fixing the thrust plate 11a to the fixed plate 13, for example, by a locking means as shown in the figure,
Assemblability is improved and assembly costs can be further reduced. The assembly accuracy is ensured by the parallelism of the thrust pressure generating portion of the thrust plate 11a, the fixed plate 13, and the joint surface fib.

FIG. 3 is a sectional view showing a deflection motor according to still another embodiment of the present invention. In the figure, the fixing plate 13 has a larger outer diameter than the sleeve 10, and the sleeve 10 is fixed so as to be sandwiched between the sleeve 10 and the motor case 12. The fixed plate 13 is provided with a thrust pressure generating groove 15 in a portion facing the shaft 3. Therefore, the thrust plate 11 can be omitted, making the structure simple, improving assembly efficiency, and reducing manufacturing costs. Furthermore, the perpendicularity between the inner surface of the sleeve 10 and the thrust pressure generating portion can be easily increased.

〔Effect of the invention〕

As explained above, according to the present invention, the sleeve is sandwiched between the thrust plate having an outer diameter larger than the sleeve outer diameter and the motor case, which improves the accuracy and ease of assembly, and also reduces the amount of dust generated during assembly. Contamination and oil leakage can be easily prevented and deterioration of bearing performance can be avoided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a deflection scanning motor according to an embodiment of the present invention, FIG. 2 is a side view showing a thrust receiver of a deflection scanning motor according to another embodiment of the invention, and FIG. This figure is a sectional view showing a deflection scanning motor according to another embodiment of the present invention, and FIG. 4 is a sectional view showing a conventional deflection scanning motor. 1: Rotating polygon mirror, 3: Shaft, 4: Dynamic pressure generating groove, 10
Nisleeve, 11 Nislast plate, 12: Motor case,
13: Fixed plate, 14: Mechanical seal member, 15: Dynamic pressure generation groove.

Claims (4)

[Claims] (1) A shaft, a sleeve that rotatably fits on the shaft and supports the shaft in the radial direction, a thrust plate that supports the shaft in the thrust direction on one end surface thereof, and a case to which the sleeve is fixed, and the shaft or sleeve In a deflection scanning motor with a built-in dynamic pressure fluid bearing, in which a groove is formed in at least one of the shaft or the thrust plate to generate dynamic pressure in the radial direction, and a groove is formed in either the shaft or the thrust plate to generate dynamic pressure in the thrust direction. , a dynamic pressure device characterized in that it has a fixing plate with an outer diameter larger than the outer diameter of the sleeve, the thrust plate is attached to the fixing plate, and the sleeve is fixed by being sandwiched between the fixing plate and the case. Deflection scanning motor with built-in hydrodynamic bearing. (2) The dynamic pressure fluid bearing built-in deflection scanning motor according to claim 1, wherein the sleeve and the fixed plate are sealed with a mechanical seal. (3) The deflection scanning motor with a built-in dynamic pressure fluid bearing according to claim 1, wherein the thrust plate is made of a resin material and is fixed to the fixed plate by press fitting or locking means. (4) The deflection scanning motor with a built-in dynamic pressure fluid bearing according to claim 1, wherein the fixed plate also serves as a thrust plate.