JPH0771703B2 - Fluid groove forming device for hydrodynamic bearing - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid groove forming device for a dynamic pressure type hydrodynamic bearing that performs high precision plastic working on the order of microns.

2. Description of the Related Art In recent years, hydrodynamic bearings have been attracting attention as consumer equipment bearings that replace conventional ball bearings as small bearings with high rotational accuracy and long bearing life.

An example of the above-described conventional fluid groove forming device for a hydrodynamic bearing will be described with reference to the drawings.

FIG. 3 shows a process for forming a fluid groove of a conventional hydrodynamic bearing, which is completed by the steps of washing, screen printing, etching, washing with water, removing resist, and washing with water. FIG. 4 shows a process for forming the fluid groove in the above step, wherein 1a is a screen, 2a is a squeegee, 3a is a printing ink, 4a is a processed product, 5a is an etching liquid, and 6a is a printed processed product. . The process until the fluid groove is completed will be described below.

First, sandwich the fixed screen 1a, place the washed workpiece 4a underneath, apply an appropriate amount of printing ink 3a on the screen 1a, and rotate the workpiece 4a while synchronizing with the moving speed of the squeegee 2a. Meanwhile, the squeegee 2a is moved laterally to uniformly apply the printing ink 3a to the surface of the workpiece 4a in the shape of the fluid groove to complete the printed workpiece 6a. The printed product 6a is dipped in the etching liquid 5a to chemically etch the portion not coated with the printing ink 6a, and then the printing ink 6a and the resist are removed by washing with water and removing the resist to complete the fluid groove 7a.

Problems to be Solved by the Invention However, in the manufacturing method as described above, if the process conditions are optimally matched, highly accurate fluid groove processing accuracy can be obtained, but changes over time such as etching solution concentration and performance deterioration occur. As a result, the machining accuracy of the fluid groove becomes unstable, and there are many manufacturing processes, so the production lead time is long, and it takes time to change and change the size and shape of the fluid groove. Had.

With respect to the above problems, the present invention provides a fluid groove forming device for a dynamic pressure type fluid bearing which can stably and easily obtain micron-order fluid groove processing accuracy and is inexpensive.

Means for Solving the Problems In order to solve the above problems, a fluid groove forming device for a hydrodynamic bearing of the present invention has a diameter of a circle forming an inner surface of a machined cylinder of a workpiece on the outer periphery of one end of a tool shaft. Tool with a plurality of balls fixed to a larger diameter, a drive unit that drives the rotation and axial movement of the tool shaft, holds the workpiece, and moves in a plane parallel to the plane including the circle. A free alignment unit and a presser for fixing the alignment unit, and the alignment unit causes the tool and the inner diameter of the workpiece to come into contact with each other so that the axis of the workpiece is aligned with the tool. It is characterized in that it is aligned and is fixed by the presser in the aligned state.

Effect According to the device of the present invention, the fluid groove can be formed earlier than the time for forming the fluid groove by the conventional chemical reaction, and the condition setting can be determined by the mechanical dimensions, and the tool and the inner diameter portion of the workpiece can be determined. The axes of both can be aligned simply by abutting and, and the aligning unit can be fixed by the presser, and processing can be performed while maintaining the aligned state, thus improving the processing accuracy. be able to.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a fluid groove forming device for a hydrodynamic bearing in an embodiment of the present invention. In FIG. 1, 1 is a slide base support, 2 is a feed ball screw, 3 is a ball screw support bearing, 4 is a slide motor, 5 is a slide motor mounting plate, 6 is a coupling A, 7 is a slide base body, and 8 is a rotation. Shaft bracket, 9 rotating shaft, 10 rotating shaft bearing, 11 rotating shaft motor, 12 rotating shaft motor mounting plate, 13
Is a coupling B, 14 is a workpiece, 15 is a chuck, 16 is a linear slide unit, 17 is a linear slide retainer, 18 is a cylinder, 19 is a guide post, and 20 is a processing tool.

On the outer periphery of one end of the tool shaft 21 of the processing tool 20, the workpiece 14
A plurality of balls 22 are equally divided into a larger diameter than the inner diameter of the ball 22.

Since the processing tool 20 is rotated and slid at the same time, when the slide motor 4 is rotated, the rotation is transmitted to the feed ball screw 2 via the coupling A6 and the slide base 7 slides. Further, the rotating portion rotates the rotating shaft motor 11 to transmit the rotation to the rotating shaft 9 via the coupling B13. In this way, the working tool 20 is given rotation and sliding. Also, the workpiece 14 is fixed by a chuck.
It is performed by opening and closing 15, the shaft core rotates the processing tool 20,
When it is inserted into the work piece 14 while sliding, the linear slide unit 16 moves arbitrarily in the X and Y2 directions and is automatically centered. The self-aligned linear slide unit 16 is fixed by a linear slide retainer 17 by the vertical movement of a cylinder 18. FIG. 2 shows a processing flow in the fluid groove forming device of the dynamic pressure type hydrodynamic bearing shown in FIG. 1. After inserting the workpiece 14, the workpiece is chucked and the slide base body 7 shown in FIG. 1 is moved forward. And the processing tool 20 is inserted into the workpiece 14 by rotating the rotary shaft 9 in the forward direction. When the machining tool 20 and the workpiece 14 contact each other, the workpiece axis moves along the center of the processing tool 20, the axis is automatically aligned and fixed, and the fluid groove forming process is performed. Immediately after the completion of the fluid groove forming process, the processing tool
20 The machining tool 20 is returned along the forward trajectory and the reverse trajectory, the machining tool 20 is removed from the workpiece 14, the linear slide retainer 17 is lifted, the self-aligning fixation is released, the chuck 15 is opened, and the workpiece 14 is taken out.

As described above, according to this embodiment, the drive unit that simultaneously rotates and slides the machining tool 20, and the aligning unit that can accurately and automatically align the axis of the workpiece 14 with the axis of the machining tool 20. By providing plastic balls with the machining tool 20 in which a plurality of balls 22 are fixed to the outer periphery of one end of the tool shaft 21, the fluid groove of the hydrodynamic bearing can be accurately and quickly obtained easily by micron-order plastic machining. it can.

EFFECTS OF THE INVENTION As described above, the present invention has the above-described configuration. Therefore, it is possible to provide a fluid groove forming device for a dynamic pressure type fluid bearing which can obtain the forming accuracy of the fluid groove with high accuracy and in a short time.

[Brief description of drawings]

FIG. 1 is a structural diagram of a fluid groove forming device for a hydrodynamic bearing in an embodiment of the present invention, FIG. 2 is a processing flow chart in the device of FIG. 1, and FIG. 3 is a fluid groove formed by a conventional etching method. FIG. 4 is a flow chart of the manufacturing process, and FIG. 4 is a molding process diagram of the fluid groove in the flow chart of FIG. 14 …… Workpiece, 20 …… Tool, 21 …… Tool axis, 22 …… Ball.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideaki Ohno 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP 61-6427 (JP, A) JP 61-124726 (JP, A) Actually open Sho 58-152334 (JP, U)

Claims (1)

[Claims] 1. A tool having a plurality of balls fixed to the outer circumference of one end of a tool shaft, the ball having a diameter larger than the diameter of a circle forming the inner surface of a work cylinder, and rotation and axial movement of the tool shaft. A drive unit for driving, an alignment unit that holds the workpiece and is movable in a plane parallel to the plane including the circle,
The aligning unit aligns the shaft center of the workpiece with respect to the tool by contact between the tool and the inner diameter portion of the workpiece, and the aligning state. And a fluid groove forming device for a dynamic pressure type hydrodynamic bearing.