JP2005022032A - Spindle device and double wheel grinding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately process a workpiece with a spindle rotating at a high speed by sufficiently increasing a critical speed of the spindle, in a spindle device and a double wheel grinding device for rotatably supporting the spindle with a bearing section and processing the workpiece. <P>SOLUTION: First and second radial hydrostatic bearing sections 30a and 32a are arranged in a bearing body 27a disposed in a first housing 15a, a third radial hydrostatic bearing section 38a is disposed in a second housing 16a disposed attachably/detachably to the first housing 15a, and the spindle 12a is rotatably supported by the first to third radial hydrostatic bearing sections 30a, 32a and 38a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spindle device and a double-headed grinding device, and more particularly to a spindle device and a double-headed grinding device that process a workpiece while rotatably supporting the spindle by a bearing portion.
[0002]
[Prior art]
In general, in a conventional main shaft device, a hydrostatic bearing portion using a hydrostatic medium is applied as a bearing portion that rotatably supports the main shaft. The hydrostatic bearing is supplied with liquid or air pressurized as a hydrostatic medium, and the main shaft is rotatably supported by the pressure of the hydrostatic medium. Such a hydrostatic bearing is disposed in a bearing body provided in the housing, and includes a thrust hydrostatic bearing that rotatably supports the main shaft from the extending direction of the main shaft, and an extending direction of the main shaft. It is comprised by the radial hydrostatic bearing part which supports a main axis | shaft rotatably from the surface direction orthogonal to. A built-in motor for rotating the main shaft is disposed between the main shaft and the housing. The main shaft disposed between the end of the main shaft on which the grindstone is disposed and the built-in motor is rotatably supported by two radial hydrostatic bearing portions. In addition, the thrust hydrostatic bearing portion is disposed on a bearing body facing a flange disposed between the two radial hydrostatic bearing portions.
[0003]
Such a spindle device is applied to a machine tool, a grinding device or the like, and it is necessary to stably rotate the spindle at a high speed in order to process a workpiece with high accuracy. Therefore, in the conventional spindle device, the outer diameter of the spindle is increased to increase the rigidity and critical speed of the spindle, and the workpiece is processed by rotating the spindle at a high speed (see, for example, Patent Document 1). . Since such a spindle device can process a workpiece with high accuracy, it is used in a double-head grinding device that processes both surfaces of a workpiece with a pair of grindstones. Here, the critical speed is a speed at which the rotational speed of the main shaft matches the natural frequency of the main shaft. When the critical speed is high, the main shaft can be stably rotated at a high speed. .
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-257037
[Problems to be solved by the invention]
However, it is difficult to stably support a spindle that rotates at high speed with only two radial hydrostatic parts provided between the end of the spindle on the side where the grindstone is disposed and the built-in motor, and the danger of the spindle Since the speed cannot be sufficiently increased, there is a problem that the workpiece cannot be processed with high accuracy.
[0006]
Accordingly, the present invention has been made in view of the above circumstances, and provides a spindle device and a double-head grinding device capable of sufficiently increasing the critical speed of the spindle and machining a workpiece with high accuracy by the spindle rotating at high speed. For the purpose.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention is characterized by the following measures.
[0008]
According to the first aspect of the present invention, in the main shaft device having a radial hydrostatic bearing portion that is disposed in the first bearing body and rotatably supports the main shaft, the radial static pressure is provided outside the first bearing main body. This can be solved by a main shaft device characterized in that a radial bearing portion is provided separately from the bearing portion, and the main shaft is rotatably supported by the radial bearing portion.
[0009]
According to the above invention, the radial hydrostatic bearing portion disposed in the first bearing body, and the radial bearing provided outside the first bearing body away from the position where the radial hydrostatic bearing portion is disposed. Since the main shaft is rotatably supported by the part, the main shaft rotating at high speed is more stable than the case where the main shaft is rotatably supported only by the radial hydrostatic bearing portion disposed in the conventional first bearing body. Can be supported.
[0010]
According to a second aspect of the present invention, two radial hydrostatic bearing portions are provided, and the main shaft is rotatably supported by the two radial hydrostatic bearing portions and the one radial bearing portion. This can be solved by the spindle device according to claim 1.
[0011]
According to the above invention, since the main shaft is supported at three points of two radial hydrostatic bearing portions and one radial bearing portion, it is compared with the case where the main shaft is supported by two conventional radial hydrostatic bearing portions. Thus, the spindle rotating at high speed can be stably supported.
[0012]
The invention according to claim 3 is characterized in that the radial bearing portion is disposed in a second bearing body that is separate from the first bearing body. This can be solved by the spindle device.
[0013]
According to the above invention, since the second bearing body is formed separately from the first bearing body, the mounting position of the second bearing body with respect to the first bearing body can be adjusted. As compared with the case where the radial hydrostatic bearing portion and the radial bearing portion are disposed in one bearing body, the main shaft can be easily accommodated in the first and second bearing bodies. Further, the radial hydrostatic bearing portion and the radial bearing portion can be easily arranged as compared with the case where the radial hydrostatic bearing portion and the radial bearing portion are arranged in the same bearing body.
[0014]
According to a fourth aspect of the present invention, a drive motor that rotationally drives the main shaft is disposed inside the second bearing body, and the radial bearing portion is adjacent to the drive motor. The spindle device according to claim 3, wherein the spindle device according to claim 3 is provided so as to sandwich the drive motor in a direction in which the spindle is extended between the hydrostatic bearing portion and the radial bearing portion. it can.
[0015]
According to the above invention, the radial bearing portion is disposed at a position away from the radial hydrostatic bearing portion, and the main shaft is supported by the radial hydrostatic bearing portion and the radial bearing portion. The main shaft can be stably supported.
[0016]
The invention according to claim 5 is solved by the spindle device according to any one of claims 1 to 4, wherein a static pressure bearing portion using a static pressure medium is used for the radial bearing portion. it can.
[0017]
According to the above invention, by using the hydrostatic bearing portion as the radial bearing portion, the main shaft rotating at high speed can be rotatably supported even when the load on the main shaft is large.
[0018]
The invention according to claim 6 can be solved by a double-head grinding apparatus comprising the spindle device according to any one of claims 1 to 5.
[0019]
According to the said invention, by providing the spindle apparatus of any one of Claim 1 thru | or 5 in a double-headed grinding apparatus, a workpiece can be processed with high precision by the spindle which rotates at high speed.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0021]
The spindle devices 11a and 11b of the present embodiment can be applied to a double-head grinding device 10 that is one of grinding devices. First, with reference to FIG. 1, the structure of the double-head grinding apparatus 10 to which the spindle apparatuses 11a and 11b are applied will be described, and the spindle apparatuses 11a and 11b will be described in detail with reference to FIG. FIG. 1 is a schematic view of a double-head grinding apparatus to which the spindle apparatus of the present invention is applied, and FIG. 2 is a schematic view of the spindle apparatus of the present embodiment. 1 and 2, the X and X directions indicate thrust directions, and the Y and Y directions indicate radial directions that are plane directions orthogonal to the X and X directions. In FIG. 2, the same components as those in FIG. The double-head grinding apparatus 10 is mainly composed of spindle apparatuses 11 a and 11 b and a work holding apparatus 18.
[0022]
Two spindle devices 11a and 11b are arranged so that the same configuration faces each other across the grinding position of the workpiece 23 which is a workpiece. Therefore, with respect to FIG. 1, the spindle device 11a located in the upper part of the figure is appended with the symbol a, the spindle device 11b located in the lower part of the drawing is appended with the symbol b, and is mainly appended with the symbol a. The main spindle device 11a on the side thus formed will be described.
[0023]
As shown in FIG. 1, the spindle device 11a is roughly constituted by a spindle 12a, a grindstone 13a, a first housing 15a, and a second housing 16a. The main shaft 12a is disposed inside the first housing 15a and the second housing 16a. The second housing 16a is the second bearing body according to claim 3. A grindstone 13a for grinding the workpiece 23 is integrally disposed at the end of the main shaft 12a on the side facing the workpiece 23. The main shaft 12a and the grindstone 13a are integrally rotated in the radial direction (Y, Y direction) by a built-in motor 35a described later disposed in the second housing 16a. The main shaft 12a and the grindstone 13a are moved in the thrust direction (X, X direction) by a moving device (not shown).
[0024]
In general, the work holding device 18 includes a work holder frame 19, a plurality of V-grooved rollers 21, and a drive source 22. The work holder frame 19 is formed with a plurality of V-grooved rollers 21 and a drive source 22 for rotating and supporting the work 23, and the work 23 supported by the V-grooved rollers 21 is a drive source. 22 is rotated in the radial direction (Y, Y direction). The processing by the double-head grinding apparatus 10 is performed when the grinding operation surfaces 14 a and 14 b of the pair of grindstones 13 a and 13 b that rotate and move toward the rotating workpiece 23 come into contact with both surfaces of the workpiece 23.
[0025]
Next, with reference to FIG. 2, the structure of the spindle device 11a which is an embodiment of the present invention will be described. In general, the main shaft device 11a includes a first housing 15a, a bearing body 27a, a main shaft 12a, a grindstone 13a, a second housing 16a, a built-in motor 35a, a thrust hydrostatic bearing 29a, and first to 3 radial hydrostatic bearings 30a, 32a, 38a.
[0026]
The main shaft 12a is roughly constituted by a first rotating shaft body 25a, a flange 26a, and a second rotating shaft body 34a. A grindstone 13a is integrally disposed at one end of the first rotating shaft 25a, and a second rotating shaft 34a is integrally disposed at the other end. Further, the outer diameter of the second rotating shaft body 34a is configured to be smaller than the outer diameter of the first rotating shaft body 25a. When the second housing 16a is connected to the first housing 15a by configuring the outer diameter of the second rotating shaft member 34a to be smaller than the outer diameter of the first rotating shaft member 25a in this way. The main shaft 12a disposed in the first housing 15a can be easily accommodated in the second housing 16a.
[0027]
A flange 26a is integrally disposed on the first rotating shaft body 25a. The first rotating shaft body 25a, the flange 26a, and the second rotating shaft body 34a are integrally disposed. The first housing 15a has a cylindrical shape, and a first rotating shaft 31a is disposed in the first housing 15a so as to penetrate the first housing 15a. A bearing body 27a is disposed between the first housing 15a and the first rotating shaft body 25a. The bearing body 27a is a first bearing body according to claim 1.
[0028]
A first radial hydrostatic bearing portion 30a is disposed on the bearing body 27a facing the end portion of the first rotating shaft body 25a on the grindstone 13a side. The second radial hydrostatic bearing portion 32a is disposed in a bearing body 27a at a position where the flange 26a can be sandwiched between the second radial hydrostatic bearing portion 30a and facing the first rotary shaft body 25a. It is installed. The first and second radial hydrostatic bearings 30a and 32a introduce a hydrostatic medium supplied in a pressurized state, and support the main shaft 12a to be rotatable in the Y and Y directions by the pressure of the hydrostatic medium. Is to do. In addition, the 1st and 2nd radial hydrostatic bearing parts 30a and 32a are the radial hydrostatic bearing parts of Claim 1.
[0029]
A seal member 31a is disposed on the grindstone 13a side of the first radial hydrostatic bearing portion 30a, and a seal member 33a is disposed on the right side of the second radial hydrostatic bearing portion 32a in FIG. ing. The seal members 31a and 33a are for preventing the static pressure medium supplied to the first or second radial static pressure bearing portions 30a and 32a from leaking to the outside. A thrust hydrostatic bearing portion 29a is disposed on the bearing body 27a facing the flange 26a. The thrust hydrostatic bearing 29a is for introducing a hydrostatic medium supplied in a pressurized state and supporting the main shaft 12a rotatably from the X and X directions by the pressure of the hydrostatic medium.
[0030]
The second housing 16a has a cylindrical shape, and is configured separately from the first housing 15a. A second rotating shaft 34a is disposed in the second housing 16a so as to penetrate the second housing 16a. The second housing 16a is the second bearing body according to claim 3. In this way, by configuring the second housing 16a to be separate from the first housing 15a, the second housing 16a has the second housing 16a in which the main shaft 12a is disposed when the main shaft device 11a is assembled. When mounting the housing 16a, the mounting position of the second housing 16a can be adjusted.
[0031]
Thereby, the 2nd rotating shaft body 34a can be accurately accommodated in the 2nd housing 16a, and the assembly precision of the main axis | shaft apparatus 11a can be improved. Further, it is a technique to arrange a third radial hydrostatic bearing portion 38a, which will be described later, disposed in the second housing 16a and first and second radial hydrostatic bearing portions 30a, 32a in the same housing. Although it is difficult, the first and second radial hydrostatic bearing portions 30a and 32a are arranged in the bearing body 27a, and the third radial hydrostatic bearing portion 38a is arranged in the second housing 16a. Thus, the three first to third radial hydrostatic bearing portions 30a, 32a, and 38a that support the main shaft 12a can be easily provided.
[0032]
A space A is formed between the second housing 16a and the second rotating shaft body 34a. A rotor 36a is disposed integrally with the second rotating shaft body 34a in the second rotating shaft body 34a located in the space A. A stator 37a is disposed on the surface of the second housing 16a facing the rotor 36a. The built-in motor 35a, which is a drive motor, is composed of the rotor 36a and the stator 37a, and the main shaft 12a is rotationally driven in the radial direction (Y, Y direction) by the built-in motor 35a. The third radial hydrostatic bearing portion 38a is disposed in the second housing 16a facing the end of the second rotating shaft body 34a. By providing the third radial hydrostatic bearing 38a, the built-in motor 35a has a second radial hydrostatic bearing 32a and a third radial hydrostatic bearing 38a in the thrust direction (X, X direction). Sandwiched between the positions. The third radial hydrostatic bearing 38 a is a radial bearing according to claim 1.
[0033]
Thus, by arranging the third radial hydrostatic bearing portion 38a at the end of the main shaft 12a away from the second radial hydrostatic bearing portion 32a, the first to third radial hydrostatic bearing portions separated from each other. The main shaft 12a that rotates at high speed can be stably supported by 30a, 32a, and 38a, and the critical speed of the main shaft 12a can be increased. In addition, unlike the conventional spindle device, when the workpiece is machined by the spindle 12a that rotates at high speed, it is not necessary to increase the rigidity of the spindle 12a. Therefore, the spindle 12a having a simple configuration can be used. Further, by applying the first to third radial hydrostatic bearings 30a, 32a, and 38a using a hydrostatic medium for the bearing, the spindle 12a that rotates at high speed can be stabilized even when the load on the spindle 12a is large. It can be supported and the critical speed of the main shaft 12a can be increased.
[0034]
Next, a description will be given of the result of calculation of the critical speed of the spindle between the conventional spindle apparatus performed by the present inventor and the spindle apparatus 11a of the present embodiment. The conventional spindle device uses a device in which the spindle 12a is supported by two radial hydrostatic bearings, the first and second radial hydrostatic bearings 30a and 32a, and the spindle is the same spindle 12a. Applied.
[0035]
As a result of calculating the critical speed, the critical speed of the main spindle 12a of the conventional main spindle apparatus was 7454 rpm, and the critical speed of the main spindle 12a of the main spindle apparatus 11a of the present embodiment was 26560 rpm. From the calculation result of the critical speed, compared to the case where the main shaft 12a is supported by the two conventional first and second radial hydrostatic bearing portions 30a and 32a, the three first to third radials of this embodiment are used. It has been found that when the main shaft 12a is supported by the hydrostatic bearing portions 30a, 32a, and 38a, the critical speed of the main shaft 12a can be increased, and the workpiece can be processed by rotating the main shaft 12a at a high speed. .
[0036]
Further, on both sides of the third radial hydrostatic bearing portion 38a, seal members 41a and 42a for preventing leakage of the hydrostatic medium supplied to the third radial hydrostatic bearing portion 38a are disposed. Thus, by disposing the seal members 36 and 37 on both sides of the third radial hydrostatic bearing portion 38a, it is possible to prevent the hydrostatic medium from leaking outside the spindle device 10 or in the space A, Damage to the built-in motor 35a can be prevented.
[0037]
The workpiece 23 processed by the double-head grinding apparatus 10 includes a silicon wafer, a glass disk, and the like. Since a fine pattern is formed on the silicon wafer, high-precision processing is required. By applying the spindle apparatuses 11a and 11b shown in the present embodiment to the double-head grinding apparatus 10, the spindles 12a and 12b can be rotated at high speed to process both surfaces of the workpiece 23 with high accuracy.
[0038]
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation / change is possible. In addition, liquid or air, such as water and oil, can be used for a static pressure medium. Moreover, in the said Example, although the 3rd radial hydrostatic bearing part 38a using a static pressure medium was used as a radial bearing part of Claim 1, instead of the 3rd radial hydrostatic bearing part 38a, a ball A contact-type bearing mechanism such as a bearing may be provided. Moreover, you may provide three or more radial hydrostatic bearing parts using a hydrostatic medium.
[0039]
【The invention's effect】
According to the first aspect of the present invention, the radial hydrostatic bearing portion disposed in the first bearing main body and the first bearing main body provided outside the position where the radial hydrostatic bearing portion is disposed. Since the main shaft is rotatably supported by the radial bearing portion provided, the main shaft can be rotated at a higher speed than the conventional case where the main shaft is rotatably supported only by the radial hydrostatic bearing portion disposed in the first bearing body. Can stably support the main shaft.
[0040]
According to the invention described in claim 2, since the main shaft is supported at three points of the two radial hydrostatic bearing portions and the one radial bearing portion, the main shaft is supported by the two conventional radial hydrostatic bearing portions. Compared to the case, the spindle rotating at high speed can be stably supported.
[0041]
According to the third aspect of the present invention, since the mounting position of the second bearing body relative to the first bearing body can be adjusted, the radial hydrostatic bearing portion and the radial bearing portion are disposed in one bearing body. Compared to the case, the main shaft can be easily accommodated in the first and second bearing bodies.
[0042]
According to the invention described in claim 4, since the radial bearing portion is disposed at a position away from the radial hydrostatic bearing portion and the entire main shaft is supported by the radial hydrostatic bearing portion and the radial bearing portion, the main shaft has a high speed. When rotated, the spindle can be stably supported.
[0043]
According to the invention described in claim 5, by using the hydrostatic bearing portion as the radial bearing portion, the main shaft rotating at high speed can be rotatably supported even when the load on the main shaft is large.
[0044]
According to the sixth aspect of the present invention, the spindle device according to any one of the first to fifth aspects is provided in the double-head grinding device, whereby the workpiece is machined with high accuracy by the high-speed spindle. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic view of a double-head grinding apparatus to which a spindle device of the present invention is applied.
FIG. 2 is a schematic view of a spindle device of the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Double-head grinding apparatus 11a, 11b Main spindle apparatus 12a, 12b Main spindle 13a, 13b Grinding wheel 14a, 14b Grinding operation surface 15a, 15b First housing 16a, 16b Second housing 18 Work holding apparatus 19 Work holder frame 21 With V groove Roller 22 Drive source 23 Work 25a First rotary shaft body 26a Flange 27a Bearing body 29a Thrust hydrostatic bearing 30a First radial hydrostatic bearings 31a, 33a, 41a, 42a Seal member 32a Second radial hydrostatic bearing Portion 34a second rotating shaft body 35a bilton motor 36a rotor 37a stator 38a third radial hydrostatic bearing portion A space

Claims (6)

In the main shaft device having a radial hydrostatic bearing portion disposed on the first bearing body and rotatably supporting the main shaft,
A main shaft device characterized in that a radial bearing portion is provided outside the first bearing main body separately from the radial hydrostatic bearing portion, and the main shaft is rotatably supported by the radial bearing portion. Two radial hydrostatic bearings are provided,
The spindle device according to claim 1, wherein the spindle is rotatably supported by the two radial hydrostatic bearing portions and the one radial bearing portion. 3. The spindle device according to claim 1, wherein the radial bearing portion is disposed in a second bearing body that is separate from the first bearing body. 4. A drive motor for rotating the main shaft is disposed inside the second bearing body,
The radial bearing portion is provided at a position sandwiching the drive motor in the extending direction of the main shaft between the radial hydrostatic bearing portion adjacent to the drive motor and the radial bearing portion. The spindle device according to claim 3. The spindle device according to any one of claims 1 to 4, wherein a static pressure bearing portion using a static pressure medium is used for the radial bearing portion. A double-head grinding apparatus comprising the spindle device according to any one of claims 1 to 5.

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