JP2004255550A - Vertical type rotary grinder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical type rotary grinder which sufficiently obtains accuracy of surface roughness on a grinding plane of a work. <P>SOLUTION: In this vertical type rotary grinder, grind stone driving device supporting devices (20, 22) supporting a grind stone driving device 30 movably in a direction parallel to a rotary shaft center of a grinding stone G, have a strut (vertical direction guiding member) 20 extending in a direction parallel to the rotary shaft center, and a vertical direction static pressure gas bearing device 22 guided in a vertical direction by the strut 20 under a condition that the grinding stone driving device 30 is connected and the static pressure gas is interposed between the device and the guiding face of the strut 20. Thereby, because the grind stone driving device supporting device is guided by the strut 20 under a condition that the static pressure gas is interposed between the device and the strut 20, and influences of indentations and projections of the guide face and dispersion of circularity of a rolling element are eliminated, slight upward and downward movement of the grinding stone G is suitably dissolved together with a downward movement, so as to sufficiently obtain accuracy of a transfer volume of the grind stone G and surface roughness of a grind plane of the work W. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
Technical means to which the present invention belongs
The present invention relates to a vertical rotary grinder for surface grinding a surface of a work with high precision.
[0002]
[Prior art]
A work rotation drive for rotating a work around a vertical rotation axis, a grinding wheel drive for rotating a grinding wheel around the vertical rotation axis to grind one surface of the work, and the grindstone A grindstone driving device supporting device that movably supports the driving device in a direction parallel to the rotation axis, and a grinding wheel feed driving device that feeds the grinding stone toward the workpiece in a direction parallel to the rotation axis, 2. Description of the Related Art A vertical rotary grinder capable of controlling the surface of the work in submicron or nanometer order is known. For example, this is a vertical rotary grinder provided with a tool feeder described in Patent Document 1.
[0003]
[Patent Document 1] Japanese Patent Application Laid-Open No. 8-276349
According to this, the stationary shaft in the vertical direction is fixed to the slider movably provided in the up and down direction, and the rotating body to which the grinding wheel is fixed rotates via the hydrostatic bearing on the shaft end of the stationary shaft. The slider is rotatably driven by a motor provided on the slider via a belt mechanism. Further, the slider is vertically guided via a normal bearing by a column (column) provided upright on the grinding machine bed, and is positioned vertically by a hydraulic cylinder.
[0005]
[Problems to be solved by the invention]
By the way, as described above, when the slider is guided by the support through a normal bearing such as a linear motion ball bearing or a metal bearing, the roundness of the rolling elements in the linear motion ball bearing is not uniform, and the surface of the support is uneven. Due to the influence of the irregularities, it is inevitable that the grinding wheel rotatably provided around the vertical axis on the slider is slightly moved up and down with the downward movement, and the control of the feeding amount of the grinding wheel is, for example, nanometer. In some cases, the surface roughness on the ground plane of the work may not be sufficiently obtained, for example, in units of Angstroms.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vertical rotary grinding machine capable of sufficiently obtaining surface roughness accuracy on a grinding plane of a work.
[0007]
[Means for Solving the Problems]
In order to achieve this object, the gist of the present invention is to provide a work rotation driving device that drives a work to rotate around a vertical rotation axis, and the vertical rotation to grind one surface of the work. A grindstone driving device that rotationally drives a grinding wheel around an axis, a grindstone driving device supporting device that movably supports the grindstone driving device in a direction parallel to the rotation axis, and the grindstone facing the work. A vertical rotary grinding machine having a grindstone feed driving device that feeds in a direction parallel to the rotation axis, wherein the grinding wheel drive device support device includes a vertical guide member extending in a direction parallel to the rotation axis. The grinding wheel drive device is connected, and has a vertical direction static pressure gas bearing device vertically guided by the guide member in a state where the static pressure gas is interposed between the guide surface and the guide surface of the guide member. In the Rukoto.
[0008]
【The invention's effect】
With this configuration, the grinding wheel driving device supporting device that supports the grinding wheel driving device so as to be movable in a direction parallel to the rotation axis of the grinding wheel, a vertical guide member extending in a direction parallel to the rotation axis, A vertical static pressure gas bearing device which is vertically guided by the guide member in a state where a static pressure gas is interposed between the wheel drive device and the guide surface of the guide member. Therefore, the above-mentioned grindstone driving device support device is guided by the vertical guide member in a state where the static pressure gas is interposed between the vertical guide member and the unevenness of the guide surface of the vertical guide member and the perfect circle of the rolling element. Since the influence of the variation in degree is eliminated, it is possible to suitably prevent the grinding wheel from being slightly moved up and down with the downward movement, and it is possible to sufficiently control the feeding amount of the grinding wheel and to grind the workpiece. Surface roughness of the surface will be obtained sufficiently.
[0009]
Other aspects of the invention
Here, preferably, a work rotation drive device support device that supports the work rotation drive device so as to be movable in the horizontal direction, the work rotation drive device support device has a horizontal guide member extending in the horizontal direction, A horizontal static pressure gas bearing device which is horizontally guided by the horizontal guide member in a state where the work rotation drive device is connected and a static pressure gas is interposed between the guide surface of the horizontal guide member and It has. With this configuration, when the workpiece is moved in the horizontal direction during the grinding, the work rotation drive device support device is moved by the horizontal guide member in a state where the static pressure gas is interposed between the horizontal rotation guide member and the horizontal guide member. Since the influence of the unevenness of the guide surface of the horizontal guide member and the variation of the roundness of the rolling element is eliminated by being guided, it is possible to preferably prevent the grinding wheel from being slightly moved up and down with the horizontal movement. Therefore, the surface roughness on the ground plane of the work is further reduced, and a smooth plane can be obtained.
[0010]
Preferably, the grinding wheel driving device includes a rotating shaft to which the grinding wheel is attached, and a static pressure gas rotary bearing device that rotatably supports the rotating shaft via a static pressure gas. . In this way, compared to the case where the rotating shaft is rotatably supported by the ball bearings, the vibration of the grinding wheel due to the variation in the roundness of the rolling element is suitably suppressed, so that the workpiece in the grinding plane is The surface roughness is further reduced, and a smooth plane can be obtained.
[0011]
Preferably, the work rotation drive device includes a rotation shaft to which the work is detachably attached, and a static pressure gas rotary bearing device that supports the rotation shaft via a static pressure gas. . With this configuration, compared to the case where the rotating shaft is rotatably supported by the ball bearings, the vibration of the work due to the variation in the roundness of the rolling elements is suitably suppressed. The roughness is further reduced and a smooth plane can be obtained.
[0012]
Preferably, the grinding wheel feed drive device is provided on a feed screw device provided on a frame having a fixed position, and on a movable member fed by the feed screw device, and moves the vertical hydrostatic gas bearing device on its movable side. A piezoelectric actuator for moving the member in a direction parallel to the moving direction of the member. With this configuration, the vertical hydrostatic gas bearing device to which the grinding wheel driving device is connected, when the grinding wheel is cut in the vertical direction during grinding, moves the piezoelectric actuator from the state positioned by the feed screw device. Since the workpiece is moved while being used, the feeding amount is controlled with high positional accuracy, so that the surface roughness on the ground plane of the work is further reduced, and a smooth plane can be obtained.
[0013]
Also, preferably, in order to alleviate the uneven distribution of the surface pressure on the guide surface of the guide member due to the load of the grinding wheel driving device connected to the vertical static pressure gas bearing device, it is pulled up to the grinding wheel driving device. It is provided with a load balancing device for applying a thrust in the direction. With this configuration, the thrust in the direction in which the grindstone driving device is pulled up is applied from the load balancing device to the grindstone driving device connected to the vertical hydrostatic gas bearing device. Since it is made to approach the device, the uneven distribution of the surface pressure on the guide surface of the guide member is suitably reduced, and the vertical hydrostatic gas bearing device is reduced in size.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, the dimensional ratios and the like of each part are not necessarily drawn accurately.
[0015]
FIG. 1 is a front view of a vertical rotary grinding machine 10 according to one embodiment of the present invention, and FIG. 2 is a side view thereof. 1 and 2, a vertical rotary grinding machine 10 includes a lower frame 12 and a rotating portion around a pin 16 in a horizontal axis direction in a remaining portion of the upper surface of the lower frame 12 on which a surface plate 14 is mounted. And an upper frame 18 fixed by a fixing device 17 so that the movement can be finely adjusted. The upper frame 18 has a pair of columns 20 in the form of a prism having a vertically elongated shape, and a pair of vertical static members which are fitted to the columns 20 functioning as vertical guide members and guided in the vertical direction. A pressurized gas bearing device 22 is provided. The pair of vertical static pressure gas bearing devices 22 are connected to each other via a connecting plate 23 and the like. FIG. 3 shows a cross section of the support column 20.
[0016]
As shown in FIG. 4, for example, a vertical static pressure gas bearing device 22 includes a housing 24 surrounding four guide surfaces of a column 20, and a small gap facing the guide surface within the housing 24 and having a small gap. And a gas supply passage 28 for supplying a compressed gas, for example, compressed air, to a side of the porous member 26 opposite to the guide surface side. By interposing a high-pressure fluid pressure (static pressure) ejected from the porous member 26 in a gap between the column 20 and the guide surface, the housing 24 is supported or restrained by the column 20 in contact.
[0017]
The above-mentioned vertical hydrostatic gas bearing device 22 includes a grindstone driving device that rotationally drives a grindstone G around a vertical rotation axis in order to grind one surface (upper surface) of a plate-like work W that is an object to be polished. 30 are connected and fixed. Therefore, the column 20 and the vertical static pressure gas bearing device 22 guided by the column 20 function as a grindstone driving device supporting device for supporting the grindstone driving device 30 so as to be movable in the vertical direction. The grinding wheel driving device 30 is supported by the vertical static pressure gas bearing device 22 so as to be movable in the vertical direction. The grindstone driving device 30 is fixed to a rotating shaft 32 having a grinding wheel G fixed to a shaft (lower) end, a fixed plate 36 to which a motor 34 for rotating and driving the rotating shaft 32 is fixed, and the motor 34. A static pressure gas rotary bearing device 38 that rotatably supports the rotary shaft 32 via a static pressure gas. The static pressure gas rotary bearing device 38 supports the rotary shaft 32 in a non-contact state with high pressure fluid pressure (static pressure) blown from a porous member facing the outer peripheral surface of the rotary shaft 32 interposed therebetween. is there.
[0018]
In order to feed the grindstone G toward the work W by a predetermined cutting amount when polishing the work W, a grindstone feed driving device 40 for feeding the grindstone G toward the work W in a direction parallel to its rotation axis, that is, in a vertical direction is provided. It is provided on the upper frame 18. The grindstone feed driving device 40 includes a feed screw device 42 provided on the fixed upper frame 18, a movable member 44 fed by the feed screw device 42, and a connecting plate connected to the vertical hydrostatic gas bearing device 22. 23, and a piezoelectric actuator 46 for moving the vertical hydrostatic gas bearing device 22 in a direction parallel to the moving direction of the movable member 44. The feed screw device 42 includes a feed screw 48 provided on the upper frame 18 so as to be rotatable around a vertical rotation axis, and a motor 50 connected to the feed screw 48 and provided on the upper frame 18. With the rotation of the feed screw 48 driven to rotate by the motor 50, the movable member 44 screwed thereto is positioned in the vertical direction. The piezoelectric actuator 46 is formed by stacking, for example, plate-shaped piezoelectric ceramics, and its total length is changed with high accuracy within a stroke of, for example, 200 μm according to the applied driving voltage. The output is what you get.
[0019]
In the upper frame 18, uneven distribution of the surface pressure distribution on the guide surface of the column 20 due to the load of the grindstone driving device 30 supported in a cantilever manner by the vertical hydrostatic gas bearing device 22 is reduced. A load balancing device 54 is provided. The load balancer 54 includes a balance weight 56 that is provided with a load substantially equal to that of the grindstone drive device 30 and that can be vertically moved within the upper frame 18, and that the balance weight 56 and the grindstone drive device 30 And a cable 60 guided in an inverted U-shape by a roller 58, and applying a thrust to the grinding wheel driving device 30 in a direction of pulling it up so as to reduce the load regardless of its vertical position. To reduce.
[0020]
On the lower frame 12, a work rotation driving device 64 for rotating the work W about a vertical rotation axis in order to polish the upper surface of the work W is provided with a surface plate 14, a three-component dynamometer 62, And a work rotation drive support device 66. The work rotation drive device support device 66 is for supporting the work rotation drive device 64 so as to be movable in the horizontal direction. The horizontal guide member 68 extending in the horizontal direction is provided with the work rotation drive device 64. A horizontal static pressure gas bearing device 70 which is connected and guided in one horizontal direction by the horizontal guide member 68 with the static pressure gas interposed between the horizontal guide member 68 and the guide surface of the horizontal guide member 68. ing. The work W fixed to the work rotation driving device 64 is set so as to overlap with the grinding wheel G in the vertical direction by a radius equal to or larger than the radius of the work W.
[0021]
The work rotation driving device 64 includes a rotation shaft (not shown) to which the suction plate 72 to which the work W is detachably attached is fixed, a motor 73 for driving the rotation shaft, and a rotation fixed to the motor 73. And a hydrostatic gas rotary bearing device 74 for supporting the shaft via a hydrostatic gas. The static pressure gas rotary bearing device 74 supports the rotary shaft 32 in a non-contact state with high pressure fluid pressure (static pressure) blown out from a porous member facing the outer peripheral surface of the rotary shaft (not shown) interposed therebetween. Things. Further, the horizontal hydrostatic gas bearing device 70 has a housing 76 surrounding the guide surface of the horizontal guide member 68, similarly to the vertical hydrostatic gas bearing device 22, and faces the guide surface in the housing 76. And a porous member (not shown) provided so as to be located with a slight gap therebetween, and a gas passage for supplying a compressed gas such as compressed air to a side of the porous member opposite to the guide surface side. The housing 76 is brought into contact with the housing so that a high-pressure fluid pressure (static pressure) ejected from the porous member is interposed in a gap between the guide surface of the horizontal guide member 68 and the guide direction of the horizontal guide member 68. Other movements are restricted.
[0022]
In the work 10 configured as described above, when the work W is fixed to the suction disk 72, the grinding grindstone G and the work W are driven to rotate in a predetermined direction and a grinding fluid (not shown) is supplied while the grinding grindstone G is supplied. G is lowered by the feed screw device 42 just before G contacts the workpiece W. Next, while the grinding wheel G is cut into the work W by the piezoelectric actuator 46, the work W is moved by one reciprocating stroke in the horizontal direction by the horizontal support device 66 by a horizontal driving device 78 such as a linear motor or by manual operation. Can be The polishing process is repeated as necessary, so that the entire upper surface of the work W is polished. 5 and 6 show the results of experiments performed by the inventor. FIG. 5 shows the cutting amount of the work W, that is, the feed amount of the grinding wheel G to the work W, and the surface roughness of the work W (or the maximum). 6 shows the relationship between the presence / absence of horizontal movement and the surface roughness of the workpiece W. FIG. As is apparent from FIG. 5, when the amount of cut in the work W per one electric signal (1 pulse) to the piezoelectric actuator 46 is set to 5 nm or less, a surface roughness of the work W of 1 angstrom or less can be obtained. . That is, the surface roughness (flatness) of the work W of 1 angstrom or less cannot be obtained unless the feed amount of the grinding wheel G to the work W is controlled to 5 nm or less. In addition, by moving the work W in the horizontal direction by the work W horizontal support device 66 during grinding, the surface roughness of the work W is improved to about 1/5. For example, as shown in FIG. 6, the flatness of the work W is determined to be 0. If the flatness of the surface shape without movement is 0.5 μm in the case where the size of the work W is 200 mm × 200 mm, it is determined that there is movement. It is improved to 1 μm or less.
[0023]
As described above, according to the present embodiment, the grindstone driving device support device (20, 22) that supports the grindstone driving device 30 so as to be movable in a direction parallel to the rotation axis of the grinding wheel G is provided with the rotation shaft center and The column (vertical guide member) 20 extending in a parallel direction and the grindstone driving device 30 are connected to each other, and the column 20 moves vertically in a state where a static pressure gas is interposed between the column 20 and the guide surface of the column 20. Since the apparatus has the guided vertical static pressure gas bearing device 22, the above-mentioned grindstone driving device supporting device is guided by the column 20 with the static pressure gas interposed between the column 20 and the column 20. Since the influence of the unevenness of the guide surface and the variation in the roundness of the rolling elements is eliminated, it is possible to preferably eliminate the possibility that the grinding wheel G is slightly moved up and down with the downward movement, and the feeding amount of the grinding wheel G And that the control of In, so that the surface roughness of the grinding plane of the workpiece W can be sufficiently obtained.
[0024]
Further, according to the present embodiment, the work rotation drive device support device 66 that supports the work rotation drive device 64 so as to be movable in the horizontal direction includes the horizontal guide member 68 extending in the horizontal direction and the work rotation drive device 64. A horizontal static pressure gas bearing device 70 that is connected and guided in the horizontal direction by the horizontal guide member with a static pressure gas interposed between the horizontal guide member 68 and the guide surface of the horizontal guide member 68. is there. For this reason, when the workpiece W is moved in the horizontal direction during the grinding, the workpiece rotation driving device support device 66 has the horizontal guide member 68 with the static pressure gas interposed between the horizontal rotation guide member 68 and the horizontal guide member 68. And the influence of unevenness of the guide surface and variation in the roundness of the rolling element is eliminated, so that the grinding wheel G can be suitably moved up and down slightly with the horizontal movement. Therefore, the surface roughness of the ground plane of the work is further reduced, and a smooth plane can be obtained.
[0025]
Further, according to the present embodiment, the grindstone driving device 30 includes a rotating shaft 32 to which the grinding grindstone G is attached, and a static pressure gas rotary bearing device 38 that rotatably supports the rotating shaft 32 via a static pressure gas. Therefore, as compared with the case where the rotating shaft 32 is rotatably supported by the ball bearing, the vibration of the grinding wheel due to the variation in the roundness of the rolling element of the ball bearing is preferably suppressed. Therefore, the surface roughness of the ground plane of the work W is further reduced, and a smooth plane can be obtained.
[0026]
Further, according to the present embodiment, the work rotation driving device 64 includes a rotation shaft (not shown) to which the work w is detachably mounted, and a static pressure gas rotary bearing device 74 that supports the rotation shaft via a static pressure gas. Therefore, the vibration of the workpiece W due to the variation in the roundness of the rolling element of the ball bearing is more preferably suppressed as compared with the case where the rotating shaft is rotatably supported by the ball bearing. Therefore, the surface roughness of the grinding plane of the work W is further reduced, and a smooth plane can be obtained.
[0027]
Further, according to the present embodiment, the grindstone feed driving device 40 is provided on the feed screw device 42 provided on the fixed upper frame 18 and the movable member 44 fed by the feed screw device 42, The piezoelectric actuator 46 for moving the pressurized gas bearing device 22 in a direction parallel to the direction of movement of the movable member 44, the vertical static pressure gas bearing device 22 to which the grinding wheel driving device 30 is connected is When the grinding wheel G is cut in the vertical direction during the grinding, the piezoelectric element 46 is used to move the grinding wheel G from the position determined by the feed screw device 42, so that the feeding amount is controlled with high positional accuracy. Therefore, the surface roughness of the ground plane of the work W is further reduced, and a smooth plane can be obtained.
[0028]
Further, according to the present embodiment, in order to alleviate the uneven distribution of the surface pressure on the guide surface of the column (guide member) 20 due to the load of the grinding wheel drive device 30 connected to the vertical hydrostatic gas bearing device 22, the grinding wheel drive is performed. A load balancing device 54 is provided to apply a thrust in the direction in which the device 30 is pulled up. For this reason, since the thrust in the direction of pulling it up is applied from the load balancing device 54 to the grindstone driving device 30 connected to the vertical hydrostatic gas bearing device 22, the center of gravity of the load is adjusted to the vertical hydrostatic gas bearing. Since it is made to approach the device 22, uneven distribution of the surface pressure on the guide surface of the column 20 is suitably reduced, and the vertical hydrostatic gas bearing device 22 is reduced in size.
[0029]
As described above, the preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other embodiments.
[0030]
For example, in the above-described embodiment, the grindstone driving device 30 may be disposed so as to be located between the pair of columns 20. In this case, the load balancing device 54 becomes unnecessary. When the load bearing capacity of the vertical hydrostatic gas bearing device 22 is large, the load balancing device 54 is not necessarily required in the embodiments of FIGS. 1 and 2.
[0031]
In the above-described embodiment, the grinding wheel feeder 40 controls the cut amount of the grinding wheel G using the piezoelectric actuator 46, but a magnetostrictive element or the like may be used instead of the piezoelectric actuator 46.
[0032]
Further, in the vertical rotary grinding machine 10 of the above-described embodiment, the grinding wheel G and the work W are provided rotatably around the vertical axes A and G. It does not have to be.
[0033]
Although not illustrated one by one, the present invention is embodied with various changes without departing from the spirit thereof.
[Brief description of the drawings]
FIG. 1 is a front view showing a vertical rotary grinder according to an embodiment of the present invention.
FIG. 2 is a side view showing the vertical rotary grinding machine of the embodiment of FIG.
FIG. 3 is a sectional view taken along the line III-III of FIG. 1 for illustrating a section of a column in the vertical rotary grinding machine of the embodiment of FIG. 1;
FIG. 4 is a cross-sectional view illustrating a main part of the configuration of the vertical static pressure gas bearing device of FIGS. 1 to 3;
5 is a result of an experiment performed using the apparatus of the embodiment of FIG. 1 and shows a relationship between a feed amount of the grinding wheel G to the work W and a surface roughness of the work W.
6 is a result of an experiment performed using the apparatus of the embodiment in FIG. 1 and shows a relationship between the presence / absence of horizontal movement of the work W during grinding and the surface roughness of the work W. FIG.
[Explanation of symbols]
10: Vertical rotary grinding machine 20: Post (vertical guide member) (Wheel driving device support device)
22: Vertical static pressure gas bearing device (grinding wheel drive device support device)
30: Grinding wheel drive device 38: Static pressure gas rotary bearing device 40: Grinding wheel feed drive device 64: Work rotary drive device 66: Work rotary drive device support device 70: Horizontal direction static pressure gas bearing device 74: Static pressure gas rotary bearing device W: Work G: Grinding wheel

Claims (6)

A work rotation drive for rotating a work around a vertical rotation axis, a grinding wheel drive for rotating a grinding wheel around the vertical rotation axis to grind one surface of the work, and the grindstone A grinding wheel driving device supporting device that supports the driving device so as to be movable in a direction parallel to the rotation axis; and a grinding wheel feed driving device that feeds the grinding wheel toward the workpiece in a direction parallel to the rotation axis. A vertical rotary grinding machine,
The grinding wheel driving device supporting device is a state in which a vertical guide member extending in a direction parallel to the rotation axis, the grinding wheel driving device is connected, and a static pressure gas is interposed between the guide surface of the guiding member. And a vertical hydrostatic gas bearing device guided vertically by the guide member. A work rotation driving device supporting device that supports the work rotation driving device so as to be movable in a horizontal direction; the work rotation driving device supporting device is connected to a horizontal guide member extending in the horizontal direction and the work rotation driving device; And a horizontal static pressure gas bearing device guided in a horizontal direction by the horizontal guide member with a static pressure gas interposed between the horizontal guide member and the guide surface of the horizontal guide member. 2. Vertical rotary grinding machine. 3. The grinding wheel drive device according to claim 1, further comprising: a rotating shaft to which the grinding wheel is attached; and a static pressure gas rotary bearing device rotatably supporting the rotating shaft via a static pressure gas. Vertical rotary grinding machine. 4. The work rotation drive device according to claim 1, further comprising: a rotation shaft to which the work is detachably attached; and a hydrostatic gas rotary bearing device that supports the rotation shaft via a static gas. Any vertical rotary grinder. The grindstone feed drive device is provided on a feed screw device provided on a frame having a fixed position, and on a movable member fed by the feed screw device, and the vertical static pressure gas bearing device is disposed in parallel with the moving direction of the movable member. The vertical rotary grinding machine according to any one of claims 1 to 4, further comprising a piezoelectric actuator for moving the vertical rotary grinding machine in any direction. In order to alleviate the uneven distribution of the surface pressure on the guide surface of the guide member due to the load of the grinding wheel driving device connected to the vertical hydrostatic gas bearing device, a thrust in a direction in which the grinding wheel driving device is pulled up is applied to the guiding device. The vertical rotary grinding machine according to any one of claims 1 to 5, further comprising a load balancing device.

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