U.S. patent application number 12/870345 was filed with the patent office on 2011-03-24 for machining apparatus using rotary grinder.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Masaaki SUDO.
Application Number | 20110070807 12/870345 |
Document ID | / |
Family ID | 43757010 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110070807 |
Kind Code |
A1 |
SUDO; Masaaki |
March 24, 2011 |
MACHINING APPARATUS USING ROTARY GRINDER
Abstract
According to one embodiment, a machining apparatus includes a
disk-like grinder, and a nozzle for discharging a cutting fluid
toward the grinder. The grinder cuts or grooves a workpiece by
rotating. The grinder is provided with a cutting portion at a
periphery of the grinder. The nozzle is provided to face the
cutting portion in a radial direction of the grinder and arranged
adjustably in a width direction of the cutting portion. The nozzle
has a rectangular or elliptic cross-section shape in which a
dimension in a width direction of the grinder is larger than a
dimension in a peripheral direction of the grinder.
Inventors: |
SUDO; Masaaki;
(Yokohama-shi, JP) |
Assignee: |
Kabushiki Kaisha Toshiba
Tokyo
JP
|
Family ID: |
43757010 |
Appl. No.: |
12/870345 |
Filed: |
August 27, 2010 |
Current U.S.
Class: |
451/5 ;
451/450 |
Current CPC
Class: |
B24B 27/06 20130101;
B24B 55/02 20130101 |
Class at
Publication: |
451/5 ;
451/450 |
International
Class: |
B24B 49/00 20060101
B24B049/00; B24B 55/02 20060101 B24B055/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 24, 2009 |
JP |
2009-218427 |
Claims
1. A machining apparatus, comprising: a grinder that is formed in a
disk-like shape and cuts or grooves a workpiece by rotating, the
grinder provided with a cutting portion at a periphery thereof; and
a nozzle that is provided to face the cutting portion in a radial
direction of the grinder and arranged adjustably in a width
direction of the cutting portion, and discharges cutting fluid
toward the grinder, the nozzle having a rectangular cross-section
shape in which a dimension in a width direction of the grinder is
larger than a dimension in a peripheral direction of the
grinder.
2. A machining apparatus, comprising: a grinder that is formed in a
disk-like shape and cuts or grooves a workpiece by rotating, the
grinder being provided with a cutting portion at a periphery
thereof and a nozzle that is provided to face the cutting portion
in a radial direction of the grinder and arranged adjustably in a
width direction of the cutting portion, and discharges cutting
fluid toward the grinder, the nozzle having an elliptic
cross-section shape in which a dimension in a width direction of
the grinder is larger than a dimension in a peripheral direction of
the grinder.
3. The machining apparatus of claim 1, further comprising: a memory
device for storing a position of the nozzle; a detector for
detecting a relative position between the grinder and the nozzle;
and an actuator for moving the nozzle.
4. The machining apparatus of claim 2, further comprising: a memory
device for storing a position of the nozzle; a detector for
detecting a relative position between the grinder and the nozzle;
and an actuator for moving the nozzle.
5. The machining apparatus of claim 1, further comprising: a
plurality of flow-straightening plates arranged inside the nozzle
in a longitudinal direction of a cross-section of the nozzle, the
flow-straightening plates for straightening flow of the cutting
fluid discharged from the nozzle.
6. The machining apparatus of claim 2, further comprising: a
plurality of flow-straightening plates arranged inside the nozzle
in a longitudinal direction of a cross-section of the nozzle, the
flow-straightening plates for straightening flow of the cutting
fluid discharged from the nozzle.
7. The machining apparatus of claim 3, further comprising: a
plurality of flow-straightening plates arranged inside the nozzle
in a longitudinal direction of a cross-section of the nozzle, the
flow-straightening plates for straightening flow of the cutting
fluid discharged from the nozzle.
8. The machining apparatus of claim 4, further comprising: a
plurality of flow-straightening plates arranged inside the nozzle
in a longitudinal direction of a cross-section of the nozzle, the
flow-straightening plates for straightening flow of the cutting
fluid discharged from the nozzle.
9. The machining apparatus of claim 5, further comprising: a
disturbed flow restrainer formed in a streamlined shape provided at
an end portion of at least one of the flow-straightening plates in
an opening of the nozzle in a flowing direction of the cutting
fluid, the disturbed flow restrainer for restraining disturbed flow
of the cutting fluid discharged from the nozzle.
10. The machining apparatus of claim 6, further comprising: a
disturbed flow restrainer formed in a streamlined shape provided at
an end portion of at least one of the flow-straightening plates in
an opening of the nozzle in a flowing direction of the cutting
fluid, the disturbed flow restrainer for restraining disturbed flow
of the cutting fluid discharged from the nozzle.
11. The machining apparatus of claim 7, further comprising: a
disturbed flow restrainer formed in a streamlined shape provided at
an end portion of at least one of the flow-straightening plates in
an opening of the nozzle in a flowing direction of the cutting
fluid, the disturbed flow restrainer for restraining disturbed flow
of the cutting fluid discharged from the nozzle.
12. The machining apparatus of claim 8, further comprising: a
disturbed flow restrainer formed in a streamlined shape provided at
an end portion of at least one of the flow-straightening plates in
an opening of the nozzle in a flowing direction of the cutting
fluid, the disturbed flow restrainer for restraining disturbed flow
of the cutting fluid discharged from the nozzle.
Description
CROSS-REFERENCE TO RELATED ART
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2009-218427, filed on
Sep. 24, 2009; the entire contents of which are incorporated herein
by reference.
FIELD
[0002] The present embodiment relates to a machining apparatus for
cutting or grooving a workpiece by pressing a rotary grinder on the
workpiece such as a semiconductor wafer.
BACKGROUND
[0003] A machining apparatus for cutting or grooving a workpiece by
pressing a rotary grinder, which rotates with a high speed, on the
workpiece such as a semiconductor wafer described in Patent
Publication 1 (U.S. Pat. No. 7,101,256) has been known.
[0004] The grinder in the machining apparatus described in Patent
Publication 1 is a machine tool to cut the workpiece such as a
semiconductor wafer, in which a width dimension of the grinder is
configured to be small, having a size approximately between 10
.mu.m to 100 .mu.m.
[0005] With respect to the grinder in process, it is required to
supply a cutting fluid in order to cool the grinder or remove
working dust. Moreover, it is required to discharge the cutting
fluid with high pressure in order to certainly supply the cutting
fluid to a contacting portion between the grinder and the
workpiece.
[0006] Therefore, the cutting fluid is supplied by use of a round
nozzle having a small diameter, such as a diameter of approximately
1 mm.
[0007] The nozzle is arranged adjustably to face the cutting
portion of the grinder. In order to improve machining accuracy, the
nozzle is adjusted to position so that a center of the nozzle and a
center of the grinder in a width direction face each other in the
same plane.
[0008] The relationship between the position adjustment of the
nozzle and the improvement of the machining accuracy is as follows.
Fluid pressure of the cutting fluid discharged from the nozzle is
the highest in the center of the nozzle, and gradually lowered
outward from the center of the nozzle. Therefore, when the center
of the nozzle is shifted from the center of the grinder in the
width direction, the fluid pressure of the cutting fluid discharged
toward the grinder differs on both sides of the grinder in the
width direction, the grinder is distorted due to the fluid pressure
difference acting on the both sides of the grinder in the width
direction, and the machining accuracy is lowered because the
grinder is rotated while being distorted.
[0009] As described in Patent Publication 1, a position adjustment
mechanism with high accuracy is required in order to adjust the
position of the nozzle so that the center of the nozzle and the
center of the grinder in the width direction face each other on the
same plane. As a result, the cost for the machining apparatus has
been high.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic view illustrating a whole constitution
of a first embodiment.
[0011] FIG. 2 is a perspective view illustrating a part of the
first embodiment.
[0012] FIG. 3 is a perspective view illustrating a part of a second
embodiment.
[0013] FIG. 4 is a partially sectional perspective view of a nozzle
according to a third embodiment.
[0014] FIG. 5 is a partially sectional perspective view of a nozzle
according to a fourth embodiment.
[0015] FIG. 6 is a partially sectional perspective view of a nozzle
according to a fifth embodiment.
[0016] FIG. 7 is a partially sectional perspective view of a nozzle
according to a sixth embodiment.
DETAILED DESCRIPTION
[0017] In general, according to one embodiment, a machining
apparatus includes a disk-like grinder, and a nozzle for
discharging a cutting fluid to the grinder. The grinder cuts or
grooves a workpiece by rotating. The grinder is provided with a
cutting portion at a periphery of the grinder. The nozzle faces the
cutting portion in a radial direction of the grinder, and is
arranged adjustably in a width direction of the cutting portion. A
cross-section shape of the nozzle has a rectangular shape or an
elliptic shape in which a dimension in a width direction of the
cutting portion is larger than a dimension in a peripheral
direction of the cutting portion.
[0018] Hereinafter, embodiments will be described with reference to
the drawings.
(First Embodiment)
[0019] A first embodiment will be described with reference to FIGS.
1 and 2. A machining apparatus according to the first embodiment is
a dicing apparatus for cutting or grooving a workpiece W such as a
semiconductor wafer, and includes a thin disk-like grinder 1. The
grinder 1 is held between two flanges 2. A rotating shaft 4 of an
actuator 3 is approximately horizontally connected to a center of
each flange 2 in a radial direction.
[0020] A periphery of the grinder 1 is provided with a cutting
portion 5 that performs cutting and grooving while intervening the
workpiece W. The cutting portion 5 is formed to have a width
dimension of 10 to 100 .mu.m in a thickness direction of the
cutting portion 5.
[0021] A chuck table 6 is provided underneath to the grinder 1
connected to the rotating shaft 4. The chuck table 6 detachably
hold the workpiece W by applying a vacuum force or by using a
wax.
[0022] A nozzle 7 is arranged facing the cutting portion 5 in a
radial direction of the grinder 1. The nozzle 7 discharges a
cutting fluid L toward an intervening portion between the cutting
portion 5 and the workpiece W. The nozzle 7 is held by a holding
member 8 being movable in an X direction, a Y direction, and a Z
direction, and pivotable in a .theta. direction. The holding member
8 is driven by an actuator 9. The nozzle 7 is appropriately
adjusted in the X direction, the Y direction, the Z direction, and
the .theta. direction by driving the holding member 8 by the
actuator 9.
[0023] The actuator 9 may be a screw feeding mechanism, a gear
drive mechanism, a piezoelectric actuator, and the like. The X
direction as one of the moving directions of the nozzle 7 is a
width direction of the grinder 1. As for the cutting fluid L, pure
water or a fluid in which a rust inhibitor is added to pure water
is adopted.
[0024] The holding member 8 is attached with a light source 10 to
direct light toward the grinder 1. The light source 10 is
positioned so that a center of a cross-section of light corresponds
to a center of the grinder 1 in the width direction in the cutting
fluid L discharged from the nozzle 7. As for the light source 10, a
semiconductor laser and the like is adopted.
[0025] A light sensor 11 is arranged to face the light source 10 on
an opposite side of the grinder 1, as a detector to detect light
emitted from the light source 10. The light sensor 11 detects an
intensity distribution of the light emitted from the light source
10 and outputs the detected intensity distribution to a controller
12.
[0026] The light emitted from the light source 10 is blocked by the
grinder 1, or diffusely reflected by the cutting fluid L.
Therefore, the intensity distribution of the light that reaches the
opposite side of the grinder 1 changes according to a position and
angle of the nozzle 7, i.e. the position and angle of the light
source 10. That is, the position and angle of the nozzle 7 can be
expected by detecting the intensity distribution of the light
emitted from the light source 10 by the light sensor 11.
[0027] The controller 12 controls the actuator 9 based on both the
intensity distribution of the light output from the light sensor 11
and an optimum intensity distribution preliminarily stored in a
memory device 13, so as to move the nozzle 7 to an optimum
position.
[0028] The above-mentioned "optimum position of the nozzle 7" is
the position where the nozzle 7 discharges the cutting fluid so as
to machine the workpiece W optimally. In addition, the "optimum
intensity distribution" is the light intensity distribution
detected by the light sensor 11 when the nozzle 7 is positioned at
the optimum position. Namely, when the light sensor 11 detects the
optimum intensity distribution, the nozzle 7 can be presumed to be
positioned at the optimum position.
[0029] The memory device 13 stores the optimum position of the
nozzle 7 as coordinate data (X, Y, Z, .theta.). The coordinate data
is stored in the memory device 13 by inputting the data through an
external terminal 14.
[0030] The cross-section of the nozzle 7 when the nozzle 7 is cut
in a plane parallel to an opening 7a of the nozzle 7 is formed to
have a rectangular shape in which a dimension "a" in the width
direction of the grinder 1 (in the X direction) is larger than a
dimension "b" in the peripheral direction of the grinder 1 (in the
Z direction) perpendicular to the X direction. Therefore, when the
cutting fluid L is discharged from the nozzle 7 toward the
intervening portion between the cutting portion 5 and the workpiece
W, the cutting fluid L is discharged widely in the width direction
of the grinder 1.
[0031] In such a configuration, when the workpiece W is cut or
grooved by use of the machining apparatus, the workpiece W is held
on the chuck table 6, the grinder 1 is rotated together with the
rotating shaft 4 of the actuator 3, and the grinder 1 is moved so
as to bring the rotating cutting portion 5 to the workpiece W.
Then, the cutting fluid L is discharged from the nozzle 7, and the
intensity distribution of light emitted from the light source 10 is
detected by the light sensor 11.
[0032] The light intensity distribution detected by the light
sensor 11 is output to the controller 12, and compared to the light
intensity distribution stored in the memory device 13. Based on the
comparison result, the controller 12 outputs a drive signal to the
actuator 9 so as to conform the light intensity distribution
detected by the light sensor 11 to the light intensity distribution
stored in the memory device 13. Accordingly, the nozzle 7 is
adjusted to be positioned at the optimum position, and the cutting
fluid L discharged from the nozzle 7 is supplied optimally for
machining.
[0033] After the nozzle 7 is positioned at the optimum position,
the grinder 1 is further moved downward to start cutting or
grooving the workpiece W.
[0034] The machining apparatus according to the first embodiment is
operated such that the nozzle 7 is automatically positioned at the
optimum position by detecting light emitted from the light source
10 by the light sensor 11 and driving the actuator 9 based on the
detected result.
[0035] Thus, the nozzle 7 can be accurately and repeatably
positioned at the optimum position. Also, cutting or grooving of
the workpiece W can be carried out with almost the same precision
regardless of skill levels of operators who operate the machining
apparatus. As a result, chipping or cracking is reduced, and a
uniformity of a machining surface quality can be achieved.
[0036] In addition, the cross-section of the nozzle 7 is formed to
have a rectangular shape in which the dimension "a" in the width
direction of the grinder 1 (in the X direction) is larger than the
dimension "b" in the peripheral direction of the grinder 1 (in the
Z direction) perpendicular to the X direction. Accordingly, a range
in which fluid pressure of the cutting fluid L discharged from the
nozzle 7 is the highest becomes wide in the width direction of the
grinder 1.
[0037] Thus, even if the nozzle 7 is roughly positioned, the
cutting fluid L with the highest fluid pressure to be discharged
from the nozzle 7 can be easily positioned at the center position
in the width direction of the grinder 1. Therefore, even if the
nozzle 7 is roughly positioned, the fluid pressure of the cutting
fluid L discharged from the nozzle 7 can become equal on both sides
of the cutting fluid L in the width direction of the grinder 1. As
a result, the fluid pressure of the cutting fluid L acting on the
both sides of the grinder 1 in the width direction is prevented
from being different from each other caused by the rough
positioning of the nozzle 7. Moreover, the grinder 1 can be
prevented from being distorted and rotating while being distorted
due to such a fluid pressure difference. Accordingly, the machining
apparatus can be maintained with high machining accuracy.
Consequently, the actuator 9 may have a lowered positioning
function in performance, which results in achievement of low cost
of the machining apparatus.
[0038] The first embodiment was described above explaining the
example of the case where the cross-section of the nozzle 7 has a
rectangular shape. However, the rectangular shape is not limited to
a quadrilateral shape with four right angles.
[0039] The rectangular shape may be a trapezoidal shape as long as
the dimension "a" in the width direction of the grinder 1 is larger
than the dimension "b" in the peripheral direction of the grinder
1.
(Second Embodiment)
[0040] A second embodiment will be described with reference to FIG.
3. Note that, in the second embodiment and the other embodiments
described below, the same constituent elements as the constituent
elements of the aforementioned embodiments are indicated by the
same reference numerals, and explanations thereof will not be
repeated.
[0041] The fundamental constitution of the second embodiment is the
same as the first embodiment illustrated in FIGS. 1 and 2.
Meanwhile, the second embodiment includes a nozzle 7A having a
different shape from the nozzle of the first embodiment.
[0042] The cross-section of the nozzle 7A when the nozzle 7A is cut
in a plane parallel to the opening 7a of the nozzle 7A is formed to
have an elliptic shape in which the dimension "a" in the width
direction of the grinder 1 (in the X direction) is larger than the
dimension "b" in the peripheral direction of the grinder 1 (in the
Z direction) perpendicular to the X direction. Therefore, when the
cutting fluid L is discharged from the nozzle 7A toward the
intervening portion between the cutting portion 5 of the grinder 1
and the workpiece W, the cutting fluid L is discharged widely in
the width direction of the grinder 1.
[0043] In such a configuration, since the cross-section of the
nozzle 7A is formed to have an elliptic shape in which the
dimension "a" in the width direction of the grinder 1 (in the X
direction) is larger than the dimension "b" in the peripheral
direction of the grinder 1 perpendicular to the X direction (in the
Z direction), a range in which fluid pressure of the cutting fluid
L discharged from the nozzle 7A is the highest becomes wide in the
width direction of the grinder 1.
[0044] Thus, even if the nozzle 7A is roughly positioned, the
cutting fluid L with the highest fluid pressure to be discharged
from the nozzle 7A can be easily positioned at the center position
in the width direction of the grinder 1. Therefore, even if the
nozzle 7A is roughly positioned, the fluid pressure of the cutting
fluid L discharged from the nozzle 7A can become equal on both
sides of the cutting fluid L in the width direction of the grinder
1. As a result, the fluid pressure of the cutting fluid L acting on
the both sides of the grinder 1 in the width direction is prevented
from being different from each other caused by the rough
positioning of the nozzle 7A. Moreover, the grinder 1 can be
prevented from being distorted and rotating while being distorted
due to such a fluid pressure difference. Accordingly, the machining
apparatus can be maintained with high machining accuracy.
Consequently, the actuator 9 may have a lowered positioning
function in performance, which results in achievement of low cost
of the machining apparatus.
(Third Embodiment)
[0045] A third embodiment will be described with reference to FIG.
4. The fundamental constitution of the third embodiment is the same
as the first embodiment illustrated in FIGS. 1 and 2. Meanwhile,
the third embodiment includes a nozzle 7B having a different inside
shape from the nozzle in the first embodiment.
[0046] A peripheral shape of the nozzle 7B is formed to have a
rectangular shape similarly to the nozzle 7 in the first
embodiment. The nozzle 7B in the third embodiment is provided
inside with a plurality of flow-straightening plates 15 along a
longitudinal direction (the X direction) of a cross-section of the
nozzle 7B. The flow-straightening plates 15 are arranged that the
flow-straightening plates 15 straighten flow of the cutting fluid L
discharged from the opening 7a of the nozzle 7B in the width
direction of the grinder 1 that is the longitudinal direction of
the opening 7a.
[0047] In such a configuration, the cutting fluid L discharged from
the opening 7a of the nozzle 7B toward the grinder 1 is
straightened by the flow-straightening plates 15, so that a
disturbed flow when the cutting fluid L is discharged from the
opening 7a of the nozzle 7B is prevented. Therefore, the fluid
pressure of the cutting fluid L acting on the both sides of the
grinder 1 in the width direction can be prevented from being
different from each other due to the disturbed flow caused when the
cutting fluid L is discharged from the opening 7a of the nozzle 7B.
Accordingly, the occurrence of the fluid pressure difference of the
cutting fluid L on the both sides of the grinder 1 in the width
direction caused by the disturbed flow of the cutting fluid L
discharged from the nozzle 7B can be prevented. Moreover, the
grinder 1 can be prevented from being distorted and rotating while
being distorted due to such a fluid pressure difference of the
cutting fluid L. As a result, high machining accuracy in the
machining apparatus can be achieved.
(Fourth Embodiment)
[0048] A fourth embodiment will be described with reference to FIG.
5. The fundamental constitution of the fourth embodiment is the
same as the third embodiment illustrated in FIG. 4. Meanwhile, the
fourth embodiment includes a nozzle 7C having a different
peripheral shape from the nozzle in the third embodiment.
[0049] The peripheral shape of the nozzle 7C is formed to have an
elliptic shape similarly to the nozzle 7A in the second embodiment.
The nozzle 7C in the fourth embodiment having the elliptic
peripheral shape is provided inside with a plurality of
flow-straightening plates 15 in a longitudinal direction (the X
direction) of a cross-section of the nozzle 7C. The
flow-straightening plates 15 are arranged that the
flow-straightening plates 15 straighten flow of the cutting fluid L
discharged from the opening 7a of the nozzle 7C in the width
direction of the grinder 1 that is the longitudinal direction of
the opening 7a.
[0050] In such a configuration, the cutting fluid L discharged from
the opening 7a of the nozzle 7C toward the grinder 1 is
straightened by the flow-straightening plates 15, so that a
disturbed flow when the cutting fluid L is discharged from the
opening 7a of the nozzle 7C is prevented. Therefore, the fluid
pressure of the cutting fluid L acting on the both sides of the
grinder 1 in the width direction can be prevented from being
different from each other due to the disturbed flow caused when the
cutting fluid L is discharged from the opening 7a of the nozzle 7C.
Accordingly, the occurrence of the fluid pressure difference of the
cutting fluid L on the both sides of the grinder 1 in the width
direction caused by the disturbed flow of the cutting fluid L
discharged from the nozzle 7C can be prevented. Moreover, the
grinder 1 can be prevented from being distorted and rotating while
being distorted due to such a fluid pressure difference of the
cutting fluid L. As a result, high machining accuracy in the
machining apparatus can be achieved.
(Fifth Embodiment)
[0051] A fifth embodiment will be described with reference to FIG.
6. The fundamental constitution of the fifth embodiment is the same
as the third embodiment illustrated in FIG. 4. Meanwhile, the fifth
embodiment includes a nozzle 7D, which is different from the third
embodiment, and is provided with disturbed flow restrainers 16
formed in a streamlined shape in a flowing direction of the cutting
fluid L at end portions of the flow-straightening plates 15 in the
opening 7a of the nozzle 7D.
[0052] In such a configuration, by providing the disturbed flow
restrainers 16 at the end portions of the flow-straightening plates
15, the occurrence of the disturbed flow when the cutting fluid L
is discharged from the opening 7a of the nozzle 7D can be further
prevented. Accordingly, the fluid pressure difference of the
cutting fluid L on the both sides of the grinder 1 in the width
direction caused by the disturbed flow can be prevented. Moreover,
the grinder 1 can be prevented from being distorted and rotating
while being distorted due to such a fluid pressure difference of
the cutting fluid L. As a result, high machining accuracy in the
machining apparatus can be achieved.
(Sixth Embodiment)
[0053] A sixth embodiment will be described with reference to FIG.
7. The fundamental constitution of the sixth embodiment is the same
as the fifth embodiment illustrated in FIG. 6. Meanwhile, the sixth
embodiment includes a nozzle 7E having a different peripheral shape
from the nozzle in the fifth embodiment.
[0054] The peripheral shape of the nozzle 7E is formed to have an
elliptic shape similarly to the nozzle 7A in the second embodiment.
The nozzle 7E in the sixth embodiment having the elliptic
peripheral shape is provided inside with the flow-straightening
plates 15 in a longitudinal direction (the X direction) of a
cross-section of the nozzle 7E. The nozzle 7D is provided with the
disturbed flow restrainers 16 formed in a streamlined shape in a
flowing direction of the cutting fluid L at the end portions of the
flow-straightening plates 15 in the opening 7a of the nozzle
7E.
[0055] In such a configuration, by providing the disturbed flow
restrainers 16 at the end portions of the flow-straightening plates
15, the occurrence of the disturbed flow when the cutting fluid L
is discharged from the opening 7a of the nozzle 7E can be further
prevented. Accordingly, the fluid pressure difference of the
cutting fluid
[0056] L on the both sides of the grinder 1 in the width direction
caused by the disturbed flow can be prevented. Moreover, the
grinder 1 can be prevented from being distorted and rotating while
being distorted due to such a fluid pressure difference of the
cutting fluid L. As a result, high machining accuracy in the
machining apparatus can be achieved.
[0057] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the inventions. Indeed, the novel
methods and systems described herein may be embodied in a variety
of other forms; furthermore, various omissions, substitutions and
changes in the form of the methods and systems described herein may
be made without departing from the spirit of the inventions. The
accompanying claims and their equivalents are intended to cover
such forms or modifications as would fall within the scope and
spirit of the inventions.
* * * * *