U.S. patent application number 15/185541 was filed with the patent office on 2017-12-21 for tail stock for a long vertically suspended workpiece that will experience heat expansion.
This patent application is currently assigned to Baker Hughes Incorporated. The applicant listed for this patent is David K. Luce, Crystal A. Parrott, Stephen L. Wiedmann. Invention is credited to David K. Luce, Crystal A. Parrott, Stephen L. Wiedmann.
Application Number | 20170361380 15/185541 |
Document ID | / |
Family ID | 60661009 |
Filed Date | 2017-12-21 |
United States Patent
Application |
20170361380 |
Kind Code |
A1 |
Luce; David K. ; et
al. |
December 21, 2017 |
TAIL STOCK FOR A LONG VERTICALLY SUSPENDED WORKPIECE THAT WILL
EXPERIENCE HEAT EXPANSION
Abstract
A tailstock for supporting a workpiece along a vertical rotary
axis includes a base member, and a housing having a wall including
a first end, and a second end, an outer surface, and an inner
surface defining a central passage extending between the first and
second ends defining a longitudinal axis. The second end is coupled
to the base member. A workpiece support extends through the central
passage. The workpiece support includes a first end, a second end
and an intermediate portion extending therebetween. A linear
bearing is coupled to the base member in the central passage. The
linear bearing slideably receives the second end of the workpiece
support. A displacement sensor assembly includes a stationary
portion mounted relative to one of the base member and the housing,
and a moveable portion mounted to the second end of the workpiece
support.
Inventors: |
Luce; David K.; (Splendora,
TX) ; Parrott; Crystal A.; (Helotes, TX) ;
Wiedmann; Stephen L.; (Boerne, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Luce; David K.
Parrott; Crystal A.
Wiedmann; Stephen L. |
Splendora
Helotes
Boerne |
TX
TX
TX |
US
US
US |
|
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
60661009 |
Appl. No.: |
15/185541 |
Filed: |
June 17, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23B 2260/128 20130101;
C23C 4/00 20130101; B22F 3/10 20130101; B23B 23/00 20130101; B23B
23/045 20130101 |
International
Class: |
B23B 23/00 20060101
B23B023/00; B23B 23/04 20060101 B23B023/04 |
Claims
1. A tailstock for supporting a workpiece along a vertical rotary
axis comprising: a base member; a housing having a wall including a
first end, and a second end, an outer surface, and an inner surface
defining a central passage extending between the first and second
ends defining a longitudinal axis, the second end being coupled to
the base member; a workpiece support extending through the central
passage, the workpiece support including a first end, a second end
and an intermediate portion extending therebetween; a linear
bearing coupled to the base member in the central passage, the
linear bearing slideably receiving the second end of the workpiece
support; and a displacement sensor assembly including a stationary
portion mounted relative to one of the base member and the housing,
and a moveable portion mounted to the second end of the workpiece
support.
2. The tailstock according to claim 1, further comprising: a
rotating member mount coupled to the first end of the workpiece
support.
3. The tailstock assembly according to claim 2, further comprising:
a biasing member arranged between the rotating assembly support and
the linear bearing, the biasing member establishing a preload on
the rotating assembly member.
4. The tailstock assembly according to claim 3, wherein the biasing
member comprises a coil spring.
5. The tailstock assembly according to claim 2, further comprising:
a shield member slidable mounted at the first end of the housing
about the rotating assembly mount, the shield member including a
first end portion, a second end portion, and an intermediate
portion extending therebetween.
6. The tailstock assembly according to claim 5, further comprising:
a cap member provided at the first end portion of the shield
member, the cap member supporting a bearing.
7. The tailstock assembly according to claim 6, wherein the bearing
comprises a Graphalloy.RTM. linear bearing.
8. The tailstock assembly according to claim 6, wherein the bearing
comprises a tapered roller bearing.
9. The tailstock assembly according to claim 8, wherein the tapered
roller bearing includes a first bearing element arranged at a first
surface of the cap member and a second bearing element arranged at
a second, opposing surface of the cap member.
10. The tailstock assembly according to claim 6, further
comprising: a rotating member rotatable operatively coupled to the
rotating member mount through the cap member.
11. The tailstock assembly according to claim 10, further
comprising: a support sleeve arranged between the rotating member
and the cap member.
12. The tailstock assembly according to claim 10, wherein the
rotating member comprises a stainless steel cone.
13. The tailstock assembly according to claim 1, wherein the linear
bearing includes a plurality of internal splines that cooperate
with external splines provided on the workpiece support, wherein
the linear bearing constrains relative rotation of the workpiece
support.
14. A method of supporting a rotating member of a tailstock
comprising: rotating a rotating member coupled to a workpiece
support slidably mounted in a housing of the tailstock; vertically
displacing the rotating member along a longitudinal axis in a first
direction; and measuring an amount of vertical displacement of the
rotating member.
15. The method of claim 13, wherein measuring the amount of
vertical displacement includes directing a laser displacement
sensor mounted to the housing at a target mounted to the workpiece
support.
16. The method of claim 13, further comprising: biasing the
rotating member along the vertical axis toward a second direction
opposite the first direction.
17. A method of processing a workpiece comprising: supporting the
workpiece on a tailstock extending along a vertical axis; thermally
processing the workpiece with a processing device; and vertically
displacing a portion of the tailstock assembly resulting from
thermal expansion of the workpiece.
18. The method of claim 16, wherein supporting the workpiece
includes mounting the workpiece on a rotating member coupled to a
workpiece support.
19. The method of claim 17, wherein vertically displacing the
portion of the workpiece includes vertically shifting the workpiece
support.
20. The method of claim 16, further comprising: sensing an amount
of vertical displacement of the workpiece through a displacement
sensor.
21. The method of claim 19, further comprising: vertically
displacing the processing device based on the amount of vertical
displacement of the workpiece.
Description
BACKGROUND
[0001] A tailstock may be used to support a rotating workpiece for
processing. Generally, the tailstock supports the workpiece along a
longitudinal rotary axis. In some cases, the workpiece is supported
at a first end by a rotary tool such as a lathe head and a second,
opposing end by the tailstock. In other cases, the tailstock may be
employed to support the workpiece along a vertical rotary axis.
During thermal processes, the workpiece may expand. Thermal
expansion of the workpiece could contribute to process errors.
Therefore, industrial processors would be receptive to a tailstock
that accounts for thermal expansion of a workpiece.
SUMMARY
[0002] A tailstock for supporting a workpiece along a vertical
rotary axis includes a base member, and a housing having a wall
including a first end, and a second end, an outer surface, and an
inner surface defining a central passage extending between the
first and second ends defining a longitudinal axis. The second end
is coupled to the base member. A workpiece support extends through
the central passage. The workpiece support includes a first end, a
second end and an intermediate portion extending therebetween. A
linear bearing is coupled to the base member in the central
passage. The linear bearing slideably receives the second end of
the workpiece support. A displacement sensor assembly includes a
stationary portion mounted relative to one of the base member and
the housing, and a moveable portion mounted to the second end of
the workpiece support.
[0003] A method of supporting a rotating member of a tailstock
includes rotating a rotating member coupled to a workpiece support
slidably mounted in a housing of the tailstock, vertically
displacing the rotating member along a longitudinal axis in a first
direction, and measuring an amount of vertical displacement of the
rotating member.
[0004] A method of processing a workpiece includes supporting the
workpiece on a tailstock extending along a vertical axis, thermally
processing the workpiece with a processing device, and vertically
displacing a portion of the tailstock assembly resulting from
thermal expansion of the workpiece.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Referring now to the drawings wherein like elements are
numbered alike in the several Figures:
[0006] FIG. 1 depicts a partial cross-sectional side view of a
tailstock assembly according to an aspect of an exemplary
embodiment;
[0007] FIG. 2 depicts a partial cross-sectional side view of a
tailstock assembly according to another aspect of an exemplary
embodiment;
[0008] FIG. 3 depicts a partial cross-sectional side view of the
tail stock assembly, in accordance with exemplary embodiments,
supporting a workpiece undergoing a thermal process; and
[0009] FIG. 4 depicts a partial cross-sectional side view of the
tail stock assembly of FIG. 3 following a vertical displacement
caused by thermal expansion of the workpiece.
DETAILED DESCRIPTION
[0010] A tailstock assembly, in accordance with an aspect of an
exemplary embodiment, is indicated generally at 10 in FIG. 1.
Tailstock assembly 10 includes a support 12 that may be coupled to
a processing device 13 (FIG. 3) that could take the form of a
sintering processing device and/or a thermal spray processing
device (not shown). A base member 14 may be mounted to support 12.
Of course, it should be understood that base member 14 and support
12 could be integrated into a single component. A housing 20
extends from base member 14. Housing 20 includes a wall 24 having a
first end 28, a second end 29, an outer surface 32 and an inner
surface 33 that defines a central passage 36. A longitudinal axis
40 extends through central passage 36. In the exemplary embodiment
shown, longitudinal axis 40 constitutes a vertical axis.
[0011] In further accordance with an aspect of an exemplary
embodiment, tailstock assembly 10 includes a workpiece support 50
arranged within central passage 36. Workpiece support 50 includes a
first end 54, a second end 55 and an intermediate portion 56
extending therebetween. A linear bearing 60 is arranged at base
member 14 and receives workpiece support 50. Linear bearing 60
allows for translation of workpiece support 50 along longitudinal
axis 40 while constraining relative rotation. More specifically,
intermediate portion 56 of workpiece support 50 may include a
plurality of grooves or splines 62. Similarly, an inner surface
(not separately labeled) of linear bearing 60 may include
corresponding grooves or splines 64 that engage with splines 62.
Interaction between splines 62 and 64 prevents, or at least
substantially limits, rotation of workpiece support 50 about
longitudinal axis 40.
[0012] In still further accordance with an exemplary aspect,
tailstock assembly 10 includes a rotating member mount 68 arranged
at second end 55 of workpiece support 50. Rotating member mount 68
includes a first recess portion 70 and a second recess portion 71
that receives second end 55. A mechanical fastener 73 secures
rotating member mount 68 to workpiece support 50. A biasing member
78 extends between rotating member mount 68 and linear bearing 60.
In accordance with an aspect of an exemplary embodiment, biasing
member 78 takes the form of a coil spring 80 that extends about
workpiece support 50. Biasing member 78 applies a biasing force to
rotating member mount 68 along longitudinal axis 40 in a direction
opposite to that of base member 14.
[0013] In yet still further accordance with an exemplary aspect,
tailstock assembly 10 includes a shield member 88 that receives
first end 28 of housing 20. Shield member 88 includes a first end
portion 90, a second end portion 91 and an intermediate portion 92
extending therebetween. A cap member 98 may be coupled to first end
portion 90 of shield member 88. Cap member 98 may include a first
surface 100 and an opposing second surface 101. A hub 104 may
extend outwardly of first surface 100 along longitudinal axis 40. A
bearing 106 may be arranged within hub 104. In accordance with an
exemplary aspect, bearing 106 may take the form of Graphalloy.RTM.
sleeve or linear bearing 110. Of course, other materials may also
be employed to form linear bearing 110.
[0014] In still yet further accordance with an exemplary aspect, a
rotating member 120 is operatively coupled to rotating member mount
68. Rotating member 120 may take the form of a stainless steel cone
122 having a workpiece support end 124 and a base 129. A shaft 131
may be coupled to base 129 and extend through hub 104. One or more
thrust washers 133 may be arranged between base 129 and hub 104.
Shaft 131 may be connected to base 129 through one or more
mechanical fasteners 137. Base 129 may be formed from a thermally
insulating material and includes a first surface 138 and an
opposing second surface 139. Base 129 may provide thermal
protection to shaft 131, shield member 88, workpiece support 50,
and biasing member 78 during high temperature processes such as
thermal spray processes.
[0015] Rotating member 120 may rotatably support a workpiece 140
(FIG. 3)) undergoing a thermal process. The workpiece may be
subjected to elevated temperatures such as those during a sintering
process, a thermal spray process, or other high temperature
processes. As such, during processing, the workpiece may thermally
expand. Tailstock assembly 10 accommodates thermal expansion of the
workpiece. More specifically, as will be detailed more fully below,
thermal expansion of the workpiece leads to a liner translation of
workpiece support 50 and shield member 88. Thermal expansion of the
workpiece may necessitate adjustments to the process.
[0016] Accordingly, tailstock assembly 10 includes a displacement
sensor 141 that determines how much workpiece support 50 translates
along longitudinal axis 40. In accordance with an aspect of an
exemplary embodiment, displacement sensor 141 may include a
stationary portion 142 and a moveable portion 143. Stationary
portion 142 may take the form of a laser 145 and moveable portion
143 may take the form of a target 146. Displacement sensor 141 may
be coupled to a controller (also not shown) that provides
displacement data or feedback to process control computers. It is
to be understood that displacement sensor 141 may also take the
form of a magnetic field sensor, a linear scale, a geared servo and
the like.
[0017] Reference will now follow to FIG. 2, wherein like reference
numbers represent corresponding parts and features in the
respective views in describing a cap member 150 in accordance with
another aspect of an exemplary embodiment. Cap member 150 includes
a first surface 154 and an opposing second surface 155. A first hub
157 extends outwardly of first surface 154 and a second hub 158
extends outwardly of second surface 155. A rotating mount member
160 is coupled to second end 55 of workpiece support 50 and extends
through cap member 150. Rotating mount member 160 passes through a
bearing 164 arranged in cap member 150. Bearing 164 may take the
form of a tapered roller bearing 166 having a first bearing element
168 arranged in first hub 157 and a second bearing element 169
arranged in second hub 158.
[0018] In further accordance with the exemplary aspect shown,
tailstock assembly 10 may include a support sleeve 174 that extends
between cap member 150 and a rotating member 178. Rotating member
178 includes a workpiece support end 180 and a base 182. Rotating
member 178 may rotatably support a workpiece (not shown) in a
manner similar to that described above.
[0019] In accordance with an aspect of an exemplary embodiment,
rotating member 120 of tailstock 10 supports workpiece 140 at
processing device 13. It is to be understood that tailstock
assembly 10 could support a variety of workpieces for various
processes including both thermal and non-thermal related processes.
A device (not shown) rotates workpiece 140. Rotation of workpiece
140 may be imparted to rotating member 120. It is to be understood
that workpiece support 50 is isolated from the rotation of
workpiece 140 and rotating member 120. It is also to be understood
that workpiece 140 could be mounted to rotating member 150. At a
start of processing, workpiece support 50 and shield member 88 are
in a first position shown in FIG. 3.
[0020] During processing, workpiece 140 may expand due to exposure
to heat generated by processing device 13. As a result of the
expansion of workpiece 14, workpiece support 50 may translate along
vertical axis 40 as shown in FIG. 4. Translation of workpiece
support 50 may include a corresponding translation of shield member
88. Displacement sensor 141 determines an amount of translation by
measuring movement of, for example, target 146. The amount of
translation sensed by displacement sensor 141 may be provided to a
control system (not shown) or an operator (also not shown) that
shifts processing device 13 a corresponding distance to continue
processing workpiece 140.
[0021] In accordance with another aspect, workpiece 140 may be
supported on workpiece support 120 with a pre-load on biasing
member 78. Temperature sensors may be employed to determine a
temperature of workpiece 140 and adjustments may be made to
compressive forces applied to biasing member 78 to account for
dimensional changes.
[0022] Workpiece 140 may vary in diameter from about 2-inches
(5.08-cm) to about 12-inches (30.48-cm) and may have a length from
about 3-feet (0.914-meters) to about 30-feet (9.14-mteres). During
processing workpiece 140 is rotated at a desired RPM. The desired
RPM may be limited by a stability of workpiece 140 as well as
process requirements. In order to reduce or prevent part or
component bending causing both off center and unstable rotation a
system which allows consistent and controlled pressure on workpiece
140 is desired. A heat intensive process may lead to an effective
length and diameter change of workpiece 140. If a fixed or a spring
loaded mechanism were used the process would not be capable of
maintaining a consistent controlled pressure within the range of
pressures that would not cause workpiece 140 to bend creating
unstable off center rotation. Additionally, a fixed or a spring
loaded mechanism may not be capable of maintaining a desired
pressure to retain or support workpiece 140. This appropriate range
of forces acting to compress workpiece 140 may also be dependent
upon composition, length and temperature.
[0023] Tailstock 10, in accordance with an exemplary embodiment,
may be employed in a processing system where a specific rotational
velocity were desired outside of range capable of being supported
by spring loaded or fixed systems. As workpiece 140 is heated or
heat is an inherent result of processing, tailstock 10 adjusts a
location of spring datum to align to an ideal pressure allowing
rotation at higher speeds as well as conform to processing
parameters and requirements.
[0024] Embodiment 1. A tailstock for supporting a workpiece along a
vertical rotary axis comprising: a base member; a housing having a
wall including a first end, and a second end, an outer surface, and
an inner surface defining a central passage extending between the
first and second ends defining a longitudinal axis, the second end
being coupled to the base member; a workpiece support extending
through the central passage, the workpiece support including a
first end, a second end and an intermediate portion extending
therebetween; a linear bearing coupled to the base member in the
central passage, the linear bearing slideably receiving the second
end of the workpiece support; and a displacement sensor assembly
including a stationary portion mounted relative to one of the base
member and the housing, and a moveable portion mounted to the
second end of the workpiece support.
[0025] Embodiment 2. The tailstock according to any prior
embodiment, further comprising: a rotating member mount coupled to
the first end of the workpiece support.
[0026] Embodiment 3. The tailstock assembly according to any prior
embodiment, further comprising: a biasing member arranged between
the rotating assembly support and the linear bearing, the biasing
member establishing a preload on the rotating assembly member.
[0027] Embodiment 4. The tailstock assembly according to any prior
embodiment, wherein the biasing member comprises a coil spring.
[0028] Embodiment 5. The tailstock assembly according to any prior
embodiment, further comprising: a shield member slidable mounted at
the first end of the housing about the rotating assembly mount, the
shield member including a first end portion, a second end portion,
and an intermediate portion extending therebetween.
[0029] Embodiment 6. The tailstock assembly according to any prior
embodiment, further comprising: a cap member provided at the first
end portion of the shield member, the cap member supporting a
bearing.
[0030] Embodiment 7. The tailstock assembly according to any prior
embodiment, wherein the bearing comprises a Graphalloy.RTM. linear
bearing.
[0031] Embodiment 8. The tailstock assembly according to any prior
embodiment, wherein the bearing comprises a tapered roller
bearing.
[0032] Embodiment 9. The tailstock assembly according to any prior
embodiment, wherein the tapered roller bearing includes a first
bearing element arranged at a first surface of the cap member and a
second bearing element arranged at a second, opposing surface of
the cap member.
[0033] Embodiment 10. The tailstock assembly according to any prior
embodiment, further comprising: a rotating member rotatable
operatively coupled to the rotating member mount through the cap
member.
[0034] Embodiment 11. The tailstock assembly according to any prior
embodiment, further comprising: a support sleeve arranged between
the rotating member and the cap member.
[0035] Embodiment 12. The tailstock assembly according to any prior
embodiment, wherein the rotating member comprises a stainless steel
cone.
[0036] Embodiment 13. The tailstock assembly according to any prior
embodiment, wherein the linear bearing includes a plurality of
internal splines that cooperate with external splines provided on
the workpiece support, wherein the linear bearing constrains
relative rotation of the workpiece support.
[0037] Embodiment 14. A method of supporting a rotating member of a
tailstock comprising: rotating a rotating member coupled to a
workpiece support slidably mounted in a housing of the tailstock;
vertically displacing the rotating member along a longitudinal axis
in a first direction; and measuring an amount of vertical
displacement of the rotating member.
[0038] Embodiment 15. The method of any prior embodiment, wherein
measuring the amount of vertical displacement includes directing a
laser displacement sensor mounted to the housing at a target
mounted to the workpiece support.
[0039] Embodiment 16. The method of any prior embodiment, further
comprising: biasing the rotating member along the vertical axis
toward a second direction opposite the first direction.
[0040] Embodiment 17. A method of processing a workpiece
comprising: supporting the workpiece on a tailstock extending along
a vertical axis; thermally processing the workpiece with a
processing device; and vertically displacing a portion of the
tailstock assembly resulting from thermal expansion of the
workpiece.
[0041] Embodiment 18. The method of any prior embodiment, wherein
supporting the workpiece includes mounting the workpiece on a
rotating member coupled to a workpiece support.
[0042] Embodiment 19. The method of any prior embodiment, wherein
vertically displacing the portion of the workpiece includes
vertically shifting the workpiece support.
[0043] Embodiment 20. The method of any prior embodiment, further
comprising: sensing an amount of vertical displacement of the
workpiece through a displacement sensor.
[0044] Embodiment 21. The method of any prior embodiment, further
comprising: vertically displacing the processing device based on
the amount of vertical displacement of the workpiece.
[0045] The term "about" is intended to include the degree of error
associated with measurement of the particular quantity based upon
the equipment available at the time of filing the application. For
example, "about" can include a range of .+-.8% or 5%, or 2% of a
given value.
[0046] While one or more embodiments have been shown and described,
modifications and substitutions may be made thereto without
departing from the spirit and scope of the invention. Accordingly,
it is to be understood that the present invention has been
described by way of illustrations and not limitation.
* * * * *