U.S. patent application number 14/743798 was filed with the patent office on 2015-10-08 for vibration damping device for a valve.
The applicant listed for this patent is Pentair Flow Services AG. Invention is credited to Michael McNeely.
Application Number | 20150285400 14/743798 |
Document ID | / |
Family ID | 51486335 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150285400 |
Kind Code |
A1 |
McNeely; Michael |
October 8, 2015 |
Vibration Damping Device for a Valve
Abstract
Embodiments provide a valve including a housing defining an
inlet, an outlet, and a valve seat between the inlet and the
outlet. The valve further includes a valve member arranged at least
partially within the housing and moveable between an open position
where flow is provided from the inlet through the valve seat to the
outlet and a closed position where flow is inhibited through the
valve seat The valve further includes an inerter element arranged
to convert linear motion of the valve member into rotary movement
beginning at the closed position, thereby damping the valve.
Inventors: |
McNeely; Michael; (Stafford,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Pentair Flow Services AG |
Schaffhausen |
|
CH |
|
|
Family ID: |
51486335 |
Appl. No.: |
14/743798 |
Filed: |
June 18, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14198401 |
Mar 5, 2014 |
9103467 |
|
|
14743798 |
|
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Current U.S.
Class: |
251/252 |
Current CPC
Class: |
Y10T 137/7904 20150401;
F16K 31/52433 20130101; Y10T 137/7793 20150401; Y10T 74/1876
20150115; F16K 17/0433 20130101; F16K 47/04 20130101; F16K 1/32
20130101; F16K 47/00 20130101; F16K 1/126 20130101; F16F 15/14
20130101 |
International
Class: |
F16K 47/00 20060101
F16K047/00; F16K 31/524 20060101 F16K031/524; F16K 1/32 20060101
F16K001/32 |
Claims
1. A valve comprising: a housing defining an inlet, an outlet, and
a valve seat between the inlet and the outlet; a valve member
arranged at least partially within the housing and movable between
an open position where flow is provided from the inlet through the
valve seat to the outlet, and a closed position where flow is
inhibited through the valve seat; and an inerter element arranged
to convert linear motion of the valve member into rotary movement
beginning at the closed position, thereby damping the valve.
2. The valve of claim 1, further comprising a biasing element
biasing the valve member toward the closed position.
3. The valve of claim 1, wherein the valve member moves linearly
between the open position and the closed position, the linear
motion of the valve member converted by the inerter element into
rotary movement of the valve member, the mass and rotational
movement of the valve member providing inertial damping.
4. The valve of claim 1, wherein the inerter element is fixed to
the housing.
5. The valve of claim 1, wherein the valve member moves linearly
between the open position and the closed position, wherein the
inerter element rotates in response to the linear movement of the
valve member, the mass and rotational movement of the inerter
element providing inertial damping.
6. The valve of claim 1, wherein the inerter element defines a cam
profile, the valve member engaging the cam profile.
7. The valve of claim 6, wherein the cam profile is helical.
8. The valve of claim 1, wherein the valve member is biased toward
the open position by a pressure.
9. The valve of claim 1, wherein the valve member actuates in
response to a non-mechanical force.
10. A valve comprising: a housing defining an inlet, an outlet, and
a valve seat between the inlet and the outlet; a valve member
arranged at least partially within the housing and movable between
an open position where flow is provided from the inlet through the
valve seat to the outlet, and a closed position where flow is
inhibited through the valve seat, the valve member coupled to the
housing for linear and rotary movement relative to the housing
about an axis; and an inerter element substantially fixed to the
housing and defining a cam profile, a portion of the valve member
engaging the cam profile such that in response to a non-mechanical
force the valve member moves between the open position and the
closed position and linear motion of the valve member is converted
to rotary motion of the valve member, thereby damping the valve
when the valve member first leaves the closed position.
11. The valve of claim 10, wherein the cam profile is helical.
12. The valve of claim 10, wherein the valve member includes a pin
that engages the cam profile.
13. The valve of claim 10, wherein the valve member is biased
toward the closed position.
14. The valve of claim 10, wherein the valve member is coupled to
the inerter element such that the inerter element supports the
valve member for linear motion along the axis and rotation about
the axis.
15. A method for damping a valve, the valve including a housing
defining an inlet, an outlet, and a valve seat between the inlet
and the outlet, a valve member arranged at least partially within
the housing and moveable between an open position where flow is
provided from the inlet through the valve seat to the outlet and a
closed position where flow is inhibited through the valve seat, and
an inerter element, the method comprising: engaging a cam profile
defined in the inerter element with the valve member; and damping
the valve by continuously rotating the valve member along the cam
profile as the valve member moves from the closed position to the
open position in response to a non-mechanical force and as the
valve member moves from the open position to the closed position in
response to a non-mechanical force.
16. The method of claim 15, further comprising engaging a pin with
the cam profile.
17. The method of claim 15, wherein continuously rotating the valve
member includes helically rotating the valve member along a helical
cam profile.
18. The method of claim 15, further comprising linearly moving the
valve member between the open position and the closed position.
19. The method of claim 18, further comprising converting the
linear motion of the valve member into rotary motion of the valve
member with the inerter element.
20. The method of claim 19, further comprising inertially damping
the valve member with the mass and rotational motion of the valve
member.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/198,401 filed on Mar. 5, 2014 which claims
the benefit of U.S. Provisional Patent Application No. 61/773,458
filed on Mar. 6, 2013, the entire disclosures of which are hereby
incorporated herein by reference.
BACKGROUND
[0002] The invention relates generally to devices for controlling
linear vibration by converting linear motion to rotary motion. In
more particular embodiments, the invention relates to devices for
controlling vibrations in valves (e.g., pressure relief
valves).
BRIEF SUMMARY OF THE INVENTION
[0003] In one aspect, embodiments provide a valve that includes a
housing defining an inlet, an outlet, and a valve seat between the
inlet and the outlet, a valve member arranged at least partially
within the housing and movable between an open position where flow
is provided from the inlet through the valve seat to the outlet,
and a closed position where flow is inhibited through the valve
seat, and an inerter element arranged to convert linear motion of
the valve member into rotary movement beginning at the closed
position, thereby damping the valve.
[0004] In some embodiments, the valve further includes a biasing
element that biases the valve member toward the closed position, or
the valve member moves linearly between the open position and the
closed position, the linear motion of the valve member converted by
the inerter element into rotary movement of the valve member, the
mass and rotational movement of the valve member providing inertial
damping, or the inerter element is fixed to the housing, or the
valve member moves linearly between the open position and the
closed position, or the inerter element rotates in response to the
linear movement of the valve member, the mass and rotational
movement of the inerter element providing inertial damping, or the
inerter element defines a cam profile, the valve member engaging
the cam profile, or the cam profile is helical, or the valve member
is biased toward the open position by a pressure, or the valve
member actuates in response to a non-mechanical force.
[0005] In another aspect, embodiments provide a valve that includes
a housing defining an inlet, an outlet, and a valve seat between
the inlet and the outlet, a valve member arranged at least
partially within the housing and movable between an open position
where flow is provided from the inlet through the valve seat to the
outlet, and a closed position where flow is inhibited through the
valve seat, the valve member coupled to the housing for linear and
rotary movement relative to the housing about an axis, and an
inerter element substantially fixed to the housing and defining a
cam profile, a portion of the valve member engaging the cam profile
such that in response to a non-mechanical force the valve member
moves between the open position and the closed position and linear
motion of the valve member is converted to rotary motion of the
valve member, thereby damping the valve when the valve member
leaves the closed position.
[0006] In some embodiments, the cam profile is helical, or the
valve member includes a pin that engages the cam profile, or the
valve member is biased toward the closed position, or the valve
member is coupled to the inerter element such that the inerter
element supports the valve member for linear motion along the axis
and rotation about the axis.
[0007] In yet another aspect, embodiment provide a method for
damping a valve, the valve including a housing defining an inlet,
an outlet, and a valve seat between the inlet and the outlet, a
valve member arranged at least partially within the housing and
moveable between an open position where flow is provided from the
inlet through the valve seat to the outlet and a closed position
where flow is inhibited through the valve seat, and an inerter
element. The method includes engaging a cam profile defined in the
inerter element with the valve member and damping the valve by
continuously rotating the valve member along the cam profile as the
valve member moves from the closed position to the open position in
response to a non-mechanical force and as the valve member moves
from the open position to the closed position in response to a
non-mechanical force.
[0008] In some embodiments, the method further includes engaging a
pin with the cam profile, or continuously rotating the valve member
includes helically rotating the valve member along a helical cam
profile, or the method further includes linearly moving the valve
member between the open position and the closed position,
converting the linear motion of the valve member into rotary motion
of the valve member with the inerter element, and inertially
damping the valve member with the mass and rotary motion of the
valve member
[0009] The foregoing and other aspects and advantages of the
invention will appear from the following description. In the
description, reference is made to the accompanying drawings which
form a part hereof, and in which there is shown by way of
illustration a preferred embodiment of the invention. Such
embodiment does not necessarily represent the full scope of the
invention, however, and reference is made therefore to the claims
and herein for interpreting the scope of the invention.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The invention will be better understood and features,
aspects and advantages other than those set forth above will become
apparent when consideration is given to the following detailed
description thereof. Such detailed description makes reference to
the following drawings.
[0011] FIG. 1 is a top view of a pressure relief valve.
[0012] FIG. 2 is a section view of the pressure relief valve of
FIG. 1 taken along the line 2-2 of FIG. 1.
[0013] FIG. 3 is a section view of the pressure relief valve of
FIG. 1 taken along the line 3-3 of FIG. 1.
[0014] FIG. 4 is a top left perspective view of an inerter system
of the pressure relief valve of FIG. 1.
[0015] FIG. 5 is a top view of the inerter system of FIG. 4.
[0016] FIG. 6 is a top right perspective view of the inerter system
of FIG. 4.
[0017] FIG. 7 is a left side view of the inerter system of FIG. 4
taken from the perspective of line 7-7 of FIG. 5.
[0018] FIG. 8 is a section view of the inerter system taken along
line 8-8 of FIG. 5.
[0019] FIG. 9 is a section view of the inerter system taken along
line 9-9 of FIG. 5.
[0020] FIG. 10 is a right side view of the inerter system of FIG. 4
taken from the perspective of line 10-10 of FIG. 5.
[0021] FIG. 11 is a top left perspective view of another inerter
system.
[0022] FIG. 12 is a top view of the inerter system of FIG. 11.
[0023] FIG. 13 is a top right perspective view of the inerter
system of FIG. 11.
[0024] FIG. 14 is a sectional view of the inerter system of FIG. 11
taken along line 14-14 of FIG. 12.
[0025] FIG. 15 is a front view of the inerter system of FIG.
11.
[0026] FIG. 16 is a section view of the inverter system of FIG. 11
taken along line 16-16 of FIG. 12.
[0027] FIG. 17 is a top view of another pressure relief valve.
[0028] FIG. 18 is a section view of the pressure relief valve of
FIG. 18 taken along line 18-18 of FIG. 17.
[0029] FIG. 19 is a section view of the pressure relief valve of
FIG. 18 taken along line 19-19 of FIG. 17.
[0030] FIG. 20 is a section view of the pressure relief valve of
FIG. 18 taken along line 20-20 of FIG. 17.
[0031] FIG. 21 is a bottom right perspective view of another
inerter system.
[0032] FIG. 22 is a top view of the inerter system of FIG. 21.
[0033] FIG. 23 is a bottom left perspective view of the inerter
system of FIG. 21.
[0034] FIG. 24 is a sectional view of the inerter system of FIG. 21
taken along line 24-24 of FIG. 22.
[0035] FIG. 25 is a front view of the inerter system of FIG.
21.
[0036] FIG. 26 is a right side view of the inerter system of FIG.
21 taken from the perspective of line 26-26 of FIG. 22.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways. Also, it is to be understood that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting. The use of "including,"
"comprising," or "having" and variations thereof herein is meant to
encompass the items listed thereafter and equivalents thereof as
well as additional items. Unless specified or limited otherwise,
the terms "mounted," "connected," "supported," and "coupled" and
variations thereof are used broadly and encompass both direct and
indirect mountings, connections, supports, and couplings. Further,
"connected" and "coupled" are not restricted to physical or
mechanical connections or couplings.
[0038] The following discussion is presented to enable a person
skilled in the art to make and use embodiments of the invention.
Various modifications to the illustrated embodiments will be
readily apparent to those skilled in the art, and the generic
principles herein can be applied to other embodiments and
applications without departing from embodiments of the invention.
Thus, embodiments of the invention are not intended to be limited
to embodiments shown, but are to be accorded the widest scope
consistent with the principles and features disclosed herein.
[0039] The following detailed description is to be read with
reference to the figures, in which like elements in different
figures have like reference numerals. The figures, which are not
necessarily to scale, depict selected embodiments and are not
intended to limit the scope of embodiments of the invention.
Skilled artisans will recognize the examples provided herein have
many useful alternatives and fall within the scope of embodiments
of the invention.
[0040] The following description includes four sections. Section I
describes a pressure relief valve that includes a first
construction of the invention with respect to FIGS. 1-10. Section
II describes a pressure relief valve including a second
construction of the invention with respect to FIGS. 11-16. Section
III describes a pressure relief valve including a third
construction of the invention with respect to FIGS. 17-26. Section
IV includes a discussion of the invention in a broader sense as it
relates to other valves types and other modes in which the
invention can be used to attenuate and dampen vibrations.
[0041] Section I
[0042] FIGS. 1-3 show a pressure relief valve (hereinafter "PRV")
10 according to one embodiment of the invention. The PRV 10 serves
to relieve pressure formed in a piping system, pressure vessel or
associated component (hereinafter "pressure vessel system"). As
shown in FIG. 2, the PRV 10 includes a housing 14, a bonnet 18, and
an inerter system 22. The housing 14 defines an inlet flange 26 for
coupling to the pressure vessel system, a flanged outlet port 30,
an interior surface or chamber 34 between the inlet flange 26 and
the outlet port 30, and bonnet flange 36 defining a shoulder 38
rimming an opening 40 adjacent an upper portion (as shown in FIG.
2) of the chamber 34. A nozzle 42 is received within the inlet
flange 26 and defines a shaped nozzle profile 46 between a nozzle
inlet 50 and a valve seat in the form of a nozzle outlet 54.
[0043] With continued reference to FIG. 2, the bonnet 18 includes a
bonnet housing 58 that defines a housing flange 62 arranged for
coupling to the bonnet flange 36 of the housing 14 and defining a
shoulder 66. The bonnet housing 58 also defines an adjustment screw
aperture 70 sized to threadingly receive an adjustment screw 74. A
spindle 78 is slidingly received within the adjustment screw 74 and
extends along a central axis 82. An upper spring washer 86 is
positioned adjacent the adjustable screw 74 and slidingly receives
the spindle 78. A lower spring washer 90 is positioned distally
from the upper spring washer 86 with a spring 94 arranged
therebetween. A spindle bracket 98 is pinned to a lower end (as
shown in FIG. 2) of the spindle 78. The lower spring bracket 90
abuts the spindle bracket 98. The spring 94 acts between the upper
spring washer 86 and the lower spring washer 90 to bias the spindle
bracket 98 downward (as shown in FIG. 2). The adjustable screw 74
can be threaded into and out of the bonnet housing 58 to increase
and decrease the biasing force applied by the spring 94.
[0044] As shown in FIGS. 4-10, the inerter system 22 includes an
inerter hub 102 and a valve member in the form of a disk holder
106. As shown in FIG. 8, the inerter hub 102 defines a hub flange
110 and a hub body 114. A vent 118 is defined in the hub flange 110
and a central hub bore 122 extends through the inerter hub 102
along the central axis 82. A bearing in the form of a bushing 126
is received within the central hub bore 122. The hub body 114
defines a first slot 130 and a second slot 134. The first slot 130
and second slot 134 together define a cam profile. In the
illustrated embodiment, the slots 130, 134 provide a generally
helical cam profile.
[0045] With continued reference to FIG. 8, the disk holder 106
includes a central shaft 138 that holds at a first end a bearing in
the form of a spherical crystal bearing 142 and defines a pin
aperture 146. A substantially cylindrical pin 148 is fixedly
received within the pin aperture 146. The disk holder 106 also
includes a disk recess 150 arranged to receive a disk 154.
[0046] Assembly of the PRV 10 will be described with reference to
FIG. 2. The inerter system 22 is inserted into the bonnet flange 36
of the housing 14 such that the hub flange 110 is received on the
shoulder 38. The bonnet 18 is installed onto the housing 14 and the
inerter system 22 with the shoulder 66 of the housing flange 62
engaging the hub flange 110. The bonnet flange 36 is then fastened
to the housing flange 62 with the hub flange 110 fixed therebetween
such that the joint is substantially hermetically sealed and the
inerter hub 102 is rotationally fixed relative to the housing 14.
The vent 118 provides fluid communication between the chamber 34
and the bonnet 18 such that no substantial pressure differential
exists therebetween.
[0047] With the housing 14, bonnet 18, and inerter system 22
assembled, the spindle bracket 98 engages the spherical bearing 142
and the spring 94 biases the disk holder 106 downward (as shown in
FIG. 2) toward a closed position. The bias force is adjusted by
manipulation of the adjustable screw 74 according to the
predetermined specifications of the greater system in which the PRV
10 is installed (e.g., the pressure vessel system).
[0048] The disk holder 106 is arranged such that the pin 148 is
received in the first slot 130 and the second slot 134 and the
central shaft 138 is guided vertically by the bushing 126 for
linear movement along the central axis 82. The disk 154 is arranged
such that in the closed position (as shown in FIG. 2), the disk 154
engages the nozzle outlet 54 to inhibit fluid flow
therethrough.
[0049] With continued reference to FIG. 2, when sufficient pressure
builds in the nozzle inlet 50, the resultant force on the disk
holder 106 will overcome the bias force exerted by the spring 94
such that the disk holder 106 will move toward an open position
wherein the disk 154 does not engage the nozzle outlet 54 and fluid
is permitted to flow from the nozzle inlet 50 and out the outlet
port 30. The pin 148 rides along the cam profile of the first slot
130 and the second slot 134 during movement between the open
position and the closed position.
[0050] When the disk holder 106 moves from the closed position
toward the open position, the slots 130, 134 guide the pin 148
along the cam profile. The result is that the linear motion of the
disk holder 106 is, at least in part, converted to rotational
motion about the central axis 82. The configuration of the slots
130, 134 determines the ratio of conversion of linear motion to
rotational motion. In particular, the conversion ratio for
helically shaped slots having a long lead angle (i.e., more travel
distance per one revolution) and a small helix angle is relatively
small. Conversely, the conversion ratio for slots having a short
lead angle (i.e., less travel distance per one revolution) and a
large helix angle is greater. In one embodiment, the conversion
ratio is approximately 9-10 inches of linear motion per one
revolution of the disc holder 106. Other cam profiles are
contemplated and would be used, as determined by one skilled in the
art.
[0051] The inerter system 22 also converts translational kinetic
energy, which is defined by:
E.sub.translation=1/2 m V.sup.2; [0052] where m=mass and [0053]
V=linear velocity along the center axis 82 to rotational kinetic
energy, which is defined by: [0054] E.sub.rotational=1/2 J
.omega..sup.2; [0055] where J=polar moment of inertia and [0056]
.omega.=angular velocity about the center axis 82. Therefore, the
disc holder 106 serves as a flywheel to which energy from linear
motion in the form of vibration is transferred.
[0057] In the embodiment shown in FIGS. 1-10, the disc holder 106
rotates in response to linear motion caused by vibration, and thus,
is sensitive to acceleration and more effective in reducing or
controlling vibration than passive damping techniques. The mass of
the disk holder 106 itself acts as the flywheel in the inerter
system 22.
[0058] Section II
[0059] FIGS. 11-16 show an inerter system 200 that can be used with
the housing 14 and bonnet 18 shown in FIGS. 1-3 in place of the
inerter system 22. When the inerter system 200 is used with the
bonnet 18, the bonnet housing 58 also defines a cap shoulder
204.
[0060] As shown in FIG. 14, the inerter system 200 includes an
inerter hub 208, a disk holder 212, a bellows 216, a flywheel 220,
and a cap 224. The inerter hub 208 defines a hub flange 228 and a
hub body 232. As shown in FIGS. 14 and 16, a bearing raceway 236 is
defined in the hub flange 228. The bearing raceway 236 is a
substantially semi-circular and annular raceway. Alternate
arrangements are conceivable, such as a raceway arranged for pin
bearings, etc. A first motion constraining slot 240 and a second
motion constraining slot 244 are formed in the hub body 232. The
motion constraining slots 240, 244 are parallel and substantially
vertically oriented (as shown in FIG. 14). A central hub bore 248
is defined and extends through the inerter hub 208 along the
central axis 82. A bearing in the form of a bushing 252 is received
within the central hub bore 248.
[0061] With continued reference to FIG. 14, the disk holder 212
includes a central shaft 256 that holds at a first end a bearing in
the form of a spherical crystal bearing 260 and defines a motion
constraining pin aperture 264 and a flywheel pin aperture 268. A
substantially cylindrical motion constraining pin 272 is fixedly
received within the motion constraining pin aperture 264 and a
substantially cylindrical flywheel pin 276 is fixedly received
within the flywheel pin aperture 268. The disk holder 212 also
defines a bellows mating feature in the form of threads 280 and a
disk recess 284 sized to receive a disk 288.
[0062] The bellows 216 includes a mating feature in the form of
threads 292 arranged to sealingly mate with the threads 280 of the
disk holder 212. The bellows 216 further include a expandable body
portion 296 arranged to accommodate vertical motion (as shown in
FIG. 14) of the disk holder 212 and a gasket portion 300 arranged
to mate with a bottom surface of the hub flange 228.
[0063] The flywheel 220 defines an annular ring that includes a
bottom surface 304, an upper aperture 308, an upper bearing raceway
312, a first cam slot 316, and a second cam slot 320. The bottom
surface 304 defines a bearing raceway and can define a different
shape intended to function optimally with different bearing types
than are illustrated herein. The first cam slot 316 and second cam
slot 320 together define a cam profile. In the illustrated
embodiment, the slots 316, 320 provide a generally helical and
linear cam profile.
[0064] The cap 224 defines an upper surface 324, an inner aperture
328, and a bearing raceway 332. The illustrated bearing raceway 332
is a shoulder recess. In other arrangements, the bearing raceway
332 can be arranged differently. For example, the raceway 332 can
be arranged to receive pin bearings, or can include a contoured
surface (e.g., semi-circular depression, rectangular recess,
etc.).
[0065] With continued reference to FIG. 14, the inerter system 200
is assembled by installing the bellows 216 onto the disk holder 212
by threading the bellows threads 292 onto the disk holder threads
280 such that a seal is formed therebetween. The disk holder 212
and bellows 216 are then installed on the inerter hub 208 by
sliding the central shaft 256 into the bushing 252 and positioning
the disk holder 212 such that the motion constraining pin 272 is
received within the motion constraining slots 240, 244. The motion
of the disk holder 212 is then constrained by the slots 240, 244 to
substantially only vertical movement (as shown in FIG. 14) and
substantial rotation is inhibited.
[0066] A bearing element in the form of a plurality of ball
bearings 336 is arranged in the bearing raceway 236 of the inerter
hub 208, and the flywheel 220 installed onto the inerter system 200
by engaging the first cam slot 316 and the second cam slot 320 with
the flywheel pin 276, and engaging the bottom surface 304 with the
ball bearings 336. As shown in FIGS. 15 and 16, the bearing raceway
236 of the inerter hub 208 does not extend around the full annulus
of the central hub bore 248, but rather inhibits the ball bearings
336 from interfering with the flywheel pin 276 when the disk holder
212 is in the closed position (as shown in FIG. 15). In other
constructions, the bearing raceway 236 can extend fully about the
central hub bore 248 and the pin 276 can be arranged differently so
no interference exists.
[0067] Another bearing element (in the form of ball bearings 336)
is arranged between the upper bearing raceway 312 of the flywheel
220 and the bearing raceway 332 of the cap 224. The ball bearings
336 provide smooth rotation of the flywheel 220 under load. As
noted above, other bearing elements can be used. For example, the
ball bearings 336 can be retained within separate raceways, the
bearing elements can be pin or needle bearings, conical bearings,
or another shape of bearing, as desired. The bearing elements can
include bushings, or other arrangements designed to provide
adequate rotation of the flywheel 220.
[0068] The assembled inerter system 200 is then installed between
the housing 14 and the bonnet 18 (see FIGS. 2 and 14). The inerter
system 200 is inserted into the housing 14 such that the gasket
portion 300 of the bellows 216 engages and seals against the
shoulder 38 of the housing 14. The shoulder 66 of the bonnet 18
engages the inerter hub 208, and the cap shoulder 204 of the bonnet
18 engages the upper surface 324 of the cap 224. When the bonnet 18
is fastened to the housing 14, the hub flange 228 and the gasket
portion 300 are compressed between the shoulder 66 of the bonnet 18
and the shoulder 38 of the housing 14 such that rotation of both
components is inhibited. The cap 224 is compressed relative to the
inerter hub 208 to constrain the flywheel 220. The ball bearings
336 provide for rotational movement of the flywheel 220.
[0069] In operation, and referring to portions of FIGS. 2, 14, and
16, the disk holder 212 is movable between a closed position in
which the disk 288 seals against the nozzle outlet 54 to inhibit
fluid flow therethrough, and an open position in which the disk
disengages from the nozzle outlet 54 to permit fluid flow through
the nozzle 42 and out the outlet port 30. Movement of the disk
holder 212 is constrained by the central shaft 256 and the motion
constraining pin 272 such that the disk holder 212 moves only in
the vertical direction (as shown in FIG. 14) between the open
position and the closed position with substantially no rotational
movement.
[0070] The bellows 216 is arranged to compress and expand along
with the motion of the disk holder 212 between the open position
and the closed position. The bellows 216 provides a barrier between
the fluid and the other components of the inerter system 200 as can
be advantageous in corrosive fluid control or other
implementations.
[0071] As the disk holder 212 moves between the open position and
the closed position, the flywheel pin 276 engages and moves along
the first cam slot 316 and the second cam slot 320 such that the
flywheel 220 is forced into rotation by the cam profile defined by
the first cam slot 316 and the second cam slot 320. The rotation of
the flywheel 220 causes inertial damping of the disk holder 212
similarly to the inerter system 22 discussed above in Section
I.
[0072] Section III
[0073] FIGS. 17-26 show a PRV 400 according to one embodiment of
the invention that includes a housing 414, a bonnet 418, and an
inerter system 422. As shown in FIG. 18, the housing 414 defines an
inlet flange 426 for coupling to a pressure vessel system, a
flanged outlet port 430, an interior surface or chamber 434 between
the inlet flange 426 and the outlet port 430, and a bonnet flange
436 defining a housing shoulder 438 rimming an opening adjacent an
upper portion 440 (as shown in FIG. 18) of the chamber 434. A
nozzle 442 is received within the inlet flange 426 and defines a
shaped nozzle profile 446 between a nozzle inlet 450 and a nozzle
outlet 454.
[0074] The bonnet 418 includes a bonnet housing 458 that defines a
housing flange 462 arranged for coupling to the bonnet flange 436
of the housing 414 and defining a bonnet shoulder 466. The bonnet
housing 458 also defines an adjustment screw aperture 470 sized to
threadingly receive an adjustment screw 474. A spindle 478 is
slidingly received within the adjustment screw 474 and extends
along a central axis 482. An upper spring washer 486 is positioned
adjacent the adjustable screw 474 and slidingly receives the
spindle 478. A lower spring washer 490 is positioned distally from
the upper spring washer 486 with a spring 494 arranged
therebetween. A spindle bracket 498 is pinned to a lower end (as
shown in FIG. 18) of the spindle 478. The lower spring washer 490
abuts the spindle bracket 498. The spring 494 acts between the
upper spring washer 486 and the lower spring washer 490 to bias the
spindle bracket 498 downward (as shown in FIG. 18). The adjustable
screw 474 can be threaded into and out of the bonnet housing 458 to
increase and decrease the biasing force applied by the spring 494,
as desired.
[0075] As shown in FIG. 24, the inerter system 422 includes an
inerter hub 502, a cam element 506, a jerk absorber 510, a cam
follower element 514, and a disk holder 518. The inerter hub 502
defines a hub flange 522, a hub body 526 extending downward (as
shown in FIG. 24) from the hub flange 522, and a jerk aperture 530
defined through the hub flange 522. The hub body 526 defines hub
body threads 532 substantially adjacent the hub flange 522. A
central aperture 534 is defined through the inerter hub 502 along
the central axis 482. In the illustrated embodiment, the central
aperture 534 is manufactured such that an inner surface of the
central aperture 534 forms a bearing surface. The bearing surface
can be machined and polished, reamed, or formed in another way to
provide a suitable bearing surface. In other constructions, a
bearing or bushing can be inserted within the central aperture
534.
[0076] With continued reference to FIG. 24, the jerk aperture 530
is sized to press fittingly receive the jerk absorber 510.
Alternatively, the jerk aperture 530 can be threaded, or can be
filleted in preparation of a welding procedure. Other arrangements
are conceivable (e.g., soldering, fastening, gluing, etc.).
[0077] The cam element 506 defines a cam element flange 538, a
central aperture 542 that is sized to receive the hub body 526, a
first cam 546, and a second cam 550. The cam element flange 538
defines a jerk aperture 554. The central aperture 542 defines cam
element threads 558 sized to loosely engage the hub body threads
532. The first cam 546 and the second cam 550 together define a cam
profile. In the illustrated embodiment, the cams 546, 550 provide a
generally helical cam profile.
[0078] As shown in FIGS. 22 and 24, the jerk absorber 510 includes
a jerk pin 562 that defines a vent 566 (as shown in FIG. 24) and is
sized to be press fit into the jerk aperture 530 of the inerter hub
502. The jerk absorber 510 also includes a bushing 570 engaged on
the jerk pin 562 and received within the jerk aperture 554 of the
cam element 506. The illustrated bushing 570 is constructed of a
shock dissipating material such as rubber, includes a bushing
flange 574 arranged to be sandwiched between the hub flange 522 and
the cam flange 538, and is snugly received within the jerk aperture
554 of the cam element 506.
[0079] The cam follower element 514 defines a follower flange 578
that includes two flat portions 582, a central aperture 586 sized
to receive the cam element 506, and a follower threaded portion
590. Each flat portion 582 includes a cam pin aperture 594 sized to
receive a cam pin 598. The cam pin apertures 594 (and therefore the
pins 598) are positioned off-center with respect to the center axis
482 (as shown in FIG. 26). The cam pins 598 are arranged to engage
the first cam 546 and the second cam 550. The follower threaded
portion 590 includes a threaded aperture 602 sized to receive a set
screw 606.
[0080] The disk holder 518 defines a central shaft 610 that holds
at a first end a bearing in the form of a spherical crystal bearing
614 (as shown in FIG. 18) and defines a disk recess 618 arranged to
receive a disk 622. The disk holder 518 further includes a holder
threaded portion 626 arranged to threadingly receive the follower
threaded portion 590, and a set screw aperture 630 arranged to
receive the set screw 606.
[0081] Assembly of the inerter system 422 will be described with
reference to FIG. 24. The jerk bushing 570 is inserted into the
jerk aperture 554 of the cam element 506. The cam element 506 is
then coupled to the inerter hub 502 by threading the cam element
threads 558 onto the hub body threads 532. The threads 558, 532
engage loosely such that the cam element 506 spins easily. The jerk
aperture 530 of the inerter hub 502 is then aligned with the jerk
aperture 554 of the cam element 506. The jerk pin 562 is press fit
into the jerk aperture 530 of the inerter hub 502, and the jerk
bushing 570 that is positioned in the jerk aperture 554 of the cam
element 506.
[0082] The threaded portion 590 of the cam follower element 514 is
then threaded onto the threaded portion 626 of the disk holder 518,
and the set screw 606 is tightened such that the cam follower
element 514 is substantially rigidly coupled to the disk holder
518.
[0083] The disk holder 518 and the cam follower element 514 are
then slid onto the cam element 506 such that the pins 598 are
engaged with the first cam 546 and the second cam 550.
[0084] As shown in FIG. 18, with the inerter system 422 assembled,
the hub flange 522 is engaged with the shoulder 438 of the housing
414 such that the disk 622 engages the nozzle outlet 454. The
bonnet 418 is then installed with the shoulder 466 of the bonnet
flange 462 engaging the hub flange 522 and the spindle bracket 498
engaging the spherical bearing 614. The bonnet 418 is then fastened
to the housing 414 such that the inerter hub 502 is fixed in place
and inhibited from rotational and linear movement.
[0085] In operation, and as shown in FIG. 18, the disk holder 518
is moveable between an open position where fluid is permitted to
flow from the nozzle inlet 450 through the nozzle outlet 454, and
out of the outlet port 430, and a closed position where the disk
622 engages the nozzle outlet 454 and inhibits fluid flow
therethrough.
[0086] The PRV 400 is typically in the closed position, and when
pressure acting on the disk holder 518 overcomes the bias force of
the spring 494, the disk holder 518 moves toward the open position.
Moving toward the open position, the pins 598 engage the first cam
546 and the second cam 550 and move the disk holder 518 along the
cam profile. This results in a translation of linear motion to
rotational work and has an inertial damping effect on the system,
as discussed above.
[0087] The jerk absorber 510 functions to absorb the initial shock
and impact that the inerter system 422 undergoes upon the pressure
in the pressure vessel or any downstream vibration overcoming the
bias force of the spring 494. The jerk bushing 570 absorbs the
impact and the threaded portions 532, 558 interact to allow a
slight rotation of the cam element 506 relative to the inerter hub
502.
[0088] Section IV
[0089] Many current PRVs form an undamped linear spring mass
mechanism and are configured to enable pressure control over narrow
pressure ranges. Resonant acoustic frequencies due to inlet pipe
and/or other periodic inlet pipe dynamics cause an undesirable
rapid cycling motion or vibration in the PRVs, sometimes known as
"chatter," wherein the disc rapidly cycles between the open and
closed positions. Such vibration reduces the capacity of the PRV
and can cause damage to internal components such as the disc and
valve seat (i.e., nozzle outlet). Attempts have been made to reduce
the effects of such vibration by modifying disc face, seat, and
nozzle geometries in order to enhance the stability of PRVs. This
method is effective at enhancing stability at relatively low
pressures but has limited effectiveness in enhancing stability at
relatively high pressures. Further, the use of passive damping
techniques such as viscous type dampers (i.e., velocity sensitive
dampers) or drag type dampers (i.e., position sensitive dampers)
have been marginally successful in addressing undesirable
vibration. In particular, such techniques are effective only after
the vibration has already started.
[0090] Embodiments of the invention provide, among other things, an
inerter system wherein linear motion along a center axis is
converted to rotational motion about the center axis. This
conversion has the effect of adding inertial damping to the PRV.
The inerter system reacts to acceleration of the system, as opposed
to the more traditional passive systems that react to velocity. In
other words, the invention has a much faster reaction and provides
better damping with significantly less movement of the disc holder
away form the nozzle outlet.
[0091] The magnitude of the inertial damping effect provided by the
inerter system is at least in part controlled by a cam profile
defined by the structure of the inerter system (e.g., slots 130,
134, 316, 320 and cams 546, 550). The cam profile can have a
constant or variable lead, a curved shape, a variable shape, a
straight shape that is angled relative to the center axis, a shape
in accordance with a square or cube root function or a combination
of such shapes, and other suitable shapes. In one construction, the
cam profile is helically shaped. In another construction, the cam
profile can include at least one stepped portion that is located
between first and second curved portions, for example. In such a
configuration, the disc holder initially rotates in a first portion
of the cam profile, dwells, then resumes rotation in a second
portion of the cam profile. In one construction, the cam profile
has a right hand lead, resulting in a corresponding rotation
direction. Alternatively, the cam profile can be positioned in an
angled orientation relative to the center axis that is opposite
than that depicted in the figures. For example, the cam profile can
have a left hand lead.
[0092] Embodiments of the invention control vibration in a PRV
without adding significant mass to the disc holder when compared
with a typical disk holder. As a result, existing PRVs can be
retrofitted in the field with the invention without extensive
modification. In addition, the invention can be used in conjunction
with other types of valves. The invention can also be used in any
suitable valve configuration having a component or components, such
as a valve stem that includes a disc or other components, which
move in a linear motion and which are susceptible to an undesirable
rapid cycling motion due to dynamic instability or vibration. For
example, the invention can be applied to various types of line
valves, check valves, relief valves, or other valves that are
subject to vibrations and pressure fluctuations.
[0093] In some embodiments of the invention, 15-20% of the energy
produced by vertical movement is converted to rotary energy in the
damping process. In other embodiments, more or less energy can be
converted, depending on the desired characteristics of the damping
system. For example, 10-50% or more of the vertical energy can be
converted to rotary energy by the inerter system. As discussed
above, the cam profile can be manipulated to produce the desired
damping characteristics.
[0094] Another advantage offered by embodiments of the invention is
the ability to produce damped valves that are functional as single
fluid valves. That is to say, a single valve design can be used for
both a gas product and a liquid product. Current passively damped
valves are not suitable for single fluid arrangement, because they
are not capable of damping the systems to stability in the presence
of the variety of conditions that are posed by a liquid product
versus a gas product, or vice versa.
[0095] The present invention recognizes the problem of damping and
chatter issues as a lack of non-active systems that dampen in
response to acceleration of a vibration and provide a wide ranging
mode for dealing with such vibrations. The concept of a floating
input (e.g., disk holder, etc.) is one that reacts to
non-mechanical force such as pressure. That is to say, the floating
input is not coupled between two fixed mechanical points for
damping vibrations formed therebetween. For example, a floating
input is not connected to a linkage (e.g., automobile suspension),
not directly moved by a contact force (e.g., physical impact by an
object), or rigidly coupled at its extremities.
[0096] Although the above described valves are direct spring
operated, the invention is capable with working with suitable
actuation systems, including but not limited to, pilot operation,
solenoid operation, and other control mechanisms.
[0097] It will be appreciated by those skilled in the art that
while the invention has been described above in connection with
particular embodiments and examples, the invention is not
necessarily so limited, and that numerous other embodiments,
examples, uses, modifications and departures from the embodiments,
examples and uses are intended to be encompassed by the claims
attached hereto. The entire disclosure of each patent and
publication cited herein is incorporated by reference, as if each
such patent or publication were individually incorporated by
reference herein.
[0098] Various features and advantages of the invention are set
forth in the following claims.
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