U.S. patent application number 14/341877 was filed with the patent office on 2016-01-28 for snubber for machine.
This patent application is currently assigned to Caterpillar Global Mining LLC. The applicant listed for this patent is Caterpillar Global Mining LLC. Invention is credited to Daniel E. Bozich, Kim G. Lunderskov.
Application Number | 20160024747 14/341877 |
Document ID | / |
Family ID | 55166282 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160024747 |
Kind Code |
A1 |
Lunderskov; Kim G. ; et
al. |
January 28, 2016 |
SNUBBER FOR MACHINE
Abstract
A snubber for a machine includes a housing mounted on an
implement, a shaft, a first member that has multiple helical
splines that is coupled to the shaft. The shaft is rotatably
received within the housing and operatively coupled to a movable
component of the implement. The snubber also includes a cylinder
defining a cavity, a piston received in the cylinder and dividing
the cavity into a first chamber and a second chamber, a second
member that has multiple helical splines and is coupled to the
piston and, a hydraulic device. The helical splines of the first
and second member engage with each other to convert a rotation of
the shaft into a linear movement of the piston. The hydraulic
device is in fluid communication with the cavity and controls a
flow of fluid between the first chamber and the second chamber to
oppose rotation of the shaft.
Inventors: |
Lunderskov; Kim G.; (East
Troy, WI) ; Bozich; Daniel E.; (Milwaukee,
WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Global Mining LLC |
Oak Creek |
WI |
US |
|
|
Assignee: |
Caterpillar Global Mining
LLC
Oak Creek
WI
|
Family ID: |
55166282 |
Appl. No.: |
14/341877 |
Filed: |
July 28, 2014 |
Current U.S.
Class: |
37/445 ;
188/295 |
Current CPC
Class: |
E02F 9/2271 20130101;
F16F 9/00 20130101; E02F 3/58 20130101; E02F 3/46 20130101; F16F
9/20 20130101; E02F 3/4075 20130101; F16F 2232/04 20130101; E02F
9/2217 20130101 |
International
Class: |
E02F 3/407 20060101
E02F003/407 |
Claims
1. A snubber for a machine, the snubber comprising: a housing
configured to be mounted on an implement of the machine; a shaft
rotatably received within the housing and operatively coupled to a
movable component of the implement; a first member coupled to the
shaft, the first member comprising a plurality of helical splines;
a cylinder at least partly disposed within the housing, the
cylinder defining a cavity therein; a piston slidably received
within the cylinder, the piston dividing the cavity of the cylinder
into a first chamber and a second chamber; a second member coupled
to the piston, the second member comprising a plurality of helical
splines configured to engage with the helical splines of the first
member to convert a rotation of the shaft into a linear movement of
the piston; and a hydraulic device in fluid communication with the
cavity of the cylinder, the hydraulic device configured to control
a flow of a fluid between the first chamber and the second chamber
to oppose the rotation of the shaft.
2. The snubber of claim 1, the hydraulic device comprising a first
flow control module configured to control a flow from the first
chamber to the second chamber to oppose the rotation of the shaft
in a first direction.
3. The snubber of claim 2, the hydraulic device further comprising
a second flow control module configured to control a flow from the
second chamber to the first chamber to oppose the rotation of the
shaft in a second direction opposite to the first direction.
4. The snubber of claim 2, the first flow control module
comprising: a first flow control valve in fluid communication with
the first chamber of the cylinder, the first flow control valve
configured to restrict a flow of the fluid therethrough, a first
check valve in fluid communication with the first flow control
valve, the first check valve configured to allow a unidirectional
flow from the first flow control valve to the second chamber of the
cylinder; and a first pressure relief valve disposed in parallel to
the first flow control valve and the first check valve, the first
pressure relief valve having an inlet end in fluid communication
with the first chamber and an outlet end in fluid communication
with the second chamber, wherein the first pressure relief valve is
configured to allow a flow of the fluid from the inlet end to the
outlet end if a pressure at the inlet end exceeds a first
predetermined threshold.
5. The snubber of claim 3, the second flow control module
comprising: a second flow control valve in fluid communication with
the second chamber of the cylinder, the second flow control valve
configured to restrict a flow of the fluid therethrough, a second
check valve in fluid communication with the second flow control
valve, the second check valve configured to allow a unidirectional
flow from the second flow control valve to the first chamber of the
cylinder; and a second pressure relief valve disposed in parallel
to the second flow control valve and the second check valve, the
second pressure relief valve having an inlet end in fluid
communication with the second chamber and an outlet end in fluid
communication with the first chamber, wherein the second pressure
relief valve is configured to allow a flow of the fluid from the
inlet end to the outlet end if a pressure at the inlet end exceeds
a second predetermined threshold.
6. The snubber of claim 3, the hydraulic device further comprising
a manifold configured to receive the first control module and the
second control module therein.
7. The snubber of claim 1, wherein the first member is disposed on
an outer surface of the shaft and the second member is disposed on
an inner surface of the piston.
8. The snubber of claim 1, wherein the cylinder further defines a
first port in fluid communication with the first chamber and a
second port in fluid communication with the second chamber, wherein
the hydraulic device is in fluid communication with the first port
and the second port.
9. The snubber of claim 1 further comprising a bearing disposed
between the shaft and the housing.
10. A dipper system for a machine, the dipper system comprising: a
dipper body; a dipper door coupled to the dipper body and
configured to move between an open position and a closed position;
and a snubber disposed on the dipper body, the snubber comprising:
a housing configured to be mounted on the dipper system; a shaft
rotatably received within the housing and operatively coupled to
the dipper door; a first member coupled to the shaft, the first
member comprising a plurality of helical splines; a cylinder at
least partly disposed within the housing, the cylinder defining a
cavity therein; a piston slidably received within the cylinder, the
piston dividing the cavity of the cylinder into a first chamber and
a second chamber; a second member coupled to the piston, the second
member comprising a plurality of helical splines configured to
engage with the helical splines of the first member to convert a
rotation of the shaft into a linear movement of the piston; and a
hydraulic device in fluid communication with the cavity of the
cylinder, the hydraulic device configured to control a flow of a
fluid between the first chamber and the second chamber to oppose
the rotation of the shaft.
11. The dipper system of claim 10 further comprising a linkage
assembly configured to transmit a movement of the dipper door to
the shaft.
12. The dipper system of claim 10, the hydraulic device comprising
a first flow control module configured to control a flow from the
first chamber to the second chamber to oppose the rotation of the
shaft in a first direction.
13. The dipper system of claim 12, the hydraulic device further
comprising a second flow control module configured to control a
flow from the second chamber to the first chamber to oppose the
rotation of the shaft in a second direction opposite to the first
direction.
14. The dipper system of claim 12, the first flow control module
comprising: a first flow control valve in fluid communication with
the first chamber of the cylinder, the first flow control valve
configured to restrict a flow of the fluid therethrough, a first
check valve in fluid communication with the first flow control
valve, the first check valve configured to allow a unidirectional
flow from the first flow control valve to the second chamber of the
cylinder; and a first pressure relief valve disposed in parallel to
the first flow control valve and the first check valve, the first
pressure relief valve having an inlet end in fluid communication
with the first chamber and an outlet end in fluid communication
with the second chamber, wherein the first pressure relief valve is
configured to allow a flow of the fluid from the inlet end to the
outlet end if a pressure at the inlet end exceeds a first
predetermined threshold.
15. The dipper system of claim 13, the second flow control module
comprising: a second flow control valve in fluid communication with
the second chamber of the cylinder, the second flow control valve
configured to restrict a flow of the fluid therethrough, a second
check valve in fluid communication with the second flow control
valve, the second check valve configured to allow a unidirectional
flow from the second flow control valve to the first chamber of the
cylinder; and a second pressure relief valve disposed in parallel
to the second flow control valve and the second check valve, the
second pressure relief valve having an inlet end in fluid
communication with the second chamber and an outlet end in fluid
communication with the first chamber, wherein the second pressure
relief valve is configured to allow a flow of the fluid from the
inlet end to the outlet end if a pressure at the inlet end exceeds
a second predetermined threshold.
16. The dipper system of claim 13, the hydraulic device further
comprising a manifold configured to receive the first control
module and the second control module therein.
17. The dipper system of claim 10, wherein the first member is
disposed on an outer surface of the shaft and the second member is
disposed on an inner surface of the piston.
18. The dipper system of claim 10, wherein the cylinder further
defines a first port in fluid communication with the first chamber
and a second port in fluid communication with the second chamber,
wherein the hydraulic device is in fluid communication with the
first port and the second port.
19. The dipper system of claim 10 further comprising a bearing
disposed between the shaft and the housing.
20. A method of damping a movement of a dipper door, the method
comprising: receiving a shaft rotatably within a housing, the shaft
operatively coupled to the dipper door; coupling a first member to
the shaft, the first member comprising a plurality of helical
splines; providing a piston slidably within a cavity of a cylinder,
the piston dividing the cavity of the cylinder into a first chamber
and a second chamber; coupling a second member to the piston, the
second member comprising a plurality of helical splines;
transmitting the movement of the dipper door to the shaft; engaging
the helical splines of the first member with the helical splines of
the second member to convert a rotation of the shaft into a linear
movement of the piston; controlling a flow of a fluid from the
first chamber of the cylinder to the second chamber of the cylinder
to oppose the rotation of the shaft in a first direction; and
controlling a flow of the fluid from the second chamber of the
cylinder to the first chamber of the cylinder to oppose the
rotation of the shaft in a second direction opposite to the first
direction.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a snubber for a machine,
and more specifically to the snubber for an implement of the
machine.
BACKGROUND
[0002] Machines such as, rope shovels typically include an
implement, such as a dipper, for loading and unloading materials.
The dipper may include a door that closes a rear of the dipper to
hold the materials that are loaded into the dipper. Further, the
door is opened to unload the contents of the dipper at a desired
location. The door may be typically held closed by a latch
mechanism. The latch mechanism may be released to allow the door to
swing open under its own weight and the weight of the contents of
the dipper. The door may be re-latched as the door rotates back in
preparation for its next loading cycle.
[0003] During the swinging movement, the door may tend to hit
against walls of the dipper or any other proximal component. Sudden
opening and closing of the door may also cause wear to components
associated with the door. Typically, dippers may be equipped with a
braking device on the door linkage to reduce a swing speed as the
door swings towards an open and/or closed position.
[0004] Conventional dipper door braking devices may utilize dry
friction to provide a braking force. As the door swings open or
close by virtue of its own weight, the braking device provides
friction thereby reducing the swing speed of the door. However, the
braking force provided by the braking device tends to reduce as the
braking device wears. To maintain the necessary braking force, the
braking devices may be subjected to regular maintenance, resulting
in machine downtime.
[0005] For reference, U.S. Patent Publication No. 2014/007468
(hereinafter the '468 publication) relates to a dipper assembly for
a mining shovel. The dipper assembly includes a dipper body and a
dipper door that is pivotably coupled to the dipper body, an arm, a
housing coupled to one of the body and the door, and a piston. The
arm includes a first end pivotably coupled to the body and a second
end pivotably coupled to the door. The movement of the door
relative to the body drives the arm to pivot relative to the body.
The housing includes an inlet in fluid communication with a fluid
source, an outlet, and a cylinder. The cylinder partially defines a
pump chamber in fluid communication with the inlet and the outlet.
The piston is movable within the cylinder and biased in a first
direction. The pivoting movement of the arm causes the piston to
move in a second direction opposite to the first direction. The
movement of the piston changes a volume of the pump chamber.
SUMMARY OF THE DISCLOSURE
[0006] In one aspect of the present disclosure, a snubber for a
machine is provided. The snubber includes a housing, a shaft and a
first member. The housing is configured to be mounted on an
implement of the machine. The shaft is rotatably received within
the housing and operatively coupled to a movable component of the
implement. The first member has a plurality of helical splines and
is coupled to the shaft. The snubber also includes a cylinder
defining a cavity therein, a piston, a second member and a
hydraulic device. The cylinder is at least partly disposed within
the housing. The piston is slidably received within the cylinder
and divides the cavity of the cylinder into a first chamber and a
second chamber. The second member has a plurality of helical
splines and is coupled to the piston. The helical splines of the
second member are configured to engage with the helical splines of
the first member to convert a rotation of the shaft into a linear
movement of the piston. The hydraulic device is in fluid
communication with the cavity of the cylinder. The hydraulic device
is configured to control a flow of a fluid between the first
chamber and the second chamber to oppose the rotation of the
shaft.
[0007] In another aspect of the present disclosure, a dipper system
for a machine is provided. The dipper system includes a dipper
body, a dipper door and a snubber. The dipper door is coupled to
the dipper body and is configured to move between an open position
and a closed position. The snubber is disposed on the dipper body.
Further, the snubber includes a housing, a shaft and a first
member. The housing is configured to be mounted on the dipper
system of the machine. The shaft is rotatably received within the
housing and operatively coupled to the dipper door. The first
member has a plurality of helical splines and is coupled to the
shaft. The snubber also includes a cylinder defining a cavity
therein, a piston, a second member and a hydraulic device. The
cylinder is at least partly disposed within the housing. The piston
is slidably received within the cylinder and divides the cavity of
the cylinder into a first chamber and a second chamber. The second
member has a plurality of helical splines and is coupled to the
piston. The helical splines of the second member are configured to
engage with the helical splines of the first member to convert a
rotation of the shaft into a linear movement of the piston. The
hydraulic device is in fluid communication with the cavity of the
cylinder. The hydraulic device is configured to control a flow of a
fluid between the first chamber and the second chamber to oppose
the rotation of the shaft.
[0008] In yet another aspect of the present disclosure, a method of
damping a movement of a dipper door is provided. The method
includes receiving a shaft rotatably within a housing. The shaft is
operatively coupled to the dipper door. The method also includes
coupling a first member having a plurality of helical splines to
the shaft and providing a piston slidably within a cavity of a
cylinder. The piston divides the cavity of the cylinder into a
first chamber and the second chamber. The method further includes
coupling a second member having a plurality of helical splines to
the piston and transmitting the movement of the dipper door to the
shaft. The method includes engaging the helical splines of the
first member with the helical splines of the second member to
convert a rotation of the shaft into a linear movement of the
piston. The method further includes controlling a flow of a fluid
from the first chamber of the cylinder to the second chamber of the
cylinder to oppose the rotation of the shaft in a first direction.
The method also includes controlling a flow of the fluid from the
second chamber of the cylinder to the first chamber of the cylinder
to oppose the rotation of the shaft in a second direction that is
opposite to the first direction.
[0009] Other features and aspects of this disclosure will be
apparent from the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side view of an exemplary machine showing a
dipper system having a dipper door, according to an embodiment of
the present disclosure;
[0011] FIG. 2 is a perspective view of the dipper system having a
snubber, according to an embodiment of the present disclosure;
[0012] FIG. 3 is a partial sectional view of the snubber of FIG. 2,
according to an embodiment of the present disclosure;
[0013] FIG. 4 is a partial sectional view of the snubber of FIG. 2
in a different configuration;
[0014] FIG. 5 is a schematic diagram of a hydraulic circuit used
with the snubber, according to an embodiment of the present
disclosure; and
[0015] FIG. 6 is a flowchart of a method for damping a movement of
the dipper door, according to an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0016] Wherever possible, the same reference numbers will be used
throughout the drawings to refer to the same or the like parts.
Referring to FIG. 1, an exemplary machine 100 is illustrated,
according to an embodiment of the present disclosure. The machine
100 is embodied as a rope shovel. Various embodiments of the
present disclosure are described with reference to a rope shovel as
the machine 100. However, the present disclosure may also be
applicable to other types of machines such as, but not limited to,
a hydraulic shovel and a dragline excavator.
[0017] The machine 100 includes a frame 102 that is configured to
mount and/or support various components of the machine 100. The
frame 102 is rotatably supported on a set of ground engaging
members, for example, tracks 104 that are configured to propel the
machine 100 forward or backward on ground. The tracks 104 may also
be configured to turn the machine 100 by varying a speed and/or a
direction of each of the tracks 104 relative to each other.
Further, the machine 100 may be configured to move between a
loading position 106 and an unloading position 108 for receiving
and dumping the material respectively as the frame 102 swings
relative to the tracks 104.
[0018] The machine 100 may also include a boom 114 extending
upwardly and outwardly from the frame 102. The machine 100 may also
includes a crowd mechanism 116 and a hoist mechanism 120 provided
on the boom 114. The crowd mechanism 116 includes a handle 117 that
is configured to slidably move with respect to the boom 114. The
hoist mechanism 120 may include a winch (not shown), a pulley 122
and a hoist cable 124. The hoist cable 124 is connected to the
winch at one end.
[0019] Referring now to FIGS. 1 and 2, a dipper system 200 for the
machine 100 is illustrated, according to an exemplary embodiment.
The dipper system 200 may be configured to hold earth and/or other
materials that may be loaded into the dipper system 200. The dipper
system 200 includes a dipper body 202 and a dipper door 204 that is
pivotally coupled to the dipper body 202. In the illustrated
embodiment, the dipper system 200 may act as an implement of the
machine 100. However, in various other embodiments, other tools
having a movable component, such as a grapple may act as the
implement.
[0020] Further, an other end of the hoist cable 124 extends over
the pulley 122 and is connected to the dipper system 200. Based on
a rotation of the winch, the cable retracts or extends relative to
the winch. Accordingly, the hoist mechanism 120 is configured to
raise or lower the dipper system 200 relative to the frame 102.
Moreover, the dipper system 200 may extend or retract relative to
the frame 102 based on the sliding movement of the handle 117.
[0021] The machine 100 may include a dipper trip mechanism 126 that
is coupled to the dipper door 204. The dipper trip mechanism 126
may be configured to operate the dipper door 204. The dipper trip
mechanism 126 may include a trip motor 134 and a trip cable 136
extending between the trip motor 134 and the dipper door 204. More
specifically, the trip cable 136 may be coupled to a locking
mechanism (not shown) of the dipper door 204. The locking mechanism
may be configured to selectively lock the dipper door 204 to the
dipper body 202. The locking mechanism may be any locking mechanism
known in the art, such as a latch bar and lever arrangement, and so
on. Based on an operation of the trip motor 134, the trip cable 136
retracts and actuates the locking mechanism. Based on an actuation
of the locking mechanism, the dipper door 204 may be unlocked to
dump the material at the unloading position 108.
[0022] Referring to FIGS. 1 and 2, the dipper body 202 includes a
forward edge 206 and dipper walls 208, 210, 212 having
corresponding rearward edges 214. Teeth 220 may be provided on the
forward edge 206 to define a cutting edge that cuts into the ground
to fill the dipper body 202.
[0023] The dipper door 204 may be pivotally connected to the dipper
body 202 and abuts the rearward edges 214 of the dipper walls 208,
210, 212 to close a bottom portion 222 of the dipper body 202. The
dipper door 204 is configured to move between an open position and
a closed position. In the illustrated embodiment, the dipper door
204 is configured to pivot about a pin joint 228 to swing between
the open position and the closed position. The dipper door 204 in
the open position may be rotated in a direction R1 (shown in FIG.
1) to reach the closed position. Similarly, the dipper door 204 in
the closed position may swing away from the bottom portion 222 in a
direction R2 (shown in FIG. 1) toward the open position to
discharge the load in the dipper body 202.
[0024] The machine 100 includes a snubber 300 that may be
configured to dampen a swinging motion of a movable component of an
implement. In the illustrated embodiment, the snubber 300 may be
configured to dampen a swinging motion of the dipper door 204, as
the dipper door 204 swings between the open and closed positions.
In the illustrated embodiment, two of the snubbers 300 are coupled
to the dipper system 200. Moreover, the snubbers 300 are mounted on
opposing ends of the rearward edges 214. Therefore, the snubbers
300 may dampen the swinging motion at respective ends of the dipper
door 204. Although two snubbers 300 is shown coupled to the dipper
system 200, it may be envisioned to use any number of snubbers that
may coupled to the dipper system 200 by suitable linkages.
[0025] The snubber 300 may be coupled to the dipper system 200 by a
linkage assembly 230. In the illustrated embodiment of FIG. 2, the
linkage assembly 230 is connected to a shaft 302 that defines a
longitudinal axis A-A'. The linkage assembly 230 may be configured
to transmit a movement of the dipper door 204 to the shaft 302. The
shaft 302 may be configured to rotate about the axis A-A' in a
first direction D1 (shown in FIG. 3) while the dipper door 204
moves in the direction R1, i.e., moving from the open position to
the closed position. Further, the shaft 302 may be configured to
rotate about the axis A-A' in a second direction D2 (shown in FIG.
4) that is opposite to the first direction D1, while the dipper
door 204 moves in the direction R2, i.e., moving from a closed
position to the open position.
[0026] It should be noted that the linkage assembly 230 illustrated
is exemplary in nature and hence non-limiting of this disclosure.
Therefore it may envisioned to use any other appropriate linkage
configurations to transmit an opening/closing movement of the
dipper door 204 to a rotation of the shaft 302.
[0027] The snubber 300 includes a housing 304 that is configured to
be mounted on the dipper system 200. The housing 304 may be mounted
on the dipper system by using bolts, welding or other suitable
methods known in the art. The shaft 302 is rotatably received
within the housing 304 and may be operatively coupled to the dipper
door 204 via the linkage assembly 230. In an embodiment, a bearing
232 may be disposed between the housing 304 and the shaft 302. The
bearing 232 may enable rotation of the shaft 302 relative to the
housing 304. In an example, the bearing 232 may be a roller
bearing.
[0028] Referring now to FIGS. 3 and 4, a first member 308 is
coupled to the shaft 302. The first member 308 includes multiple
helical splines 309. Moreover, the first member 308 may be disposed
on an outer surface 311 of the shaft 302 such that an axis of the
first member 308 aligns with the axis A-A'. In an example, the
first member 308 may be a helical gear. Alternatively, the shaft
302 and the first member 308 are integral with each other and the
helical splines 309 are provided on the outer surface 311 of the
shaft 302. Further, a rotation of the shaft 302 about the axis A-A'
imparts rotational motion to the first member 308 about the axis
A-A'.
[0029] The snubber 300 also includes a cylinder 310 that is at
least partly disposed within the housing 304. The cylinder 310
defines a central axis that is substantially parallel to the axis
A-A' of the shaft 302. The cylinder 310 also defines a cavity 312
that is configured to slidably receive a piston 314 therein. The
piston 314 is configured to divide the cavity 312 into a first
chamber 316 and a second chamber 318. The cylinder 310 further
defines a first port 320 that is in fluid communication with the
first chamber 316 and a second port 322 that is in fluid
communication with the second chamber 318. Volumes V1, V2 of the
first and second chambers 316, 318 may depend on a position of the
piston 314 with respect to the cylinder 310. The piston 314 may
also define an opening 324 to receive the first member 308
therein.
[0030] The snubber 300 further includes a second member 326 that is
coupled to the piston 314. The second member 326 may be disposed in
the housing 304 such that an axis of the second member 326 is
substantially parallel to the axis A-A'. Further, the second member
326 includes multiple helical splines 329 that are configured to
engage with the helical splines 309 of the first member 308. The
second member 326 may be a tubular shaft that has the helical
splines 329 disposed on an interior surface thereof. In an
embodiment, the second member 326 may be provided on an interior
surface 327 of the piston 314. Alternatively, the second member 326
may be integral with the piston 314 and the helical splines 329 may
be disposed on the interior surface 327 of the piston 314.
[0031] The piston 314 may be positioned in the housing 304 such
that the second member 326 may face the first member 308. Moreover,
the helical splines 329 of the second member 326 engage with the
helical splines 309 of the first member 308 such that a rotational
movement of the shaft 302 is converted to a linear movement of the
piston 314. Further, as the shaft 302 rotates about the axis A-A',
the piston 314 may also rotate about the axis A-A' and
simultaneously translate along the axis A-A'.
[0032] As illustrated in FIG. 3, rotation of the first member 308
and the shaft 302 in the first direction D1 during opening of the
dipper door 204, may cause the piston 314 to move linearly in a
direction L1 that is substantially parallel to the axis A-A'. As
illustrated in FIG. 4, rotation of the first member 308 and the
shaft 302 in the second direction D2 during closing of the dipper
door 204, may cause the piston 314 to move linearly in a direction
L2 that is opposite to the direction L1.
[0033] In an embodiment, the piston 314 may include multiple teeth
330 that are disposed on an outer surface 332 of the piston 314.
The teeth 330 may be configured to engage with corresponding teeth
334 provided on an inner surface 336 of the cylinder 310. The teeth
330, 334 may extend to a sufficient length such that at least one
or more of the teeth 330, 334 may remain engaged with each other
during linear movement of the piston 314. The engagement between
the teeth 330, 334 may support rotation and translation of the
piston 314 relative to the cylinder 310.
[0034] Therefore, as the piston 314 moves in the directions L1, L2
based on the rotational movement of the shaft 302, volumes V1, V2
of the corresponding first chamber and the second chamber 316, 318
may vary. Moreover, a fluid may tend to flow between the first
chamber 316 to the second chamber 318 through the respective first
and second ports 320, 322 based on changes in the volumes V1 and V2
of the first chamber 316 and the second chamber 318. For example,
the volume V1 of the first chamber 316 may decrease as the piston
314 moves in the direction L1 and the fluid may tend to flow from
the first chamber 316 to the second chamber 318 through the
respective first and second ports 320, 322. The flow of the fluid
between the first chamber 316 and the second chamber 318 may be
controlled so as to oppose the rotation of the shaft 302 in the
first and second directions D1, D2.
[0035] Accordingly, the snubber 300 includes a hydraulic device 344
that may be configured to control the flow of fluid between the
first chamber 316 and the second chamber 318. The hydraulic device
344 may include a manifold 348. In an embodiment, the manifold may
be releasably coupled to the housing 304 of the snubber 300.
[0036] The hydraulic device 344 may be in fluid communication with
the cavity 312 of the cylinder 310. Therefore, as the volume V1 of
the first chamber 316 or the volume V2 of the second chamber 318
decreases, the fluid may flow to the hydraulic device 344. The
fluid flow may be controlled so as to increase pressure inside one
of the first and second chambers 316, 318. Such increased pressure
may provide necessary torque to oppose the rotation of the shaft
302, and thereby dampen the movement of the dipper door 204.
[0037] For example, during opening of the door, the shaft 302 may
rotate in the first direction D1 causing the piston 314 to move
linearly in the direction L1. As such, the volume V1 of the first
chamber 316 decreases and the fluid may flow from the first chamber
316 to the hydraulic device 344. The hydraulic device 344 may
control the flow of the fluid to the second chamber 318 thereby
increasing a pressure inside the first chamber 316. Such increased
pressure may exert force on the piston 314 that converts to an
opposing torque on the shaft 302. The torque may oppose the
rotation of the shaft 302 in the first direction D1. Similarly,
during closing of the dipper door 204, the fluid flow from the
second chamber 318 to the first chamber 316 may be controlled so as
to oppose rotation of the shaft 302 in the second direction D2.
Such opposition to the rotation of the shaft 302 may be transmitted
to the dipper door 204 through the linkage assembly 230 thereby
opposing rotation of the dipper door 204.
[0038] Referring to FIG. 5, an exemplary hydraulic circuit 500 that
may be used in the hydraulic device 344 is schematically
illustrated. The hydraulic circuit 500 includes a first flow
control module 502 and a second flow control module 504. The first
flow control module 502 and the second flow control module 504 may
have appropriate hydraulic lines in fluid communication with the
corresponding first and second ports 320 and 322. Accordingly, the
fluid in the housing 304 may tend to flow between the first and
second chambers 316 and 318 by passing through the hydraulic lines
of the hydraulic circuit 500.
[0039] The first flow control module 502 may be configured to
control a flow from the first chamber 316 to the second chamber 318
to oppose the rotation of the shaft 302 in the first direction D1,
while the second flow control module 504 is configured to control a
flow from the second chamber 318 to the first chamber 316 to oppose
the rotation of the shaft 302 in the second direction D2.
[0040] The first flow control module 502 may include a first flow
control valve 506 and a first check valve 508. The first flow
control valve 506 is in fluid communication with the first chamber
316 of the cylinder 316 and is configured to restrict a flow of the
fluid therethrough. Therefore, as the fluid flows from the first
chamber 316 to the first flow control module 502, the first flow
control valve 506 allows only a portion of the fluid to flow
therethrough.
[0041] The first check valve 508 is in fluid communication with the
first flow control valve 506 and is configured to allow a
unidirectional flow from the first flow control valve 506 to the
second chamber 318. In the illustrated embodiment, the first check
valve 508 is configured to allow the flow in a direction from the
first flow control valve 506 to the first chamber 316 and restricts
flow in an opposite direction thereof.
[0042] The first flow control module 502 may also include a first
pressure relief valve 510 that may be disposed in parallel to the
first flow control valve 506 and the first check valve 508. As
shown in FIG. 5, the first pressure relief valve 510 has an inlet
end 511 that is in fluid communication with the first chamber 316
and an outlet end 513 that is in fluid communication with the
second chamber 318. The first pressure relief valve 510 is
configured to allow a flow of the fluid from the inlet end 511 to
the outlet end 513 if a pressure at the inlet end 511 exceeds a
first predetermined threshold. Due to the restriction provided by
the first flow control valve 506, a pressure at the inlet end 511
may increase as the piston 314 moves in the direction L1.
Therefore, when the pressure at the inlet end 511 exceeds the first
predetermined threshold, the fluid flows from the first chamber 316
to the second chamber 318 through the first pressure relief valve
510. As such, the pressure inside the first chamber 316 may be
decreased.
[0043] Due to the increase in pressure to the first predetermined
threshold, the fluid exerts a force on the piston 314 such that the
movement of the piston 314 in the direction L1 is opposed. The
force translates to a torque on the shaft 302. The torque is in a
direction opposite to the first direction D1 of the shaft 302, and
hence the rotational speed of the shaft 302 decreases. The linkage
assembly 230 may communicate such decreased speed to the dipper
door 204, thereby decreasing the swinging speed of the dipper door
204.
[0044] Similarly, when the dipper door 204 is moving in the
direction R2, the shaft 302 may rotate in the second direction D2.
Accordingly, the piston 314 moves in the direction L2 thereby
decreasing the volume V2 of the second chamber 318. Therefore the
fluid may tend to flow from the second chamber 318 to the first
chamber 316 through the respective second and first ports 322, 320.
The second flow control module 504 may be configured to control a
flow of fluid from the second chamber 318 to the first chamber 316
thereby increasing the pressure inside the second chamber 318. Such
increased pressure may exert force on the piston 314 that converts
to an opposing torque on the shaft 302. The torque may oppose the
rotation of the shaft 302 in the second direction D2.
[0045] The second flow control module 504 may be substantially
similar to the first flow control module 502. However, the first
flow control module 502 may be operable to control the flow from
the first chamber 316 to the second chamber 318 to oppose the
rotation of the shaft 302 in the first direction D1, while the
second flow control module 504 may be operable to control the flow
from the second chamber 318 to the first chamber 316 so as to
oppose the rotation of the shaft 302 in the second direction
D2.
[0046] Accordingly, the second flow control module 504 may include
a second flow control valve 512 and a second check valve 514. The
second flow control valve 512 is in fluid communication with the
second chamber 318 and is configured to restrict a flow of the
fluid therethrough. Therefore, as the fluid flows from the second
chamber 318 to the second flow control module 504, the second flow
control valve 512 allows only a portion of the fluid to flow
therethrough.
[0047] The second check valve 514 is in fluid communication with
the second flow control valve 512 and is configured to allow a
unidirectional flow from the second flow control valve 512 to the
first chamber 316. In the illustrated embodiment, the second check
valve 514 is configured to allow the flow in a direction from the
second flow control valve 512 to the second chamber 318 and
restricts flow in an opposite direction.
[0048] The second flow control module 504 may also include a second
pressure relief valve 516 that may be disposed in parallel to the
second flow control valve 512 and the second check valve 514. As
shown in FIG. 5, the second pressure relief valve 516 has an inlet
end 518 that is in fluid communication with the second chamber 318
and an outlet end 520 that is in fluid communication with the first
chamber 316. The second pressure relief valve 516 is configured to
allow a flow of the fluid from the inlet end 518 to the outlet end
520 if a pressure at the inlet end 518 exceeds a second
predetermined threshold. In an embodiment, the first predetermined
threshold may be equal to the first predetermined threshold.
Operation of various components of the second flow control module
504 may be substantially similar to operation of the equivalent
components of the first flow control module 502.
[0049] It may be apparent to a person ordinarily skilled in the art
that the second flow control module 504 may not function when the
piston 314 moves in the direction L1. The second check valve 514
may prevent flow of the fluid to the second check valve 514 from
the first chamber 316. Further, the second pressure relief valve
516 may not allow flow from the first chamber 316 to the second
chamber 318. Similarly, the first flow control module 502 may not
function when the piston 314 moves in the direction L2.
[0050] In an embodiment, the hydraulic device 344 may include one
or more accumulators (not shown) that are configured to maintain
the fluid at a predetermined pressure. Each of the accumulators may
be in fluid communication with the hydraulic circuit 500, and one
of the first and second chambers 316, 318. The accumulator may
receive a fluid from the corresponding first and second chambers
316, 318 when a volume of the fluid increases. The accumulator may
include a pressurized gas (for example, nitrogen) that may be used
to maintain a predetermined pressure therein.
[0051] It should be noted that the hydraulic circuit 500
illustrated in FIG. 5, is exemplary in nature and hence
non-limiting of this disclosure. Any other appropriate hydraulic
circuit may be used as an alternative to the circuit of FIG. 5.
INDUSTRIAL APPLICABILITY
[0052] The present disclosure relates to the dipper system 200
including the snubbers 300 and a method 600 of damping a movement
of the dipper door 204. At step 602, the method 600 includes
receiving the shaft 302 rotatably within the housing 304. The shaft
302 is operatively coupled to the dipper door 204. At step 604, the
method 600 includes coupling the first member 308 to the shaft 302.
The first member includes multiple splines 309. At step 606, the
method 600 includes receiving the piston 314 slidably within the
cavity 312 of the cylinder 310. The piston 314 divides the cavity
312 into the first chamber 316 and the second chamber 318.
[0053] At step 608, the method 600 includes coupling the second
member 326 to the piston 314. The second member 326 includes
multiple splines 329. At step 610, the method 600 includes
transmitting the movement of the dipper door 204 to the shaft 302.
At step 612, the method 600 includes engaging the helical splines
309 of the first member 308 with the helical splines 329 of the
second member 326 to convert a rotation of the shaft 302 into a
linear movement of the piston 314.
[0054] At step 614, the method 600 includes controlling the flow of
a fluid from the first chamber 316 to the second chamber 318 to
oppose the rotation of the shaft 302 in the first direction D1. At
step 616, the method 600 includes controlling the flow of the fluid
from the second chamber 318 to the first chamber 316 to oppose the
rotation of the shaft 302 in the second direction D2 that is
opposite to the first direction D1.
[0055] The snubber 300 according to the present disclosure, may be
retrofitted onto any rope shovel or other machines having an
implement with a movable door. The snubber 300 may reduce the
swinging speed of the dipper door 204 by opposing the rotation of
the shaft 302 that is operatively coupled to the dipper door
204.
[0056] The first and second predetermined thresholds for the first
and second pressure relief valves 510, 516 may be selected to
provide a desired pressure inside the first chamber 316 or the
second chamber 318, and the corresponding torque to the shaft 302.
Further, using the helical splines 309, 329 to convert the rotation
of the shaft 302 to the linear movement of the piston 314 may
enable a simple and robust design of the snubber 300.
[0057] Additionally, use of the hydraulic device 344 may minimize
mechanical couplings and/or friction that may result in wear.
Therefore, the snubber 300 may have reduced maintenance costs. The
snubber 300 may also have reduced frequency of maintenance, thereby
decreasing machine downtime and associated costs. Moreover, the
snubber 300 may have an increased service life and reliability.
[0058] While aspects of the present disclosure have been
particularly shown and described with reference to the embodiments
above, it will be understood by those skilled in the art that
various additional embodiments may be contemplated by the
modification of the disclosed machines, systems and methods without
departing from the spirit and scope of what is disclosed. Such
embodiments should be understood to fall within the scope of the
present disclosure as determined based upon the claims and any
equivalents thereof.
LIST OF ELEMENTS
Title: Snubber for Machine
[0059] File: 14-0737 [0060] 100 Machine [0061] 102 Frame [0062] 104
Tracks [0063] 106 Loading Position [0064] 108 Unloading Position
[0065] 114 Boom [0066] 116 Crowd Mechanism [0067] 117 Handle [0068]
120 Hoist Mechanism [0069] 122 Pulley [0070] 124 Hoist cable [0071]
126 Dipper Trip Mechanism [0072] 134 Trip Motor [0073] 136 Trip
Cable [0074] 200 Dipper System [0075] 202 Dipper Body [0076] 204
Dipper Door [0077] 206 Forward Edge [0078] 208 Dipper Wall [0079]
210 Dipper Wall [0080] 212 Dipper Wall [0081] 214 Rearward Edge
[0082] 220 Teeth [0083] 222 Bottom Portion [0084] 228 Pin Joint
[0085] 230 Linkage Assembly [0086] 232 Bearing [0087] 300 Snubber
[0088] 302 Shaft [0089] 304 housing [0090] 308 First Member [0091]
309 Helical Splines [0092] 310 Cylinder [0093] 311 Outer Surface of
Shaft [0094] 312 Cavity [0095] 314 Piston [0096] 316 First Chamber
[0097] 318 Second Chamber [0098] 320 First Port [0099] 322 Second
Port [0100] 324 Opening [0101] 326 Second Member [0102] 327
Internal Surface [0103] 329 Helical Splines [0104] 330 Teeth [0105]
332 Outer Surface [0106] 334 Teeth [0107] 336 Inner surface [0108]
344 Hydraulic Device [0109] 348 Manifold [0110] 500 Hydraulic
Circuit [0111] 502 First flow Control Module [0112] 504 Second Flow
Control Module [0113] 506 First Flow Control Valve [0114] 508 First
Check Valve [0115] 510 First Pressure relief Valve [0116] 511 Inlet
End [0117] 512 Second Flow Control Valve [0118] 513 Outlet End
[0119] 514 Second Check Valve [0120] 516 Second Pressure relief
Valve [0121] 518 Inlet End [0122] 520 Outlet End [0123] 600 Method
[0124] 602 Step [0125] 604 Step [0126] 606 Step [0127] 608 Step
[0128] 610 Step [0129] 612 Step [0130] 614 Step [0131] 616 Step
[0132] A-A' Longitudinal Axis [0133] D1 Direction [0134] D2
Direction [0135] R1 Direction [0136] R2 Direction [0137] L1
Direction [0138] L2 Direction [0139] V1 Volume [0140] V2 Volume
* * * * *