U.S. patent application number 11/984380 was filed with the patent office on 2009-05-21 for electrically powered hydraulic actuating system.
This patent application is currently assigned to Caterpillar Inc.. Invention is credited to Richard Mark Hyde, Bryan Edward Nelson.
Application Number | 20090129951 11/984380 |
Document ID | / |
Family ID | 40377479 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090129951 |
Kind Code |
A1 |
Hyde; Richard Mark ; et
al. |
May 21, 2009 |
Electrically powered hydraulic actuating system
Abstract
An electrically powered hydraulic actuating system is disclosed.
The system includes a pump that has a plurality of
electro-magnetically actuated pumping chambers. The plurality of
electro-magnetically actuated pumping chambers have a common inlet
situated to supply the plurality of electro-magnetically actuated
pumping chambers with low-pressure fluid. The plurality of
electro-magnetically actuated pumping chambers also have a common
outlet situated to receive fluid pressurized by the plurality of
electro-magnetically actuated pumping chambers.
Inventors: |
Hyde; Richard Mark;
(Naperville, IL) ; Nelson; Bryan Edward; (Lacon,
IL) |
Correspondence
Address: |
CATERPILLAR/FINNEGAN, HENDERSON, L.L.P.
901 New York Avenue, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
Caterpillar Inc.
|
Family ID: |
40377479 |
Appl. No.: |
11/984380 |
Filed: |
November 16, 2007 |
Current U.S.
Class: |
417/322 |
Current CPC
Class: |
F04B 17/04 20130101;
F04B 23/06 20130101 |
Class at
Publication: |
417/322 |
International
Class: |
F04B 17/03 20060101
F04B017/03 |
Claims
1. A pump, comprising: a plurality of electro-magnetically actuated
pumping chambers; a common inlet situated to supply the plurality
of electro-magnetically actuated pumping chambers with low-pressure
fluid; and a common outlet situated to receive fluid pressurized by
the plurality of electro-magnetically actuated pumping
chambers.
2. The pump of claim 1, further including a piston disposed within
each of the plurality of electro-magnetically actuated pumping
chambers and magnetically urged in alternating directions to
pressurize fluid.
3. The pump of claim 2, wherein: the piston includes a magnetic
element; and the hydraulic pump includes a plurality of conductive
coils substantially encompassing each of the plurality of pumping
chambers, wherein each of the plurality of conductive coils are
configured to receive an electrical current and generate a force
that urges the magnetic element in a direction corresponding to a
direction of the electrical current through the conductive
coil.
4. The pump of claim 1, further including a piston disposed within
each of the plurality of pumping chambers and magnetically urged in
a first direction to pressurize fluid, and spring biased in a
second direction.
5. The pump of claim 1, wherein each of the plurality of pumping
chambers are actuated individually based on a demand.
6. A machine, comprising: a power source; at least one linkage
member; at least one hydraulic actuator located remote from the
power source and configured to move the at least one linkage
member; and at least one hydraulic pump located proximal to the at
least one hydraulic actuator, wherein the at least one hydraulic
pump is electrically driven by the power source and configured to
power the at least one hydraulic actuator.
7. The machine of claim 6, wherein: the at least one linkage member
includes a plurality of the linkage members; the at least one
hydraulic actuator includes a plurality of the hydraulic actuators
located remote from the power source and configured to move the
plurality of the linkage members; and the at least one hydraulic
pump includes a plurality of hydraulic pumps located proximal the
plurality of the hydraulic actuators, wherein the plurality of the
hydraulic pumps are electrically driven by the power source and
configured to power the plurality of the hydraulic actuators.
8. The machine of claim 7, wherein: the plurality of hydraulic
actuators are paired with the plurality of linkage members to
separately move the plurality of linkage members; and each of the
plurality of hydraulic pumps is associated in a closed loop
configuration with a different pairing of the plurality of
hydraulic actuators and the plurality of linkage members.
9. The machine of claim 8, wherein each of the plurality of
hydraulic pumps is sized for a particular pairing of the plurality
of hydraulic actuators and the plurality of linkage members.
10. The machine of claim 6, wherein at least one of the plurality
of hydraulic pumps is single acting and spring biased.
11. The machine of claim 7, wherein at least one of the plurality
of hydraulic pumps is double acting.
12. The machine of claim 7, wherein each of the plurality of
hydraulic pumps is a rail pump.
13. The machine of claim 7, wherein at least one of the plurality
of hydraulic pumps is comprised of: at least two inlets; at least
two outlets; and at least two check valves configured to allow a
flow of fluid between the plurality of hydraulic actuators and the
plurality of hydraulic pumps.
14. The machine of claim 6, wherein the at least one hydraulic pump
includes: a piston configured to be affected by a magnetic force; a
conductive coil substantially encompassing the piston, wherein the
conductive coil is configured to receive an electrical current and
generate a force that urges the piston in a direction corresponding
to a direction of the electrical current through the conductive
coil.
15. A method, comprising: producing electrical power at a first
location; directing the electrical power to pressurize fluid at a
second location, remote from first location; and directing
pressurized fluid at the second location to move a work tool at the
second location.
16. The method of claim 15, further including directing the
electrical power from the first location to a plurality of
locations remote from the first location to pressurize fluid at the
plurality of locations; and directing the pressurized fluid at the
plurality of locations to move the work tool at the plurality of
locations.
17. The method of claim 16, wherein the fluid pressurized at the
plurality of locations has a different characteristic at each of
the plurality of locations.
18. The method of claim 17, wherein the characteristic includes a
flow rate.
19. The method of claim 17, wherein the characteristic includes a
pressure.
20. The method of claim 16, wherein pressurizing fluid at the
plurality of locations includes generating a variable magnetic
field.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to a hydraulic
actuating system, and more particularly, to an electrically powered
hydraulic actuating system.
BACKGROUND
[0002] Machines such as, for example, dozers, loaders, excavators,
motor graders, and other types of machinery use one or more
hydraulic actuators to accomplish a variety of tasks. These
hydraulic actuators are fluidly connected to pumps that provide a
flow of pressurized fluid to the actuators in order to do work.
Current pumping systems commonly employ mechanical means to urge
fluid to the actuators. These mechanical means tend to make the
pumping systems large, expensive, and inefficient. In addition, the
many moving parts associated with mechanical pumping systems often
lead to high maintenance costs and the potential for early pumping
system failure. Furthermore, since mechanical pumping systems
require a direct mechanical connection to a power source, remote
location of mechanical pumping systems can be difficult.
[0003] One method of countering the negative aspects of mechanical
pumping systems is set forth in U.S. Pat. No. 6,468,057 (the '057
patent) issued to Beck on Oct. 22, 2002. The '057 patent describes
a pump having a pumping chamber and a magnetic piston located
therein. In addition, the '057 patent discloses a power source
connected to an electromagnetic drive system associated with the
magnetic piston. The electromagnetic drive system is used to move
the magnetic piston throughout the pumping chamber. The movement of
the magnetic piston in the pumping chamber pressurizes fluid and
urges it in a desired direction. This process is completed without
the pumping system being mechanically connected to a power
source.
[0004] Although the electromagnetic pump described in the '057
patent may overcome some of the drawbacks of mechanically powered
pumping systems, the pump in the '057 patent may be inefficient for
varying flow rate and/or pressure demand situations. That is, the
pump in the '057 patent may not have the ability to fluidly connect
to multiple actuators with varying flow rate and/or pressure
demands. Furthermore, the electromagnetic pump described in the
'057 patent may also have limited applicability in high flow
situations due to the pump's size. In order to accommodate large
flow rates, the pump in '057 patent may need to be scaled up,
resulting in high manufacturing costs and difficulty in remote
placement.
[0005] The disclosed system is directed to overcoming one or more
of the problems set forth above.
SUMMARY
[0006] In one aspect, the present disclosure is directed to a pump.
The pump includes a plurality of electro-magnetically actuated
pumping chambers, a common inlet situated to supply the plurality
of electro-magnetically actuated pumping chambers with low-pressure
fluid, and a common outlet situated to receive fluid pressurized by
the plurality of electro-magnetically actuated pumping
chambers.
[0007] In another aspect, the present disclosure is directed to a
method of operating a machine. The method may include producing
power at a first location, and directing the power to pressurize
fluid at a second location, remote from first location. The method
may also includes directing pressurized fluid at the second
location to move a work tool at the second location.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a diagrammatic illustration of an exemplary
disclosed machine;
[0009] FIG. 2 is a schematic illustration of an exemplary disclosed
hydraulic circuit that may be used with the machine of FIG. 1;
[0010] FIG. 3 is a cross-sectional illustration of an exemplary
disclosed pump that may be used in conjunction with the hydraulic
circuit of FIG. 2; and
[0011] FIG. 4 is a schematic illustration of another exemplary
disclosed pump that may be used in conjunction with the hydraulic
circuit of FIG. 2.
DETAILED DESCRIPTION
[0012] FIG. 1 illustrates an exemplary machine 100. Machine 100 may
be a fixed or mobile machine that performs some type of operation
associated with an industry such as mining, construction, farming,
transportation, or any other industry known in the art. For
example, machine 100 may be an earth moving machine such as an
excavator, a dozer, a loader, a backhoe, a motor grader, or any
other earth moving machine. Machine 100 may include a linkage
system 101, a work tool 102 attachable to linkage system 101, and
an operator interface 106 used to control motion of linkage system
101.
[0013] Linkage system 101 may include any structural unit that
supports movement of machine 100 and/or work tool 102. Linkage
system 101 may include, for example, a stationary base frame (not
shown), a boom 109, and a stick 110. Boom 109 may be pivotally
connected to the frame, while stick 110 may be pivotally connected
to boom 109 at a joint 111. Work tool 102 may pivotally connect to
stick 110 at a joint 112. It is contemplated that linkage system
101 may include an alternative configuration and/or a different
number of linkage members than what is depicted in FIG. 1, if
desired.
[0014] Numerous different work tools 102 may be attachable to stick
110 and controllable via operator interface 106. Work tool 102 may
include any device used to perform a particular task such as, for
example, a bucket, a fork arrangement, a blade, a shovel, a ripper,
a dump bed, a broom, a snow blower, a propelling device, a cutting
device, a grasping device, or any other task-performing device
known in the art. Work tool 102 may be configured to pivot, rotate,
slide, swing, lift, or move relative to machine 100 in any manner
known in the art.
[0015] Operator interface 106 may be configured to receive input
from a machine operator indicative of a desired work tool movement.
Specifically, operator interface 106 may include an operator
interface device 113 and an electronic control module 114. In one
embodiment, operator interface device 113 may be a multi-axis
joystick located to one side of an operator station. Operator
interface device 113 may be a proportional-type controller
configured to position and/or orient work tool 102 by producing and
sending an interface device position signal to electronic control
module 114. The interface device position signal sent from operator
interface device 113 to electronic control module 114 may be
indicative of a desired movement of work tool 102. It is
contemplated that additional and/or different operator interface
devices may be included within operator interface 106 such as, for
example, wheels, knobs, push-pull devices, switches, pedals, and
other operator interface devices known in the art.
[0016] Electronic control module 114 may include all the components
required to perform the required system controls such as, for
example, a memory, a secondary storage device, and a processor,
such as a central processing unit. One skilled in the art will
appreciate that electronic control module 114 can contain
additional or different components. Associated with electronic
control module 114 may be various other known circuits such as, for
example, power supply circuitry, signal conditioning circuitry, and
solenoid driver circuitry, among others.
[0017] Machine 100 may also include a plurality of hydraulic
circuits 130, 140, 150 interconnecting linkage system 101 and
controlled by electronic control module 114. Electronic control
module 114 may communicate with hydraulic circuits 130, 140, 150
via control communication lines (not shown), and may be used to
regulate operation of hydraulic circuits 130, 140, 150 in response
to an operator input received via operator interface device
113.
[0018] As illustrated in FIG. 2, hydraulic circuits 130, 140, 150
may each have a plurality of fluid components that cooperate
together to move linkage system 101 and/or work tool 102.
Furthermore, while FIG. 1 depicts three hydraulic circuits 130,
140, 150, for the purposes of simplicity, FIG. 2 only depicts one
that may be representative of any or all of hydraulic circuits 130,
140, 150.
[0019] Each of hydraulic circuits 130, 140, 150 may include an
electromagnetic pump 201 drivingly coupled to a hydraulic actuator
202, and a tank 203 configured to hold a supply of low-pressure
fluid. Electromagnetic pump 201 may be a rail pump. Furthermore,
the fluid may include, for example, a dedicated hydraulic oil, an
engine lubrication oil, a transmission lubrication oil, an engine
fuel, or any other fluid known in the art. Electromagnetic pump 201
may draw fluid from tank 203, and hydraulic actuator 202 may return
fluid to tank 203. It is also contemplated that each hydraulic
circuit 130, 140, 150 may alternatively be connected to separate
fluid tanks, if desired.
[0020] Hydraulic actuator 202 may include a tube 204 and a piston
assembly 205. Piston assembly 205 may be disposed within tube 204
to form a first pumping chamber 206 and a second pumping chamber
207. First and second pumping chambers 206, 207 may be selectively
supplied with pressurized fluid from electromagnetic pump 201, and
selectively drained of the fluid to cause piston assembly 205 to
displace within tube 204. This displacement may change an effective
length of hydraulic actuator 202, thereby moving linkage system 101
and/or work tool 102.
[0021] Piston assembly 205 may include a piston 208 axially aligned
with and disposed within tube 204. Piston assembly 205 may further
include a piston rod 209 connectable to the frame of machine 100,
boom 109, stick 110, and/or work tool 102 (disclosed to FIG. 1).
Piston 208 may include a first hydraulic surface 210, and a second
hydraulic surface 211 opposite first hydraulic surface 210. An
imbalance of force caused by fluid pressure on first and second
hydraulic surfaces 210, 211 may result in movement of piston
assembly 205 within tube 204. For example, a force on first
hydraulic surface 210 being greater than a force on second
hydraulic surface 211 may cause piston assembly 205 to increase the
effective length of hydraulic actuator 202. Similarly, when a force
on second hydraulic surface 211 is greater than a force on first
hydraulic surface 210, piston assembly 205 may retract within tube
204, thereby decreasing the effective length of hydraulic actuator
202. A flow rate of the fluid into and out of first and second
pumping chambers 206, 207 may relate to a velocity of the change in
effective length of hydraulic actuator 202. Furthermore, a pressure
of the fluid in contact with first and second hydraulic surfaces
210, 211 may relate to an actuation force of hydraulic actuator
202. A sealing member (not shown), such as an o-ring, may be
connected to piston 208 to restrict a flow of fluid between an
internal wall of tube 204 and an outer cylindrical surface of
piston 208. In another exemplary embodiment, actuator 202 may be a
hydraulic motor (not shown).
[0022] A drain passageway 212 may be used to relieve fluid from
hydraulic actuator 202 to tank 203 by way of a valve 213. Although
disclosed as a single valve mechanism, the described functions of
valve 213 may, alternatively, be accomplished by multiple separate
or cooperating valve mechanism if desired. Fluid may be drawn from
tank 203 and supplied to electromagnetic pump 201 via a fluid
passageway 214. Electromagnetic pump 201 may pressurize the fluid,
and direct the pressurized fuel to hydraulic actuator 202 through a
fluid passageway 215 and valve 213.
[0023] Electromagnetic pump 201 may include a housing 216 that at
least partially defines a first pumping chamber 217 and a second
pumping chamber 218. Electromagnetic pump 201 may also include a
piston 219 configured to be affected by magnetic forces. In one
embodiment, piston 219 may be made of magnetic material. In another
embodiment, piston 219 may be a ferromagnetic material such as, for
example, iron nickel, and/or cobalt. Piston 219 may be disposed
within housing 216 between first and second pumping chamber 217,
218.
[0024] Electromagnetic pump 201 may include a first inlet 220 and a
second inlet 221 fluidly connecting first and second pumping
chambers 217, 218 to fluid passageway 214 in parallel. A first
inlet check valve 223 may be disposed between tank 203 and first
pumping chamber 217, and may be configured to allow a
unidirectional flow of low-pressure fluid from tank 203 to first
pumping chamber 217. A second inlet check valve 224 may be disposed
between tank 203 and second pumping chamber 218, and may be
configured to allow a unidirectional flow of low-pressure fluid
from tank 203 to second pumping chamber 218.
[0025] Electromagnetic pump 201 may also include a first outlet 225
and a second outlet 227 fluidly connecting first and second pumping
chambers 217, 218 to fluid passageway 215 in parallel. A first
outlet check valve 226 may be disposed between first pumping
chamber 217 and valve 213, and may be configured to allow a
unidirectional flow of fluid from first pumping chamber 217 to
hydraulic actuator 202 via valve 213. A second outlet check valve
228 may be disposed between second pumping chamber 218 and valve
213, and may be configured to allow a unidirectional flow of fluid
from second pumping chamber 218 to hydraulic actuator 202 via valve
213.
[0026] Electromagnetic pump 201 may have a conductive material 229
encompassing and/or forming a point of contact with first and
second pumping chambers 217, 218. In one embodiment, conductive
material 229 may be wound around first and second pumping chambers
217, 218 as a continuous coil. In another embodiment, conductive
coil 229 may form two non-connected portions, with a first portion
wrapped around first pumping chamber 217, and a second portion
wrapped around second pumping chamber 218.
[0027] Conductive material 229 may be any type of material that
allows electrical current to pass through it such as, for example,
copper or aluminum. Conductive material 229 may be electrically
connected (not shown) to electronic control module 114 and/or a
power source 107 (shown in FIG. 1). Conductive material 229 may be
configured to receive electrical current from power source 107. In
one embodiment, power source 107 may be the primary mover of
machine 100.
[0028] The electrical current supplied from power source 107 may be
used to create a variable magnetic force (i.e., variable magnetic
field) that urges piston 219 in a direction corresponding to the
direction of the electrical current in conductive material 229. If
the conducting material is formed into two non-connecting portions,
power source 107 may connect to each of the two portions
individually. The two connections may allow for power source 107 to
supply electrical current to conductive material 229 at different
levels and/or in different directions.
[0029] The cyclical movements of piston 219 may force high-pressure
fluid to hydraulic actuator 202 via fluid passage way 215 and valve
213, causing piston assembly 205 to either increase or decrease the
effective stroke length of hydraulic actuator 202. The change in
effective length of hydraulic actuator 202 may be dependent upon
the amount and direction of electrical current supplied to
conductive material 229 from power source 107, as well as the
position of valve 213. A sealing member (not shown) such as, for
example, an o-ring, may be connected to piston 219 to restrict a
flow of fluid between an internal wall of housing 216 and an outer
cylindrical surface of the piston 219.
[0030] Control signals generated by electronic control module 114,
and directed to hydraulic circuits 130, 140, 150 via communication
line (not shown), may determine when and how much electrical
current, as well as the direction of electrical current supplied to
conductive material 229. For example, an operator may move operator
interface device 113 to indicate a desired movement of linkage
system 101. In response, electronic control module 114 may receive
and/or generate communication signals indicative of the operator
desired movement. The signals received and/or generated by
electronic control module 114 may be used to determine the amount,
as well as the direction of electrical current supplied to
conductive material 229 in order to accomplish the desired movement
of linkage system 101.
[0031] An alternative embodiment of electromagnetic pump 201 is
depicted in FIG. 3. In this embodiment, electromagnetic pump 300
may only be electro-magnetically urged in a first direction.
Specifically, electromagnetic pump 201 may include a return spring
301 that returns piston 219 in a second direction, opposite of the
first direction. Because electromagnetic pump 300 is only
electro-magnetically urged in a single direction, electromagnetic
pump 300 only includes a single inlet and outlet.
[0032] Spring 301 may be a coil spring, a helical spring, a conical
spring, or any other type of spring known in the art. Furthermore,
spring 301 may be a tension spring, or a compression spring. Spring
301 may be made of any material that can be elastically formed to
store and use mechanical energy. For example, spring 301 may be
made out of spring steel, an elastomeric material, or any other
type of material known in the art.
[0033] In an alternative embodiment illustrated in FIG. 4, machine
100 may include a single pump 400 having a plurality of
electromagnetic pumping chambers 401, 402, 403 that may be used in
place of multiple separate electromagnetic pumps 201 (disclosed in
FIG. 1 and FIG. 2). Although FIG. 4 discloses three pumping
chambers within a common housing 404, any number of pumping
chambers may be used.
[0034] Housing 404 may include a common inlet 405 being connected
to fluid passageway 214, and a common outlet 406 being connected to
fluid passageway 215 (illustrated in FIG. 2). The plurality of
pumping chambers 401, 402, 403 may have individual inlets, outlets,
and check valves that allow the flow of fluid between pumping
chambers 401, 402, 403, and inlet 405 and outlet 406. The
individual inlets, outlets, and check valves of FIG. 4 may be at
similar locations and perform similar tasks as the inlets, outlets,
and check valves disclosed in FIG. 2. Each of pumping chambers 401,
402, 403 may be substantially similar to electromagnetic pump 201.
Furthermore, the movement of piston 219 may cause high-pressure
fluid to travel from pumping chambers 401, 402, 403 to one or more
hydraulic actuators 202.
[0035] Pumping chambers 401, 402, 403 may be any combination of
electromagnetic pump 201, electromagnetic pump 300, and/or any type
of pump known in the art. For example, in one embodiment, pumping
chamber 401 may be electromagnetic pump 201, with pumping chambers
402, 403 being electromagnetic pump 300 (disclosed in FIG. 3). In
another embodiment, pumping chambers 401, 402, 403 may all be
composed of electromagnetic pump 300.
[0036] The pumps described herein may be paired in a closed-loop
configuration with specific actuators. This closed-loop pairing may
include pumps that are individually sized to meet the demands of
the specific actuator with which the pump is paired. The sizing may
be determined by the desired pump and actuator characteristics such
as, for example, flow rate and/or pressure.
[0037] Furthermore, for electromagnetic pump 400 (disclosed in FIG.
4), pumping chambers 401, 402, 403 may be actuated individually
and/or at different rates depending on the desired flow rate
output. For example, in one embodiment, a small desired flow rate
(associated with work tool 102 moving a small load) may result in
power source 107 supplying electrical current to only the
conductive material encompassing pumping chamber 401. If the
desired flow rate increases (associated with work tool 102 moving a
large load), power source 107 may then supply electrical current to
conductive material encompassing additional pumping chambers 402,
and/or 403. Furthermore, the electrical current supplied to pumping
chambers 401, 402, 403 may at different times, in different
directions, and/or in different amounts.
INDUSTRIAL APPLICABILITY
[0038] The disclosed system may be applicable to any machine where
it is desirable to minimize cost of hydraulic circuits, and allow
for remote placement of hydraulic circuits. Furthermore, the
disclosed system may be applicable to any machine requiring flow
rates of pressurized fluid and/or having multiple actuators
demanding different flow rates. The disclosed system may minimize
cost and size, while improving response and efficiency by allowing
for fewer parts in creation of the disclosed system. The disclosed
system may be more efficient and responsive since the individual
pumps can be sized with an actuator depending upon the desired
task. Furthermore, the disclosed system may allow for remote
placement since it may be powered electrically instead of
mechanically. The operation of hydraulic circuits 130, 140, 150, as
illustrated in FIG. 1 and FIG. 2, will now be explained.
[0039] During operation of machine 100, an operator may manipulate
interface device 113 to indicate a desired movement of machine 100.
Throughout this manipulation process, electronic control module 114
may receive the desired movement indications, generate
corresponding signals indicative of desired flow rates of fluid,
and supply the signals to power source 107, and hydraulic circuits
130, 140, 150 accordingly.
[0040] In response to operator input to either extend or retract
piston assembly 205, fluid may be pressurized by electromagnetic
pump 201, and selectively directed to hydraulic actuator 202
through fluid passage way 215. Electronic control module 114 may
move valve 213 to a flow-passing position, thereby allowing
pressurized fluid to the appropriate one of first and second
pumping chambers 206, 207. Substantially simultaneously, valve 213
may allow the draining of the appropriate one of the first and
second pumping chambers 206, 207 to tank 203, thereby creating a
force imbalance on piston 208 that causes piston assembly 205 to
move.
[0041] For example, if an extension of at least one of hydraulic
circuits 130, 140, 150 is requested, valve 213 may be moved to the
position that allows pressurized fluid to flow from electromagnetic
pump 201 to first pumping chamber 206. Substantially simultaneous
with the directing of pressurized fluid to first pumping chamber
206, valve 213 may allow fluid from second pumping chamber 207 to
drain to tank 203. If retraction of at least one of hydraulic
circuits 130, 140, 150 is requested, valve 213 may be moved to the
position that allows pressurized fluid to flow from electromagnetic
pump 201 to second pumping chamber 207. Substantially simultaneous
to the directing of pressurized fluid to second pumping chamber
207, valve 213 may allow fluid from first pumping chamber 206 to
drain to tank 203.
[0042] Power source 107 may supply electrical current to conductive
material 229 to create an electromagnetic force that urges piston
219 in a desired direction with a desired velocity and force. The
movement of piston 219 may urge the fluid in a desired direction,
thereby efficiently accomplishing the desired movements of machine
100. The amount and direction of electrical current supplied to
conductive material 229 may be dependent upon the desired movement
of machine 100.
[0043] The disclosed system may efficiently handle varying flow
rate and/or pressure demand situations since the plurality of rail
chambers (FIG. 4) may fluidly connect to multiple actuators with
varying flow rate and/or pressure demands.
[0044] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed hydraulic
system. Other embodiments will be apparent to those skilled in the
art from consideration of the specification and practice of the
disclosed hydraulic system. It is intended that the specification
and examples be considered as exemplary only, with a true scope
being indicated by the following claims and their equivalents.
* * * * *