CA1085267A - Dual pump flow combining system - Google Patents
Dual pump flow combining systemInfo
- Publication number
- CA1085267A CA1085267A CA301,984A CA301984A CA1085267A CA 1085267 A CA1085267 A CA 1085267A CA 301984 A CA301984 A CA 301984A CA 1085267 A CA1085267 A CA 1085267A
- Authority
- CA
- Canada
- Prior art keywords
- pump
- valve
- motor
- port
- chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/2053—Type of pump
- F15B2211/20538—Type of pump constant capacity
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20576—Systems with pumps with multiple pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/30505—Non-return valves, i.e. check valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
- F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
- F15B2211/31582—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having multiple pressure sources and a single output member
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/505—Pressure control characterised by the type of pressure control means
- F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
- F15B2211/50536—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using unloading valves controlling the supply pressure by diverting fluid to the return line
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/50—Pressure control
- F15B2211/52—Pressure control characterised by the type of actuation
- F15B2211/528—Pressure control characterised by the type of actuation actuated by fluid pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/65—Methods of control of the load sensing pressure
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
- Control Of Fluid Gearings (AREA)
- Details Of Reciprocating Pumps (AREA)
Abstract
Abstract of the Disclosure A control valve of a fluid circuit connecting a first pump to a fluid motor has a signal port in communication with an inlet port when the control valve is at a selected position at which substantially the total output of the first pump is directed to the motor. A valve device connects a second pump to the fluid circuit in response to a valve spool of the control valve being moved to said selected position. The valve device has a valve member, a chamber at one end of the valve member, and biasing means. The valve member is movable between a first position at which the second pump is in communication with a tank and a second position at which the output of the second pump is combined with the output of the first pump in the fluid circuit. The biasing device urges the valve member to the first position and said chamber is connected to the signal port of the control valve.
Description
10~5Z6~
Back~round of the Invention Many hydraulic systems have a large capacity pump as the primary source of fluid for several control valves, each of which controls fluid flow to one or more fluid motors. In some systems, a smaller capacity pump is provided to supplement the output of the larger pump when the fluid pressure of the system is below a predetermined magnitude.
One of the problems encountered with such systems is that although the output of the small pump generally is needed for only the motor or motors controlled by one control valve or for only a small percentage of the time, the output of both pumps passes through the control valves all the time that the fluid pressure is below the predetermined magnitude.
This causes additional problems particularly when fluid flow to the motors is being modulated by the control valves since the control valves must then modulate the total output of both pumps.
The Applicant of the present application is aware of one system which solves the above problem. Such system has a fluid circuit which connects a first pump to a fluid motor and has a control valve for controlling fluid flow from the first pump to the motor. The control valve has an inlet port connected to the pump, a motor port connected to the motor, and a valve spool movable between a first position at which the inlet port is blocked from communication with the motor port, a second position at which fluid flow from the inIet port to the motor port is controllably modulated, - and a third position at which substantially the total output of the first pump passes from the inlet port to the motor port. The second pump is connected to the fluid circuit ~ ' iZ6~7 through a combining valve in response to the valve spool being moved to the third position. At the third position, the valve spool blocks a flow path from a signal chamber of the combining valve to a drain port so that the fluid pressure e~ualizes on both ends of a valve rnember of the combining valve. A spring then moves the valve member to a combining position. However, it has been found in practice that in some instances a combining valve which is shifted to the combining position directly by pressurized fluid is more responsive and is less subject to false pressure signals due to sudden pressure fluctuations in the system than a combining valve having the valve member moved to the combining position solely by the bias of a spring.
Summary of the Invention ~he present invention is directed to overcoming one or more of the problems as set forth above.
A dual pump flow combining system has first and second pumps, a double acting fluid motor, and a fiuid circuit connecting the first pump to the motor. The fluid circuit has a control valve for controlling fluid flow therethrough from the first pump to the motor. The control valve has an inlet port connected to the pump, a motor pump connected to the motor and a valve spool movable between a first position at which the inlet port is blocked from communication with the motor port, a second position at which fluid flow through the control valve from the inlet port to the motor port is controllably modulated, and a -` - third position at which substantlally the total output of the first pump passes through the control valve from the inlet pcrt to ~he motor port. A first means connects the .
~0~526~7 second pump to the fluid circuit in response to the valve spool being moved to the third position. The control valve has a signal port connected to the inlet port at the third position of the valve spool. The first means includes a valve means having a valve member, a chamber at one end of the valve member, and biasing means. The valve member is movable between a first position at which the second pump is in communication with a tank and a second position at which the second pump is blocked from communication with the tank and the output of the second pump is combined with the output of the first pump in the fluid circuit. The biasing means urges the valve member to the first position. The chamber is connected to the signal port of the control valve.
The second pump is connected to the motor port of the `
control valve.
Brief Description of the Drawing The sole figure is a diagrammatic view of an embodiment of this invention.
Detailed Description Referring to the drawing, a dual pump flow combining system is generally indicated at 10 for selectively combining the fluid output of first and second pumps 11, 12 driven by an engine, not shown. A fluid circuit 13 connects the first pump to a fluid motor 14 and includes conduits 16-18 and a valve means 19.
The valve means 19 can be, for example, a direc-tional control valve 21 which controls fluid flow from the first pump 11 to and from the fluid motor 14. The control valve has a valve member or spool 22 which is shown at a ; 30 neutral or centered position indicated by the letter "N".
At this position, fluid passing through an inlet port 23 connected . ~
1085Z6~
to the conduit 16 is returned to a tank 2LI through a drain passage 26 and the inlet port is blocked from communication with a pair of motor ports 27, 28 connected to the conduits 17, 18, respectively. The valve spool 22 is movable to the left as viewed in the drawing between the centered position and a fully actuated position indicated by the letter "R".
At thls position, the inlet port 23 ls blocked from communi-cation with the drain passage 26 and is in communication with the motor port 27 sufficient for the total output of the first pump 11 to be directed through the motor port 27 and to the head end'of the fluid motor 14. The fluid motor ', can be connected to an earthworking tool so that directing 'fluid to the head end raises the tool. The valve spool is movable to a plurality or range of modulating positions intermediate the centered position and the fully actuated position as indicated by the letter "m". At each of these ; modulating positions, fluid flow from the inlet port 23 to the motor port 27 is controllably modulated with the amount - of fluid passing from inlet port 23 to motor port 27 progres-sively increasing as the valve spool moves from the centered position to the fully actuated position.
The control valve 21 has a signal port 29 which is , connected with a drain port 31 through a slot 32 in the valve spool 22 at the centered position and substantially , 25 all of the modulating positions of the valve spool. When ', the valve spool is moved from the modulating position to the fully actuated position, the signal port 29 is communicated with the inlet port 23 through a passageway 33 in the spool.
The signal port is preferably positioned relative to the ,passageway 33 so that as the valve spool 22 is moved to the : , , ~0~5;~7 lef~" communication between the passageway and the signal port is established when the spool reaches a position at which substantially the total output of the first pump 11 passes from the inlet port 23 to the motor port 27.
A valve means 36 is connected to the second pump 12 through a conduit 37 and to the motor port 27 through a conduit 38. A valve member 39 is movable between a first position at which the second pump 12 is in communication with the tank 24 and a second position at which the second pump is blocked from communication with the tank and is in communication with the motor port 27 for combining the output of the second pump 12 with the output of the first ; pump 11 at the motor port 27. A check valve 41 is positioned in the conduit 38 for preventing fluid from passing from the motor port 27 to the valve means 36. A biasing means, for example a spring 42, is positioned within a chamber 40 at one end of the valve member and urges the valve member to the first position. A passageway 45 in the valve member vents the chamber 40 to the tank 24. A signal chamber 43 is positioned at the opposite end of the valve member.
An unloading valve assembly 44 has a chamber 46 connected to the signal port 29. Another chamber 47 is connected to the chamber 46 through a flow restrictor or orifice 48 and to the signal chamber 43 through a passage 49. A poppet valve 51 is positioned for blocking a passage -~ 52 connected to the chamber 46. The poppet valve is movable - between a closed position at which the chamber 47 is blocked from communication with the tank and an opened position at which chamber 47 is in communication with the tank through passage 52. A spring 53 biases the poppet valve to the ~ .
. . . . . . , , : , , ~)85Z67 closed position and is of a size sufflcient for allowing the poppet valve to move to its opened position in response to fluid pressure in chamber 47 exceeding a preselected magnitude.
A piston 54 is slidably positioned within a bore 5 56 having an open end in communication with the cha~ber 46.
An enlarged head portion 57 of the piston is disposed within the chamber 47 adjacent the inner end of the poppet valve In the operation of this apparatus, the valve member 39 of valve means 36 is moved to the second positionin response to pressurized fluid in the signal chamber 43.
With valve spool 22 of control valve 21 in either the centered or modulating positions, the signal port 29 is in communication with the drain port 31 thereby venting signal chamber 43 to the tank. With signal chamber 43 vented, the spring 42 biases the valve member to the first position shown.
Moving,the valve spool 22 from the modulating ' position to its fully open position blocks communication , between the signal port 29 and drain port 31 and establishes communication between the signal port 29 and the inlet port '~ 23 through the passageway 33. Pressurized fluid from the ` inlet port passes through the signal port and into chamber 46, through the orifice 48 and into chamber 47, and through , passage 49 and into signal chamber 43 where it moves the valve member 39 to the second position,. The fluid exhausted from the chamber 40 pas,ses through the passageway 45 and ~; into the tank 24. At the second position of the valve member, the output of the second pump 12 is combined with the output of the first pump 11.
3o io~s~q Should the fluid pressure in the fluid c-Lrcuit 13 and thus in inlet port 23, signal port 29 and chambers 46, 47 exceed a preselected magnitude the fluid pressure in the chamber 47 unseats the poppet valve 51 thereby communicating chamber 47 with the tank. The signal chamber 43 is also '.
vented to the tank resulting i,n the valve member 39 being moved to the first position under the influence of the spring 42.
~1ith chamber 47 opened to the tank, a pressure differential across the orifice 48 between chambers 46, 47 is also created. .he higher fluid pressure in chamber 46 then moves the piston 54 into abutment with the poppet.valve ,~
51 holding the poppet valve in the opened position until the fluid pressure in the chamber 46 decreases t,o a second preselected magnitude at which time the poppet valve will be moved to its closed position by the spring 53. ' , - Other aspects, objects and advantages of this invention can be obtained from a study of the drawing, the disclosure and the appended claims.
. 20 ~ ~, ' ''' ' .
, ' ' 30 . , _~_
Back~round of the Invention Many hydraulic systems have a large capacity pump as the primary source of fluid for several control valves, each of which controls fluid flow to one or more fluid motors. In some systems, a smaller capacity pump is provided to supplement the output of the larger pump when the fluid pressure of the system is below a predetermined magnitude.
One of the problems encountered with such systems is that although the output of the small pump generally is needed for only the motor or motors controlled by one control valve or for only a small percentage of the time, the output of both pumps passes through the control valves all the time that the fluid pressure is below the predetermined magnitude.
This causes additional problems particularly when fluid flow to the motors is being modulated by the control valves since the control valves must then modulate the total output of both pumps.
The Applicant of the present application is aware of one system which solves the above problem. Such system has a fluid circuit which connects a first pump to a fluid motor and has a control valve for controlling fluid flow from the first pump to the motor. The control valve has an inlet port connected to the pump, a motor port connected to the motor, and a valve spool movable between a first position at which the inlet port is blocked from communication with the motor port, a second position at which fluid flow from the inIet port to the motor port is controllably modulated, - and a third position at which substantially the total output of the first pump passes from the inlet port to the motor port. The second pump is connected to the fluid circuit ~ ' iZ6~7 through a combining valve in response to the valve spool being moved to the third position. At the third position, the valve spool blocks a flow path from a signal chamber of the combining valve to a drain port so that the fluid pressure e~ualizes on both ends of a valve rnember of the combining valve. A spring then moves the valve member to a combining position. However, it has been found in practice that in some instances a combining valve which is shifted to the combining position directly by pressurized fluid is more responsive and is less subject to false pressure signals due to sudden pressure fluctuations in the system than a combining valve having the valve member moved to the combining position solely by the bias of a spring.
Summary of the Invention ~he present invention is directed to overcoming one or more of the problems as set forth above.
A dual pump flow combining system has first and second pumps, a double acting fluid motor, and a fiuid circuit connecting the first pump to the motor. The fluid circuit has a control valve for controlling fluid flow therethrough from the first pump to the motor. The control valve has an inlet port connected to the pump, a motor pump connected to the motor and a valve spool movable between a first position at which the inlet port is blocked from communication with the motor port, a second position at which fluid flow through the control valve from the inlet port to the motor port is controllably modulated, and a -` - third position at which substantlally the total output of the first pump passes through the control valve from the inlet pcrt to ~he motor port. A first means connects the .
~0~526~7 second pump to the fluid circuit in response to the valve spool being moved to the third position. The control valve has a signal port connected to the inlet port at the third position of the valve spool. The first means includes a valve means having a valve member, a chamber at one end of the valve member, and biasing means. The valve member is movable between a first position at which the second pump is in communication with a tank and a second position at which the second pump is blocked from communication with the tank and the output of the second pump is combined with the output of the first pump in the fluid circuit. The biasing means urges the valve member to the first position. The chamber is connected to the signal port of the control valve.
The second pump is connected to the motor port of the `
control valve.
Brief Description of the Drawing The sole figure is a diagrammatic view of an embodiment of this invention.
Detailed Description Referring to the drawing, a dual pump flow combining system is generally indicated at 10 for selectively combining the fluid output of first and second pumps 11, 12 driven by an engine, not shown. A fluid circuit 13 connects the first pump to a fluid motor 14 and includes conduits 16-18 and a valve means 19.
The valve means 19 can be, for example, a direc-tional control valve 21 which controls fluid flow from the first pump 11 to and from the fluid motor 14. The control valve has a valve member or spool 22 which is shown at a ; 30 neutral or centered position indicated by the letter "N".
At this position, fluid passing through an inlet port 23 connected . ~
1085Z6~
to the conduit 16 is returned to a tank 2LI through a drain passage 26 and the inlet port is blocked from communication with a pair of motor ports 27, 28 connected to the conduits 17, 18, respectively. The valve spool 22 is movable to the left as viewed in the drawing between the centered position and a fully actuated position indicated by the letter "R".
At thls position, the inlet port 23 ls blocked from communi-cation with the drain passage 26 and is in communication with the motor port 27 sufficient for the total output of the first pump 11 to be directed through the motor port 27 and to the head end'of the fluid motor 14. The fluid motor ', can be connected to an earthworking tool so that directing 'fluid to the head end raises the tool. The valve spool is movable to a plurality or range of modulating positions intermediate the centered position and the fully actuated position as indicated by the letter "m". At each of these ; modulating positions, fluid flow from the inlet port 23 to the motor port 27 is controllably modulated with the amount - of fluid passing from inlet port 23 to motor port 27 progres-sively increasing as the valve spool moves from the centered position to the fully actuated position.
The control valve 21 has a signal port 29 which is , connected with a drain port 31 through a slot 32 in the valve spool 22 at the centered position and substantially , 25 all of the modulating positions of the valve spool. When ', the valve spool is moved from the modulating position to the fully actuated position, the signal port 29 is communicated with the inlet port 23 through a passageway 33 in the spool.
The signal port is preferably positioned relative to the ,passageway 33 so that as the valve spool 22 is moved to the : , , ~0~5;~7 lef~" communication between the passageway and the signal port is established when the spool reaches a position at which substantially the total output of the first pump 11 passes from the inlet port 23 to the motor port 27.
A valve means 36 is connected to the second pump 12 through a conduit 37 and to the motor port 27 through a conduit 38. A valve member 39 is movable between a first position at which the second pump 12 is in communication with the tank 24 and a second position at which the second pump is blocked from communication with the tank and is in communication with the motor port 27 for combining the output of the second pump 12 with the output of the first ; pump 11 at the motor port 27. A check valve 41 is positioned in the conduit 38 for preventing fluid from passing from the motor port 27 to the valve means 36. A biasing means, for example a spring 42, is positioned within a chamber 40 at one end of the valve member and urges the valve member to the first position. A passageway 45 in the valve member vents the chamber 40 to the tank 24. A signal chamber 43 is positioned at the opposite end of the valve member.
An unloading valve assembly 44 has a chamber 46 connected to the signal port 29. Another chamber 47 is connected to the chamber 46 through a flow restrictor or orifice 48 and to the signal chamber 43 through a passage 49. A poppet valve 51 is positioned for blocking a passage -~ 52 connected to the chamber 46. The poppet valve is movable - between a closed position at which the chamber 47 is blocked from communication with the tank and an opened position at which chamber 47 is in communication with the tank through passage 52. A spring 53 biases the poppet valve to the ~ .
. . . . . . , , : , , ~)85Z67 closed position and is of a size sufflcient for allowing the poppet valve to move to its opened position in response to fluid pressure in chamber 47 exceeding a preselected magnitude.
A piston 54 is slidably positioned within a bore 5 56 having an open end in communication with the cha~ber 46.
An enlarged head portion 57 of the piston is disposed within the chamber 47 adjacent the inner end of the poppet valve In the operation of this apparatus, the valve member 39 of valve means 36 is moved to the second positionin response to pressurized fluid in the signal chamber 43.
With valve spool 22 of control valve 21 in either the centered or modulating positions, the signal port 29 is in communication with the drain port 31 thereby venting signal chamber 43 to the tank. With signal chamber 43 vented, the spring 42 biases the valve member to the first position shown.
Moving,the valve spool 22 from the modulating ' position to its fully open position blocks communication , between the signal port 29 and drain port 31 and establishes communication between the signal port 29 and the inlet port '~ 23 through the passageway 33. Pressurized fluid from the ` inlet port passes through the signal port and into chamber 46, through the orifice 48 and into chamber 47, and through , passage 49 and into signal chamber 43 where it moves the valve member 39 to the second position,. The fluid exhausted from the chamber 40 pas,ses through the passageway 45 and ~; into the tank 24. At the second position of the valve member, the output of the second pump 12 is combined with the output of the first pump 11.
3o io~s~q Should the fluid pressure in the fluid c-Lrcuit 13 and thus in inlet port 23, signal port 29 and chambers 46, 47 exceed a preselected magnitude the fluid pressure in the chamber 47 unseats the poppet valve 51 thereby communicating chamber 47 with the tank. The signal chamber 43 is also '.
vented to the tank resulting i,n the valve member 39 being moved to the first position under the influence of the spring 42.
~1ith chamber 47 opened to the tank, a pressure differential across the orifice 48 between chambers 46, 47 is also created. .he higher fluid pressure in chamber 46 then moves the piston 54 into abutment with the poppet.valve ,~
51 holding the poppet valve in the opened position until the fluid pressure in the chamber 46 decreases t,o a second preselected magnitude at which time the poppet valve will be moved to its closed position by the spring 53. ' , - Other aspects, objects and advantages of this invention can be obtained from a study of the drawing, the disclosure and the appended claims.
. 20 ~ ~, ' ''' ' .
, ' ' 30 . , _~_
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a dual pump flow combining system having first and second pumps; a double acting fluid motor; a fluid circuit connecting the first pump to the motor and having a control valve for controlling fluid flow therethrough from the first pump to the motor, said control valve having an inlet port connected to the pump, a motor port connected to the motor, and a valve spool movable between a first position at which the inlet port is blocked from communica-tion with the motor port, a second position at which fluid flow through the control valve from the inlet port to the motor port is controllably modulated, and a third position at which substantially the total output of the first pump passes through the control valve from the inlet port to the motor port; the improvement comprising:
first means for connecting the second pump to the fluid circuit in response to the valve spool being moved from the second position to the third position;
said control valve having a signal port connected to the inlet port at the third position of the valve spool;
said first means including a valve means having a valve member, a chamber at one end of the valve member, and biasing means, said valve member being movable between a first position at which the second pump is in communication with a tank and a second position at which the second pump is blocked from communication with the tank and the output of the second pump is combined with the output of the first pump in the fluid circuit, said biasing means urging the valve member to the first position, and said chamber being connected to the signal port of the control valve;
and said second pump being connected to the motor port of the control valve.
first means for connecting the second pump to the fluid circuit in response to the valve spool being moved from the second position to the third position;
said control valve having a signal port connected to the inlet port at the third position of the valve spool;
said first means including a valve means having a valve member, a chamber at one end of the valve member, and biasing means, said valve member being movable between a first position at which the second pump is in communication with a tank and a second position at which the second pump is blocked from communication with the tank and the output of the second pump is combined with the output of the first pump in the fluid circuit, said biasing means urging the valve member to the first position, and said chamber being connected to the signal port of the control valve;
and said second pump being connected to the motor port of the control valve.
2. The combining system of claim 1 including second means for venting said chamber in response to the fluid pressure in the fluid circuit exceeding a preselected magnitude.
3. The combining system of claim 1 including a second chamber at the other end of the valve member and passageway means for venting the second chamber to the tank, said biasing means being positioned within said second chamber.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US81426077A | 1977-07-11 | 1977-07-11 | |
| US814,260 | 1977-07-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1085267A true CA1085267A (en) | 1980-09-09 |
Family
ID=25214565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA301,984A Expired CA1085267A (en) | 1977-07-11 | 1978-04-26 | Dual pump flow combining system |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5419071A (en) |
| CA (1) | CA1085267A (en) |
| DE (1) | DE2829551A1 (en) |
| FR (1) | FR2397548A1 (en) |
| GB (1) | GB1566385A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5811236A (en) * | 1981-07-08 | 1983-01-22 | Toshiba Mach Co Ltd | Hydraulic device for vehicle |
| DE3210759A1 (en) * | 1981-09-17 | 1983-10-06 | Walter Schopf | Pump combination with flow control device |
| JPS6039343U (en) * | 1983-08-22 | 1985-03-19 | 海野 治男 | Sorting and crushing equipment for demolished concrete |
| DE3608469A1 (en) * | 1986-03-14 | 1987-10-01 | Bosch Gmbh Robert | HYDRAULIC SYSTEM |
| DE3611973C2 (en) * | 1986-04-09 | 1994-04-14 | Rexroth Mannesmann Gmbh | Shunt valve |
| DE19640103C2 (en) * | 1996-09-28 | 2000-12-07 | Danfoss Fluid Power As Nordbor | control valve |
| CN109372814B (en) * | 2018-12-15 | 2023-09-19 | 浙江海宏液压科技股份有限公司 | Converging lifting load sensitive multi-way valve |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2728194A (en) * | 1954-03-29 | 1955-12-27 | Vickers Inc | Control circuit for hydraulic power transmission |
| US4002027A (en) * | 1973-10-01 | 1977-01-11 | Tyrone Hydraulics, Inc. | Multiple pump control system |
| DE2445979A1 (en) * | 1973-10-01 | 1975-04-10 | Sargent Industries | CONTROL DEVICE FOR SEVERAL MOTOR-DRIVEN PUMPS |
-
1978
- 1978-04-13 GB GB1454778A patent/GB1566385A/en not_active Expired
- 1978-04-26 CA CA301,984A patent/CA1085267A/en not_active Expired
- 1978-06-28 FR FR7819319A patent/FR2397548A1/en active Granted
- 1978-07-05 DE DE19782829551 patent/DE2829551A1/en not_active Withdrawn
- 1978-07-05 JP JP8107578A patent/JPS5419071A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| DE2829551A1 (en) | 1979-01-25 |
| GB1566385A (en) | 1980-04-30 |
| FR2397548A1 (en) | 1979-02-09 |
| JPS5419071A (en) | 1979-02-13 |
| FR2397548B1 (en) | 1984-06-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |