US3649134A - Control apparatus for limiting the power received by a plurality of adjustable hydraulic pumps - Google Patents

Control apparatus for limiting the power received by a plurality of adjustable hydraulic pumps Download PDF

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Publication number
US3649134A
US3649134A US51858A US3649134DA US3649134A US 3649134 A US3649134 A US 3649134A US 51858 A US51858 A US 51858A US 3649134D A US3649134D A US 3649134DA US 3649134 A US3649134 A US 3649134A
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Prior art keywords
control
valve
circuits
output
pumps
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Expired - Lifetime
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US51858A
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English (en)
Inventor
Ludwig Wagenseil
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Constantin Rauch KG
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Constantin Rauch KG
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/007—Installations or systems with two or more pumps or pump cylinders, wherein the flow-path through the stages can be changed, e.g. from series to parallel

Definitions

  • the invention relates to a control apparatus for limiting the total power received by a plurality of adjustable hydraulic pumps driven by a prime mover which may be speed-regulated.
  • control apparatus comprising a device which responds to the speed of the prime mover and acts on the adjusting device of an adjustable pump.
  • the ad justing device can be influenced from outside for regulating the response thereof.
  • the adjustment takes place by means of a control of the output pressure of the hydraulic pumps supplied through a control valve to a control pressure circuit so as to reduce the rate of delivery when the speed of the prime mover drops.
  • Such apparatus are intended to prevent the overloading of prime movers, such as speed-regulated prime movers, and nevertheless guarantee full utilization of the installed power capacity of the prime mover over as wide a range as possible.
  • the object of the invention is to improve a control apparatus of the type mentioned initially, wherein overloading of the prime mover is prevented, in such a manner that the power of the prime mover can be fully utilized in every operating state of the individual pumps.
  • each pump with a corresponding adjusting means which is independent of that of the other pumps and may be ofdifferent design.
  • a control valve is responsive to the speed-dependent device and is associated jointly with all the adjusting devices with the interposition of a nonreturn valve leading to an auxiliary control-pressure circuit.
  • the adjusting means may comprise in a manner known per se a hydraulic piston responsive to the auxiliary control pressure and a biasing spring which may have a controllable characteristic.
  • each pump can be adjusted independently of the others. If one of the pumps is set to have zero stroke, the full power of the prime mover can be supplied to the other pumps. Since the power taken from the prime mover is not controlled by the total outputs of the pumps but by the speed of the motor, the power actually available therefrom is taken into account, even if temporarily further units have to be driven by the same motor.
  • the invention makes it possible for pumps of different sizes to be driven simultaneously by the same prime mover with the use of one and the same control apparatus. Furthermore, if the adjusting means associated with the different pumps have different characteristics, it is possible to make one of the pumps respond first or to a higher degree when overloading of the prime mover occurs.
  • individual valves for limiting the maximum delivery pressure are associated with the delivery circuits of the pumps so that each delivery pressure can be limited independently of the other circuits.
  • the pressure in the control-pressure circuit is taken by way of a two-way or by way of nonreturn valves from the highest delivery pressure of the pumps at each moment. This removes the need for a special auxiliary feed pump for the control pressure circuit.
  • An internal combustion engine 1 by way of an intermediate gear 2 drives pumps 3 and 4, which supply pressure oil through delivery conduits 5 and 6 to consumers 7 and 8, which are independent of one another.
  • the pumps can be cut off from the consumers by shutoff valves 9 and 10.
  • a two-way valve 11 connects the one of delivery conduits 5 and 6 having the higher pressure to a control valve 16 which supplies control-pressure oil by way of a conduit 12 and nonreturn valves 28, 29 to pump-adjusting means 13 and I4 in response to a centrifugal governor 15 driven by engine I through intermediate gear 2.
  • the adjusting characteristics of pumps 3 and 4 are determined by the design of return springs 17 and 18 of the adjusting means (I3, 17; I4, 18). Furthermore, each circuit has its own maximum operating pressure determined by pressure valves 19 and 20.
  • control or regulating devices are connected which permit individual regulation of pump adjusting means 13, 14.
  • Shown in broken lines is an additional unit 23 coupled to intermediate gear 2 for reducing the power delivered by engine 1, the control apparatus of the invention still protecting engine 1 from overload.
  • the invention can also be used for pumps 3, 4 of different sizes and for more than two pumps.
  • Engine 1 is kept by a speed governor (not shown) at about maximum speed, the governor increasing the supply of fuel as the load increases. If maximum power of engine I has been attained and the load increases further, the speed drops, governor I5 responds and operates valve I6 which opens control pressure circuit 12. Adjusting means 13, I4 cuts down pumps 3 and 4 in accordance with the characteristics of return spring 17 and 18 to prevent overloading of engine 1. When the load drops again, the speed rises and pumps 3, 4 are turned up again. I N
  • pump 3 actuates adjusting means 13, 17 by way of conduit 24 and sets it back owing to the dynamic pressure building up at the throttle 26 until the resulting pressure is in equilibrium with spring 17. Throttle 26 is adjusted to make pump 3 return almost to zero position and deliver only leakage and lubricating oil at relatively low pressure. Since the total load on engine 1 has now decreased, the circuit 6 of pump 4 can take a correspondingly greater load before the control apparatus of the invention responds.
  • both pumps 3 and 4 are cut down to approximately zero, the zero position of pump 4 being determined by the setting of throttle 27.
  • Nonreturn valves 28, 29 are essential to the operation of the control apparatus, since they make possible regulation of adjusting means 13, 17; 14, 18 when centrifugal governor l5 responds without removing the possibility of individual and independent regulation of each pump in a desired manner, for example, by means of regulating and control devices 21, 22.
  • the function of nonreturn valves 28, 29 would have to be taken over by throttle valves if the apparatus were so modified that with falling pressure on adjusting means 13, 14, the pumps are cut back to reduce the output.
  • the combination comprising a plurality of hydraulic pumps driven by a prime mover, each of said pumps having individual and independent means for adjusting the output thereof, said pumps being connected through hydraulic output circuits to a like number of energy-consuming devices whereby each of said devices is associated in an energy-receiving relation with a corresponding one of said pumps, hydraulic control circuits connected to said adjusting means, control means responsive to the speed of said prime mover, and a normally closed control valve interconnecting said control circuits and said output circuits, said control means being connected to said control valve, whereby said valve is opened by said control means when the speed of said prime mover falls below a predetermined value, and whereby said adjusting means are actuated to effect a reduction of pump output, said control valve being connected to said circuits through nonreturn valves arranged to permit flow from said output circuits to said control circuits.
  • valve means for limiting the pressure in at least one of said output circuits, said valve means being normally closed and interposed between said one output circuit and the control circuit of the pump associated with said one output circuit, said valve means including means responsive to the pressure of said one output circuit, whereby said valve means will open and actuate the control means of said associated pump to reduce the output of said associated pump when said pressure rises to a predetermined maximum.
  • nonreturn valves include a valve unit connected to the inlet of said control valve, said unit having a branch connection to each of said output circuits and including nonreturn means arranged to permit flow only in directions from each of said output circuits to said control valve, whereby when said control valve is in open position it will transmit pressure from that output circuit having the highest pressure.
  • nonreturn valves include a valve assembly connected to the outlet of said control valve, said assembly having a branch connection to each of said control circuits, and comprising nonreturn means arranged to permit flow only in directions to each of said control circuits from said control valve.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Control Of Fluid Gearings (AREA)
  • Fluid-Pressure Circuits (AREA)
US51858A 1969-07-04 1970-07-02 Control apparatus for limiting the power received by a plurality of adjustable hydraulic pumps Expired - Lifetime US3649134A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1933951A DE1933951C3 (de) 1969-07-04 1969-07-04 Regelvorrichtung für die Begrenzung der Summe der abgenommenen Leistung zweier oder mehrerer verstellbarer Hydropumpen

Publications (1)

Publication Number Publication Date
US3649134A true US3649134A (en) 1972-03-14

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Family Applications (1)

Application Number Title Priority Date Filing Date
US51858A Expired - Lifetime US3649134A (en) 1969-07-04 1970-07-02 Control apparatus for limiting the power received by a plurality of adjustable hydraulic pumps

Country Status (5)

Country Link
US (1) US3649134A (fr)
DE (1) DE1933951C3 (fr)
FR (1) FR2054049A5 (fr)
GB (1) GB1305116A (fr)
SE (1) SE350572B (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3739974A (en) * 1970-04-13 1973-06-19 Production Technology Inc Conversion of variable delivery pump to fixed delivery pump for a friction welder
US3891354A (en) * 1973-06-22 1975-06-24 Bosch Gmbh Robert Regulating system for pumps
US4008004A (en) * 1975-12-22 1977-02-15 Abex Corporation Control system for variable displacement pumps
US4029439A (en) * 1975-12-22 1977-06-14 Abex Corporation Control system for variable displacement pumps
US6016691A (en) * 1998-02-25 2000-01-25 Siemens Canada Ltd. Calibrated toggle lever of leak detection module pump

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3841795A (en) * 1972-07-17 1974-10-15 Caterpillar Tractor Co Combined engine speed and pressure responsive control for variable displacement pumps
DE3728207A1 (de) * 1987-08-24 1989-03-09 Rexroth Mannesmann Gmbh Ventilanordnung fuer zwei von einem gemeinsamen antrieb angetriebene leistungsgeregelte pumpen

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2588481A (en) * 1942-07-22 1952-03-11 Niles Bement Pond Co Fuel injector pump mechanism
US2594790A (en) * 1947-03-03 1952-04-29 Rolls Royce Fuel system for internal-combustion engines
US2629982A (en) * 1947-01-23 1953-03-03 Rolls Royce Fuel system for gas-turbine engines
US2936712A (en) * 1958-01-20 1960-05-17 Deere & Co Variable displacement pump
US3065700A (en) * 1961-04-11 1962-11-27 Fairchild Stratos Corp Hydrostatic steering arrangement

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2588481A (en) * 1942-07-22 1952-03-11 Niles Bement Pond Co Fuel injector pump mechanism
US2629982A (en) * 1947-01-23 1953-03-03 Rolls Royce Fuel system for gas-turbine engines
US2594790A (en) * 1947-03-03 1952-04-29 Rolls Royce Fuel system for internal-combustion engines
US2936712A (en) * 1958-01-20 1960-05-17 Deere & Co Variable displacement pump
US3065700A (en) * 1961-04-11 1962-11-27 Fairchild Stratos Corp Hydrostatic steering arrangement

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3739974A (en) * 1970-04-13 1973-06-19 Production Technology Inc Conversion of variable delivery pump to fixed delivery pump for a friction welder
US3891354A (en) * 1973-06-22 1975-06-24 Bosch Gmbh Robert Regulating system for pumps
US4008004A (en) * 1975-12-22 1977-02-15 Abex Corporation Control system for variable displacement pumps
US4029439A (en) * 1975-12-22 1977-06-14 Abex Corporation Control system for variable displacement pumps
US6016691A (en) * 1998-02-25 2000-01-25 Siemens Canada Ltd. Calibrated toggle lever of leak detection module pump

Also Published As

Publication number Publication date
DE1933951C3 (de) 1974-08-29
SE350572B (fr) 1972-10-30
DE1933951A1 (de) 1971-01-21
GB1305116A (fr) 1973-01-31
DE1933951B2 (de) 1973-06-14
FR2054049A5 (fr) 1971-04-16

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