Multiple pump control system
AssigneesTyrone Hydraulics, Inc., Sargent Industries, Inc.
InventorsJames M. Eley, Fred T. Smith
Life of this patent
Estimating the term…
Abstract
A control system for plural motor driven pumps is disclosed. The control system includes a control valve which provides for unloading one pump by diverting the flow of operating fluid from that pump back to reservoir whenever the flow through the valve or the load pressure exceeds a preselected level.
Claims20
In a fluid control system, a pair of fixed displacement pumps each having supply and discharge passages for supplying operating fluid from a reservoir to a load, control valve means including a movable valve member and valve passages for delivering the fluid discharged from the pumps to the load, said valve member being movable to a first position to combine the flow of fluid from said pumps for delivery to the load and to a second position in which the flow of fluid from a first one of said pumps is delivered to the load and in which flow from the other one of the pumps is by-passed from delivery to the load and valve actuating means operative in response to a predetermined upper limit of flow and to a predetermined upper limit of pressure downstream from one of the said pumps for moving the valve member to the second position when either the predetermined upper limit of flow or the predetermined upper limit of pressure is reached.
A vehicle having driving means and auxiliary equipment adapted to be power operated, a variable speed motor for selectively operating the driving means at different speeds, and hydraulic actuating means for the auxiliary equipment comprising two hydraulic pumps connected to be driven by the motor at different speeds according to the speed of operation of the motor and having a common hydraulic operating connection with the auxiliary equipment, control valve means for unloading one of said pumps from the common hydraulic operating connection with the auxiliary equipment, and means operatively coupled to the control valve means for actuating the control valve means to unload said one pump, said actuating means being responsive to increase in the hydraulic fluid pressure above a predetermined value in said common hydraulic operating connection and to increase in flow rate of the hydraulic fluid above a predetermined value in said common hydraulic operating connection to actuate the control valve means to unload said one pump.
In a fluid control system, a reservoir;
- a pair of engine driven fixed displacement pumps, each having supply and discharge passages for the supply and discharge of operating fluid from the reservoir;
- a control valve comprising a valve housing, said valve housing including first and second inlet passages each connected to the discharge passage of an individual one of said pumps, first and second valve outlet passages, said second valve outlet passage communicating with the reservoir, said control valve further including a spool member mounted for movement within said housing between first and second positions, said spool member being operative in the second position to provide for a communication of said second valve inlet passage with said second valve outlet passage, said spool member being operative in the first position to connect said first and second valve inlet passages to said first valve outlet passage, and means for moving the spool member to the second position whenever a predetermined pressure or flow is exceeded.
In equipment having a principal mechanism for performing a primary function and auxiliary mechanism for performing a collateral function, a variable speed motor for selectively operating the principal mechanism at different speeds, and hydraulic actuating means for the auxiliary mechanism comprising a plurality of hydraulic pumps connected to be driven by the motor at different speeds according to the speed of operation of the motor and having a common hydraulic operating connection with the auxiliary mechanism, control means for diverting the fluid output of at least one of said pumps from the common hydraulic operating connection with the auxiliary mechanism, and two control devices for actuating the control means to divert the fluid output of the pump whose output is to be diverted from the common hydraulic operating connnection with the auxiliary mechanism, one of said devices being responsive to increase in the hydraulic fluid pressure above a predetermined value in said common hydraulic operating connection to divert the fluid output of said pump from the common hydraulic operating connection with the auxiliary mechanism and the other of said devices being responsive to increase in flow rate of the hydraulic fluid above a predetermined value in said common hydraulic operating connection to divert the fluid output of said pump from the common hydraulic operating connection with the auxiliary mechanism.
In combination in a vehicle, an engine operative at variable speeds to provide a propulsion of the vehicle in accordance with the speed of the engine and capable of operating at low speeds approaching idling, an auxiliary mechanism having properties of operating on a cyclic basis and of providing an individual load at different times in the operation cycle and of providing functions independent of the operation of the vehicle, reservoir means for the hydraulic fluid, pump means operated by the engine for providing for a flow of fluid from the reservoir means to the auxiliary mechanism in accordance with the speed of the engine, the pump means having a first state of operation for providing for the introduction of the hydraulic fluid from the reservoir means to the auxiliary mechanism and having a second state of operation for providing for a by-pass of at least a portion of the fluid from the reservoir means to prevent such fluid from being effective in operating the auxiliary mechanism, and valve means responsive to the pressure of the fluid from the pump means and to the volume of fluid flow from the pump means for providing for the operation of the pump means in the second state at a fluid pressure above a particular value or a fluid flow above a particular value and for providing for an operation of the pump means in the first state at other times corresponding to speeds approaching the idling speed of the engine.
In combination in a vehicle, an engine operative at variable speeds to provide a propulsion of the vehicle in accordance with the speed of the engine and capable of operating at low speeds approaching idling, an auxiliary mechanism providing properties independent of the movement of the vehicle and operative on a cyclic basis and providing a variable load at different times in each cycle, pump means operatively coupled to the engine and having properties of providing fluid to the auxiliary mechanism in accordance with the speed of the engine and having first and second states of operation and operative in the first state to provide a full flow of the fluid to the auxiliary mechanism to operate the auxiliary mechanism and operative in the second state to by-pass at least a portion of the fluid from flowing to the auxiliary mechanism to operate the auxiliary mechanism;
- and valve means operatively coupled to the pump means and the auxiliary mechanism for providing the operation of the pump means in the first state to obtain a full flow of the fluid from the pump means to the auxiliary mechanism for pressures of the fluid below a particular pressure value and for volumes of fluid flow below a particular flow value corresponding to speeds of the engine approaching idling and for providing an operation of the pump means in the second state for pressures of the fluid at least equal to the particular pressure value or for volumes of fluid at least equal to the particular flow value to obtain a by-pass of at least a portion of the fluid back to the pump means.
Dependencies are inferred from the claim text.