Caterpillar Inc.

Michael D Hudson

Thomas J Hajek

William James Tate

Edward William Mate

Cameron T Lane

Keith A Kabrick

Michael D Staub

Daniel T Mather

Srikrishnan T Tolappa

Michael Anthony A'Hearn

Joseph Edward Tabor

Tom N Brooks

Carl McIlheran

Lawrence F Schexnayder

Andrew J Vitale

David Mork

Andrew Kleitsch

Dennis Ray Barber

John P Mitchell

John J Kaufman

John Cody Vacca

Moses Imo Akpan

Eric P Jakubiak

Scott D Vollmer

David J Carlson

Patrick Quinn

Christopher W Johnson

Derek W Holmes

Jeffery McCullough

Andy Hatcher

Susan E Bieker

Thomas Brooks

A hydraulic system is provided to selectively and independently route pressurized fluid to one or more operational systems of a machine. The hydraulic system is capable of switching fluid flow in operation from one of the operational systems to another of the operational systems in the event of hydraulic drive power being required by the latter one of the operational systems. The hydraulic system is also configured to continue supplying a nominal amount of fluid to support one or more auxiliary functions, for example, a lubrication system for bearings associated with the former one of the operational systems while routing the pressurized fluid to the latter one of the operational systems. A recirculation and anti-cavitation arrangement is also provided to allow recirculation of fluid to a hydraulic motor in the former one of the operational systems when pressurized fluid is being routed to the latter one of the operational systems.

System for selectively bypassing fluid supply to one or more operational systems of a machine

A hydraulic fluid supply portion of a hydraulic steering control system may include an accumulator holding a quantity of pressurized steering fluid, and a priority valve. The priority valve may have a priority supply inlet port fluidly connected to the accumulator for receiving pressurized steering fluid from the accumulator, and a priority supply outlet port fluidly connected to a steering flow amplifier circuit. The priority valve may have a normally open position with a minimal pressure drop between the priority supply inlet port and the priority supply outlet port, and a flow restriction position where fluid flow between the ports is restricted. A load signal line from a steering control circuit to the priority valve may bias the priority valve toward the normally open position in response to an operator steering command to provide pressurized steering fluid to the steering flow amplifier circuit.

Hydraulic steering control system

A relief valve in a hydraulic system in a machine selectively sends pressurized oil to both a brake cooling apparatus and a cylinder used to hoist a load. A relief valve lowers pressure spikes in a brake cooling line by dumping fluid in a brake cooling line to tank responsive to a pressure spikes at the head end of the cylinder during hoisting or other transitions in the hydraulic system. Reducing the pressure spikes in the brake cooling line improves reliability of the brake cooling apparatus by protecting seals from undue stresses.

Hydraulic system with an unloading valve

System and methods for managing operations of one or more machines are disclosed. One method includes receiving first information relating to an operation of a dump body of a hauling machine operating in at least a partially autonomous manner, determining a failure condition of the operation based at least on the received first information, transmitting a notification relating to the failure condition, and causing a boost pressure to be applied to the dump body of the hauling machine.

Managing dump body controls on automonous machines

A hydraulic fan circuit is provided. The hydraulic fan circuit includes a tank, a motor having a fluid inlet and a fluid outlet and a pump to draw fluid at a low pressure from the tank and discharge the fluid at elevated pressures to the motor via the fluid inlet. The hydraulic fan circuit further includes a directional control valve disposed between the fluid outlet of the motor and the tank. The directional control valve is operable to move between a flow blocking position and a flow passing position. Further, the directional control valve is configured to reduce a positive speed of the motor below a lowest positive speed attainable through control of pump output. Furthermore, the hydraulic fan circuit includes a pressure control circuit configured to provide a pilot fluid flow at varying pressure to move the directional control valve.

Hydraulic system having low speed operation

The disclosure relates, in one aspect, to a friction brake cooling system for a machine. The cooling system includes at least one pump connected to at least one reservoir containing cooling fluid. A controller is configured to divert a cooling fluid flow through a valve to a first friction brake system and to a second friction brake system based on the use of the systems. In another aspect, the disclosure relates to a method of cooling a first friction brake system and a second friction brake system including diverting a flow of brake cooling fluid to the systems based on the use of the systems.

Brake cooling fluid diverter for an off-highway machine

A hydraulic system includes a pressurized fluid supply, a plurality of non-priority elements each including a signal port and a supply port, at least one priority implement including a signal port and a supply port and a priority valve arrangement. The priority valve arrangement is adapted to receive fluid from the pressurized fluid supply and selectively apportion fluid between the supply port of the priority implement and the supply ports of the plurality of non-priority elements. The valve arrangement includes a signal circuit operative to establish a flow priority between the priority implement and the plurality of non-priority implements and the signal circuit is in fluid communication with the priority supply. The signal circuit includes a pilot portion and a dynamic load portion and the signal port of the priority implement is in fluid communication with the priority valve arrangement through the dynamic load portion of the signal circuit. The signal ports of the plurality of non-priority implements are in fluid communication with the priority supply, wherein the dynamic load signal and the load signal are substantially prevented from fluid communication with one another to provide a stabilized dynamic load signal.

Hydraulic system with flow priority function

A hydraulic ride control system is disclosed and adapted to control the ride of a machine having a load. The ride control includes an accumulator arrangement that is selectively connected with the actuator that is carrying the load to provide a cushion ride during traveling and to enable the pressure in the accumulator arrangement to be maintained substantially the same as the pressure in the actuator when raising the load and to permit the pressure in the accumulator arrangement to be lowered to that of the pressure in the actuator in the event the load is lessened. The ride control system also provides an arrangement that permits the accumulator arrangement to be bled down whenever the machine becomes disabled or when the machine is shut off.

Hydraulic ride control system

A ride control system adapted for use in a fluid system of a machine to cushion the ride of the machine, the machine having a frame with an actuator arrangement disposed between the frame and a load to raise the load relative to the frame, the actuator arrangement having a raise port and being operative in a raise mode to raise the load to a desired height in response to pressurized fluid being directed to the raise port from a source of the pressurized fluid, the ride control system including an accumulator arrangement and a valve arrangement connected between the accumulator arrangement, the actuator arrangement, and the source of pressurized fluid, and operative to selectively connect the accumulator arrangement to the raise port of the actuator arrangement when in the raise mode while maintaining the load at the desired height.

Ride control

Growing community of inventors

Mount Zion, IL, United States of America

Michael D Hudson