Caterpillar Inc.

Other

David J Lomax

Jeremy Todd Peterson

Jeffrey Lee Kuehn

Aleksandar M Egelja

Michael L Knussman

Joshua D Callaway

Paul Alan Rousseau

Steven James Juricak

Ryan Patrick McEnaney

Kalpeshkumar N Patel

Paul Lomax, Jr

Paul A Lomax

Barrett A Flinn

Darren A Blum

Trung Q Nguyen

One embodiment of a hydraulic system for a machine has a first hydraulic circuit including a first pump coupled to a first hydraulic actuator configured to move a first implement of the machine. A second hydraulic circuit includes a second pump coupled to a second hydraulic actuator configured to move a second implement. An electric motor mechanically couples to the first pump and to the second pump. An operator interface receives input from an operator requesting movement of the first and second implements. A controller communicatively coupled to the electric motor and to the operator interface determines, based on the requested movement of the first and second implements respectively, first and second flow allocations respectively for the first and second pumps and determines respective target displacements for the first and second pumps. The controller also determines first and second target electric motor speeds based on the target displacements for the first and second pumps, respectively, and controls the electric motor to operate at the larger of the first and second target electric motor speeds.

Method and systems for controlling electrically-powered hydraulic circuits

A hydraulic system for a machine includes a first pump, an implement pump, a control valve, and an auxiliary circuit. The first pump is configured to supply a first fluid flow to a first circuit, such as a steering circuit. The implement pump is configured to supply a second fluid flow to an implement circuit to actuate a primary implement function. The auxiliary circuit is configured to deliver fluid flow to actuate an auxiliary implement function. The auxiliary circuit is fluidly coupled to the implement circuit. The auxiliary circuit is also coupled to the first circuit by the control valve. The control valve is located downstream, in the direction of fluid flow, of the implement pump and the first pump. The control valve is configured to allow at least a portion of the first fluid flow to enter the auxiliary circuit and be delivered to the auxiliary implement function.

Hydraulic systems and methods for powering auxiliary circuits

A system and method for detecting uncommanded positioning of at least one valve spool in a plurality of valve spools and for stopping fluid flow to a plurality of hydraulic actuators fluidly connected to the plurality of valve spools is disclosed. The method may comprise receiving a signal fluid pressure detected in a signal passageway, identifying whether at least one activation command is currently enabled, and stopping the flow of fluid to the plurality of hydraulic actuators if no activation command is enabled for any of the plurality of valve spools, and the signal fluid pressure when detected (1) upstream of the plurality of valve spools is greater than a first threshold or (2) downstream of the plurality of valve spools is less than a second threshold.

Method to detect uncommanded spool valve positioning and stop fluid flow to hydraulic actuators

A machine is disclosed. The machine can include a frame and ground engaging propulsion elements coupled with the frame. A hydraulically actuated implement system can be coupled with the frame, and can include a linkage configured to couple with an implement, a hydraulic actuator coupled with the linkage and the frame, and a ride control and downforce control circuit configured to implement a ride control mode and a downforce control mode. The ride control mode can be configured to maintain a pressure of hydraulic fluid in the hydraulic actuator at a ride control pressure, and the downforce control mode can be configured to maintain the pressure of hydraulic fluid in the hydraulic actuator at a downforce control pressure to oppose the weight of the linkage and the implement such that the implement engages a substrate with a predetermined down force pressure which is proportionate to the downforce control pressure.

Machine having hydraulically actuated implement system with combined ride control and downforce control system

A vehicle, such as a sport utility vehicle, is provided with a vertically moving panel for opening and closing the rear of the vehicle. The panel is mounted on telescoping tracks located on opposited sides of an opening in the rear of the vehicle, and moves from a closed position covering the opening to an open position located vertically above the vehicle. The panel moves in a plane parallel to the opening in the vehicle; and gas cylinders are provided to facilitate the opening and closing of the panel, and to hold it in an open position after it has been lifted to such a position.

Vertically moving vehicle door

Growing community of inventors

Clayton, NC, United States of America

David J Lomax