David J Lomax

US Patent:

20220381006, Dec 1, 2022

Filed:

May 28, 2021

Appl. No.:

17/334653

Inventors:

- Peoria IL, US
Darren A. Blum - Plainfield IL, US
Aleksandar M. Egelja - Naperville IL, US
Barrett A. Flinn - Mount Holly NC, US
Ryan P. McEnaney - Clayton NC, US
Trung Q. Nguyen - Apex NC, US
David J. Lomax - Clayton NC, US

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

E02F 9/22
F04B 23/06
F04B 17/03
F04B 49/06
F04B 49/20
E02F 3/43
E02F 9/20
E02F 9/12
E02F 3/32
E02F 3/42
F15B 15/20

Abstract:

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.

US Patent:

20190323525, Oct 24, 2019

Filed:

Apr 19, 2018

Appl. No.:

15/957172

Inventors:

- PEORIA IL, US
David J. Lomax - Clayton NC, US
Paul A. Rousseau - Raleigh NC, US

Assignee:

CATERPILLAR INC. - PEORIA IL

International Classification:

F15B 11/17
F15B 1/26
F15B 13/02
F15B 21/00

Abstract:

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.