Eaton Corporation

Michael J Voigt

Don Rulon Draper

Timothy Isaac Meehan

David Loren Makis

Rodney V Singh

Michael William Olson

Brian Lewis Van Batavia

David S Remba

David G Swartzer

A vehicle drivetrain has a first driver, a first clutch to selectively couple the first driver with an engine, an energy storage device coupled to the first driver, a second driver coupled to the energy storage device and connected to a driveshaft, and a second clutch that selectively couples the first and second drivers. In one embodiment, the first clutch is opened and the second clutch is closed during a vehicle operating condition requiring high torque, the first clutch is closed and the second clutch is opened during a transient vehicle operating condition, and the first clutch and the second clutch are closed during a steady-state vehicle operating condition. Additional clutches may be included to reduce energy losses or provide multiple mechanical ratios. The drivers themselves may be pumps, motors, generators, combined pump/motors, or combined motor/generators, making the invention suitable for both hydraulic implementation and electric implementation.

Hybrid hydraulic drive system architecture

A pump-motor unit () including a swashplate () having a neutral position (FIG.) and first and second displaced positions and comprising first () and second () pressure actuators associated with the swashplate. Displacement of the swashplate is proportional to substantially only the difference in fluid pressure between a high pressure source () and a low pressure source (). The first pressure actuator includes a first control piston () having a first effective area (A), and the second pressure actuator includes a second control piston () having a second effective area (A), the second effective area being at least somewhat greater than the first effective area. If the high and low pressure sources are at substantially the same pressure, the pressure acting on both of the first and second effective areas will displace the swashplate from neutral toward the second displaced position.

Hydraulic kicker control piston

A variable displacement pump assembly (11) of the type including a tiltable swashplate (29) to vary the pump displacement. The assembly includes a main control valve (43) having a housing (44). The assembly includes an input section (65) disposed between the valve housing (44) and the pump housing (61). The input section (65) defines a cylinder bore (77, 79) in which a piston member (81) is disposed and is connected by a mechanical input (59) to a valve spool (51) of the main control valve. The piston defines first (87) and second (89) piston chambers and a solenoid valve (105) is responsive to a remote electrical input signal (111, 113) to control the fluid pressure in the piston chambers, and therefore, the position of the valve spool (51). The mechanical linkage (91,99,101) between the piston (81), the valve spool (51) and the swashplate (29) is totally enclosed within the valve housing (44) and the body portion (67) of the input section, thus eliminating the need for remote mechanical control cables, and improving the reliability of the control system. The control of the present invention thus enables the vehicle operator to vary pump displacement by either a manual input to the main control valve (43) or by varying the electrical input signal (111, 113).

Variable displacement pump and optional manual or remote control system

Growing community of inventors

Chaska, MN, United States of America

Michael J Voigt