Stepless hydrostatic-mechanical transmission

US5052987A · kind A · utility

Assignee

• MAN Nutzfahrzeuge AG · DE

Inventors

• Faust Hagin · Munich, DE
• Hans Drewitz · Munich, DE

Key dates

• Filing date: Mar 23, 1990
• Grant date: Oct 1, 1991
• Expiry date: Mar 23, 2010

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S903/96
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A stepless hydrostatic mechanical transmission between a prime mover and a power output train in which an epicyclic differential is incorporated in the transmission and includes at least four shafts, a large and a small sun wheel, two planet wheels in mesh with the sun wheels, a web supporting the planet wheels and an annulus. Two main shafts constituting input and output shafts are connected with respectively different shafts of the epicyclic differential. Two hydrostatic machines are connected to the epicyclic differential such that in at least one working range of the power transmission the hydrostatic machines are adapted to be connected to the epicyclic differential and operated as pumps and motors. The operation of at least one of the hydrostatic machines is changed over by a clutch, when the other hydrostatic machine is stationary and during transition from one working range to another, from connection with the output shaft to the small sun wheel and, during traction operation, from the motor function to the pump function. In the epicyclic differential, the large sun wheel is driven by the input shaft and is located between the small sun wheel and the prime mover.