Zf Friedrichshafen Ag

Hans Hofmann

Werner Breitweg

Andreas Kruttschnitt

Wolfgang Walter

Method for mounting a steering valve with a centring unit

A centering device for steering valves which includes a rotary rod (1) that is firmly connected at an endpiece (1A) with a drive shaft (3) and at another endpiece (1B) with a power takeoff shaft (4). Fine-centering is provided because rotary rod (1) cannot establish any exact mid-way centering between a rotary slide (3A) and a valve bushing (6). The fine-centering device consists of a tube-shaped endpiece (7) that is attached to the drive shaft and that bears a metal bellows (8) and a centering piece (10) that is connected with the bellows. Centering piece (10) is axially prestressed by metal bellows (8) and, via roller bodies (12) presses against another centering piece (14). Centering piece (14) is part of a bearing race (15) of a needle bearing (16) that is pressed upon the endpiece (1B) of rotary rod (2), the endpiece (1B) being connected to the power takeoff shaft (3). The centering pieces (10, 14) are provided with oblique-surface grooves (11, 13) that--when the two shafts (3, 4) are twisted toward each other--generate a centering force via the roller body.

Growing community of inventors

Mögglingen, Germany

Hans Hofmann