Zugkraft

For the comparative evaluation of the traction behavior when using different vehicles different approaches were realized at the department. First attempts were based on towing with a second vehicle for braking.


Traction vehicle with braking vehicle - connected via towing bar with intermediate load cell

The control of the braking process is not standardized, which is why a braking winch was designed for these purposes. The department's existing brake winch allows the design of vehicles with tensile forces up to 300 kN and can be operated in different modes. On the one hand, it is possible to detect the entire tensile force spectrum by increasing pull-out forces and, on the other hand, there is the option to work with fixed draft specifications or slip specifications. Despite the design for larger forestry machines, tests with smaller and thus less attractive vehicles have shown that the winch can be used in a wide range of tractive forces.


Delay technique for tensile force measurements

The investigations ranged from fork-lift trucks to trucks and special forestry machines to link chain vehicles under different operating conditions - on unbound and bound ground.

The following figures show the metrological solutions for the measurement of traction and slippage, which could be adapted depending on the requirements.


Tensile load cell between forwarder and pulley


Incremental encoder for determining the theoretical speed


Spill construction to determine the actual speed