Tensile force-limiting device for a working machine

A continuously variable transmission for a working machine, the transmission comprising:

• a sensor device for determining a drive output torque of the transmission;
• a controllable variator for adjusting a torque ratio of the transmission independently of a rotational speed ratio of the transmission;
• and
• a traction force limiting device having a traction force interface for providing information for determining a traction force of the working machine, a limit value interface for setting a traction force limit value of the working machine, a control interface for emitting a control signal to the variator of the transmission of the working machine, a computer unit designed to determine the traction force of the working machine on a basis of the information provided by the traction force interface, to compare the traction force of the working machine with the traction force limit value set by the limit value interface, and, on a basis of the comparison, to control the variator of the transmission, via the control interface, in such a manner that the traction force of the working machine does not exceed the traction force limit value, and
• the computer unit is designed to control the variator in such a manner that the rotational speed ratio of the transmission is increased without thereby changing drive output torque of the transmission when a continuous change of the transmission ratio of the transmission to a higher rotational speed ratio is required and the traction force determined corresponds to the traction force limit value;
• and
• the sensor device is connected to the traction force interface and the variator is connected to the control interface.

A method for limiting traction force of a working machine having the continuously variable transmission including a sensor device for determining a drive output torque of the transmission;

• a controllable variator for adjusting a torque ratio of the transmission independently of a rotational speed ratio of the transmission;
• and a traction force limiting device having a traction force interface for providing information for determining a traction force of the working machine, a limit value interface for setting a traction force limit value of the working machine, a control interface for emitting a control signal to the variator of the transmission of the working machine, a computer unit designed to determine the traction force of the working machine on a basis of the information provided by the traction force interface, to compare the traction force of the working machine with the traction force limit value set by the limit value interface, and, on a basis of the comparison, to control the variator of the transmission, via the control interface, in such a manner that the traction force of the working machine does not exceed the traction force limit value, and the computer unit is designed to control the variator in such a manner that the rotational speed ratio of the transmission is increased without thereby changing drive output torque of the transmission when a continuous change of the transmission ratio of the transmission to a higher rotational speed ratio is required and the traction force determined corresponds to the traction force limit value;
• and the sensor device is connected to the traction force interface and the variator is connected to the control interface, the variator enabling the adjustment of the torque ratio of the transmission independently of the rotational speed ratio of the transmission, the method comprising:
• setting the traction force limit value;
• determining an existing traction force of the working machine;
• comparing the existing traction force with the traction force limit value;
• and
• adjusting the variator of the continuously variable transmission on the basis of the comparison, in such a manner that the traction force of the working machine does not exceed the traction force limit value.