VPD gearbox (Variable Power Divider)

The VPD transmission is a variably controllable transmission module that is installed between the combustion engine and an automatic transmission (AT) or automated manual transmission (AMT) (sandwich configuration). By using the VPD gearbox module, a conventional drivetrain becomes a continuously variable drivetrain. A power take-off (PTO) is installed in the VPD gearbox, which can be coupled directly to the combustion engine via a multi-plate clutch.

The core element of the VPD transmission is a planetary superimposed transmission with hydrostatic variator. This allows the input speed to the automatic or automated manual transmission to be controlled independently of the current engine speed. The main functional advantage of the VPD transmission is that implements can be driven by the vehicle drive motor via power take-offs at the desired speed, while at the same time the desired travel speed can be set continuously.

Truck sweepers are a typical area of application for the VPD gearbox module. Additional motors to drive the auxiliary units are not required.

Functionality:

Transport mode: The transmission ratio from the engine to the vehicle transmission remains stable in this mode. The vehicle speed is controlled using the accelerator pedal or cruise control.

Working mode: The engine speed is fixed by the driver. The VPD control unit regulates the input speed to the vehicle transmission (AT or AMT) and thus determines the speed of the vehicle. The mounted implement is driven at a constant speed in working mode.

Advantages:

• Stepless control of the vehicle speed with constant engine and PTO speed for the implement
• The change between driving mode and working mode is fully automatic and is set by the driver
• Wear-free variator system with small units for optimum efficiency
• Extremely simple operation thanks to electronic control of all functions