Bosch Rexroth’s HYDROTRAC GFT 8000 gearbox enables an approximate 10% increase in drive train performance for larger mobile working machines. Launched earlier this year and now available from Hytec, a Hytec Group Company, these transmission units are based on a modular design. Ideal for use in harsh, rugged environments including African mining operations, they have two- and three-stage combined planetary gearing with axial piston motors to match the needs of heavy and bulky mobile working machines such as trucks and excavators.

 An optional internal brake reduces the installation space needed, but adheres to the safety specifications for worldwide roadworthiness certification. The mechanical planetary drives in these transmission units transfer the torque from the hydrostatic drive to the wheels or tracks. Bosch Rexroth uses the newest versions of variable axial piston motors or fixed-displacement axial piston motors, which operate in either an open or closed circuit.

Travel capacity is significantly improved as the higher fluid capacity of the motors and the higher hydraulic pressures, along with the exact matching with the two- and three-stage planetary drives, boost torques, and therefore performance by approximately 10%. At the same time, vehicle manufacturers can sometimes select a smaller nominal size to achieve the same output. This saves installation space.

The optional integrated multi-disk brake inside the unit requires minimal maintenance and is designed for protection against soiling, an added advantage when working in demanding environments. Also, when used in conjunction with Bosch Rexroth’s High Level Braking System, they satisfy the exacting safety requirements for speeds up to 50 km/h.

All units are delivered as complete assemblies, ready for installation, and vehicle manufacturers can select a smaller nominal size to achieve the same output, which also saves on installation space. Due to the platform’s modular concept, OEMs can vary the drive torques and transmission rations, closely matching them to the vehicle used.

Two models in the 8000 series, which achieve nominal torques of 20 and 30 kNm, are available off-the-shelf, and an additional seven models are currently being rolled out to the market.