New transmissions with incorporated actuators and sensors deliver optimised fuel economy and continuously variable vehicle speeds up to 42 km/h.
ZF’s Off-highway division launched the first new models in its innovative HC range of hydrostatic transmission systems at the company’s recent world press day in Lenningen Quarry, southern Germany. The 1 HC 85 and 2 HC 85 transmissions for construction machinery up to 9.5 t, are designed with incorporated actuators and sensors, providing optimised fuel economy and the capability for continuously variable vehicle speeds up to 42 km/h. In addition, the integration of crankshaft-driven radial piston motors into the drive unit increases efficiency and eliminates the requirement for external hoses and valves, resulting in a reduction in interfaces to the vehicle.
The new HC-range of hydrostatic drives meets all the market requirements for compact drive systems offering improved fuel economy, reduced levels of noise, and also increased vehicle speeds to improve productivity. The new transmissions provide improved ride performance with a continuously variable transmission system which requires no gear shifts. This means no interruption of traction, resulting in improved handling performance.
The electronically controlled driveline management system of the HC range also provides low start speed; and a load sensor control feature optimises diesel speed even under load. In addition, the use of crankshaft radial piston motors means that efficiency is increased and, consequently, fuel consumption is reduced.
The radial piston motors are extremely compact, giving designers increased degrees of freedom in terms of vehicle installation. Moreover, due to their integration into the transmission system, there is no longer a requirement for external hose pipes and valves, which leads to a reduction of interfaces to the vehicle.
Compared to other hydrostatic driveline solutions using bent axis axial piston motors, ZF’s crankshaft radial piston motor design is quieter in operation and has less leakage due to the efficiency of its piston seals. In addition, the pistons in the radial piston motor are guided in pivoted cylinders, so there no lateral forces to unbalance the transmission.
The HC series transmissions are supported by a full range of service, inspection, service of installation and warranty packages by ZF GB. These services are provided direct by ZF from its main UK service centre in Nottingham, or via the company’s three UK drive centres in Birmingham, Manchester or Glasgow, and one covering the whole of Ireland.
