Especially in machines where rotary motion is one of the main functions – e.g. material handlers – precise acceleration and braking of the motion is immensely important. This accuracy is possible thanks to the Linde Hydraulics Torque Control in combination with a variable displacement pump and a fixed displacement motor. The hydraulics immediately follow the operator's control signal and thus perform the movement precisely.
By rotating in a closed loop, no energy is lost during acceleration or braking. So when the operator of the machine now accelerates the rotary motion, the pump delivers only the amount of oil that is needed. As a result, there is no power loss and yet the movement immediately follows the control signal. In this case, little signal means a soft and gentle movement, while a lot of signal means sporty and fast turning.
If, on the other hand, the operator brakes, the pump is swung back and switches from pump to motor operation. The resulting braking energy can be transferred to the open-circuit system, for example, leading to fuel reductions of up to 20% in contrast to open-circuit turning.
Design Features
Torque Control on variable displacement pump (HPV) combined with fixed displacement motor (HMF or CMF)
Integrated pressure relief valves
Pilot control
Advantages
Sensitive control
Brake energy is transferred to the open loop
Jerk-free acceleration after deceleration phase
No drifting on gradients
20 % fuel savings compared with open-loop swing
Utilization of braking energy (recuperation)
Adjustable maximum pressure, Adjustable acceleration/braking torque
Simple recuperation for compound movements