The design of energy-efficient power transmissions: learning hydraulic systems and zero-inertia power transmission

摘要

In applications most power transmissions are subjected to variable loads or variable load sequences. This paper describes the design of power transmissions for such loads in an energy-efficient manner. The use of an accumulator seems to be a fruitful concept for the solution of the problem of this design. Such approach generally leads to smaller and optimal loaded components operating at sufficient high efficiencies. In the event of changes in the variable loads or load sequences the power transmission should adapt properly to archive best feasible efficiencies. Some kind of intelligent control is necessary to accomplish this task in power transmissions. On basis of the concept of an accumulator and of control two different types of energy-efficient power transmissions were developed: a fluid power transmission, called Learning Hydraulic Systems (LHS) and a mechanical power transmission, called Zero-Inertia (ZI). These transmissions are aimed at different applications, i.e. LHS for example for variable load sequences in production machines and ZI especially for automotive drivelines. Although common in concept the actual designs of these energy-efficient power transmissions differ for a number of reasons. Different demands from the users of these applications lead to different practicable solutions and certain types of control components are not always common available in the two types of power transmissions. There is a significant difference between the two designs leading to time dependent and time independent behaviour. The differences in control range from continuous variable analogue solutions to digital software (optimisation) solutions. This paper describes the common basis for the two types of energy-efficient power transmissions and a number of aspects concerning the different practical solutions of these transmissions. This paper is based on theoretical work as well on practical research on different test rigs.