This works describes the modelling and simulation of a compact cartridge pressure amplifier for linear actuators, especially designed to fit within the rod of the piston. Hydraulic pressure amplifiers of the cylinder type are appreciated in hydraulic systems where high pressure work is needed, especially for a small part of the overall duty cycle. The use of these boosters allows the designer not to oversize the system, which will perform confining the high pressure operation only on the side of the hydraulic actuator. Starting from a previous research work on the same topic, this work proposes new designs for the cartridge amplifier to explore the influence of the control valve, which is the responsible for the delivering of the fluid to the amplifier. The new designs are discussed and then the results coming from the simulation performed with a lumped parameter model in a virtual test rig are shown. The operation of the amplifier is then applied to a more realistic duty cycle to illustrate and validate its operation.

Hydraulic pressure amplifiers of the cylinder type are much appreciated in hydraulic systems where high pressure work is needed only for a limited period of time, while during the remaining duty cycle the system operates at a standard level of pressure. The use of these elements allows the designer not to oversize the system, which will perform the work with a considerable power saving, confining the high pressure operation only on the side of the hydraulic cylinder. This works describes the modelling and simulation of a compact cartridge pressure amplifier for linear actuators. The cartridge amplifier is able to double or more the pressure in the system when needed and to not interfere during normal operation of the system. It has been designed to fit in the narrow space of the rod of normal hydraulic cylinder, being extremely compact and efficient. Designing such a component and the study of the main design parameters influence have required a strong work of modelling and simulation, performed with a lumped parameters approach to depict the dynamic behaviour of the amplifier. This work illustrates the building of the model and a first comparison between simulated and experimental data. Moreover, the simulation activity is enlarged to analysis of the influence of some operating and design parameters on the amplifier dynamic behavior.

This paper deals with the power saving prediction of hydrostatic drivetrains achieved with a variable roller charge pump. Focusing on the charge pump in a hydrostatic transmission, shows, that fixed pumps don’t act in all operating conditions very efficient. The charge pump delivers in some conditions a higher flow than required. The unused energy is dissipated into heat. According to this assumption, using variable charge pump is another possible way to save energy. In the end it means reduce fuel consumption. Generally, the power saving potential is depending on the application, but two main factors can be highlighted: the first one is the charge pump size and the second is the application of an intelligent loop flushing system. The standard loop flushing system demands more cooling flow than required in some conditions, but a variable charge pump is able to more efficiently cover demands of intelligent loop flushing system. The power saving potential will be analyzed for two different example systems/vehicles in their typical operation conditions. All analyses are made with simulation models, which include simplified thermal behavior of the hydraulic circuit, also. The results in this paper confirmed the power saving potential for different applications with bigger charge pumps with an intelligent loop flushing function could be the most interesting applications.