The Multi-Parametric Weight Optimization of a Hydraulic Actuator

Abstract

This research was derived from the experimental observation that hydraulic actuators are positioned on machines that are subjected to movements and whose dynamic actions, the accelerations, are very high; it is acceptable to think of an actuator for an anthropomorphic robot. From this point of view, the weight of the actuator plays a fundamental role in the performance of the machine. In order to face this problem, a real hydraulic cylinder has been designed (for use on an earth moving machine) both analytically (adopting the theories of continuous mechanics) and numerically through finite element analysis. The results obtained were then generalized by determining functions that in relation to specific values of the variables, such as working pressure, allow one to determine the minimum weight of the component and its geometric configuration. The functions also made it possible to identify the most significant contributions to the overall weight of the component and therefore the elements on which to focus the subsequent lightening process. In particular, the greatest contribution is made by obtaining relations that are completely general and therefore adaptable to different case studies.

Overview of Materials Used for the Basic Elements of Hydraulic Actuators and Sealing Systems and Their Surfaces Modification Methods

“…This material in the context of this application is also described in the article [62]; however, there is a designation according to European standards: S355J2G3. Similar material is also described in [22], where it appears as S355JR. The latter two types of steel differ only permanently in the temperature of the impact test, as indicated by the mark at the letter "J."…”

“…Additionally, a tendency to reduce the weight of machine elements is observed. Less weight is usually associated with energy savings, increased efficiency, and reduced financial outlays [19][20][21][22]. Reducing the weight of an element by changing the material can be carried out, for example, by changing steel to light metals or plastics.…”

“…In [22], it was noted that the change of material from structural steel to Al 7075-T6 resulted in a significant reduction of the cylinder weight, which had a positive impact on the degree of the ecology of the hydraulic system as well as on its power demand. In [63], similar tests were carried out, but here the Al 7075-T6 aluminium pipe was wrapped in a composite consisting of epoxy resin and carbon fibers with the same proportions as in [21].…”

“…These are unalloyed steels that are very easy to heat treat, but difficult to weld. Other steels are S275 JR [63], S 355 JR [22], and BS970070M20 [45]. These are structural steels already mentioned in the hydraulic cylinders.…”

Hidrolik Silindir Tasarımı Ve Optimizasyonunda Arı Algoritmasının Uygulanması

“…Mass optimization of cylinders has been investigated with different algorithms and theoretical or experimental approaches by many researchers. For instance, Solazzi et al have focused on the weight optimization problem of hydraulic actuator that has many parameters with the help of a classical mechanic and finite element analysis (Solazzi et al, 2020). Ghasemi et al studied on minimum mass cost and maximum buckling pressure of cylinders using a non-dominated sorting genetic algorithm (NSGA) Ghasemi et al, 2017).…”