Investigation and analysis of hydraulic cylinder cushioning of excavator

Abstract

Hydraulic cylinders are linear actuators used in applications such as excavators. The backhoe of an excavator can dig with enormous force and its movements are carried out by hydraulic system. The piston movement swings the backhoe in seconds and if not slowed down at the end using cushioning, it stops suddenly causing jerk, vibration and bounce leading to higher maintenance cost. The size and profile of cushion nose plays an important role in slowing down the piston movement. In this work, an attempt is made to investigate the cushioning effect by changing the size and profile of the cushion nose that cause pressure variation using computational fluid dynamics (CFD). From the results, design of experiments (DOE) analysis is carried to find the most significant factor that affects the back pressure. It is found that the cushion nose with curved internal profile produces better results as compared to the existing taper and other profile variations.