A new piston designed by Parker Hannifin for use in rotary actuators could help reduce the weight and cost of material handling lines.
Engineers in the firm’s cylinder division have invented the decelerator, a piston design which smooths out shock loads, allowing lighter construction materials to be used.
Shock loads occur during the operation of hydraulic pistons. Traditional straight-cushion spears cause a sudden deceleration of the load resulting in high gear loading and excessive internal pressure. This is generated when the straight cushion spear enters the bush and impedes the fluid flow, which causes a rapid rise in back pressure, making the load stop abruptly.
The decelerator uses a tapered-end cushion spear which gradually reduces fluid flow. A progressive rise in back pressure acts against piston travel.
This produces a self-compensating cushion and allows smoother deceleration, reducing shock loads.
Parker Hannifin claims the decelerator will reduce gear wear, improve seal life and extend the life of the application system.