Like all cylinders, a single acting hydraulic cylinder (a.k.a single acting ram) is based on the concepts of pressure and piston effective area. With only one inlet through which an incompressible fluid, such as hydraulic oil, can be applied, a single acting hydraulic cylinder depends on the load or springs to retract the piston.

Let’s take a closer look at how it works.

Basic Principles of a Single Acting Hydraulic Cylinder

A single-acting hydraulic cylinder utilizes hydraulic fluid, such as hydraulic oil, which is typically supplied from a hydraulic hose and in line with a pump. The pump adds pressure to the system by transferring fluid into the hydraulic cylinder through the hose. As the hydraulic fluid enters the inlet and applies pressure, it forces the piston to move.

When resistance is added to the other side, this resistance causes the fluid pressure to increase.

The pressure will remain until there is no more resistance or the fluid pressure exceeds the system’s limits and leaks. When the pressure is gone, the spring, a load on the cylinder or gravity causes the piston to retract.

The example below shows the design of a single acting hydraulic cylinder.

Selecting a Single Acting Hydraulic Cylinder

When choosing a single acting hydraulic cylinder, consider the lifting capacity and closed height you need. The equation for calculating the output force of a hydraulic cylinder is (Effective Area (square inches) x Pressure (PSI))/2000 = Output Force (tons). Of course, you should also consider the design maximum working pressure of your system.

Winshaw Hydraulic Tools offers a variety of high-performance single acting hydraulic cylinders with a maximum lifting capacity of up to 10,006 tons (20,000,000 lbs). Some of our top single acting hydraulic cylinders include an HLS and HPS.

By understanding how a single acting hydraulic cylinder works, you can more easily find the right one to fit your capacity and operational needs.

To learn more about our single acting hydraulic cylinders, contact Winshaw Hydraulic Tools today.