Single acting spring return cylinder
What is a single acting spring return cylinder?
A single acting cylinder is a cylinder in which the working fluid acts on only one side of the piston. The other side of the cylinder utilizes a mechanical rod, spring, compressed air or the momentum of a fly wheel to push the piston back in the other direction. This particular cylinder utilizes a spring on the non-fluid side. this spring retracts in the pull direction.
The purpose of a fluid system is to transmit power from one location to the another. The fluid power is converted into a mechanical power by means of an actuator. The cylinder type actuator gives a linear push-pull motion with a rod with a piston in the cylindrical tube.
The above figure shows. A single acting spring actuator produces a linear motion in one direction. When a control valve directs fluid in the inlet port into the blind end, the pressure builds up and generates a force on the piston. When the pressure built up is large enough the piston and begins to move to extend the rod. This is called the forward stroke.
When the control valve directs fluid out of the port, the fluid pressure is removed. The force of the spring pushes against the piston in the other direction and the rod returns to the cylinder. This is called the retraction stroke. Single acting cylinders are most often found in reciprocating engines, pumps etc.