Hydraulic & Pneumatic Cylinders

Other Hydraulic and Pneumatic Cylinders

Hydraulic cylinders and pneumatic cylinders are actuators. Also known as movers, these are machine components made of aluminum or steel that control a mechanism.

Here are some differences between hydraulic and pneumatic cylinders.

• Force: Hydraulic cylinders provide up to 100 times the force of a pneumatic cylinder. They can produce between 1,500 to 10,000 pounds per square inch (psi).
• Method of power: Hydraulic cylinders use oil to transmit power while pneumatic cylinders use compressed gas, usually air, to transmit power.

Both types of cylinders work similarly. In a pneumatic cylinder, the pressure that comes from a manual pump or external compressor moves the piston that is inside the hollow cylinder. The increase in pressure creates a linear force. A spring-back force or fluid supply returns the piston to its original position. The only difference in the way a hydraulic cylinder works is that an unyielding liquid causes the cylinder to move.

Hydraulic cylinders are used in many applications. If you need to lift, load, and pull loads regardless of size, you can use a machine with a hydraulic cylinder. Here is a list of just some of the equipment that uses hydraulic cylinders:

• Backhoes
• Graders
• Loaders
• Excavators
• Dump trucks

The following is a list of some of the parts that make up a hydraulic cylinder:

• Cylinder barrel: Holding cylinder pressure is the main use of this part. It is where the piston moves back and forth.
• Cylinder base or cap: The chamber is closed at one end with this part. You connect it to the cylinder body with bolts, with tie rods, by welding, or by threading. A cap can also be used as a cylinder mounting component.
• Cylinder head: This encloses the other end of the chamber. There is either a seal gland option or a unified rod sealing arrangement. You connect the body to the head by tie rod, bolts, or threading.
• Piston: This separates the pressure zones inside the barrel. This difference in tension on both sides is what causes the cylinder to extend and retract.
• Rod: This connects the part of the appliance that is doing the work to the hydraulic actuator.
• Seal gland: This is used for seal replacement and easy seal removal.
• Seals: There are different types of seals in use. Single-acting or double-acting piston seals are one type. Rod seals are another type. Seals prevent fluids from leaking outside the cylinder.