Selecting the Right Hydraulic Cylinder

A hydraulic cylinder is a linear actuator engineered to create a pushing or pulling force in a straight line. It consists essentially of a piston and rod assembly contained within a cylindrical bore which is actuated by the pressure and flow of hydraulic fluid to produce mechanical force and linear motion. For a hydraulic cylinder to properly function, several factors should be considered, including:

• Rod size
• Geometry
• Mass
• Bore size
• Cushions
• Load weight
• Accuracy and control requirements
• Cylinder materials
• Hydraulic pressure requirements

Additionally, there is a quick formula for finding the correct bore size for the extended direction of the cylinder.

F = force required (lbs.)
P = operating pressure (psi.)
D = bore diameter (in.)
D = F / (.7854 * P)

Hydraulic cylinders are available in several style options to provide your application with the best possible outcome. Common hydraulic cylinder types include welded rod, tie-rod, and telescopic options. Hydraulic cylinders are also available in standard and custom formats.

Telescopic Hydraulic Cylinders

Telescopic hydraulic cylinders utilize multiple nested stages, achieving a long working stroke in compact/retracted form. Telescopic hydraulic cylinder features include:

• Manufactured in single-acting or double-acting options
• Ideal for installation where space is an issue or limited
• Often used in mobile or industrial hydraulic systems like dump trucks, garbage trucks, or roll-off/roll-on trucks

Welded Rod Hydraulic Cylinders

Compared to tie-rod cylinders, welded rod cylinders have a narrower body and often a shorter overall length enabling them to fit better into the tight confines of machinery. Additionally, Welded cylinders do not suffer from failure due to tie rod stretch at high pressures and long strokes. Welded rod features include:

• Ideal for medium to heavy-duty hydraulic applications, including mobile hydraulics due to its light/compact design
• Used for low-profile, high-pressure applications
• Also used for applications with limited space

Tie-Rod Cylinders

Tie-rod style hydraulic cylinders use high-strength threaded steel rods to hold the two end caps to the cylinder barrel. This method of construction is most often seen in industrial factory applications. Tie rod cylinder features include:

• Ideal for heavy-duty industrial manufacturing applications such as automotive or machine manufacturing applications
• Better for applications that require space for installation
• Often used for low-pressure applications

Operational conditions should also be considered before choosing a specific hydraulic cylinder. Factors such as corrosion and temperature play an essential part in determining which type of cylinder to choose. Moreover, the hydraulic seals used within the cylinders must also withstand the temperature changes or harsh environment where the hydraulic system will be used.