Understanding the Telescoping Hydraulic Cylinder

Hydraulic and Pneumatic

In single stage hydraulic cylinders, the length of the cylinder is the sum of the stroke, the thickness of the piston, the thickness of the bottom and head, and the length of the connections. Sometimes the length that is necessary to complete a job will not fit into a machine. In this case, a telescoping hydraulic cylinder is used. In these cylinders the piston rod is used as a piston barrel and more piston rods are used, allowing the cylinder to extend to the required length. Keep reading to learn about the many advantages of the telescoping hydraulic cylinder.

Basics of the Telescoping Hydraulic Cylinder
Telescopic hydraulic cylinders are only a fraction of their total length when they are compacted. They consist of steel tubes, each of which gets progressively smaller to fit within the next. The largest tube or sleeve is referred to as the barrel and each of the smaller tubes are stages. Usually no more than six stages are used in order to maintain stability. During use a telescopic cylinder it extends like a telescope to its full length, thereby maximizing equipment functionality.

There are two main types of telescopic hydraulic cylinders: single-acting and double-acting (although special designs do exist). Single-acting telescopic cylinders extend through the use of hydraulic pressure and compress through external forces such as gravity. Double-acting telescopic cylinders use hydraulic pressure to extend and contract themselves.

Applications for Telescopic Hydraulic Cylinders
The most commonly known application for telescopic hydraulic cylinders is dump trucks, where long output travel at varying angles in a challenge. Other applications include:

  • Excavators
  • Cranes
  • Forklift mast cylinders
  • Oil drilling rigs
  • Roll off trucks

Essentially, a telescoping cylinder is useful in any application in which something has to be pushed or raised at varying angles.

Benefits of Telescopic Hydraulic Cylinders
The main advantage the telescoping hydraulic cylinder has over other types of cylinders is that they are able to provide an exceptionally long stroke in a compact length. The collapsed length of these cylinders is typically 60% to 80% smaller than their extended length, therefore making them ideal for application in which mounting space is limited and a long stroke is needed.