Telescopic hydraulic cylinders

Description

Gidrolast specialises in the design and manufacture of both Single Acting and Double Acting Telescopic Hydraulic Cylinders. We build both standard catalogue telescopic designs as well as custom application engineered telescopic cylinders.
Often a hydraulic cylinder is required to fit into a very tight space and yet provide a stroke that is actually longer than its fully retracted length. A standard rod cylinder cannot do this.
A telescopic cylinder, however, can achieve a very long stroke from a compact retracted length. Telescopic cylinders use a series of nested tubular segments sliding within one another (see diagram below). This enables them to provide a very long output stroke from a very short retracted length in one combined actuator. These cylinders are available in 2, 3, 4, 5, or even 6 stages.
Most telescoping cylinders are single acting. That means that they extend using hydraulic pressure but then retract using gravity and the mass of the load. A typical example is that of a telescopic cylinder on a dump truck.
Double acting telescopic cylinders are much more complicated. They incorporate internal return pistons, additional seals and complex internal fluid passageways to enable the cylinder to retract using hydraulic power. Double acting telescopic cylinders are often used in horizontal applications where gravity is not available to retract the cylinder. Applications include waste compaction and push-off cylinders.
The maximum available force output of any telescopic cylinder is limited to the effective area of its smallest stage.
Because of their long length when fully extended (see illustration above), telescopic cylinders must be very carefully designed. A poorly designed telescopic actuator will wear out quickly in the field and cause a machine failure. It may even buckle and collapse, causing a dangerous catastrophic failure of the machinery. The result to the end user would be machine downtime, lost production, very expensive repairs and perhaps even loss of life.
At Gidrolast, we have decades of experience designing and building telescoping actuators. In addition to our standard catalogue range of telescopic cylinders, we have built custom-designed models with bores as large as 500mm (20″). This experience gives our customers peace of mind knowing that their actuators have been designed and built by people that truly know what they are doing. We are committed to quality and reliability.