Tandem cylinders provide multiple force output

The force of a hydraulic cylinder is defined by the difference in cross-sectional areas of the master and slave cylinders. The effective increase in force is proportional to the increase in the pressure areas. A tandem cylinder practically doubles this pressure area or multiplies it further.

Design of a tandem cylinder

A tandem cylinder consists of at least two hydraulic cylinders connected in series. The piston rod passes through both cylinders or is rigidly coupled to the next one. The master cylinder or the hydraulic pump operates both cylinders simultaneously. Internally, they are equipped as normal with inlet and outlet valves. This doubles the effective working area of the slave cylinder.

Advantages of a tandem cylinder

• higher force increase
• compact installation space
• constant pressure source
• improved controllability
• higher operational reliability

The increase in pressing force can be multiplied as many times, by using a tandem cylinder, as cylinders are connected in series. They do become longer, but there is no further increase in installation space. Especially on the master side, higher force can be generated with the same power units by using a tandem cylinder. With intelligent control, the pressing force and the extension speed of the tandem cylinder can be controlled precisely.

Since the tandem cylinder essentially consists of two standard cylinders connected in series, its operational reliability is correspondingly higher. If the seal or line in one cylinder fails, the remaining cylinder can continue to perform the work. This is very advantageous in critical systems, for example in avionics.

Use of tandem cylinders

A tandem cylinder is used where high pressing forces must be combined with limited installation space on the master side. A typical application is particularly high-performance construction machinery or hydraulic presses. A tandem cylinder can also be effective in complex hydraulic power units equipped with many actuators. With an unchanged hydraulic power unit, it can increase the potential at a specific point. As long as working speed is not a factor, it is a quick and simple way to achieve more power.

Maintenance of tandem cylinders

Technically speaking, the tandem cylinder is hardly more complex in design than a conventional hydraulic cylinder. It simply consists of twice the number of components. Maintenance and repair are just as time-consuming as with any standard hydraulic cylinder.