RETARDER CYLINDER

CUSTOMERAPPLICATION

The customer is a manufacturer of piston retarders for controlling the speed of freight wagons in marshalling yards. The hydraulic retarders decelerate freight wagons that move under gravity.

BUSINESSCHALLENGE

The customer required a pneumatic system to retract and hold down the hydraulic retarder pistons so that trucks can pass over a set of retarders unimpeded when they are pulled out of a yard. The cylinder would face temperatures down to –40 degrees Celsius, and needed to be resistant to vibration and dirt. Sealing the cylinder would also be problematic due to the acid rain present in the area, which could cause standard polyurethanes to swell.

NORGRENSOLUTION

Norgren’s engineers developed a new seal with a specialist seal manufacturer that is heavy duty, enabling it to deal with any build up of ice on the piston rod as well as resisting with the acid rain. This seal has proved to be effective and durable. The cylinder used in the assembly is a Roundline series cylinder and the piston rod is manufactured from rust-resisting stainless steel. All aluminium parts are also hard anodised to resist wear and corrosion.

ENGINEERINGADVANTAGE

The solution provided by Norgren gave the customer the added feature of retractability on its retarder product. The solution was robust and was able to operate in the harsh conditions outlined in the specification due to the specially commissioned seal that was developed with a seal manufacturer.