BWI Group combines the light weight of a monotube damper with the ride comfort of a twintube design

BWI Group has developed a new type of monotube damper that, for the first time, combines the benefits of both twintube and monotube dampers. The new product allies the light weight and temperature stability of a typical monotube design with the wide compression damping range at low gas charge pressures normally only available on twintube dampers.

“The breakthrough in performance means vehicle manufacturers can achieve the ride comfort demanded by their customers while reducing suspension mass, to support overall reductions in vehicle weight, in the quest for lower CO₂ emissions,” explained Marcin Knapczyk, Engineering Manager – Ride Development Group. “Our new dampers are up to 40 percent lighter than equivalent twintube products.”

The new technology does not increase manufacturing complexity; only one additional component is required, compared to a conventional monotube damper. The pressure tube contains a fixed base valve assembly, a floating piston and the piston rod which carries its own piston valve assembly.

The piston and fixed base compression valves work together simultaneously during the compression stroke in order to provide a wide tuning range, while in the rebound stroke, the damper performance is defined only by the piston rebound valve, as in a conventional monotube damper.

“Our unique arrangement enables low gas pressures to be used, giving better isolation from road shocks and features, while maintaining stable damping forces over a wide temperature range,” said Knapczyk “The damper remains fully functional in any orientation – inclined, horizontal or even inverted – and separation of the oil and gas chambers by a floating piston ensures superior fade resistance. The unit also provides exceptional energy dissipation.”

The new dampers are especially aimed at vehicles in market segments such as electric cars where mass reduction is strongly demanded.