Inventive Axle Lift Devices (Editorial Global Trailer 49)
From the November 2019 Global Trailer issue.
Inventive Axle Lift Devices
For nearly 100 years, VDL Weweler has been a suspension supplier, manufacturing multi-leaf springs and parabolic trailing arms in the Netherlands. Currently, the main business of VDL Weweler is the development of trailer air suspension systems for its customers.
As trailers in general have multiple axles, it is quite interesting to provide trailers with a lift axle, as a lifted axle saves tyres and brakes, has less resistance, saves fuel and improves manoeuvrability (particularly when the axle lift is on the last axle).
In some countries lift axles can even save fleet operators in road taxes. In the 1970s the axle lift of choice was a pivoting side lift. By 1979, VDL Weweler developed a pivotless centre lift. On this inventive and new version the axle lift air spring is mounted to the trailer chassis in front of the suspension system pivot points and the lift arm is connected to the axle body of the liftable axle.
This kind of axle lift was revolutionary, according to VDL Weweler, because it was independent of the suspension system and axle make. So, with the correct axle clamping (square or round), known nowadays as a mid-lift could and can be used by every trailer builder.
Some 10 years later, in 1989, VDL Weweler was asked to mount an air bellow direct to the parabolic part of the trailing arm by drilling holes in the trailing arm. VDL Weweler obviously refused as this would destroy the functionally of the trailing arm and so a two-sided axle lift was developed using a pivoting lever so the air spring or actuator was kept in position without damaging the trailing arm.
“This was the birth of our patented Bolt-On® axle lift range,” said VDL Weweler. “The unique selling points of this light weight solution is that it can be bolted to the suspension`s pivot bolt without welding the axle lift to the underside of the hanger bracket. Particularly for retrofit this was ideal.”
Over time, these Bolt-On® axle lifts evolved into a wide family, suitable for practically any axle and suspension brand in the market today.
The second-generation Bolt-On® axle lifts were developed to be hooked on existing parts of the air suspension and without the need to remove the pivot bolt. This proved to be a major advantage as realignment of the suspension was not necessary.
Currently, VDL Weweler is market leader in the European market and develops tailor made axle lift systems for several big players in the global market.
One of the latest developments is the Rocker lift, which was also displayed at the 2018 IAA Commercial Vehicles Show in Hannover, Germany.
The Rocker lift was developed for those situations where it’s not possible to mount a Bolt-On® axle lift, due to ground clearance or when there is no space between the (dual) tyres and the hanger bracket.
Like an engine rocker, the axle lift arm is partly adjacent the hanger bracket and angled, with the actuator placed inwards, creating sufficient clearance towards the tyres and the ground.
Particularly low-loader builders have responded really enthusiastic, but the opportunities in other applications are endless.
Currently VDL Weweler has, next to their wide range of air suspensions, over a 100 axle lift variants on stock for many common brands of air suspension systems and applications. "Making one thing for sure, VDL Weweler is and will be your partner for axle lift systems."