Three wheeled hybrid generates power using a chain-driven drive system

Its designer has turned to Stieber Clutch to ensure a smooth power delivery. The Me-Mover is a three wheeled hybrid between a bike and a scooter, allowing its rider to generate power using a chain-driven drive system while remaining in an upright position which is more stable and less prone to accidents than that of a bike. The pedals of the Me-Mover have an oscillating movement rather than a rotating movement which allows power to be generated using a stepping motion.

The force from each step is transferred from the pedals to another oscillating mechanism that, in turn, is connected to a rotating drive wheel. The drive wheel rotates in one direction only, so a freewheel is needed to connect the transmission and the drive wheel, just like on a bicycle. However, unlike the freewheel on a bicycle which only overruns occasionally, the Me-Mover will constantly shift from overrunning to fixed, sometimes up to 100 cycles per minute. This puts a high demand on the freewheel making the quality of the component vital to the overall reliability of the Me-Mover.

Jonas Eliasson, CEO and founder, Me-Mover, explains: “The Me-Mover has been ergonomically designed to deliver natural, balanced and fluid movement which offers the user the same fitness benefits as running, without the danger of injury through joint impact or back, knee or ankle strain. The oscillating movement is key to the design of the product so it was vital that we found a free wheel which could cope with the demands. We initially tested components imported from Asia; however, the service life was always too short and the internal resistance was too high. Instead we turned to Stieber Clutch who we knew had a reputation for quality.”

The requirements of the Me-Mover meant that a compact overrunning clutch with instant locking / engagement was preferable to a traditional bike freewheel. The clutch needed to offer a long service life with high resistance to wear and tear and the ability to function in all weather and environmental conditions. Having been approached to offer a solution, the sales engineers at Stieber Clutch were quick to suggest the CSK30 PP overrunning clutch due to its long service life and exceptional durability.

The CSK30 PP is a sprag-type clutch integrated into a 62 series ball bearing. It is bearing supported, grease-lubricated and protected against dust particles of more than 0.3 mm diameter. It provides instant locking/engagement when the clutch shifts from overrunning to engaged, with a maximum overrunning speed of 4,200 RPM and a 102lb.ft. (138nm) torque capacity.

The sprag-type clutch keeps the drive wheel shaft from turning backwards and keyways on both the inner and outer race prevent the bearing from rotating on the shaft. Just like all CSK clutches from Stieber, the clutch features ultra-hard Formchrome sprags which provide extra-long life, maximum wear resistance and lower maintenance costs. Formchrome sprags, exclusive to Stieber/Formsprag, are made by diffusing chromium into the surface of hardened high carbon alloy steel to form a chromium-carbide alloy.

Jonas continues: “The Stieber solution is robust yet inexpensive, which is an important commercial consideration for us. For our application, Stieber recommended a special low-temperature grease to make sure they can be used year round in Denmark and other cold countries. Since we launched the Me-Mover in early 2014 we’ve had a lot of interest within Europe and further afield. Everyone who tries one loves it, I’m proud that we have managed to find a smooth power transmission solution that is both cost effective and durable.”