December 10, 2004 Contrary to folklore wisdom, French company Osmos has reinvented the wheel. Gone are the hubcaps of the past, jettisoned to make way for a revolutionary "orbital" design with a circular runner as a tyre/ road interface that offers increased safety, performance and reliability.
Osmos Wheels founder Dominique Mottas is an avant-garde entrepreneur and motoring enthusiast who invested in technology in the late 1980s when he had a manufacturer design a sportscar with four empty wheels. The revolutionary hubless or orbital wheel was born and over the next ten years international patents were secured to bring the wheel redesign to the global market.
With the orbital wheel the forces in action at the point of contact between tyre and ground no longer pass through the mid-wheel, but are transmitted directly to the suspended elements. The connecting points of the steering components are located peripherally for steering precision and to decrease pressure and vibration. Driving comfort and adherence have improved by lowering the centre of gravity. The forces also act at the CGM point to improve braking between 20 - 100%.
Accurate steering: The increased precision is due to the use of the new front and rear wheel axles, with their large diameter bearings providing a high degree of resistance during tilt, and with the layout of the ball joints reducing the angle allowance. Current steering pins are made up of two axle bearings or ball joints on the swivel pin with a variable ground clearance, which can be quite high in the case of two-wheelers. The steering pin created for the orbital wheel is designed around a second large diameter bearing in the hollow section of our circular runner and is slightly inclined with respect to the horizontal plane. This allows for increased precision due to the elimination of effects of deformation at the level of the stub axles and forks of the motorbikes.
Reduced forces and structural stress: In a traditional configuration, the dynamic forces acting at the tyre/road interface are increased in terms of torque and stress as they pass through the mid-wheel, thereby allowing an indirect passage. Up to now this has always been considered unavoidable. The advent of the orbital wheel means that these forces are transmitted directly to the suspended elements.
Roll Angle: A road vehicle's stability when proceeding in a straight line depends on the roll angle - the greater the angle, the more stable the vehicle. However, manoeuvrability will be reduced on turns and tight bends. The orbital wheel has a roll angle variator designed along the lines of the single steering pin, with the distinctive characteristic of a second bearing mounted on an articulated plate so that the roll angle is variable. The inclination of this plate is controlled by a speed-related double-effect hydraulic cylinder. The greater the speed, the higher the roll angle, and so maximum stability is maintained at all times. The reverse is also true. When the vehicle slows down, the roll angle is reduced, thereby increasing manoeuvrability.
Reduced unsprung mass: The optimised front and rear axles are specially designed to meet the new requirements and promise a significant reduction in terms of unsprung mass - up to 40% compared with traditional systems.
Resistance to wear: The reduction of specific pressure means that the bearings in particular will be extremely long-lasting: up to 100,000 km.
Drift: The new front and rear heel axles provide excellent rigidity (a more "rational" layout of parts, elimination of give and structural strain). The forces, no longer amplified by complex channelling, are transmitted directly. The unit as a whole is perfectly solid. The Osmos wheel (free central space, single steering pin) has a circular plate (A), containing an eccentric axle bearing (B), which is fitted into the second large bearing (C). This eccentric axle bearing (B) constitutes the steering pin. In its normal position, the swivel pin passes through the mid-plane of the wheel.
Rotating the eccentric plate (A) to the left or right leads respectively to a negative or a positive wheel drift. This mechanism is controlled by an electronically operated motor (D). A central unit continually analyses the parameters picked up by sensors (speed, roll angles, drift, support surface, etc...) and decides on the necessary adjustments. This system means improved roadholding and will undoubtedly be an added advantage in competition racing.
Braking: Braking must occur at the centre of the wheel, which requires substantial energy and a complex brake structure. The Osmos wheel is a step forward, offering the possibility of mounting large diameter brake rings or discs. The grip can be located close to the ground where the forces act. The brake ring design with its peripheral support could lead to multiple ring brakes being produced in the near future.
Osmos wheels have been heavily prototyped on a wide variety of vehicles and are currently looking for investment funding to bring their redesign to the market. With upwards of 4 million wheels produced daily around the world, the "orbital" wheel concept could soon be coming to a car, motorbike, heavy vehicle or bicycle near you.
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