Hubless wheel
Encyclopedia
A hubless wheel is a type of wheel
with no center hub. To be precise, however, the hub is actually almost as big as the wheel itself. The axle
is hollow, following the wheel at very close tolerances. The hubless wheel was invented by Franco Sbarro (who has built a variety of working hubless wheel vehicles, including at least two motorcycle
s and a car
, the 1989 Sbarro Osmos), and patented by Globeholding of Geneva
. The wheel has yet to reach its full technical potential. Tolerances, transfer of energy, and materials are elements of the design which are yet to be fully exploited.
Although hubless wheels are striking in appearance, their numerous practical disadvantages have precluded their widespread use as an alternative to conventional wheels. They are difficult and expensive to manufacture, requiring a great deal of precision machining, and the design leaves the bearing
s and other mechanical parts largely exposed to the elements. The drive system is especially problematic since a conventional axle
and CV joint cannot be used; options include using chain
or belt drive. Another solution, developed by Sbarro, is to house the entire propulsion system inside the wheel itself.
A great example of a hubless wheel are those used in a 2011 "made to order" Tron Legacy Light Cycle. The illuminated, street-legal motorcycle was made by Hammacher Schlemmer, inspired by the computer animated cycle from the 2010 film "Tron: Legacy." Designed for casual cruising and slow ride-bys at shows, it is made from a steel frame covered by a fiberglass cowling that replicates the sleek look of its computer-generated imagery counterpart. Electroluminescent strips built into the tire cowlings, wheel rims, and body illuminate the cycle. It is powered by a fuel-injected Suzuki 996cc, 4-stroke engine. Riders lay at a near-horizontal position astride the padded leather seat, with feet on foot pegs that control its 6-speed constant mesh manual transmission and hands on the handlebars for throttle and braking. The hubless wheels are former truck tires built up then custom-shaped to fit onto one of two counter-rotating rims spinning within each other, providing the broad-tired authenticity of the computer cycles from the movie.
Another example of a hubless vehicle is the "Zero Bike", a lightweight hubless bicycle whose non working prototype won an Industrial Design Excellence Award in 1991. Its design is based on the principle of magnetic superconductivity
, also used in high-speed trains that are suspended above rails.
The orbital wheel was designed in 1990 by Dominique Mottas of the French Osmos company in an attempt to reduce the number of moving parts by removing the center shaft and hub
of the wheel and relying upon a circular rim inserted inside the wheel to support it instead. The orbital wheel was created by using two circular bearings
inserted inside of each other. The inner bearing provides steering, support, and attachment to the frame. The outer bearing consists of a tire with a brake ring also fixed in. Some of the advantages seen by this design are more accurate steering, less weight, and enhanced braking.
Wheel
A wheel is a device that allows heavy objects to be moved easily through rotating on an axle through its center, facilitating movement or transportation while supporting a load, or performing labor in machines. Common examples found in transport applications. A wheel, together with an axle,...
with no center hub. To be precise, however, the hub is actually almost as big as the wheel itself. The axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
is hollow, following the wheel at very close tolerances. The hubless wheel was invented by Franco Sbarro (who has built a variety of working hubless wheel vehicles, including at least two motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
s and a car
Čar
Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:...
, the 1989 Sbarro Osmos), and patented by Globeholding of Geneva
Geneva
Geneva In the national languages of Switzerland the city is known as Genf , Ginevra and Genevra is the second-most-populous city in Switzerland and is the most populous city of Romandie, the French-speaking part of Switzerland...
. The wheel has yet to reach its full technical potential. Tolerances, transfer of energy, and materials are elements of the design which are yet to be fully exploited.
Although hubless wheels are striking in appearance, their numerous practical disadvantages have precluded their widespread use as an alternative to conventional wheels. They are difficult and expensive to manufacture, requiring a great deal of precision machining, and the design leaves the bearing
Bearing (mechanical)
A bearing is a device to allow constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified broadly according to the motions they allow and according to their principle of operation as well as by the directions of applied loads they can...
s and other mechanical parts largely exposed to the elements. The drive system is especially problematic since a conventional axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
and CV joint cannot be used; options include using chain
Chain drive
Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles...
or belt drive. Another solution, developed by Sbarro, is to house the entire propulsion system inside the wheel itself.
A great example of a hubless wheel are those used in a 2011 "made to order" Tron Legacy Light Cycle. The illuminated, street-legal motorcycle was made by Hammacher Schlemmer, inspired by the computer animated cycle from the 2010 film "Tron: Legacy." Designed for casual cruising and slow ride-bys at shows, it is made from a steel frame covered by a fiberglass cowling that replicates the sleek look of its computer-generated imagery counterpart. Electroluminescent strips built into the tire cowlings, wheel rims, and body illuminate the cycle. It is powered by a fuel-injected Suzuki 996cc, 4-stroke engine. Riders lay at a near-horizontal position astride the padded leather seat, with feet on foot pegs that control its 6-speed constant mesh manual transmission and hands on the handlebars for throttle and braking. The hubless wheels are former truck tires built up then custom-shaped to fit onto one of two counter-rotating rims spinning within each other, providing the broad-tired authenticity of the computer cycles from the movie.
Another example of a hubless vehicle is the "Zero Bike", a lightweight hubless bicycle whose non working prototype won an Industrial Design Excellence Award in 1991. Its design is based on the principle of magnetic superconductivity
Superconductivity
Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...
, also used in high-speed trains that are suspended above rails.
The orbital wheel was designed in 1990 by Dominique Mottas of the French Osmos company in an attempt to reduce the number of moving parts by removing the center shaft and hub
Bicycle wheel
A bicycle wheel is a wheel, most commonly a wire wheel, designed for bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels....
of the wheel and relying upon a circular rim inserted inside the wheel to support it instead. The orbital wheel was created by using two circular bearings
Bearing (mechanical)
A bearing is a device to allow constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified broadly according to the motions they allow and according to their principle of operation as well as by the directions of applied loads they can...
inserted inside of each other. The inner bearing provides steering, support, and attachment to the frame. The outer bearing consists of a tire with a brake ring also fixed in. Some of the advantages seen by this design are more accurate steering, less weight, and enhanced braking.