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This project is developed for the users to rotate the rear wheel of a two-wheeler using propeller shaft. Power transmission through chain drive is the oldest and widest used method in case of bicycle. In this paper we implemented the chainless transmission to the bicycle to overcome the various disadvantages of chain drive. Shaft drives were introduced over a century ago, but were mostly supplanted by chain-driven bicycles due to the gear ranges possible with sprockets and derailleur.
Recently, due to advancements in internal gear technology, a small number of modern shaft-driven bicycles have been introduced. Usually in two wheelers, chain and sprocket method is used to drive the back wheel. The shaft drive only needs periodic lubrication using a grease gun to keep the gears running quiet and smooth. A shaft driven bicycle is a bicycle that uses a shaft drive instead of a chain which
contain two set of roller bearing at both the ends to make a new kind of transmission system for bicycle for getting high reliability system, and more safe system. Shaft-driven bikes have a pinion style drive shaft system where a conventional bike would have its chain ring. Pinion meshes with another roller bearing mounted on the drive shaft. The use of roller bearing allows the axis of the drive torque from the pedals to be turned through 90 degrees.
The drive shaft then has another roller bearing near the rear wheel hub which meshes with a pinion on the hub where the rear sprocket would be on a conventional bike, and cancelling out the first drive torque change of axis. According to the direction of motion of pedal, the wheel will be moved forward or reverse. This avoids the usage of chain and sprocket method. This “chainless” drive system provides smooth, quiet and efficient transfer of energy from the pedals to the rear wheel. It is attractive in look compare with chain driven bicycle. It replaces the traditional method.
A shaft-driven bicycle is a bicycle that uses a drive shaft instead of a chain to transmit power from the pedals to the rear wheel. Shaft drives were introduced over a century ago, but were mostly supplanted by chain-driven bicycles due to the gear ranges possible with sprockets and derailleur. If roller bearing could be accurately and cheaply made by machinery, it is possible that bearing of this description might supplant, to a great extent.
The pinion drive shaft system eliminates eight points of chain sliding friction and replaces it with just two points of higher-efficiency bearing rolling friction. Shaft-driven bikes have a roller and pinion where a conventional bike would have its chain ring. Pinion meshes with the roller bearing provided at the rear side of shaft. The use of roller and pinion allows the axis of the drive torque from the pedals to be turned through 90degrees. The drive shaft then has another roller bearing near the rear wheel hub which meshes with a pinion on the hub where the rear sprocket would be on a conventional bike, and cancelling out the first drive torque change of axis.
An automotive drive shaft transmits power from the engine to the differential gear of a rear wheel drive vehicle. The drive shaft is usually manufactured in two pieces to increase the fundamental bending natural frequency because the bending natural frequency of a shaft is inversely proportional to the square of beam length and proportional to the square root of specific modulus which increases the total weight of an automotive vehicle and decreases fuel efficiency.
So, a single piece drive shaft is preferred here and the material of it is considered to be Titanium alloy because of its high strength and low density. Drive shafts are carriers of torque and are subject to torsion and shear stress, equivalent to the difference between the input torque and the load. They must therefore be strong enough to bear the stress, whilst avoiding too much additional weight as that would in turn increase their inertia.
ADVANTAGES AND DISADVANTAGES OF CHAINLESS BICYCLE
- Driven is lighter than a conventional drivetrain as the chain and derailleurs are eliminated.
- There is a high potential for aerodynamic advantages.
- Lower friction in general, and the elimination of chain link stiction and chain sliding friction.
- Endless possibilities for gear range options of a 1x gear.
- Different diameter front and rear pinions can be used to increase or decrease the overall final drive ratios.
- Drive system is less likely to become jammed, a common problem with chain-driven bicycles.
At 250W, Ceramic Speed Driven creates 32% less friction than the Ceramic Speed upgraded drivetrain, and 49% less friction than the standard Dura-Ace drivetrain.
- Difficulty in shaping and machining of cog profile.
- Difficult to change gears.
- Complex shaft mechanism.
- Costly due to use of ceramics and carbon fiber.
CHAINLESS BICYCLE PROJECT REPORT DOWNLOAD
This project report is submitted by ABHYUDAYA PRAKASH, ARPIT SONDHIYA, CHANDAN KUMAR, PRATEEK SAHU, SOURABH DIXIT. This document is used for educational purpose only. We don’t own any copyrights for this document. If you want to remove this doc please contact us.