Kinetic Energy Recovery System

Implementation of Kinetic Energy Recovery System (KERS) on a Bicycle

V.Arun1, R. Nataraj2

1Department of Mechanical Engineering, College of engineering, Guindy, Chennai-600025, India.

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Abstract- The recovery system of momentum energy in a flywheel is complicated, but it is based on some very basic physics. The mechanical kinetic energy recovery system stores kinetic energy, the energy of motion in a flywheel. This can be explained by the law of conservation of energy. Energy in a system can be transformed from one form to another but creation of energy is not possible. In a bicycle, during braking, energy is lost to the atmosphere as heat. The energy which is wasted during braking in a bicycle can be stored and being

I. CONCEPT

A Kinetic Energy Recovery System (often known known simply as KERS) is an automotive system for recovering a moving vehicle's kinetic energy under braking. The recovered energy is stored in a reservoir (flywheel) for later use under acceleration [1], [2]. Physicist Richard Feynman postulated the concept of transferring the vehicle’s kinetic energy using flywheel energy storage.

KERS is a collection of parts, which takes some of the kinetic energy of a vehicle under deceleration, stores this energy and then releases this stored energy back into the drive train of the vehicle, providing easy acceleration to that vehicle.

During braking, energy is wasted because kinetic energy is mostly converted into heat energy that is dissipated to the environment.

Vehicles with KERS are able to harness this kinetic energy and in doing so will assist in braking. By engaging a clutch mechanism, this stored energy is converted back into kinetic energy.

In this project, the Kinetic Energy Recovery System on a bicycle has been implemented with the help of with the help of a flywheel assembly.

II. WORKING

The rear wheel sprocket has 48 teeth and has a thickness of 10 mm.

The sprocket is attached to the rear wheel by welding it to the wheel hub [5], [6]. Fig 8 Sprocket

The metal disc with sprocket is used to transfer the kinetic energy from the rear wheel to the flywheel. The metal disc and the sprocket are welded together. The metal disc is fixed with a rubber sheet for creating friction between the disc and the flywheel and hence for effective energy transfer.

The metal disc is 125 mm in diameter and 6 mm thick while the sprocket has 13 teeth and is 6mm thick. They both are 20 mm apart. The sprocket is connected to the rear wheel by means of chain and is rotated along with the wheel initially

Fig 9 Metal disc

When the kinetic energy has to be conserved, the rotating metal disc with sprocket is pushed front by the engage gear to mate with the flywheel. By the action of friction between the rubber pad and the flywheel, the flywheel starts rotating in sync with the metal disc. When enough energy is stored in the flywheel, the engage gear is released and hence the metal disc comes back to its original