Gas-Hybrid Two-wheeler Kanishka Banerjee

1Mechanical Engineering, Camellia Institute of Technology and Management, Boinchi, INDIA

ABSTRACT

The purpose of this final year design project is to build a two wheeled hybrid vehicle that can be powered by both human effort and an internal combustion engine. The internal combustion engine can power the vehicle once it is pedaled to a short distance and can be switched off during clutching action and resumed with the momentum of the vehicle itself. The vehicle may also be powered with sole human effort. The design is an attempt to address the shortcomings of a conventional engine powered two wheeler in terms of fuel efficiency by incorporating engine turnoff during clutching action and a parallel pedal drive to keep the engine at its economic power-band by starting the vehicle and sharing load at low engine revolution speed.

Index Terms—hybrid, internal-combustion-engine, pedal, fuel-efficiency, engine-switch-off

INTRODUCTION

The project is about building a two wheeled human hybrid vehicle closely resembling a motorized bicycle. The concept of strapping an engine to power a bicycle is not a new one and has seen its use for the need of cheap personalized transportation during and post world war period. The motors used was generally of two stroke variety though some elegant and expensive four stroke designs have been tried by some well known motorcycle manufacturers during their infancy, exemplified by Ducati and Honda.

The design suggested by the team however incorporates some modifications in transmission and engine control, coupled with hybrid drive, with an aim to strive for maximum fuel efficiency notwithstanding practicality. The design is aimed with the following aspirations:

high gas mileage lightweight gas independency

Major parts for making the vehicle were recycled from moped parts, primarily including the engine. The frame was from a donor bicycle and all other parts were made in-house aided by some degree of improvisation.

Engine

The engine used in this project is a two stroke, 49.6 cc air-cooled horizontal type engine which was taken from a moped sold under the brand name KINETIC MOTORS. The technical specification is as follows:

Bore: 38.42mm

Stroke: 43.00mm

Displacement: 49.77 cm3

Compression Ratio: 8:1

Ignition advance: 21˚+/-1˚

Spark Plug: Mico W 145 z1

Carburetor: Spaco 1210

Output: 1.75bhp @ 5000rpm

2.943Nm@ 3000rpm

The specific engine is chosen due to the following reasons given below.

lightweight enough to be fitted to a bicycle frame meets the power requirement to haul for the designed loads

this particular engine has a de-compressor lever placed in the head which could be made to act like an engine kill switch if the crank is immediately disconnected from load.

Transmission

The transmission used for this hybrid vehicle is actually two separated unit-one with human effort by pedaling and the other engine powered. To meet the design aim they must be arranged in relation as shown by the following diagram

pedal wheel

engine wheel

Arrowheads point in the direction from driver to driven

element and the diagonal box represents the engine kill switched on position only.

This problem requires a manual clutch system connecting engine and drive wheel which would work both way transmitting torque. during startup and immediately on engaging the clutch, the engine would be either pedal started on rear wheel turning or by the momentum of the vehicle along with the rider.

The clutch used is a belt clutch system. The system comprises of a driver pulley attached to the output shaft of the engine and a driven pulley attached to the bike frame. The belt pulley on the driven side is designed so that the centre distance between the pulleys may be reduced to allow slipping during clutching action. This is accomplished by a spring loaded lever turning a screw on which the nut rides housing the bearings of the driven pulley. The driven pulley is also compounded with a chain sprocket which is the driver chain sprocket for the rear wheel power transmission. On reducing the centre distance between the clutch pulleys during clutching action, the centre distance between the driver and driven chain sprocket increases causing a tightness in chain and on releasing the clutch the chain slacks. Though this change in chain tension is small but the design compensates for this effect by incorporating an idler sprocket riding on the chain and is hinged on a spring loaded arm. The technical specifications of the clutch pulleys and the belt are given below.

Pulley specification

Driver pulley

Outside diameter-85 mm

Driven pulley

Outside diameter-102 mm

Both the pulleys are “v-grooved” pulley made of cast iron

with groove angle of 34 degrees.

Belt specification

Catalogue name-AX belt

Make-Grayton

Type Cogged V-belt

Length-770 mm

Width-92 mm

Frame

The frame used is from a donor bicycle of fixed frame design. Some necessary modifications done to the frame was attaching a telescopic type shock absorber for the front suspension, stretching and chopping the necessary frame bars to accommodate the engine and the transmission parts. The seat is mounted on a leaf spring platform to compensate the unavailability of a rear suspension system in the present design, however provisions are made in the frame to incorporate the latter design modifications as well.

Acknowledgment

Inspiration for this project is the quest for designing a vehicle that could be ridden independently by human effort with all the possible assistance from an engine thus practically leaving the rider to be free to explore all and every possible places, often out of the fuel and reaching range of conventional motorbikes. this coupled with the drive to create something new to two wheeled transport was the real fuel for this bike design project.

CONCLUSIONS

The project work is still undergoing in its assembly stage. The engine and the transmission parts such as pulleys and belts have been acquired and waiting its mounting on the frame. The frame has been assigned and disassembled for mounting. A full conclusion is yet to be met.

REFERENCES

Design of Machine Elements, V.B Bhandari

Theory Of Machines, R.S Khurmi

Internal Combustion Engines, Richard Van Basshuysen & Fred Shauffer

Advanced Welding Methods

Machining And Machine tools, A.B Bhattacharya

Engineering Mechanics Statics, Merium & Kraige