How we made an E-Cycle
For the final year project of Mechanical Engineering I and my friends teamed up to make an electric cycle, which was capable of running at a speed of approximately 25km/h up to a maximum distance of 20km in a single charge with zero emission. In the project we transformed a conventional cycle into an ecycle by making making necessary modifications on on the rear rim of tire, also some constructed a housing for the battery. This post comprises each and every material that you will ever need to make one for yourself and the process depicted here is cheap and effective.
Such ecycles are most suitable for city conditions. China is the biggest manufacturer and user of e-cycle and combined with the fact of world’s biggest population the data is overwhelming. Implementation of policies which promotes electric transport in India will help us in putting a check on pollution and traffic.
1.Requirements for the projects:-
1. A cycle which could be modified or you can make one for yourself
2. An electric motor with required specification(Discussed in the post)
3. Lead Acid Batteries required to drive the DC motor.
4. Mountings and fixtures to mount the motor.
5. Basic tools and equipment.
2.Calculations:-
We started with basic calculations to figure out the following-
1. Torque available on the rear wheel
2. Maximum RPM of rear wheel
3. Required power of the motor
Following data was available to us at hand-
1. Radius of rear wheel=0.65m
2. Radius of sprocket of motor=0.09m
3. Radius of freewheel=1.2m
4. Frictional Coefficient=1 or 0.8
Following formula were used to Calculate The Power Required:-
N1/N2=D2/D1=T2/T1
T=F.r
F-f=ma (Also f=μmg)
P=T.W
Here, N1=RPM of Sprocket of Motor N2=RPM of freewheel N3=RPM of Rear wheel D1=Diameter of sprocket D2=Diameter of Freewheel D3=Diameter of Rear WheelT1=Torque on Sprocket of motor T2=Torque on Freewheel of motor T3=Torque on Rear Wheel
These equations provided us the following results:-
N2=300Rpm N3=666.66RPM
T2=20Nm T3=22.5Nm
Also, a=2.04m/s2 T=20.22Nm W=69rad/sec
Hence, power required on motor to lift a weight of 120kg is approximately P=245Watt or 0.32 horsepower. We also found that a 24V, 12Ah battery would be able to drive the system for an hour while covering a distance of 20km, which would be sufficient for city ride in single charging.
We used dry battery with 7Ah and 12v batteries. You can always beef up the batteries to travel longer distances depending on the space available on your bike.
3. Components we used:-
1 pcs 250W 24V brush motor
1 pcs motor controller
1 pcs throttle
1 Modified Hub
2 Freewheels
1 Modified cycle
Specifications:
MY1016Z
24 Volt DC Operation
Permanent Magnet DC Motor
Rated Load RPM: 400
No Load Current: <2.2 Amps
Rated Wattage: 250W (0.33 Horsepower)
Torque (NM): 22
Rated Current: 13.4 Amps
Efficiency: 78%
Reduction Ratio: 9.78:1
Direct Drive (No Free Spooling)
Suitable for Forward and Reverse Operations
Base Mount Model
9 Tooth Sprocket for ½" x 1/8" Pitch Chain
4.) Design we used:-
The major challenge in the project in front of you is devising the method of transferring the power of motor to the hub of tire. It could be done in multiple ways i.e. you can use a hub motor which will itself rotate the tire or you could copy our design.
We designed and planned a rear-dual-chain drive mechanism which is depicted in the image below. In this design both chain are independent of each other, employed to propel the cycle on demand either of them (pedal or electric motor) one can move at once and other can remain stationary. Both of the chains have their one end mounted on free wheels whereas other end of chain is connected with manual or electric power source. Both of freewheels are mounted on the opposite end of the rear hub separated by spokes. Following image envisages the idea presented above:
Following is the design of the electric motor we used:-
Similarly, the secondary chain can be used to drive the bicycle manually with the help of pedals in case of discharged batteries. In this situation because of the rear dual chain drive mechanism the primary chain and electric motor remains stationary.
5. Working Process:-
The following pictures will help you understand about the design and working of our project. The image below shows the basic idea of our project and placement of the various components on the cycle.
As you can see in the picture below the hub consists freewheel on both sides and receives power from both sides, from one side it receives power from pedal and other receives power from the electric motor. The design keeps both the freewheel independent of each other.
5. Remarks:-
The project was thoroughly functional and efficient from our experience I can tell you that with proper knowledge you can effectively build a same project for yourself. You would certainly require to manipulate the design according to the situation and tools available at hand.
Useful Website References:-
1. nycewheels.com/electric-bicycles.html
2. ebikes.ca/learn/intro-to-ebikes.html
3. wikipedia.org/wiki/Electric_bicycle
Useful Published Papers:-
1. APSC 262 Justin Lemire-Elmore Term Paper 81781999 April 13, 2004
2. An Improved & Efficient Electric Bicycle system with the Power of Real-time Information Sharing Prof. Jayashree Deka Department of Electrical Engg. K.J. College of Engineering Pune, India.
7. Final Costs:-
On Date: 25/5/2016
The Total Cost of the project=10,540 Rs
The whole project was built on the most economical basis irrespective of most efficient basis because of the constraints of budget. And it was endeavored to achieve best possible results in the limited resources as shown above.
8. Meet Our Team:-
Links to their profile:-
Abhishek Daryani
Bhagirath Gurjar
Arvind Agrawal
Ashish Kumar
Keshav Galav
9. You May also like:-
The Audi e-bike
Bosch e-bike
Watch this video
These two IItians made up scooter which charges faster than your mobile phone click here to know more
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