International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 10 Issue: 06 | Jun 2023
p-ISSN: 2395-0072
www.irjet.net
Design and Validation of Efficient Flywheel Cup of Magneto to Improve the Thermal Behaviour Rakesh Narsayya Gundu1, Amol B. Gaikwad2, Atul Jain3, Kharad B.N.4 1Scholar, Dept. of Mechanical Engg, Vishwabharti Academy’s College of Engineering, Ahmednagar, Maharashtra, India 2Asst. Prof. Dept. of Mechanical Engg, Dr. D.Y. Patil School of Engineering, Pune, Maharashtra, India 3General Manager (R&D), Varroc Engineering Limited, Pune, Maharashtra, India
4Asst. Prof. Dept. of Mechanical Engg, Vishwabharti Academy’s College of Engineering, Ahmednagar, Maharashtra, India
---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract – A flywheel magneto is an electromechanical
signals are also used by the speedometer for engine RPM display. The magneto is the source of energy generation in the magneto ignition system. Magneto generates AC electrical power which will be used to drive electrical loads in vehicles. The AC power from magneto will be going to the signal conditioning part which is more popularly known as regulator. Based on the loads the power is getting processed in this signal conditioning & power is converted into Regulated DC, Regulated AC etc. The magneto is also responsible for generating signals for the ignition circuit. Magneto has a pulser coil which acts as a magnetic sensor & senses the position of the rotor with the help of pulser pip present on the rotor. As this function of the magneto of signal generation is directly related to the ignition of the vehicle, the same is very important. The components of magneto causing the signal generation are to be treated very much carefully as any defect in these components will make the engine to stop & the vehicle will not start at all. A magneto consists of a rotor assembly & a stator assembly as shown in fig. 1.1. A rotor assy. is a part which will be rotating with magnets fixed on it which will produce rotating magnetic field. Stator assy. will be a stationary part with conductor coils fixed on it. Because of rotating (changing) magnetic field, e.m.f. is induced in the conductor placed on the stator.
device for generating AC electric power which is used to drive electrical loads in vehicles. The flywheel magneto is also responsible for generating signals for the ignition system of the vehicle. Flywheel magneto produces heat which makes thermal behaviour management complicated and very difficult. All losses from the flywheel magneto are converted into heat. The most of heat generated in magneto assembly due to winding copper losses & these losses increase the winding temperature.
This paper demonstrates the design and validation of efficient flywheel cup of magneto to improve thermal behavior. The cup is designed with cooling holes in such a manner that those holes assist the cooling of the winding. To study the thermal performance (heat loss dissipation) due to peripheral holes, the thermal analysis is performed using Ansys software. The CFD analysis is performed for different scenarios, no flow (no holes on cup), maximum flow through axial holes and maximum flow through lateral holes aiming on the winding. CFD results are compared with physical testing results. The maximum air flow rate with lateral cooling holes condition indicates lower temperature generation compared to no flow with no cooling holes and maximum flow with axial holes of flywheel cup. The lower temperature achieved in copper winding ensures the winding insulation is not affected due to excess heat.
Key Words: flywheel magneto, electromechanical, thermal behaviour, flywheel cup, copper losses, efficiency, Ansys software, etc.
1. INTRODUCTION A magneto is an AC power generator used for generating AC electrical power in automobiles (two, three wheelers). Magneto is working as per faraday’s law of electromagnetic induction, which states that when a conductor is placed in a rotating (changing) magnetic field, e.m.f. is induced in it. Magneto is used in vehicles for electrical power generation to drive electrical loads such as: lighting loads, horn & electrical circuits (Ignition Circuit, Speedometer Circuits etc.) Apart from electrical power generation, magneto also generates signals which are used by the ignition circuit for the spark timing, duration etc. The
© 2023, IRJET
|
Impact Factor value: 8.226
Fig -1: Flywheel magneto assembly
|
ISO 9001:2008 Certified Journal
|
Page 58