MECHANICAL ROCKS

INTRODUCTION An electrical motor is a electric device which converts electrical energy into mechanical energy (one form of energy into another form).Dc motors are widely used in applications that require control of speed ,initially high torque(used in elevator , vacuum cleaner)engine starters etc . In general in every mechanical machine such as lathe, drill machine, grinding machine, we use series motor due to its capacity of supplying constant speed. They are made in sizes form 1/100 hp to thousands of hp. We know that Dc electric devices are basically of two types: Dc motors and Dc generators, both are similar in appearance and construction. Construction of Dc motors: Yoke is the outer most part of the Dc motor which protects the Dc motor and act as cover. The other main parts are as follow: Pole core/pole shoe:-It contains the pole coil (provide support to the pole coil). It also provide low resistance path for current (which is carrie

Most Common troubles mentioned below:     Engine fails to start. Ignition switch off. Fouled spark plugs or Faulty breaker points or faulty condenser. Current may not be flowing due to loose battery terminals or weak battery. Fuel supply stopped or fuel tank empty or air lock in diesel fuel line. Too rich mixture due to carburetor flooding. Faulty diesel pump and injection nozzle. Poor compression, leaky valves, worn piston rings. Incorrect valves timing or ignition.   Engine fails to develop full power. Air cleaner clogged. Poor compression. Carburetor too rich or too lean, or choke stuck or throttle lever loose. Diesels fuel filters dirty or injection system trouble. Incorrect spark timing. One or more cylinders misfiring. Overheated engine.   Engine overheats. Low radiator water level or radiator fan belt loose. Thermostat valve stuck, wat

Introduction Pre-ignition  refers to the burning of mixture in the combustion chamber before the piston has reached the top dead center .This may be due to excessive heat in the cylinder.

Procedure Electric motors must be kept clean and lubricated if they are expected to work efficiently for a longer period. The following procedure should be keep a motor clean : After having disconnected the motor from the power ,it is necessary to disassemble it by removing the rotor, shaft and fan assembly. All possible care should be taken not to break any wire connection or centrifugal switch mounted on the rotor shaft or elsewhere. The second step is to blow out the loose dirt from the motor winding and from inside the end plates by using pressurized air from a blower. If necessary a dry paint brush or cloth can be used to carefully wipe off dirt that might remain even after using pressurized air. All dirt from the passage in the frame and in the rotor should be removed .metal parts may be washed with inflammable fluid. All the accessories like the starting switch the commutator and brushes should be checked and repaired

The mixture of fuel and air in an engine cylinder cannot produce power, unless it is ignited in every cycle at the proper instant. The basic methods for igniting the fuel charge are:-- ·        Ignition by an electric spark. ·        Ignition by compression. In a  carburetor  engine a mixture of fuel and air is compressed in the cylinder. Then a high voltage spark jumps across the spark plug electrode gap to fire the charge. The spark must be strong enough to jump across the gap and it must do so at predetermined time. If the spark to early, before the piston has reached TDC then the engine tends to run in the reversed direction, or kicks. At full engine speed ,however the spark must occurs earlier so that proper pressure from the burning fuel charge is built up ,just as piston starts moving down from TDC to BDC .the ignition system is so design that the spark is retarded for starting the engine and as the engine picks the speed the spark is advanced .

  Introduction: Spark Plug is a device which generate the spark within the engine cylinder for ignition of the fuel. For ignition of the fuel we want approximately 20,000 Volts. But as we know that in Two Wheelers only 6V or 12 V batteries are placed. Then from where we get 20,000 Volts.      We get 20,000 Volts by using ignition Coil. Spark plug consists Ignition coil. Ignition Coil: The ignition coil is a pulse transformer that transforms or steps up the low battery or generator voltage to the high voltage, necessary to jump the gaps at the spark plugs. By using this coil voltage can be stepped up from 6V to 20,000 volts. This coil has a laminated core, around which is wrapped the primary winding, consisting of hundred turn of relatively heavy wire and the secondary winding which several thousand fine wire. The windings are properly insulated from each other. The ignition coil is sealed to prevent entry of moisture which would c