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© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois.

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Presentation on theme: "© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois."— Presentation transcript:

1 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois by Russell Krick

2 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only

3 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Starting system principles  Starting motor construction

4 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only The starting system uses battery power and an electric motor to turn the engine crankshaft for engine starting

5 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Basic Starting System  The ignition switch energizes the solenoid, which allows the battery to energize the starting motor, which turns the flywheel gear, starting the engine

6 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Components  Battery  source of energy  Ignition switch  allows the driver to control operation  Solenoid  high current relay (switch)  Starting motor  high-torque electric motor

7 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Energizing the Starting System  Turning the ignition key to the “start” position allows current to flow through the solenoid coil  Magnetism closes the solenoid contacts, connecting the battery to the starting motor  The motor turns the flywheel ring gear until the engine runs on its own

8 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only De-energizing the Starting System  When the ignition key is released to the “run” position, no current flows to the solenoid coil  The solenoid contacts open, the starter stops turning, and the starter gear moves away from the flywheel

9 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starting Motor Fundamentals  Converts electrical energy from the battery to mechanical energy to crank the engine  Like other electric motors, the starting motor produces a turning force through the interaction of magnetic fields inside the motor assembly

10 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Magnetic Field Action  Made up of invisible lines of force  Since like charges (fields) repel each other and unlike charges (fields) attract each other, magnetic fields can be used to produce motion

11 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Magnetic Field Action

12 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Simple Electric Motor If a current-carrying winding is placed inside a magnetic field, the winding rotates away from the pole shoes

13 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Commutator and Brushes  Keep a motor turning by controlling the current through the windings  The commutator serves as a sliding connection between the motor windings and the brushes  The brushes ride on top of the commutator, carrying current to the spinning winding

14 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only The commutator reverses the electrical connection when the loop rotates around Commutator and Brushes

15 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Increasing Motor Power  Several windings (loops of wire) and a commutator with many segments are used to increase motor power  As the motor spins, many windings contribute to the motion, producing a smooth turning force

16 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Armature  Supports the windings  Increases the strength of each winding’s magnetic field

17 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Field Windings  Stationary insulated wire wrapped in a circular shape  When current flows through the field windings, the magnetic field between the pole shoes becomes very large  This field acts against the armature’s field, producing motion

18 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Armature and Field Windings

19 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starter Pinion Gear  Small gear on the armature shaft  Engages a large ring gear on the engine flywheel  Moves into and meshes with the flywheel ring gear

20 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starter Pinion Gear

21 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Overrunning Clutch  Locks in one direction  Releases in the other direction  Allows the pinion gear to turn the flywheel ring gear for starting  Lets the pinion gear freewheel when the engine starts

22 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Locks the flange to the pinion gear in one direction and releases in the other direction Overrunning Clutch

23 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Overrunning Clutch Operation Rollers jam and lock in one direction and release in the other direction

24 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Pinion Gear Assembly Pinion gear assembly slides on the shaft for engagement

25 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starter Solenoid  An electromagnetic switch  Makes an electrical connection between the battery and the starting motor  Allows the low current ignition switch circuit to control the high current starting motor

26 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starter Solenoid Plunger movement pulls the disc into contact with the battery terminal and the starter terminal to activate the starter motor

27 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Solenoid Operation  Low current flows through the windings when the ignition is in the start position  The magnetic field pulls the solenoid plunger and disc toward the windings  The disc touches both of the high- current terminals  High current flows to the starter motor

28 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Solenoid Operation

29 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Solenoid Functions  Closes the battery-to-starter circuit  Pushes the starter pinion gear into mesh with the flywheel ring gear  Bypasses the resistance wire in the ignition circuit

30 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only All starting motor construction is similar, but there are slight variations in design

31 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Main Parts of a Starting Motor  Armature  windings, core, shaft, and commutator assembly that spins inside a stationary field  Pinion drive assembly  pinion gear, overrunning clutch, and sometimes a shift lever and solenoid  Commutator end frame  end housing for brushes, brush springs, and shaft bushing

32 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Main Parts of a Starting Motor  Field frame  center housing that holds field coils and pole shoes  Drive end frame  end housing around pinion gear; has bushing for armature shaft

33 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starting Motor Types  Classified by type of pinion gear engagement  There are two main types:  movable pole shoe starting motor  starter-mounted solenoid (starting motor with solenoid)

34 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Movable Pole Shoe Starting Motor Uses a drive yoke lever to move the pinion gear into contact with the flywheel gear

35 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Movable Pole Shoe Starting Motor A magnetic field pulls the pole shoe downward, forcing gear engagement as the armature starts to spin

36 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Solenoid plunger moves a lever to engage the pinion gear Starter-Mounted Solenoid

37 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starter-Mounted Solenoid The solenoid not only operates the pinion gear but also completes the battery-to-starter circuit

38 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Solenoid Operation

39 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Permanent-Magnet Starter Uses special high-strength magnets in place of conventional field windings

40 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starting Motor Torque  A starting motor must produce high torque  Difference in gear size between the small pinion and large flywheel ring gear increases turning force

41 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Reduction Starter Extra gears further increase torque

42 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Internal Motor Circuits  Series-wound motor  Shunt-wound motor  Compound-wound motor

43 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Series-Wound Motor Develops maximum torque at initial start-up and decreases as motor speed increases

44 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Shunt-Wound Motor Produces less starting torque but more constant torque at varying speeds

45 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Compound-Wound Motor Has both series and shunt windings and produces good starting power and constant operating speed

46 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Neutral Safety Switch  Prevents the engine from cranking unless the shift selector is in neutral or park  Mounted on the shift lever or on the transmission

47 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Neutral Safety Switch Wired in series with the starter solenoid

48 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starter Relay  Opens or closes one circuit by responding to an electrical signal from another circuit  Uses a small current from the ignition switch to control a larger current through the starter solenoid  Reduces the load on the ignition switch

49 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starter Relay Operation  Ignition switch is turned to “start”  Current flows through the relay windings  Magnetism closes the relay contacts  Contacts complete the circuit to the solenoid windings  Solenoid contacts close, which energizes the starting motor

50 © Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Starting System Circuit


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