Welcome To,The Starter Operation & Diagnosis,SECTION 9,Objectives,Explain the purpose of the starting system. List the components of the starting system, starter circuit, and control circuit. Explain the different types of magnetic switches and starter drive mechanisms. Explain how a starter motor operates.,continued,Objectives,Describe the operation of the different types of starter motors. Perform basic tests to determine the problem areas in a starting system. Perform and accurately interpret the results of a current draw test.,continued,Starting System,The vehicles starting system is designed to turn or crank the engine over fast enough until it can start and operate under its own power. To do this, the starter motor receives electrical power from the battery. The starter motor then converts this energy into mechanical energy, which it transmits through the drive mechanism to the engines flywheel.,continued,Starting System Components,Battery Cable and wires Ignition switch Starter solenoid or relay,Starter motor Starter drive Flywheel ring gear Starter safety switch,continued,A typical engine-starting system,电磁线圈,起动机,驻车空档开关,点火开关,连接点,蓄电池,Cutaway view of a solenoid starter,螺线管线圈绕组,回位弹簧,柱塞,拨叉,枢轴销,衬套,电枢轴,驱动转动齿轮,单向离合器,极靴,励磁线圈,电刷组,电动机端子,柱塞接触盘,Components of the field coil starter,励磁线圈,夹刷器,碳刷,换向器,电枢绕组,电枢轴,电枢铁心,极靴,The connection between the field coil and the armature,换向器,电刷,极靴,励磁线圈,电机端子,A cutaway view of an overrunning clutch with pinion gear,壳,驱动齿轮套圈,驱动齿轮,滚轮弹簧,滚轮,A Typical Starting System,continued,Starter Motor Drives,Solenoid-actuated direct drive Positive engagement, movable pole shoe drive Used on older Ford products Solenoid-actuated gear reduction drive Used with gear reduction starters Used in conjunction with a planetary gearset,continued,Control Circuit Components,Starting safety switch Prevents vehicle from starting unless in park or neutral or with clutch disengaged. Ignition switch Solenoid or relay Allows a small amount of current to control the high current starter circuit.,continued,Starter Motor Construction,The starter is a special type of electric motor designed to operate under great electrical overloads and to produce very high horsepower. The starter motor consists of a housing, field coils, an armature, a commutator and brushes, and end frames.,continued,Starter Motor Construction,The starter housing and starter frame enclose the internal starter components and protects them from damage, moisture, and foreign materials. The field coils and their pole shoes are securely attached to the inside of the starter housing.,continued,Starter Motor Construction,The field coils are insulated from the housing but are connected to a terminal that protrudes through the outer surface of the housing.,continued,Starter Motor Construction,The armature is the only rotating component of the starter. It is located between the drive and commutator end frames and the field windings. The armature has 2 main components: the armature windings and the commutator which are both mounted to the armature shaft.,continued,Starter Motor Construction,The armature The armature windings are made of several coils of a single loop each. These loops are mounted on the armature shaft, but they are insulated from it. The commutator assembly is made up of heavy copper segments that are connected to the ends of the windings and separated from each other and the armature shaft by insulation.,continued,Starter Motor Construction,Starter motor end frame The starters end frame in many starters support the armature and hold the brushes. Most starter motors have 2 to 6 brushes that ride on the commutator segments The brushes mount on and operate in a holder, which contain springs to hold the brushes against the commutator with the correct pressure. The brush holders are alternately insulated from the end frame or grounded.,continued,Starter Motor Operation,The starter motor converts electric current into torque or twisting force through the interaction of magnetic fields. It has a stationary magnetic field - the field windings, and a current-carrying conductor -the armature windings. When the armature windings are placed in this stationary magnetic field and current is passed through the windings, a second magnetic field is generated with its lines of force wrapping around the wire.,continued,Starter Motor Operation,Since the lines of force in the stationary magnetic field flow in one direction across the winding, they combine on one side of the wire, increasing the field strength, but are opposed on the other side, weakening the field strength. This unbalanced magnetic force pushes the wire in the direction of the weaker field.,continued,Starter Motor Operation,In a starter motor, many armature segments must be used. As one segment rotates past the secondary magnetic field pole, another segment immediately takes it