(7) Drive assembly. The drive assembly (T) is an over-running clutch-
type drive consisting primarily of a shell, ratchet, spring sleeve, and drive
pinion. The shell has internal splines which mesh with those of the armature shaft
and external flanges which serve as contact surfaces for the shift lever.
(a) It also serves as a housing and outer contact surface for the
ratchet. The sleeve supports the drive pinion and ratchet. The spring-loaded
drive pinion has 12 external teeth and internal helical splines, which match with
the splines on the sleeve.
(b) The ratchets engage the sleeve in a locked position when the
starter is driving the flywheel. When the drive assembly reaches overrunning
speed, the ratchets disengage and allow the drive assembly to run free until
disengaged by the solenoid relay.
(8) Solenoid relay assembly. The solenoid relay assembly (G) consists
terminal plate assembly.
(9) Solenoid core and shift lever yoke. A spring-loaded cylindrical
solenoid core (J) is in the bore of the solenoid relay. It provides the shifting
action when the solenoid is actuated.
(a) The spring returns the core to the disengaged position when the
solenoid is deenergized.
(b) The shift lever yoke (P) is connected between the solenoid core
and the drive clutch assembly, where it pivots at its center.
(c) A rubber boot (K) covers the core spring (L) and seals the end
of the solenoid relay.
b. Operation. The solenoid relay makes possible the control of the starter
from an outside source. When the switch circuit to the solenoid is closed, the
coil energizes producing a magnetic field. The magnetic field applies a force to
the core and causes it to move.
(1) As the core moves it exerts a pull on the shift lever yoke, which
shifts the drive clutch pinion into mesh with the ring gear on the engine flywheel.
(2) Once the pinion meshes with the flywheel, the end of the core
presses against the shaft of the solenoid relay contact assembly. When the contact
assembly closes, the battery is connected to the starter motor.
(3) With current flowing in the starter, magnetic fields are formed
about the field coils and armature. The current through the armature causes an
interaction of the magnetic fields and it begins to turn or rotate.
(4) The armature torque is transferred to the engine through the drive
assembly. When the drive ratchets lock the inner race on the sleeve to the outer
race in the shell, the pinion rotates and torque is transmitted as the armature
starts rotating. When the flywheel exceeds the speed of the armature, the ratchet
slips between the sleeve and shell, thus protecting the starter.
(5) When the outside control circuit to the solenoid relay is broken,
the solenoid deenergizes. The spring pressure then returns the core to its
original position. This removes the contact disk and stops the current flow to the
starter. .At the same time the shift lever yoke pulls the drive assembly back to
its original position and disengages the pinion from the engine flywheel ring gear.
OS 010, 6-P10
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