clutch fundamentals and service Flashcards
clutches can act as a safety device by
coupling and un coupling drive and driven units
allow different transmission gear selections without gear clash
stationary engine to remain running while a pump is disconnected
can slip when overloaded
an over center clutch is intended for
intermittent use and is not practical for gear shifting
where are over center clutches usually used
on stationary applications such as pumps and generators
what do over center clutches use to hold the clutch in the engaged position
a unique lever arrangement
what are the two types of flywheels used on a over center clutch
counter sunk or flat
what is used to center the front end of the over center clutch output shaft
a pilot bearing
what do over center clutches need to center and drive the clutch discs
a drive ring ( adapter plate )
the engine flywheel and drive ring will always
rotate at the same speed because they are fastened together
what is another name for clutch discs
driving plates
what are clutch discs on a over center driven by
the drive ring
what are the two construction types of clutch discs used on over center
segmented or solid
when would you use a split type of pressure plate assembly
when more surface area is required
the section of a pressure plate assembly closest to the flywheel is composed of
a backpressure plate and a central hub assembly
the section of a pressure plate assembly closest to the output shaft is
a floating style of pressure plate
floating style pressure plates
move towards the engine as the clutch is adjusted to eliminate the increased clearances caused by clutch disc lining and pressure plate friction surface wear
what are the drive members of a clutch assembly
the flywheel - drive ring - clutch discs
what is considered the driven assembly
pressure plates - central hub - intermediate plates and output shaft
overcenter clutches do not require what to apply force to the pressure plate assemblies
spring force
what do over center clutches use to apply force to the pressure plates
an unusual link and pin system witch applies a locking force on the pressure plate assemblies
what will allow the clutch discs to become free of the the pressure plate assembly
by moving a release lever attached to the release bearing yoke shaft , the release linkage assembly snaps over center and becomes quite loose
where is the mechanical release pin and linkage assembly positioned
between the floating pressure plate and the release bearing assembly
how can the amount of force required to cause the mechanical linkage to snap over center be changed
by rotating the internal adjusting ring toward or away from the floating pressure plate
moving the internal ring toward the pressure plate will
increases the amount of force required to snap over center
the output shaft is often piloted in the
flywheel bore or crankshaft bore
the other end of the output shaft not in the piloted bore will be supported by
a large double set of anti-friction bearings ( tapered roller or spherical roller ) at the rear of the clutch housing
how are the pressure plate and central hub assembly are attached to the output shaft
by a large long key
how can power be power be directed to a unit that is 90 degrees from the engine
with the use of a pulley
when a long set of pulley systems are being used what will the output shaft and clutch housing design include
straddle mounts
before the adjusting ring can be turned for maintenance purposes
a locking pin or strap must first be released
use a spring scale to check
the amount of force applied to the engagement lever by the operator
oil leaking form a engine seal will cause the friction disc to
glaze and therefore more slippage will occur
when checking the pressure plates during an inspection you should be looking for
signs of overheating - warping - wear - cracks
after clutch installation make sure that
crankshaft end play has not been affected
when checking flywheel face runout make sure to
set the crankshaft end endplay full forwards or backwards as to not affect your result
if flywheel runout is beyond spec
the clutch disc will experience uneven contact during engagement and disengagement ( will seem like a dragging or grabbing experience )
what is an overrunning clutch
a device that will drive in one direction and freewheel in the opposite direction
what clutch would used spring loaded roller that move up a ramp
spring and roller clutch
what would use triangular shaped sprags that as they tilt they wedge the inner and outer races together only in one direction
sprag clutch
what clutch would use a sliding shift collar that forces two sections together to form a solid connection
dog clutch or jaw clutch
where are the two places that cone and bevel clutches can be found
in transmissions and rear axle assemblies
what type of clutch would use a special lining material that are not affected by oil
wet clutch or oil clutch
