Clutch Fundamentals Flashcards
What are the 3 types of pressure springs?
Diaphragm
Perpendicular
Angled
Pressure springs are located between what to components?
Clutch cover and pressure plate
What are the 2 main types of spring loaded clutches?
Push style
Pull style
Push type clutch
Used in lighter duty applications, release shaft and yolk assembly push release bearing toward flywheel. uses a type 1 lever pulling pressure plate and anchored to clutch cover
Pull type clutch
Fork pulls the release bearing away from flywheel, this pulls lever arms carrying spring pressure off pressure plate, type 2 lever
What are the different ways of actuating the clutch? (3)
Mechanical
Hydraulic
Air-over-hydraulic assist
What are the 4 common ways to determine clutch size?
Diameter of disc
O.D. of clutch shaft
Number of splines
Number of dampening springs
What it is the most obvious function of the flywheel?
Provide a smooth friction surface for one side of the clutch disc
What is the purpose of the pilot bearing?
Bearing that is mounted in hub of flywheel of crankshaft that provides a guide for the nose of input shaft
Flat flywheel
Has 2 surfaces, one machined surface where cover is fastened, one friction surface for clutch disc to work against. Will work with both single and double disc clutch assemblies
Countersunk flywheel
Has a recessed friction surface, has lugs to drive intermediate plate on double disc assembly.
Heavy duty clutch covers are made of what?
Cast iron
Pressure plates
Usually made form cast iron, is located inside of the clutch cover and is driven by cover during operation.
Perpendicular coil springs
Stand at 90 degrees to the pressure plate, exert tremendous force on the pressure plate
Angled coil springs
Placed on an angle to the pressure plate
Diaphragm springs
Is a single large plate, creates a multiple of clutch release levers that are used during engagement and disengagement process, made of flat spring steel
Rigid clutch disc
Often riveted to a central splined hub that slides on the transmission input shaft splines
Dampened clutch disc
Disc is attached to the central splined hub through a limited movement mechanism, commonly springs that are designed to absorb some of the torsional shock loads
Marcel spring
Are a wavy spring that may be used to attached disc to hub, used to help reduce impact loads during engagement
Organic clutch lining
Often called non-asbestos organic (NAO) linings. Constructed of various binders, resins and fillers.
Semi-metallic linings
Similar to organic but have the addition of metallic particles to help where high heat loads could be created
Ceramic linings
May be used where heat and heavy load are present
Clutch release levers
Are used to move the pressure plate closer to the cover during disengagement. they compress the pressure springs
Push type release bearing
Only rotate when foot on pedal, Commonly a type of yolk mechanism that pushes the thrust type bearing toward the release levers
Pull type release bearing
Rotates when engine is running, only has load on it when foot on pedal. Yolk pulls the bearing and sleeve assembly including levers away from P.P.
How are push type clutches adjusted?
Using the threaded rod in the linkage
Clutch brake
The input shaft requires 2 long grooves to line up with the tangs on the brake plate that will connect the 2 parts. Require the trans. input retainer to have machined surface for brake to act against.
Torque-limiting clutch brake
Designed to slip above a certain torque load, increasing service life when used improperly.
What is the function of the clutch cover
Used to drive the pressure plate, also contain the pressure springs used to apply force to the P.P. Used to mount the P.P to the flywheel
What are 3 drive members in a clutch assembly
Flywheel
Clutch cover/P.P assm
Intermediate plate
Why would a dampened disc be used
Different types of dampened discs are used to absorb torsional loads depending on application
What are the 3 bearings associated with clutches
Pilot
Release
Trans input
