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Automotive Drivetrains CLUTCHES. Purpose To connect and disconnect engine power flow to the transmission at the will of the driver

Dec 16, 2015

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  • Slide 1
  • Automotive Drivetrains CLUTCHES
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  • Purpose To connect and disconnect engine power flow to the transmission at the will of the driver.
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  • Clutch systems are used to disengage the engine from the road When the clutch pedal is depressed, the clutch (and transmission) is disengaged from the engine Clutch System
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  • With your foot off of the pedal, the clutch is engaged to the engine. The pressure plate holds the clutch against the flywheel, allowing power to travel through the clutch to the input shaft of the transmission... Clutch System The engine power will transfer through the clutch to the road
  • Slide 5
  • Flywheel: Transfers engine power to the clutch Input shaft: Transfers power from clutch to the transmission Clutch Disk (clutch): Splined to input shaft; transfers power from engine to the input shaft Pressure Plate Assembly: Spring pressure tightly holds the clutch to the flywheel System Components
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  • Components cont: Release Bearing (throw-out bearing): Connected through linkage or hydraulics to the clutch pedal; Provides a way for the pressure plate to release pressure on the clutch Pilot Bearing (bushing) : Mounted in the tail of the crankshaft. Stabilizes the input shaft. Not always used for FWD. Clutch Fork (if applicable): Slides the release bearing into and away from the pressure plate assembly
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  • Components cont: Clutch Linkage (or hydraulic plumbing): Allows the driver to operate the clutch fork Clutch (bell-housing) Housing: Encloses the clutch assembly May be integral with the transmission or removable
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  • Mounted on the rear of the crankshaft Acts as balancer for engine Adds inertia to the rotating crankshaft Provides a surface for the clutch to contact Usually surrounded by a ring gear for electric starter operation Clutch Components - Flywheel
  • Slide 10
  • Usually constructed of nodular cast iron which has a high graphite content The graphite helps lubricate engagement of the clutch May also be constructed from cold rolled steel Flywheel Construction
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  • Dual-mass Flywheel The flywheel hub and clutch mating area are two separate components Springs are used to dampen engine and clutch engagement oscillations
  • Slide 12
  • Dual-mass Flywheel
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  • Run-out measured with a dial indicator Parallelism straight-edge & feeler gauge Thickness micrometer or dial indicator Flywheel Measurements
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  • Projects from the front of the transmission Usually has a pilot which rides in a bearing or bushing in the end of the crankshaft The clutch disc is splined to the clutch shaft Clutch Components Input (clutch) shaft
  • Slide 18
  • Clutch Components Clutch Disc Is squeezed between the flywheel and the pressure plate Transmits power from the engine crankshaft to the transmission input shaft
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  • Clutch Disc Construction Facing manufactured with frictional material (may contain asbestos) Other surface materials include: paper-based ceramic cotton brass
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  • Clutch Disc Types Rigid - used primarily for industrial/racing applications. Flexible - most common, everything from grandmas cruiser to street/strip racing.
  • Slide 22
  • Flexible Clutch Disc Hub flange - in direct contact with the input shaft Friction ring - in direct contact with the flywheel/pressure plate.
  • Slide 23
  • Flexible Clutch Disc Clutch facing - friction material marcel springs - facing dampener Torsional springs - further dampening for clutch application Stop pins - limits the torsional springs travel Rivets -fastens the facing material to marcel (springs)
  • Slide 24
  • Squeezes clutch disc onto flywheel Can be engaged or disengaged Acts like a spring-loaded clamp Clutch Components Pressure Plate (clutch cover)
  • Slide 25
  • Pressure Plate - Types Belleville/diaphragm-type Spring: uses a cone-shaped diaphragm spring for clamping force. Multiple-Coil Springs: DUGH! Semi-centrifugal: clamping force increases as rotational (centrifugal) force increases
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  • Belleville/diaphragm Spring:
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  • Spring-type Pressure Plate
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  • Benefits and Disadvantages: Belleville/diaphragm type: cost effective uniform engagement limited spring pressure Spring: unlimited pressure capabilities as springs wear, pressure may become inconsistent
  • Slide 29
  • Operated by the clutch linkage Presses against the pressure plate to release the clutch Clutch Components Release (throw-out) bearing
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  • Slide 31
  • Clutch Components Pilot Bearing (bushing) Installed (pressed) into a machined bore in the end of the crankshaft or flywheel May be a bushing, ball-bearing or roller-bearing
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  • Clutch linkage Mechanical Linkage-type
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  • Clutch linkage Mechanical Cable-type
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  • Clutch linkage Hydraulic Most Commonly used today
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  • Hydraulic Clutch Master
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  • Hydraulic Clutch Slave
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  • Concentric-type
  • Slide 39
  • Dual-clutch Transmission Essentially an automatic manual transmission Delivered to the mainstream by Volkswagen now being used/developed by most mfg. Eliminates the power sucking torque- converter of an automatic transmission
  • Slide 40
  • Dual-clutch Transmission Utilizes two input shafts one inside of the other Each input shaft will have a dedicated clutch or clutch pack splined to it. A processor (computer) will engage one or the other clutches (or neither for neutral.)
  • Slide 41
  • Dual-clutch Transmission May use a wet or dry clutch-pack
  • Slide 42
  • Dual-clutch Transmission or conventional clutch disc design
  • Slide 43
  • Dual-clutch Transmission Each of the input-shafts controls half of the transmissions gear-sets
  • Slide 44
  • Dual-clutch Transmission