DualRatio Crank Pulley

1
Dual-Ratio Crank Pulley
2
Dual-Ratio Crank Pulley

• Concept
• Single 2-position actuator gives two speed
  ratios, 11 and a configurable second ratio
  (typically 2.51)
• Minimal impact on package with integrated T.V.
  damper
• A/C mode enabling electrical machine to drive
  compressor whilst engine is stopped
• De-coupler function to improve dynamics and
  prevent belt squeal
• Simple spur gears (no ring gear)
• Benefits
• Major reduction in rating of electrical machine
  and power electronics.for similar starting and
  re-generative braking capability
• May enable robust cold-cranking and hence
  elimination of starter motor
• Major reduction in belt tension requirement
• A/C operation with stop/start

3
Dual-Ratio Pulley - Layout
Planetary Gears
Sun Ring-gear
Secondary Clutch-pack
Timing-drive
Crank
Crank spline-gear
Primary Clutch-pack
Primary Clutch-pack
Annulus Ring-gear
Integrated Torsional Damper
Crank-Pulley (Dual-Ratio 11 /
41)
4
Transmission Modes
High ratio for starting, motoring and
re-generative braking
Carrier
Block
Clutch 1 overruns Ns1 ? Ns2
P1
P2
S2
Crankshaft
S1
P1
P2
Clutch 2 closed Nc 0
Block
1st Sun-Gear
1st Planet Set
5
Transmission Modes
Direct drive ratio for generating
Carrier
Block
Clutch 1 closed Ns1 Ns2
P1
P2
S2
Crankshaft
S1
P1
P2
Clutch 2 open Nc Ns1
Block
1st Sun-Gear
1st Planet Set
6
Transmission Modes
Zero torque transmission for de-coupler function
and A/C with stationary crankshaft
Carrier
Block
Clutch 1 overruns Ns1 ? Ns2
P1
P2
S2
Crankshaft
S1
P1
P2
Clutch 2 open
Block
1st Sun-Gear
1st Planet Set