Power Splitting Devices

Dan Farley

ELM Project

11/13/2006

Team Hybrid

• Construct a hybrid propulsion system– Series vs Parallel connection

• Series connection – Run ICE at optimum speed to charge

generator to charge batteries– Only electric motor is connected to driveshaft

• Parallel Connection– Allow both ICE and electric motor connect to

driveshaft

Conventional Transmission

• Allows user to alter power output to meet their immediate needs

• Allows change in rotational speed for change in torque value

• Engine has redline (max RPM value)

• Each engine has a range where horsepower and torque are at maximum values

Continuously Variable Transmission

• Automatic transmission which is not constrained to a fixed number of gear ratios

• Types– Variable Diameter Pulley (VDP)– Roller Based– Hydrostatic– Electronically controlled planetary gear set (ECVT)– Cone and belt

Continuously Variable Transmission

Roller based

Engine

Driveshaft

Continuously Variable Transmission

Pulley diameter changed by oil pressure

Continuously Variable Transmissions

• Three modes– Low speed: hydraulic– High speed: mechanical– In between: combination

of the two

Hyrdrostatic

Continuously Variable Transmission

Cone and Belt

Planetary Gear Sets

• Consists of a sun, planets and ring gear

• Planets are attached to a planet carrier

• Produce different gear ratios depending on which gear is input and which one is held

Gear TerminologyYellow = SunRed = PlanetsBlue = Ring gear

Planetary Gear Sets

Nsun+2Nplanet=Nring

Calculate input rpm from output rpm

Allow for proper distance

Sun 30 teethRing 72 teeth

Input Ouput Stationary Calculation Gear RatioSun Carrier Ring 1+R/S 3.4Carrier Ring Sun 1/(1+S/R) 0.71Sun Ring Carrier -R/S -2.4

If one arm is fixed, the other gears are a simple train

Questions