Design and operating principle of a Ravigneaux planet gear set - RA27007229050X(27-9050)

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The Ravigneaux planet gear set is basically a planet gear train composed of two single planet gear sets.

The benefit is the simplified design with only one annulus and a common planet carrier.

The Ravigneaux planet gear set has two different sized sunwheels, four narrow and four wide planet wheels, a common planet carrier (not shown in the illustrations) and an internally-toothed outer ring gear (annulus).

With the design used in the transmission, the power input is performed through the large sunwheel. Output is performed in the forward gears through the planet carrier to the annulus of the rear planet gear set in the transmission.

Fig 1: Identifying Operating Principle Of Ravigneaux Planet Gear Set

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

In reverse, the planet carrier is locked with the aid of the multiple-disc brake B3. Output is then performed through the annulus to the rear planet gear set.

Refer to power flow in the gears (Power flow in the gears ).

Fig 2: Power Flow In Gears

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.