Follow the explanation
Back to the model ↑How the parts work together
Start in a straight line
Play the model with zero cornering split. Both white wheel markers advance together. The pinions orbit without needing to spin relative to the carrier.
Change the gearbox ratio
Select a 3:1 reduction. With the same engine speed, the driveshaft and both wheels turn more slowly. The final-drive ratio stays at 3:1.
Follow a right turn
Play this preset. The left wheel runs faster and the right wheel slower. The gold pinions now turn relative to the carrier.
Reverse the turn
The faster wheel swaps sides. Add the left and right RPM readings and divide by two: the result is still the carrier RPM.
The main parts
- Engine input
- The orange shaft supplies the rotation. The scene displays a steady input speed, without simulating combustion or engine torque.
- Selected gearbox pair
- A smaller input gear driving a larger output gear reduces speed. The visible pair changes with the chosen ratio; the rest of a real transmission is omitted.
- Driveshaft
- Carries rotation from the gearbox toward the rear axle. Its marker makes the change in speed visible.
- Final drive and carrier
- A fixed 3:1 final reduction drives the carrier around the axle axis. This carrier sets the average of the two wheel speeds.
- Differential pinions
- These small gears orbit with the carrier. During a turn they also spin on their own axes, permitting unequal output speeds.
- Left half-shaft and wheel
- During a right turn this wheel travels the longer outside path and turns faster.
- Right half-shaft and wheel
- During a left turn this wheel travels the longer outside path and turns faster.