# Gears

Gear sets serve to transfer rotational motion and torque at a known ratio from one driveline axis to another. Simscape™ Driveline™ contains angular gears for transferring rotational motion and torque and linear gears, for transferring translational motion and force. Determine how heat generation affects the efficiency and temperature of driveline components using thermal variants of gear blocks.

## Simscape Blocks

## Topics

**Couple Two Spinning Inertias with a Simple Gear**Use gears to couple inertias that are spinning at the same or at different velocities.

**Couple Two Spinning Inertias with a Variable Ratio Transmission**Model a transmission that has a variable gear ratio.

**Couple Three Spinning Inertias with a Planetary Gear**Model a simple planetary gear and a planetary gear with a locked carrier.

**Custom Planetary Gear Model**Model a coupled planetary gear train.

**Model Gears with Losses**Model frictional losses in gear couplings.

**Constant and Load-Dependent Gear Efficiencies**Model power loss due to nonideal gear meshing.

**Couple Rotational Motion with Gears**Learn about the rules for coupling gears.

**Rotational-Translational Couplings**Couple rotational and translational dynamics.

**Model Thermal Losses in Driveline Components**Evaluate the effects of thermal losses on device temperature and performance.