| Term | Definition |
| Axle | a central shaft for a rotating wheel or gear |
| Thermostat | a device for regulating the temperature of a system so that the system's temperature is maintained near a desired setpoint temperature. |
| Carburetor | a device that blends air and fuel for an internal combustion engine. |
| Torque converter | a hydrodynamic fluid coupling used to transfer rotating power from a prime mover to a rotating driven load. |
| Crankshaft | the part of an engine which translates reciprocating linear piston motion into rotation. |