In mechanical engineering terms, transmissions consist of a series of connected parts (or mechanisms) whereby a source of power can be applied to another component which is able do the required work in the form of motion.
Transmissions can be used to:
- Connect two (or more) shafts so that one provides drive to another (or others).
- Change the speed of one shaft relative to another.
- Change the direction of rotation of one shaft relative to another.
- Convert one type of motion to another (rotary to linear or vice versa).
Aerospace transmissions involve the use of a wide range of sources to provide the power, which eventually results in the desired motion in a particular system and those power sources include:
- Muscle and assisted muscle power
- Hydraulic, pneumatic and electrical power
- External and internal combustion engines
The means of transmitting power from a source to provide eventual motion is achieved by such devices as:
- Belts and Pulleys
- Chains and Sprockets