GEARS

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SPUR GEARS

Simple gear, just a disc/cylinder with spikey teeth jutting out from the radius.

In spur gears teeth suddenly meet at a line contact across their entire width, causing stress and noise.

Spur gears make a characteristic whine at high speeds.

Spur gears are used for low speed applications and those situations where noise control is not a problem.

WORM GEARS

Screw-like gear. Cylinder with spiraling ridges down the inside.

A worm gear is usually meshed with a spur gear or a helical gear

The worm can always drive the spur, but if the spur is too small, it cant always push the worm

CROWN GEARS

Bevel that looks like a crown

Crown gears are a particular form of bevel gear whose teeth project at right angles to the plane of the wheel; in their orientation the teeth resemble the points on a crown.

A crown gear can only mesh perfectly with another bevel gear, although crown gears are sometimes meshed with spurs

ROTARY TO LINEAR MOTION

Using a gear’s rotation to move a meshed object forward/backward

Mechanical linear actuators typically operate by conversion of rotary motion into linear motion.

A screw, wheel, and music-box are all linear actuators that convert rotary motion to linear motion