Definition:Epicycloid

Definition

Let a circle $C_1$ roll around the outside of another circle $C_2$.

The locus of a given point on the circumference of $C_1$ is known as an epicycloid.

Generator

The circles $C_1$ and $C_2$ can be referred to as the generators of the epicycloid.

Stator

The circle $C_2$ can be referred to as the stator of the epicycloid.

Rotor

The circle $C_1$ can be referred to as the rotor of the epicycloid.

Cusp

A cusp of the epicycloid is defined as a point where the epicycloid meets the static circle, the stator.

Arc

An arc of the epicycloid is defined as one of the curves between two of the cusps of the epicycloid.

Also see

• Results about epicycloids can be found here.

Linguistic Note

The epi- prefix in the term epicycloid comes from the Greek word meaning on or above.

The prefix can be seen in other common words, for example epicenter.