pitch circle

American  

noun

Machinery.

1. an imaginary circle within the profiles of the teeth of a gear, such that it rotates against a similar circle rotating at the same rate on a meshing gear.

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pitch circle British  

noun

1. an imaginary circle passing through the teeth of a gearwheel, concentric with the gearwheel, and having a radius that would enable it to be in contact with a similar circle around a mating gearwheel

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Etymology

Origin of pitch circle

First recorded in 1810–20

Example Sentences

See Examples For:

pitch circle

Let the point b represent the centre of the generating circle when that circle is in contact with the pitch circle at a.

From Modern Machine-Shop Practice, Volumes I and II by Joshua Rose

The amount of error thus induced diminishes as the diameter of the pitch circle of the cutter is increased.

From Modern Machine-Shop Practice, Volumes I and II by Joshua Rose

The diameter of the pitch circle cannot be obtained from that of the addendum circle unless the pitch of the teeth and the proportion of the pitch allowed for the addendum be known.

From Modern Machine-Shop Practice, Volumes I and II by Joshua Rose

A circle of less diameter than the pitch circle of the wheel is, therefore, introduced, wherefrom to produce the involute curves forming the full side of the tooth.

From Modern Machine-Shop Practice, Volumes I and II by Joshua Rose

Ultimately, then, the motions of h, h′, are those of two equal describing circles rolling in external and internal contact with a fixed pitch circle.

From Modern Machine-Shop Practice, Volumes I and II by Joshua Rose