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

It is obvious then that the generating circle is rolled within the pitch circle for the face of the wheel and without for its flank, or the reverse of the process for spur-wheels.

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

The wheel having 10 teeth was then given the form of tooth that would be obtained by rolling upon it another wheel of the same diameter of pitch circle and pitch of teeth.

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

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 Rose, Joshua

Then, diameter of addendum circle 19.943 inches less 1.8 inches = 18.143 inches, which is the diameter of the pitch circle.

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

The flank of each wheel is struck with a tracing point, thus attached to the pitch circle of the other wheel.

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