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

But if these be known the diameter of the pitch circle may be obtained by subtracting from that of the addendum circle twice the amount allowed for the addendum of the tooth.

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

Thus, to strike the other curve of the tooth, mark off from a the thickness of the tooth on the pitch circle p p, producing the point h.

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

Internal or annular gear-wheels have their tooth curves formed by rolling the generating circle upon the pitch circle or base circle, upon the same general principle as external or spur-wheels.

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

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 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