Noncircular gear pair
AssigneeUniversity of Maryland, Baltimore County
InventorsWeidong Zhu, Gang Li
Life of this patent
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Abstract
The present disclosure describes innovations to improve the use of noncircular gear pairs in a transmission, e.g., an infinitely variable transmission. The noncircular gear pair includes a first noncircular gear with a first pitch curve; and a second noncircular gear with a second pitch curve. The first pitch curve includes a plurality of elliptical portions, and a curvature of the first pitch curve is positive along the entire first pitch curve; and wherein the second pitch curve is a conjugate of the first pitch curve.
Claims12
A noncircular gear comprising:
- a pitch curve having
- a first elliptical portion relating to a first ellipse;
- a second elliptical portion relating to a second ellipse, different than the first ellipse;
- and
- a modified transition portion positioned between the first elliptical portion and the second elliptical portion;
- and
- wherein the pitch curve includes no cusps;
- and
- wherein an eccentricity of each of the first elliptical portion and the second elliptical portion is within a range of 0.1 to 0.9.
A method of manufacturing a non-circular gear pair, the method comprising:
- calculating kinematic equations of the non-circular gear pair;
- generating a non-circular pitch curve including a plurality of lobes based on the kinematic equations;
- modifying the non-circular pitch curve to remove cusps to create a modified pitch curve;
- wherein the modified pitch curve includes a first elliptical portion relating to a first ellipse, a second elliptical portion relating to a second ellipse, different than the first ellipse, and a modified transition portion positioned between the first elliptical portion and the second elliptical portion;
- generating a tooth profile based on the modified pitch curve;
- and
- cutting the tooth profile with a shaping cutter having a constant radius.
Dependencies are inferred from the claim text.