Tooth gap relieved enveloping worm
AssigneeKinematics, LLC
InventorsKenneth D. Miller, Kyle Zech
Life of this patent
Estimating the term…
Abstract
A worm comprises enveloping worm teeth having relieved ends. The worm is machined in three steps comprising machining a threaded section, machining a first end section, and machining a second end section. The threaded section is machined utilizing a rack-form tool having a rack-form thickness. The first end section and the second end section are machined utilizing a larger rack-form thickness, thereby, providing relieved ends. The teeth of the worm having such relieved ends mesh with the teeth of a mating gear at full depth throughout preventing partial teeth engagement.
Claims8
A worm made from a worm blank, said worm blank comprising a length thereby defining a center point, an axial axis along the length and through the center point, and a positive direction and a negative direction along the axial axis and about the center point, said worm comprising:
- (a) a threaded section made by machining the worm blank into a conjugate worm comprising a conjugate-thread length along the axial axis thereby defining a conjugate-thread center point that coincides with the center point, a positive half-conjugate length in the positive direction, and a negative half-conjugate length in the negative direction, via a rack-form tool utilizing a first rack-form thickness;
- (b) a first end section made by machining the conjugate worm starting at the positive half-conjugate length for a first predetermined length in the positive direction, via the rack-form tool utilizing a second rack-form thickness;
- (c) a second end section made by machining the conjugate worm starting at the negative half-conjugate length for a second predetermined length in the negative direction, via the rack-form tool utilizing the second rack-form thickness;
- and
- wherein the worm blank is machined into the conjugate worm according to equations:
- Ratio=NG÷NW;
- R=Module×NG÷cos H÷2;
- P=2R×π÷NG;
- and
- AT=tan−1(tan AN÷ cos H);
- and
- wherein,
- NG=number of teeth in a gear;
- NW=number of enveloping worm teeth in the worm;
- AN=normal pressure angle;
- AT=transverse pressure angle;
- R=operating pitch radius;
- P=transverse circular pitch;
- H=helix angle;
- AR=rack form addendum;
- and
- T=rack-form thickness.
Dependencies are inferred from the claim text.