Worm gear drive
OwnerWinthrop Jamesinventor
Life of this patent
Estimating the term…
Abstract
A worm gear drive wherein revolvable spheres captured in respective cages are equally spaced about a wheel rim with their centers on a common circle to mesh with a worm groove by rolling only on a track defined by a sidewall of that groove without sliding engagement, the track following a variable diameter hour-glass locus corresponding to an arucate locus of a radius equal to that of the common circle.
Claims7
A worm gear drive comprising
- (a) an unitary wheel sub-assembly comprising
- i. an axially rotatable circular rim,
- ii. radially outwardly extending cages attached in equal spacing about the rim,
- iii. a plurality of spheres respectively held in freely rotatable relation within the cages with their centers on a common circle, and
- iv. anti-friction means between each sphere and its associated cage,
- v. each cage defining at least one aperture through which a face of the associated sphere projects on an axis skewed at an acute angle to a plane of said common circle;
- and
- (b) a worm comprising
- i. an axially rotatable shaft,
- ii. at least one land formed about the shaft and defining at least one hour-glass worm groove with a pitch lead angle equal to said acute angle and a depth and width sufficient to receive the individual spheres and cages,
- iii. at least one side wall of said groove formed with at least one track surface, said track surface having a variable diameter locus corresponding to an arcuate locus of a radius equal to that of said common circle said track surface engages the plurality of spheres carried by the wheel subassembly;
- (c) the wheel sub-assembly being disposed with its rotation axis at a right angle to that of the worm so that the plurality of spheres meshed within the groove in rolling engagement along the track surface without sliding engagement between the wheel and worm.
In a worm gear which includes a unitary wheel subassembly having a peripheral array of equally spaced freely rotatable individual spheres and cages and sphere faces with respective centers thereof on a common circle, a worm comprising
- (a) an axially rotatable shaft,
- (b) at least one land formed about the shaft and defining at least one hour-glass worm groove with a pitch lead angle equal to an acute angle and a depth and width sufficient to receive the individual spheres and cages,
- (c) at least one side wall of said groove defining at least one track surface, said track surface having a variable diameter locus corresponding to an arcuate locus of a radius equal to that of said common circle said track surface engages the plurality of spheres carried by the wheel subassembly upon its rotational engagement with the worm groove of said rotatable shaft.
Dependencies are inferred from the claim text.