Cushioned starter pinion
AssigneeEaton Stamping Company
InventorLeon D. Greenwood
Life of this patent
Estimating the term…
Abstract
The invention pertains to electric starters for internal combustion engines, and in particular, to electric starters for small engines such as used with yard equipment, for instance, lawn tractors, snow blowers lawnmowers, and the like wherein the starter includes a pinion gear having cushioning means associated therewith which is of a variable characteristic such that soft cushioning is initially produced to protect the initial engagement of the pinion gear with the engine flywheel teeth, and stiffer cushioning occurs during high torque transmission during engine cranking. Preferably, the resiliency of cushioning achieved is proportional to the radius of contact between the cushioning means and the starter pinion gear.
Claims11
In an electric starter for internal combustion engines including an electric motor having a rotatable shaft having a screw thread defined thereon, a nut member threaded upon said shaft thread wherein relative rotation thereon axially translates said nut member on said shaft, a pinion gear member concentrically mounted on said shaft for rotational and axial movement thereon, a stop mounted on said shaft limiting movement of said gear member upon said shaft, the improvement comprising a variable compression characteristic resilient member formed of elastic resilient deformable material interposed between the nut member and pinion gear member establishing a frictional rotative drive between the nut member and gear member for rotating the gear member and variably cushioning the gear member relative to axial forces imposed thereon by the nut member whereby initial cushioning of axial forces is relatively soft and sequentially cushioning increases in stiffness, said resilient member being circumferentially unconfined to permit radial expansion of said resilient material thereof, and an axially extending projection defined upon one of said members axially extending toward the adjacent member causing limited radial displacement and deformation of said resilient member material during initial cushioning.
In an electric starter for internal combustion engines including an electric motor having a rotatable shaft having a screw thread defined thereon, a nut member threaded upon the shaft thread having a radially extending flange wherein rotation of the nut member upon the shaft thread axially displaces said nut member upon the shaft, the improvement comprising, a pinion gear rotatably mounted upon the shaft and axially displaceable thereon, an elastic body bonded to the gear, said body including a radial end in opposed relation to the nut member flange, said radial body end including a first radial surface of first radial dimension, an axially extending projection extending from said first surface having a second radial dimension less than that of said first dimension, the nut member flange initially engaging said projection upon rotation of the shaft in an engine cranking direction whereby said projection deforms and provides an initial relatively soft cushioning of axial forces imposed on the gear by the nut member.
Dependencies are inferred from the claim text.