Planetary gear transmission systems or components – Differential planetary gearing
Reexamination Certificate
2001-11-09
2003-07-29
Estremsky, Sherry (Department: 3681)
Planetary gear transmission systems or components
Differential planetary gearing
C475S252000
Reexamination Certificate
active
06599217
ABSTRACT:
BACKGROUND OF THE INVENTIONS
The invention relates generally to differentials, and more particularly to limited slip differentials.
Limited slip differentials are known generally and employed commonly in rear wheel and center differentials, among many other applications.
U.S. Pat. No. 3,292,456 entitled “Spin Limiting Differential”, assigned commonly herewith, for example, discloses a rotatable carrier having a plurality of open-sided bores with a corresponding plurality of planetary gears disposed symmetrically therein about a rotation axis of the carrier. A portion of each planetary gear protrudes from the open side of the corresponding bore and is coupled to a drive shaft, or axle. Friction between the planetary gears and the carrier bores limits the slip of the differential.
An object of the present invention is to provide novel limited slip differentials that improve upon and overcome problems in the art.
Another object of the invention is to provide novel limited slip differentials that are economical.
A further object of the invention is to provide novel limited slip differentials having improved reliability.
Still another object of the invention is to provide novel limited slip differentials that produce less noise.
Yet another object of the invention is to provide novel limited slip differentials having improved performance.
A more particular object of the invention is to provide novel limited slip differentials comprising a carrier having a plurality of recesses disposed therein about a rotation axis thereof, each recess having an open side portion with opposite first and second edges, a chamfer disposed in the recess along each of the first and second edges thereof, and a planetary gear disposed in each of the plurality of carrier recesses having a portion protruding from the open side portion thereof.
Another more particular object of the invention is to provide novel limited slip differentials comprising a carrier having a plurality of recesses disposed about a sun gear opening, the sun gear opening having a sun gear diameter, and each of the plurality of recesses having a recess diameter. Each of the plurality of recesses having a circular portion, an opening, and first and second chamfers extending along tangents of the recess diameter on first and second sides of the recess toward the opening thereof. The sun gear diameter intersecting the recess diameter of each of the plurality of recesses at corresponding first and second intersections, an acute angle between a line tangent to the recess diameter at the first intersection and the first chamfer between approximately 30 degrees and approximately 32 degrees, and an acute angle between a line tangent to the recess diameter at the second intersection and the second chamfer between approximately 30 degrees and approximately 32 degrees.
Another more particular object of the invention is to provide novel limited slip differentials comprising a carrier having a plurality of recesses disposed symmetrically relative to a gear opening. The gear opening having a gear diameter, and each of the plurality of recesses having a recess diameter. Each of the plurality of recesses having a circular portion, an opening, and first and second chamfers extending along tangents of the recess diameter on first and second sides of the recess toward the opening thereof. The gear diameter intersecting the recess diameter of each of the plurality of recesses at corresponding first and second intersections, an acute angle between a line tangent to the recess diameter at the first intersection and the first chamfer between approximately 30 degrees and approximately 32 degrees, and an acute angle between a line tangent to the recess diameter at the second intersection and the second chamfer between approximately 30 degrees and approximately 32 degrees.
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Rohregger, et al. “Advanced Development of Self-Controlled Torque Sensitive Limited-Slip Differential by Means of Helical Gears”, SAE Technical Paper Series, 1994, pp. 934-941.
Warren, Andrew, “What's Limited Slip”, Publication in PCA Editor's Digest & December Spiel, 1 pg.
ITW Spiroid, “Concurve Gears and Gear Systems, Design Manual No. 1”, 34 pgs.
ITW Spiroid, “Spiroid Gearing Design Manual No. 6”, 54 pgs.
Caringella Anthony R.
Gruszkowski James A.
Nowakowski Wesley P.
Breh Donald J.
Croll Mark W.
Donovan Paul F.
Estremsky Sherry
Illinois Tool Works Inc.
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