Title of Invention

"FLUCTUATING GEAR RATIO LIMITED-SLIP DIFFERENTIAL ASSEMBLY"

Abstract

For the purpose of providing a differential with wide range of variable gear ratio and high level of locking coefficient, the present invention concerns a limited slip differential of variable gear ratio type. The periodic change of gear ratio between planet pinions and side gears results in the torque distribution on both the side gears being a periodic function of the rotating angle of the planet pinions thereby limiting the slip on a single wheel. The present device includes a differential case containing a cross shaft or a simple shaft and the planet pinions/side gears assembly of variable gear ratio. In operation, the gear ratio between planet pinions and side gears varies with the period of at least two pitches. The number of pitches ...

Full Text

DESCRIPTION (COMPLETE) OCR NOT PREPARE DUE TO HAND WRITTEN PROBLEM We Claim: 1. A fluctuating gear ratio limited-slip differential assembly utilizing periodic fluctuation in the gear ratio between pinions and side gears to make the torque bias ratio between two side gears become a periodic function of the angle of rotation of the pinions, so that slip in one of driving wheels is limited, said assembly comprising: a differential case; a pinion shaft fixed within said differential case and supporting plurality of pinions; plurality of side gears situated within said differential case and engaging with said pinion gears; characterized in that the gear ratio between said pinions and said side gears fluctuates during the engagement process, and said gear ratio fluctuates with a period of at least two pitches, and the number of said pitches involved in each said period is corresponding to the common factor in the number of teeth in said pinion and said side gears, whereby each said period of gear ratio involves a group of teeth, and the number of teeth involved in each group are corresponding to the number of said pitches involved in each said penod of gear ratio, the combined working range of the teeth involved in ach said group covers the whole working range involved in a said period of gear ratio, and for each group of the same gear the corresponding teeth have the same structure. 2. The fluctuating gear ratio hmited-slip differential assembly as claimed in claim 1, wherein the working range for each pair of tooth in each said group is determined m design process, and there is a small overlap in said working range between adjacent tooth pairs. 3. The fluctuating gear ratio hmited-slip differential assembly as claimed in claim 1, wherein both tooth numbers of said pinion and said side gears arc multiples of 3, during the process of engagement, said gear ratio fluctuates m a period of three puches. 4. he fluctuating gear ratio limited-slip differential assembly as claimed in claim 1 or 3, wherein said pinion has an odd group number, so that during the engagement process, when the gear ratio between said pinions and one side gear reaches the maximum, the gear ratio between said pinions and other said side gear reaches the minimum. 5. The fluctuating gear ratio limited-slip differential assembly as claimed in claim 1 or 3, wherein the group number in said side gears is a multiple of the number of said pinions, so that each said pinion works at the same phase angle. 6. The fluctuating gear ratio limited-slip differential assembly as claimed in claim 3 or 4, wherein each of said group comprises successively one lower tooth, a higher tooth and another lower tooth of the same height of said lower one; between said higher tooth and said lower tooth is a shallower tooth groove, and between two said lower teeth is a deeper tooth groove. 7. The fluctuating gear ratio limited-slip differential assembly as claimed in claim 3 or 4, wherein each of said group cornprises successively one higher tooth, a lower tooth and another higher tooth of the same height of said higher one; between said higher tooth and said lower tooth is a deeper tooth groove, and between two said higher teeth is a shallower tooth groove. 8. The fluctuating gear ratio limited-slip differential assembly as claimed in claim 1, wherein said gear ratio between said side gears and said pinions and wherem when said conjugate profiles in contact with said analytic profiles on the matching teeth, said gear ratio meet the equation as follows: where z, denotes the number of teeth in said side gears.½ is the number of teeth in said pinions, Φ(1) represents the angle of rotation of said gears, while Φ(2) indicates the angle of rotation of said pinions. 9. The fluctuating gear ratio limited-slip differential assembly as claimed in claim 8, wherein the range of the number of teeth for said side gear 2, is 9, 12, 15 and 18; and the corresponding range of number of teeth for said pinion z, is 9 and 15. 10. The fluctuating gear ratio limited-slip differential assembly as claimed in claim 8, wherein the codomain of C is from 0.2 to 0.4. 11 The fluctuating gear ratio limited-slip differential assembly as claimed in claim 8, wherein the codomain of rat is from 0.7 to 1.0, 12. The fluctuating gear ratio limited-slip differential assembly as claimed any one claims 1 to 11, wherein the profiles of the lower part of said teeth in said pinions and said side gears, i.e. beneath the pitch lines are analytic curves, while the upper part of said teeth are conjugate profiles of said analytic curve profiles of the teeth that match with, which is determined point by point based on the theorem of engagement that the relative speed between said tooth surfaces is perpendicular to the normal of said analytic tooth profiles at the point. 13. The fluctuating gear ratio limited-slip differential assembly -as claimed in claim 12, wherein said analytic curve is a combination of straight line, circular and elliptical arcs. 14. The fluctuating gear ratio limited-slip differential assembly as claimed in claim 12, wherein all said profiles are convex curves. 15. A fluctuating gear ratio limited-slip differential assembly substantially as herein described with reference to the accompanying drawings

Documents:

1106-delnp-2004-abstract.pdf

1106-delnp-2004-claims(cancelled).pdf

1106-delnp-2004-claims.pdf

1106-delnp-2004-complete specification(granted).pdf

1106-delnp-2004-correspondence-others.pdf

1106-delnp-2004-correspondence-po.pdf

1106-delnp-2004-description (complete).pdf

1106-delnp-2004-drawings.pdf

1106-delnp-2004-form-1.pdf

1106-delnp-2004-form-19.pdf

1106-delnp-2004-form-2.pdf

1106-delnp-2004-form-26.pdf

1106-delnp-2004-form-3.pdf

1106-delnp-2004-form-5.pdf

1106-delnp-2004-pct-101.pdf

1106-delnp-2004-pct-210.pdf