Hypoid Gear Set For Drive Axle

Abstract

A hypoid gear set for a vehicle drivetrain includes a pinion gear in meshing engagement with a ring gear. The hypoid gear set has a negative pinion offset. The hypoid pinion and ring gears provide a predetermined gear ratio that can be varied up to a fifty percent faster ratio within a single carrier packaging envelope defined by a maximum ring gear diameter.

What is claimed is: 
     
         1 . A vehicle axle comprising:
 a hypoid pinion gear having spiral gear teeth which are first-handed; and   a hypoid ring gear having a pinion gear engagement side with spiral gear teeth which are second-handed and opposite handed to the pinion gear spiral gear teeth for pinion gear engagement;   wherein when viewing the pinion gear engagement side of the ring gear with the pinion gear to the right of a ring gear vertical axis, the pinion gear engages the ring gear in a manner selected from the group consisting of:   (a) the pinion gear is offset below a horizontal axis of the ring gear and the pinion gear spiral gear teeth are right-handed; and   (b) the pinion gear is offset above the horizontal axis of the ring gear and the pinion gear spiral gear teeth are left-handed.   
     
     
         2 . The axle of  claim 1 , wherein the pinion gear spiral gear teeth are right-handed and the ring gear spiral gear teeth are left-handed. 
     
     
         3 . The axle of  claim 1 , wherein the pinion gear spiral gear teeth are left-handed and the ring gear spiral gear teeth are right-handed. 
     
     
         4 . The axle of  claim 1 , wherein the ring gear has a diameter between 100 mm to 600 mm. 
     
     
         5 . The axle of  claim 1 , wherein a ratio of number of teeth in the ring gear to number of teeth in the pinion gear is between 1.3:1 and 2.5:1. 
     
     
         6 . The axle of  claim 1 , wherein the ring gear spiral gear teeth have a spiral angle between 30 and 50 degrees. 
     
     
         7 . The axle of  claim 1 , further comprising a carrier housing, wherein the ring gear is disposed within the carrier housing. 
     
     
         8 . The axle of  claim 1 , wherein the axle is a commercial vehicle axle. 
     
     
         9 . The axle of  claim 1 , wherein the axle is an off-highway vehicle axle. 
     
     
         10 . The axle of  claim 1 , further comprising an axle housing and a carrier housing. 
     
     
         11 . A vehicle axle comprising:
 an axle housing defining an internal cavity;   a differential gear assembly within the cavity and driving left and right half shafts;   a hypoid ring gear fixed to the differential gear assembly and having an engagement side with a number of spiral gear teeth having a ring gear spiral angle; and   an input hypoid pinion gear within the cavity, the pinion gear having a number of spiral gear teeth engaged with the spiral gear teeth on the ring gear wherein a ratio of the number of teeth on the ring gear to the number of teeth on the pinion gear is less than 2.5:1 and wherein the spiral teeth on the pinion gear have a pinion gear spiral angle which is less than the ring gear spiral angle forming a negative pinion offset configuration thereby achieving a small pinion diameter such that the pinion is contained within a cavity size associated with tooth ratios greater than 2.5:1.   
     
     
         12 . The axle of  claim 11 , wherein the pinion gear spiral gear teeth are right-handed and the ring gear spiral gear teeth are left-handed. 
     
     
         13 . The axle of  claim 11 , wherein the pinion gear spiral gear teeth are left-handed and the ring gear spiral gear teeth are right-handed. 
     
     
         14 . The axle of  claim 11 , wherein the ring gear has a pitch diameter, the pinion gear has an outside diameter, and a ratio of the pitch diameter to the outside diameter is greater than the ratio of the number of teeth on the ring gear to the number of teeth on the pinion gear. 
     
     
         15 . The axle of  claim 11 , wherein the ring gear spiral angle is between 30 and 50 degrees. 
     
     
         16 . A vehicle axle comprising:
 a hypoid pinion gear having a first number of spiral gear teeth and an outer diameter; and   a hypoid ring gear having a second number of spiral gear teeth and a pitch diameter wherein the spiral gear teeth of the ring gear are in meshing engagement with the spiral gear teeth of the pinion gear and wherein a ratio of the pitch diameter to the outside diameter is greater than a ratio of the second number to the first number.