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.

1 . A gear set for a vehicle drivetrain comprising:
 a hypoid ring gear; and   a hypoid pinion gear in meshing engagement with said hypoid ring gear, said hypoid pinion gear and said hypoid ring gear adapted to be positioned within a single carrier packaging envelope defined by a maximum ring gear diameter, and wherein the hypoid ring and pinion gears provide a predetermined gear ratio that can be varied up to a fifty percent faster ratio within the single carrier packaging envelope.   
     
     
         2 . The gear set according to  claim 1  wherein said hypoid ring gear is defined by a first spiral angle and said hypoid pinion gear is defined by a second spiral angle that is less than said first spiral angle such that the gear seat has a negative pinion offset. 
     
     
         3 . The gear set according to  claim 1  wherein said pinion gear includes a right hand spiral and said ring gear includes a left hand spiral, and wherein said pinion gear is offset below a gear center defined by said hypoid ring gear. 
     
     
         4 . The gear set according to  claim 1  wherein said pinion gear includes a left hand spiral and said ring gear includes a right hand spiral, and wherein said pinion gear is offset above a gear center defined by said hypoid ring gear. 
     
     
         5 . The gear set according to  claim 1 :
 wherein said hypoid ring gear rotates about an axis defining a gear center and includes a front face with a plurality of ring gear teeth, and wherein when facing said front face, said pinion gear is positioned on a right side of said front face such that a pinion gear head is in meshing engagement with said plurality of ring gear teeth; and   wherein said pinion gear is either offset above said gear center or below said gear center; and   wherein when said pinion gear is offset above said gear center said pinion gear has a left hand spiral and said ring gear has a right hand spiral; and   wherein when said pinion gear is offset below said gear center said pinion gear has a right hand spiral and said ring gear has a left hand spiral.   
     
     
         6 . The gear set according to  claim 1  wherein said single carrier packaging envelope is no larger than an amount of space required to package a gear set having a maximum ring gear diameter of 600 mm. 
     
     
         7 . The gear set according to claim, wherein said ring gear includes a spiral angle between 30 and 50 degrees. 
     
     
         8 . The gear set according to  claim 7  wherein said ring gear includes a profile tooth contact ratio within a range of 1.0 to 1.4, and includes a tooth face contact ratio within a range of 1.1 to 1.5. 
     
     
         9 . The gear set according to  claim 1  wherein said ring gear has a minimum ring gear diameter of 100 mm and a maximum ring gear diameter of 600 mm. 
     
     
         10 . The gear set according to  claim 1  wherein the predetermined gear ratio falls within a gear ratio range of 1.3:1 to 7.0:1 within the single carrier packaging envelope. 
     
     
         11 . A gear set for a vehicle drivetrain comprising:
 a differential gear assembly including first and second side gears configured to drive first and second axle shafts to rotate about a wheel axis of rotation;   a hypoid pinion gear in meshing engagement with a hypoid ring gear, wherein said hypoid ring gear is configured to drive said differential gear assembly; and   said hypoid pinion gear and said hypoid ring gear providing a gear ratio range of 1.3:1 to 7.0:1 within a single carrier packaging envelope that is defined as being no larger than an amount of space required to package said differential gear assembly and said hypoid pinion and ring gears where said hypoid ring gear has a maximum ring gear diameter of 600 mm.   
     
     
         12 . The gear set according to  claim 11  including a first planetary gear set to receive driving input from the first axle shaft and a second planetary gear set to receive driving input from the second axle shaft. 
     
     
         13 . A drive axle comprising:
 an axle housing including a carrier portion, said carrier portion having an interior cavity that defines a single maximum packaging envelope;   a differential gear assembly housed within said interior cavity of said carrier portion;   first and second axle shafts driven by said differential gear assembly, said first and said axle shafts configured to provide driving output to a pair of laterally spaced wheel components; and   a hypoid gear set comprising a hypoid ring gear and a hypoid pinion gear in meshing engagement with said hypoid ring gear, said hypoid pinion gear and said hypoid ring gear providing a predetermined gear ratio that can be varied up to a fifty percent faster ratio within said single maximum packaging envelope, and wherein said single maximum packaging envelope is no larger than an amount of space required to package a hypoid gear set having a maximum ring gear diameter of 600 mm.   
     
     
         14 . The drive axle according to  claim 13  wherein said hypoid ring gear is defined by a first spiral angle and said hypoid pinion gear is defined by a second spiral angle that is less than said first spiral angle such that said hypoid gear set has a negative pinion offset. 
     
     
         15 . The drive axle according to  claim 13  including a first planetary gear set driven by said first axle shaft and a second planetary gear set driven by said second axle shaft. 
     
     
         16 . The drive axle according to  claim 13  wherein said ring gear rotates about an axis defining a gear center and wherein said pinion gear includes a right hand spiral and said ring gear includes a left hand spiral, and wherein said pinion gear is offset below said gear center. 
     
     
         17 . The drive axle according to  claim 13  wherein said ring gear rotates about an axis defining a gear center and wherein said pinion gear includes a left hand spiral and said ring gear includes a right hand spiral, and wherein said pinion gear is offset above said gear center. 
     
     
         18 . The drive axle according to  claim 13 :
 wherein said ring gear rotates about an axis defining a gear center and includes a front face with a plurality of ring gear teeth, and wherein when facing said front face, said pinion gear is positioned on a right side of said front face such that a pinion gear head is in meshing engagement with said plurality of ring gear teeth; and   wherein said pinion gear is either positioned above said gear center or below said gear center; and   wherein when said pinion gear is positioned above said gear center, said pinion gear has a left hand spiral and said ring gear has a right hand spiral; and   wherein when said pinion gear is positioned below said gear center, said pinion gear has a right hand spiral and said ring gear has a left hand spiral.   
     
     
         19 . The drive axle according to  claim 13 , wherein said ring gear includes a ring gear spiral angle between 30 and 50 degrees. 
     
     
         20 . The drive axle according to  claim 13 , wherein the predetermined gear ratio falls within a gear ratio range of 1.3:1 to 7.0:1 within the single maximum packaging envelope.