Net-shaped gears for a differential assembly

Abstract

A differential assembly for a motor vehicle includes a plurality of pinion gears in meshing engagement with a plurality of side gears. At least one of the pinion gears and side gears is formed from a heated tubular preform in a forging die. A method for manufacturing a differential assembly is also provided.

1 . A differential assembly for a motor vehicle, the differential assembly comprising: 
 a rotatable case;    a plurality of pinion gears rotatably coupled to the case;    a plurality of side gears rotatably coupled to the case, each of the side gears being in meshing engagement with each of the pinion gears, wherein at least one of the pinion gears and the side gears includes net-shaped teeth.    
   
   
       2 . The differential assembly of  claim 1  wherein the gear including net-shaped teeth includes a predetermined length of seamless tubing.  
   
   
       3 . The differential assembly of  claim 2  wherein the seamless tubing includes a carbon content greater than 0.4 percent.  
   
   
       4 . The differential assembly of  claim 1  wherein the gear including net-shaped teeth includes a weld interconnecting the ends of a previously substantially flat panel.  
   
   
       5 . The differential assembly of  claim 1  wherein the net-shaped teeth include drivable contact surfaces in selective engagement with contact surfaces of another gear rotatably supported by the case.  
   
   
       6 . The differential assembly of  claim 1  wherein the net-shaped teeth are operable to be hardened without the addition of carbon to the net-shaped teeth.  
   
   
       7 . The differential assembly of  claim 1  wherein the gear including net-shaped teeth includes an aperture extending therethrough.  
   
   
       8 . An axle assembly for a motor vehicle, the axle assembly comprising: 
 a housing;    an input gear rotatably supported by the housing;    a differential assembly being rotatably supported by the housing and including a ring gear mounted on a case, the ring gear being in meshed engagement with the input gear, the differential assembly further including a pair of pinion gears rotatably coupled to the case and a pair of side gears rotatably coupled to the case, each of the pinion gears being in meshed engagement with each of the side gears, wherein one of the ring gear, the pinion gears and the side gears includes net-shaped teeth.    
   
   
       9 . The axle assembly of  claim 8  wherein the gear including net-shaped teeth includes an aperture circumferentially surrounded by the net-shaped teeth.  
   
   
       10 . The axle assembly of  claim 9  wherein each of the net-shaped teeth includes a first drivable contact surface on a front tooth face and a second drivable contact surface on a rear tooth face.  
   
   
       11 . The axle assembly of  claim 10  wherein the first and second contact surfaces are in selective engagement with contact surfaces formed on teeth of another gear.  
   
   
       12 . The axle assembly of  claim 8  wherein the gear including net-shaped teeth includes a predetermined length of seamless tubing.  
   
   
       13 . The axle assembly of  claim 12  wherein the seamless tubing includes a carbon content greater than 0.4 percent.  
   
   
       14 . The axle assembly of  claim 8  wherein the gear including net-shaped teeth includes a weld interconnecting the ends of a previously substantially flat panel.  
   
   
       15 . A differential assembly for a motor vehicle, the differential assembly comprising: 
 a rotatable case;    a pair of pinion gears rotatably coupled to the case;    a pair of side gears rotatably coupled to the case, each of the side gears being in meshing engagement with each of the pinion gears, wherein at least one of the pinion gears and the side gears includes net-shaped teeth having drivable contact surfaces circumferentially spaced apart from one another.    
   
   
       16 . The differential assembly of  claim 15  wherein the gear including net-shaped teeth includes a predetermined length of seamless tubing.  
   
   
       17 . The differential assembly of  claim 16  wherein the seamless tubing includes a carbon content greater than 0.4 percent.  
   
   
       18 . The differential assembly of  claim 15  wherein the gear including net-shaped teeth includes a weld interconnecting the ends of a previously substantially flat panel.  
   
   
       19 . The differential assembly of  claim 15  wherein the gear including net-shaped teeth includes an aperture extending therethrough.  
   
   
       20 . The differential assembly of  claim 19  wherein the aperture includes an internal spline.