Differential mechanism assembly

Abstract

A method for manufacturing a differential assembly, comprising producing a first case portion by cold flow forming a first workpiece on a first mandrel, producing a second case portion by cold flow forming a second workpiece on a second mandrel, installing in a cavity formed in the first case portion a spider assembly including radially extending spider pins located at an axial position, pinions supported for rotation on the spider assembly, and a first side gear engaged with the pinions, installing in a cavity formed in the second case portion a second side gear engaged with the pinions, and securing the second case portion to the first case portion.

1 . A method for manufacturing a differential assembly, comprising the steps of:
 (a) producing a first case portion by cold flow forming a first workpiece on a first mandrel;   (b) producing a second case portion by cold flow forming a second workpiece on a second mandrel;   (c) installing in a cavity formed in the first case portion a spider assembly including radially extending spider pins located at an axial position, pinions supported for rotation on the spider assembly, and a first side gear engaged with the pinions;   (d) installing in a cavity formed in the second case portion a second side gear engaged with the pinions; and   (e) securing the second case portion to the first case portion.   
   
   
       2 . The method of  claim 1  further including the step of:
 securing a ring gear to at least one of the first case portion and the second case portion, the ring located radially outboard of the spider assembly and at the axial position of the spider pins.   
   
   
       3 . The method of  claim 2  further including the step of:
 using a laser weld to secure the ring gear to at least one of the first case portion and the second case portion.   
   
   
       4 . The method of  claim 1  wherein step (a) further includes the steps of:
 selecting the first workpiece of material that is one of a low carbon steel and a low carbon microalloyed steel;   placing the first workpiece on the surface of the first mandrel; and   forming a wall thickness, an inner surface and an outer surface of the first case portion by cold flow forming the first workpiece on the first mandrel.   
   
   
       5 . The method of  claim 1  wherein step (a) further includes the steps of:
 selecting a first workpiece of sheet metal whose material is one of a low carbon steel and a low carbon microalloyed steel;   placing the first workpiece on the surface of the first mandrel; and   forming a wall thickness, an inner surface and an outer surface of the first case portion by cold flow forming the first workpiece on the first mandrel.   
   
   
       6 . The method of  claim 1  wherein step (a) further includes the steps of:
 selecting first workpiece that is forged and whose material is one of a low carbon steel and a low carbon microalloyed steel;   placing the first workpiece on the surface of the first mandrel; and   forming a wall thickness, an inner surface and an outer surface of the first case portion by cold flow forming the first workpiece on the first mandrel.   
   
   
       7 . The method of  claim 1  wherein:
 step (b) further includes forming axially-directed, angularly spaced grooves on the inner surface of the second case portion; and   step (d) further includes the steps of:   installing in the cavity formed in the second case portion friction plates including radial tabs, each tab fitted into a groove and secured to the second case portion, friction discs, each disc interleaved between two successive friction plates and secured to the second side gear for rotation therewith.   
   
   
       8 . The method of  claim 1  wherein step (d) further includes the steps of:
 forming first clutch teeth on the second side;   forming an actuator with second clutch teeth;   installing in the cavity formed in the second case portion an actuator ring such that the first clutch teeth and second clutch teeth alternately engage and disengage mutually; and   installing on the second case portion an electromagnetic actuator that alternately urges the actuating ring into engagement with the second side gear and permits the actuating ring to disengage the second side gear.   
   
   
       9 . A method for manufacturing a differential assembly, comprising the steps of:
 (a) producing a first case portion by cold flow forming a first workpiece on a first mandrel;   (b) producing a second case portion including a flange by cold flow forming a second workpiece on a second mandrel;   (c) installing in a cavity formed in the first case portion a spider assembly including radially extending spider pins located at an axial position, pinions supported for rotation on the spider assembly, and a first side gear engaged with the pinions;   (d) securing a ring gear to the first case portion, the ring being located radially outboard of the spider assembly and at the axial position of the spider pins; and   (e) using the flange to secure the second case portion to the ring gear.   
   
   
       10 . The method of  claim 9  wherein step (d) further includes the step of using a laser weld to secure the ring gear to the first case portion. 
   
   
       11 . The method of  claim 1  wherein step (a) further includes the steps of:
 selecting the first workpiece of material that is one of a low carbon steel and a low carbon microalloyed steel;   placing the first workpiece on the surface of the first mandrel; and   forming a wall thickness, an inner surface and an outer surface of the first case portion by cold flow forming the first workpiece on the first mandrel.   
   
   
       12 . The method of  claim 1  wherein step (a) further includes the steps of:
 selecting a first workpiece of sheet metal whose material is one of a low carbon steel and a low carbon microalloyed steel;   placing the first workpiece on the surface of the first mandrel; and   forming a wall thickness, an inner surface and an outer surface of the first case portion by cold flow forming the first workpiece on the first mandrel.   
   
   
       13 . The method of  claim 1  wherein step (a) further includes the steps of:
 selecting a first work piece that is forged and whose material is one of a low carbon steel and a low carbon microalloyed steel;   placing the first workpiece on the surface of the first mandrel; and   forming a wall thickness, an inner surface and an outer surface of the first case portion by cold flow forming the first workpiece on the first mandrel.   
   
   
       14 . The method of  claim 1  wherein step (b) further includes forming axially-directed, angularly spaced grooves on the inner surface of the second case portion; and the method further includes the steps of:
 installing in the cavity formed in the second case portion a second side gear, friction plates including radial tabs, each tab fitted into a groove and secured to the second case portion, friction discs, each disc interleaved between two successive friction plates and secured to the second side gear for rotation therewith.   
   
   
       15 . The method of  claim 1  further including the steps of:
 forming first clutch teeth on a second side;   installing the second side gear in the cavity formed in the second case portion;   forming an actuator with second clutch teeth;   installing the actuator ring in the cavity formed in the second case portion such that the first clutch teeth and second clutch teeth alternately engage and disengage mutually; and   installing on the second case portion an electromagnetic actuator that alternately urges the actuating ring into engagement with the second side gear and permits the actuating ring to disengage the second side gear.