Method and apparatus for automatically assembling side gears, pinions and pinion shaft within differential case

An apparatus for assembling a differential gear device including a differential case with a chamber formed therein, and components which are accommodated in said chamber and which include a pair of opposed differential side gears, a pair of opposed differential pinions interposed between and meshing with said side gears, and a differential pinion shaft for rotatably supporting said pinions, said differential case being adapted to be disposed in a differential assembly, rotatably with a ring gear about a first axis, said side gears being rotatable about said first axis, while said differential pinions being rotatable about a second axis perpendicular to said first axis, said case having a pair of openings which communicate with said chamber and are open to an external space outside said case and which are opposed to each other in a direction perpendicular to said second axis, in a plane parallel to said second axis and perpendicular to said first axis, said apparatus comprising:

• a pinion support device for introducing said pinions into said chamber through said pair of openings, respectively, and rotatably holding said pinions between said differential side gears disposed within said chamber, at respective symmetrical positions which are symmetrical with each other with respect to said first axis in said plane;
• a side gear rotating device for rotating one of said side gears about said first axis;
• and
• a gear meshing device for effecting meshing engagement of said pinions with said pair of side gears, while holding said pinions at said respective symmetrical positions.