Differential gear mechanism

Claim 2

A differential gear mechanism comprising a housing, a drive pinion rotatably supported in said housing, a one-piece rotary case rotatably supported in said housing, said rotary case having a pair of axially spaced radially extending end walls and a cylindrical wall extending between said end walls, one of said end walls having a flange, a ring gear secured to said flange and meshing with said drive pinion, a pair of side gears rotatably supported in said case, a differential gear rotatably supported in said case and meshing with both said side gears, a permanent opening in said cylindrical wall normally large enough to permit installation of all internal parts including said side gears and differential gear in said case, at least one strengthening bolt extending axially of said case and spanning said installation opening, said bolt received in an axially extending hole in the other of said end walls and having a threaded end engaging a tapped hole in said one end wall and a bolt head at the other end engaging the outer side of said other end wall whereby after the internal parts are installed in said differential case through said installation opening and said bolt is then torqued a predetermined amount there is provided added bending stiffness by said bolt to offset the affect of said opening.

Claim 3

A differential gear mechanism comprising a housing, a drive pinion rotatably supported in said housing, a one-piece cast iron rotary case rotatably supported in said housing, said rotary case having a pair of axially spaced radially extending end walls and a cylindrical wall extending between said end walls, one of said end walls having a radially outwardly located flange, a ring gear secured to said flange and meshing with said drive pinion, a pair of side gears rotatably supported in said case, a differential gear rotatably supported in said case and meshing with both said side gears, a plurality of lightening holes in said cylindrical wall including an opening larger than any other hole by an amount sufficient to permit installation of said side gears and differential gear in said case, a plurality of strengthening bolts equally circumferentially spaced in said installation opening and extending axially of said case and spanning said installation opening, each said bolt received in an axially extending hole in the other of said end walls and having a threaded end engaging a tapped hole in said one end wall and a bolt head at the other end engaging the outer side of said other end wall whereby after the internal parts are installed in said differential case through said installation opening and said bolts are then torqued a predetermined amount of portion of the axial load in said case is carried directly across said installation opening between said end walls by said bolts so that the largeness of said installation opening is not permitted to affect the bending stiffness of said differential case.

Claim 4

A differential gear mechanism comprising a housing, a drive pinion rotatably supported in said housing, a one-piece cast iron rotary case rotatably supported in said housing, said rotary case having a pair of axially spaced radially extending end walls and a cylindrical wall extending between said end walls, one of said end walls having a radially outwardly located flange, a ring gear secured to said flange and meshing with said drive pinion, a pair of side gears rotatably supported in said case, a differential gear rotatably supported in said case and meshing with both said side gears, a plurality of lightening holes in said cylindrical wall including an opening larger than any other hole by an amount sufficient to permit installation of said side gears and differential gear in said case, a plurality of strengthening bolts equally circumferentially spaced in said installation opening and extending axially of said case and spanning said installation opening, each said bolt received in an axially extending hole in the other of said end walls and having a threaded end engaging a tapped hole in said one end wall and a bolt head at the other end engaging the outer side of said other end wall whereby after the internal parts are installed in said differential case through said installation opening and said bolts are then torqued a predetermined amount of portion of the axial load in said case is carried directly across said installation opening between said end walls by said bolts so that the largeness of said installation opening is not permitted to affect the bending stiffness of said differential case.

Claim 5

A differential gear mechanism comprising a housing, a drive pinion rotatably supported in said housing, a one-piece cast iron rotary case rotatably supported in said housing, said rotary case having a pair of axially spaced radially extending end walls and a cylindrical wall extending between said end walls, one of said end walls having a radially outwardly located flange, a ring gear secured to said flange and meshing with said drive pinion, a pair of side gears rotatably supported in said case, a differential gear rotatably supported in said case and meshing with both said side gears, a plurality of lightening holes in said cylindrical wall including a generally rectangularly shaped opening larger than any other hoLe by an amount sufficient to permit installation of said side gears and differential gear in said case, at least a pair of strengthening bolts equally circumferentially spaced in said installation opening and extending axially of said case and spanning said installation opening, each said bolt received in an axially extending hole in the other of said end walls and having a threaded end engaging a tapped hole in said one end wall and a bolt head at the other end engaging the outer side of said other end wall whereby after the internal parts are installed in said differential case through said installation opening and said bolts are then torqued a predetermined amount a portion of the axial load in said case is carried directly across said installation opening between said end walls by said bolts so that the largeness of said installation opening is not permitted to affect the strength of said differential case.

Claim 6

A differential gear mechanism comprising a housing, a drive pinion rotatably supported in said housing, a one-piece cast iron rotary case rotatably supported in said housing, said rotary case having a pair of axially spaced radially extending end walls and a cylindrical wall extending between said end walls, one of said end walls having a radially outwardly located flange, a ring gear secured to said flange and meshing with said drive pinion, a pair of side gears rotatably supported in said case, a differential gear rotatably supported in said case and meshing with both said side gears, a plurality of lightening holes in said cylindrical wall including a generally rectangularly shaped opening larger than any other hoLe by an amount sufficient to permit installation of said side gears and differential gear in said case, at least a pair of strengthening bolts equally circumferentially spaced in said installation opening and extending axially of said case and spanning said installation opening, each said bolt received in an axially extending hole in the other of said end walls and having a threaded end engaging a tapped hole in said one end wall and a bolt head at the other end engaging the outer side of said other end wall whereby after the internal parts are installed in said differential case through said installation opening and said bolts are then torqued a predetermined amount a portion of the axial load in said case is carried directly across said installation opening between said end walls by said bolts so that the largeness of said installation opening is not permitted to affect the strength of said differential case.