Zexel Torsen Inc.

Ward E Bowerman

Charles T D'Agostino

Paolo Sacchettini

A parallel-axis torque-proportioning differential has four pairs of planet gears arranged symmetrically-but-non-equiangularly about a common axis in two mirror-image gear sets separated by angular spacings adequate to permit access for C-clip assembly. A thrust-block, positioned between the opposed end faces of the sun/side gears, is not supported in a housing window but rather is supported on the outer circumferential surfaces of four planet gears, two from of each set, so that the housing window can be significantly larger than the thrust-block, thus increasing lubrication and lessening the cost and weight of the housing and reducing the weight of the required thrust-block. Also, the thrust-block may include two side-by-side mating members separated by a spring element to exert a preload force between the opposed end faces of the side gears.

Thrust-block for C-clip differential

A gear for use in automotive differentials and a method for its manufacture in which, initially, the gear teeth are roll-formed in a cylindrical rod workpiece between a pair of toothed dies so that a fissure is created in the top land of each rolled tooth, the roll-forming being continued until (a) the diameter of the top land of each tooth is slightly greater than the desired cylindrical outside diameter of said gear and (b) each fissure is narrowed to form a seam at the top land surface of each tooth. The gears are then further processed in a relatively short machining operation that removes the narrowed seam in the top land of each gear tooth to reduce the depth of the fissure so that the normal force vector of the highest point single tooth loading ('HPSTL') on the gear tooth is directed below the bottom of the fissure. Preferably, this same finishing operation re-opens the fissure and forms the cylindrical journal/top lands of the gear teeth to a finished outside diameter slightly smaller than the inside diameter of the cylindrical differential housing pocket into which the gear will be received and supported.

Roll-formed differential gear

An automotive differential (10) is modified to provide better control over torque transfers between a housing (12) and a pair of output shafts (16 and 18), as well as torque transfers between the output shafts (16 and 18). Friction modifiers (66 and 86) are located at various end faces of side gears (30 and 32) coupled to the output shafts (16 and 18) for varying bias ratios in opposite directions of torque transfer between output shafts (16 and 18) independently of directions of torque transfers between the housing (12) and the output shafts (16 and 18).

Differential with bias control

A parallel-axis torque-proportioning differential includes four sets of planetary gear pairs mounted within a differential housing having exterior dimensions substantially identical to those presently being used for comparable prior art designs. The four planetary pairs are arranged in two planetary sets positioned symmetrically-but-non-equiangularly with the axes of the planet gears in a mirror-image relationship about the common axis of the sun/side gears and with each planetary set comprising two of the separate and distinct planet gear pairs. The two planetary sets are separated from each other by large angular spacings; and two large windows, which are positioned in circumferential alignment with each of said large angular spacings, facilitate lubrication and also provide appropriate access to accommodate C-clip assembly.

Differential with distributed planet gears

A parallel-axis gear differential includes one or more pairs of planet gears (68 and 70) for interconnecting two side gears (34 and 36). The planet gears (68 and 70) include at least three meshing portions (82, 84, and 88 and 94, 96, and 98). One of the meshing portions (82 or 96) of each planet gear (68 or 70) engages one of the side gears (34 or 36), and the other two meshing portions (84 and 88) of one planet gear (68) engage respective meshing portions (94 and 98) of its paired planet gear (70). The two planet-to-planet meshes (84/94 and 88/98) straddle one of the side gears (36), and the two side gears (34 and 36) straddle one of the planet-to-planet gear meshes (84/94). A spacer block (46) is positioned between the side gears (34 and 36 ).

Growing community of inventors

Rochester, NY, United States of America

Ward E Bowerman