Articulated differential crowning

A pair of gears having mating teeth with a working surface on at least one of said pair that has a first crown at a first roll angle and a second crown at a second roll angle,

• said second crown differing in form from said first crown,
• said first crown including (a) a center segment having a length substantially shorter than the face width at said first roll angle, and (b) two outer segments that make an articulation angle with said center segment,
• said second roll angle being located substantially at the inner end of one of the loading ramps,
• said first roll angle being located one half a pitch angle inside the roll angle of the end of the synchronization length closest to said second roll angle,
• the loaded width ratio of said first crown being substantially smaller than that of said second crown.

A pair of gears having mating teeth with a working surface on at least one of said pair that has a first crown at a first roll angle and a second crown at a second roll angle,

• said second crown differing in form from said first crown,
• said first crown including (a) a center segment having a length substantially shorter than the face width at said first roll angle, and (b) two outer segments that make an articulation angle with said center segment,
• said first roll angle being located substantially at the roll angle of one end of the synchronization length,
• said second roll angle being located one half a pitch angle inside said first roll angle,
• the loaded width ratio of said first crown being substantially smaller than that of said second crown.

A pair of gears having mating teeth with a working surface on at least one of said pair that has a first crown at a first roll angle, a second crown at a second roll angle and a third crown at a third roll angle,

• said first, second and third roll angles all being different from each other, said first, second and third crowns all differing in form from each other,
• at least one of said crowns including (a) a center segment having a length substantially shorter than the face width at the roll angle of said one of said crowns, and (b) two outer segments that make an articulation angle with said center segment,
• said second roll angle being located substantially at the inner end of one of the loading ramps,
• said first roll angle being located one half a pitch angle inside the roll angle of the end of the synchronization length closest to said second roll angle,
• said third roll angle being located substantially at the roll angle of one end of the synchronization length.