Patent ID: 8881401

Claim:
A method of designing a hypoid gear comprising a pair of gears including a first gear and a second gear, the method comprising: (a) setting a shaft angle Σ, an offset E, and a gear ratio i 0 of the hypoid gear; (b) calculating, based on the shaft angle Σ, the offset E, and the gear ratio i 0 , an instantaneous axis S which is an axis of a relative angular velocity of the first gear and the second gear, a line of centers v c with respect to rotational axes of the first gear and the second gear, an intersection C s between the instantaneous axis S and the line of centers v c , and an inclination angle Γ of the instantaneous axis S with respect to the rotational axis of the second gear, to determine coordinate systems C 1 , C 2 , and C s for calculation of specifications; (c) setting three variables of a subset including one of a reference circle radius R 1w of the first gear and a reference circle radius R 2w of the second gear, one of a spiral angle ψ pw of the first gear and a spiral angle ψ gw of the second gear, and one of a pitch cone angle γ pw of the first gear and a pitch cone angle Γ gw of the second gear; (d) calculating a design reference point P w which is a common point of contact of pitch cones of the first gear and the second gear, and three other variables from the subset of variables listed in the step (c) but which are not set in the step (c), based on the three variables which are set in the step (c); (e) setting a contact normal g wD of a drive-side tooth surface of the second gear; (f) setting a contact normal g wC of a coast-side tooth surface of the second gear; and (g) calculating specifications of the hypoid gear based on the design reference point P w , the three variables which are set in the step (c), the contact normal g wD of the drive-side tooth surface of the second gear, and the contact normal g wC of the coast-side tooth surface of the second gear, wherein the hypoid gear is produced based upon the steps (a)-(g).