As shown in the figure, the geometric relationship of hypoid gear pitch cone is shown. The pitch circle radius r1 of the small wheel, the node radius r2 of the large wheel, and the cone angle of the large wheel pitch are given δ 2. Conical angle of small wheel pitch δ 1. Helical angle of big wheel β 2. Small wheel helix angle β 1. Pitch of big wheel R2, pitch of small wheel R1, offset angle ε ※ and the spatial location of the intersection O1 and O2.
In combination with the design research and standard specifications of quasi double curved surface at home and abroad, we propose a calculation method for the spiral angle of small gears by presetting the spiral angle of large gears to meet the limit normal curvature radius conditions, by giving the basic design parameters of gear blanks, according to Gleason’s calculation formula for hypoid gear blanks and the characteristics that the super reduction ratio is greater than that of hypoid gears, The geometric parameters of the hypoid gear pair with super reduction ratio can be calculated.
The design parameters of hypoid gears with constant height tooth super reduction ratio mainly include helix angle, pitch cone angle, tooth width, pitch, pressure angle and working tooth height. Because it is an equal height tooth, the root cone angle and face cone angle are equal to the pitch cone angle. In addition, when determining the above gear blank parameters, the phenomenon of undercutting during gear processing should be avoided.
Before the wheel blank design of hypoid gears with equal high tooth super reduction ratio, the number of teeth z2 and z1 of big and small gears and the shaft intersection angle should be determined Σ， Offset E and gear rotation.
According to the knowledge of space geometry, the position of a point in space must be determined by three independent parameters. Similarly, when designing hypoid gears with super reduction ratio, the node position is determined by the offset angle of the pinion shaft section η 1. Small wheel helix angle β 1 and the radius r2 of the big wheel node.
According to the bearing capacity of the gear, the pitch radius of the big wheel can be determined as a basic parameter; Then the pitch cone angle of the big wheel can be estimated according to the formula, including:
Where, Σ Is the axis intersection angle.