Worm Reduction Gear and Steering System

摘要

A worm reduction gear satisfies following relational Formula (1) and Formula (2):;3≧D2/D1≧1.7  (1);0.1°≦α−β≦0.5°  (2);where D1 is an outside diameter of a worm, D2 is an outside diameter of a hob for cutting a worm wheel to form tooth spaces, and α is a pressure angle of the worm wheel and β is a pressure angle of the worm at an intermeshing pitch circle of the worm and the worm wheel.

主权项

1. A worm reduction gear comprising:
a worm; and a worm wheel including tooth spaces that mesh with the worm, wherein following relational Formula (1) and Formula (2) are satisfied:
3≧D2/D1≧1.7  (1)0.1°≦α−β≦0.5°  (2)where D1 is an outside diameter of the worm, D2 is an outside diameter of a hob for cutting the worm wheel to form the tooth spaces, and α is a pressure angle of the worm wheel and β is a pressure angle of the worm at an intermeshing pitch circle of the worm and the worm wheel.