Generalization of Multispeed Gear Pitch Curves Design

Abstract

Defined by various geometries and kinematics characteristics, noncircular gears represent special mechanical systems able to produce nonuniform motion of the driven element. Multispeed gears are a less investigated category of noncircular gears, used to combine constant and variable speed, recommended for industrial applications that require uniform speeds for different parts of a cycle, with a smooth transition between the parts. Due to the motion requirements, the design of a multispeed gear train has as input data either the driven gear law of motion or the gear transmission ratio variation. This paper presents a specific original algorithm for the generalization of the multispeed gear pitch curve modeling, based on the definition of the gear instantaneous transmission ratio. The next step of the multispeed gear design, the teeth generation, accessible through solid modeling or analytical procedure, will be approached in a future study.