On the Development of a Novel Class of “Mechanical Stepper Motors”

The development of a novel class of actuation devices, referred to as “mechanical stepper motors”, which can be constructed to provide high-force linear or high-torque rotary motion is presented. The operation of this novel class of mechanical stepper motor type actuators is based on the principles of operation of a simple Vernier. The actuators may be constructed to provide multiple step sizes. The motion generation mechanism of the stepper motors may be designed to lock the actuator at each motion step, thereby providing the actuator with a built-in precision in-position braking mechanism. The actuators may be powered pneumatically, hydraulically, electrically or via gas-generating charges. The actuators operating pneumatically or hydraulically may be constructed with non-metallic materials and be fully submersible, making them particularly suitable for use in medical, food, beverage and chemical industries and where electricity poses fire or explosion hazard. In this paper, the basic design and operation of this novel class of mechanical stepper motors are described. As examples of such mechanical stepper motors, the details of the design and construction of a linear and a rotary mechanical stepper motor and their characteristic are provided.