Design and prototyping of a retrofittable motorized module for hand powered tricycles for Developing countries

Abstract

Current wheelchair designs in developing countries create many difficulties for their users. In Kenya, wheelchair users are often unable to use public transportation, and thus are isolated and usually without work. This thesis outlines a feasible design for a retrofittable motorized module for a hand-powered tricycle produced and widely distributed throughout Kenya. There are many mobility aids that are similar to the Kenyan handcycle, which can also adapt the module design. By using this innovative module, users will be able to increase their range of travel and access areas where human-powered transport is not sufficient. This simple addition will improve the quality of life for the physically disabled user. This work will be presented to a wheelchair workshop summer 2008 in hopes to convert it into a feasible design for production. Increased reliable mobility will allow the disabled community in Kenya to apply for jobs, and even be afforded opportunities in micro-business for the first time. The design of the powertrain consists of a common motorized bicycle 2 hp engine and a two-stage gear reduction. The control system uses an analogous setup to that of a motorcycle. This control system is integrated into the layout of the chair. Three operation modes are possible with this design: hand-powered only, engine-powered only, or hand-powered with motor-assist.