Innovativt Drivpaket för Rullstol

This is a thesis for a Bachelor Degree Project, performed in the subject Mechanical Engineering. The students Roger Malmberg and Simon Hagberg have carried out a design project on behalf of the recently established company J&D Assisting systems, located in Halmstad. The project consisted in developing J&D's first prototype of a power assisting solution for wheelchairs. A power assisted wheelchair combines human power, which is delivered by the arms through the pushrims, with electrical motors, which are powered by a battery. The power assisted wheelchair is aimed at customers, who have used a regular wheelchair for a long time, but who have become weaker or just need additional power when driving uphill. This kind of wheelchair will provide additional power for users, which will spare their wrists, elbow and shoulders. The product is torque sensor free and instead it relies on the velocity. Engines and gearboxes from the company All motion was a requirement. The construction could not impair the wheelchair's trafficability and the performance would at least match up with the performance of the first prototype. To build a working prototype was a part of the task. The work was early focused on the specific wheelchair Etac Next. At the same time, the result should be, as much as possible, suitable for the most common wheelchairs. The result is a design where the engine packet is assembled in a 90° angle towards the wheelaxle. In the angle, the power is transferred by bevel gears, assembled on shafts supported by ball bearings. Then, the force is transmitted via a modified wheel axle to a structure mounted outside the hub. Eight stokes transfers the force to the hand rims. An operational prototype has been built and then been assembled on the wheelchair Etac Next. The part mounted outside of the wheel has got a plastic hood to cover up and to protect the inner parts. The plastic hood has been produced with SLS technology