Driveshaft and bearing
At first we used a full shaft, but we decided to take a hollow shaft, after the calculation. The shaft is still massive and it has to be, because off the high torque.
An adaptor is the connection between shaft and generator.
The driveshaft turns in between the upper flanged pendulum bearing and the lower self-made plain bearing. It is an update to regular bearings and cylindrical plain bearings, because it is flexible and simple to mount.
Stainless steel pendulum bearings aren´t standard because they are too expensive. Normally you got waterproof bearing modules, but that is too complicated for the rotor, so we end up in China. There was the idea, to fix an axial bearing with span sets, but you need a conical bearing seat for that. We couldn’t find that kind of bearing made of stainless steel. A Chinese Producer offered it for 100 pieces or more. It’s not worth for the prototype, so we used a flanged gear that’s axial fixed by two screws.
We talked to many bearing manufacturers, like boat-, under water builders and so on. Pendulum functions on sliding bearings are used at joint bearings on hydraulic cylinders but only translationally without rotation between driveshaft and bearing. That´s the reason for our own construction.
What could be improved?
The bearing system got a good performance. There is just low friction. You can optimize the costs and the complexity