MONTAGE | LEAFLET
Rivabo have added a new range of propeller shafts to its existing brass model boat propeller programme.
These new propeller shafts are manufactured using a stainless steel shaft, running within a brass tube. The shafts also incorporate an innovative approach to bearing location and construction.
The thrust bearing for the shaft is placed at the drive end of the tube instead of the more usual propeller end.
The simple advantage is that the thrust bearing cannot be affected by the ingress of water. In addition, due to the greater available space in-board, it allows the construction to be both simple and robust.
The thrust bearing assembly consists of ball-races without a retainer, these are set into a conical housing. During operation the ball-races are spun outward due to centrifugal force and are pushed back against the bearing face by the pressure exerted by the propeller.
The combination between these forces result in the perfect positioning of the ball-races during operation.
Due to the thrust-bearing holder being fitted within the tube, a drive motor or gearbox can be fitted directly onto the tube.
The bearing at the propeller end of the tube consists of a plain bush, which has been made out of a new kind of plastic. This plastic material is designed to work at its best when lubricated by water.
An O-Ring near the thrust bearing takes care of the separation between the lubricating oil of the thrust bearing and the water surrounding the plastic bearing at the propeller end.
There is currently available a range of 4 different shafts, light and a heavy duty design in both M4 and M5. These shafts are specifically designed for use in electric powered model boats.
The shaft and tube can be adjusted to the required length, this can be done without the need for special tools.
An exploded view plan and a part list makes the shafts easy to adapt and therefore a valuable innovation in the radio control model boat area.