Mechanical Flaps RASSOR Drum Design

Last crawled date: 2 years ago

Section Diameter= 450mm
Drum Diameter = 450mm
Drum length = 350 mm
Mass= 4.5 kg
Material= Aluminum/Aluminum alloy, Delrin
Fill ratio = 75 - 80%
Fill volume = 50000 cm^3, 50 liters
Maximum engaged length = 150mm


The flaps design is a system of active regolith flow direction by way of bi-direcional flaps located inboard of each toothed intake channel. The flaps are driven by crank arms connected to the flap on a sliding pivot joint. The crank arms are connected to a central drive axle. When the drive axle rotates, the crank arms first move the flaps into either the intake or dumping position. For intake, the flaps rotate such that they face inward, promoting a regolith inflow. The drum itself is not directly driven by the drive shaft, rather is mechanically linked to the flap mechanism. When the flaps move to the inflow position, they eventually hit a mechanical hardstop. When this happens, the torque from the drive axle is transferred to the entire drum.
To release regolith, the axle reverse rotational direction. The drum, no longer driven by the flap mechanism, stops rotating. The flaps, driven by the crank arms move to point outwards, promoting an outflow of regolith. Once the flaps hit the outflow hardstops, the torque is once again transferred to the drum and the entire system rotates in the opposite direction to dump its contents.
The goal of the active flap control design is to make the regolith flow direction actively controlled. The intent is to minimize regolith losses in passive systems like gravity driven flow control or geometric flow control. By having the intake direction control system dependent on the direction of the rotation, a more concrete (certain) mechanically driven flow control is achieved.