The SW-system means quick change system (in Dutch: Snel Wissel system). The assembly system with bayonet fitting has been used for over decades on brushes for sweeping machines. This is done because everybody can change the brushes easily on the spot and by themselves.
The system exists out of a SW-plate with a fixed sealing ring and assembly plate. The sealing ring protects the engine from dirt penetration.
The quick change plate is directly assembled to the motor shaft which has bayonet fittings (see picture). The bolts of the gutter brush match the bayonet fittings. If the gutter brush is slipped in to the bayonet fittings and makes a little turn, the gutter brush stays fixed completely. Now there are two hands free which can fasten the bolts.
Advantages of the quick changing system: