Abstract: A brush drive unit is coupled to rotating means such as an electric motor. The brush drive unit maintains first and second belt brushes in an oval configuration and in fore and aft alignment. The brush drive unit causes the motor drive shaft to rotate the first and second belt brushes in opposing directions. The brush drive unit also includes a transmission assembly which is coupled between the motor drive shaft and the first and second belt brushes to alternately rotate the first belt brush in a first direction while maintaining the second belt brush in a substantially fixed position and for rotating the second belt brush in a second direction while maintaining the first belt brush in a substantially fixed position.