An autonomous mobile work system (20) includes a drive wheel (34) that is connected to a frame (24) and a rotating blade assembly (36). The rotating blade assembly (36) includes a blade assembly axis of rotation (38) and is connected to the frame (24) within a housing (26). The mobile work system (20) further includes a single motor (40) operably connected to the blade assembly (36). The motor (50) includes a motor output shaft (44) and the motor output shaft (44) includes an output shaft axis of rotation (46). The mobile work system (20) still further includes a gear box (50) operably connected to the drive wheel (34) and the motor output shaft (44). The single motor (50) urges rotation of both the rotating blade assembly (36) and the drive wheel (34). The gear box (50) can include a planetary gear set (104) including a ring gear (110) defining cavities (120) at its outside diameter (124). A locking shaft (126) can rotate between an engaged position and a disengaged position with one of the cavities (120).
