#$%^&*AU2019202721A120191219.pdf#####Vacuum motor, surgical drive system, and method for operating a vacuum motor Abstract The invention relates to a vacuum motor, comprising a housing (1, 2) with a cylindrical internal space (4), a working piston (5) that is arranged in axial direction of the cylinder axis of the cylindrical internal space (4) such as to be mobile by linear oscillation between the front side and the rear side of the internal space (4)； a first restoring element (6) that is arranged in the internal space (4)； a gas outlet (7) in the housing (1, 2)； a gas inlet (8) in the housing (1, 2) for supplying ambient air, whereby the gas outlet (7) and the gas inlet (8) terminate in the internal space (4) between the working piston (5) and the rear side of the housing (1, 2), and whereby the working piston (5) does not fully or even partially cover the gas outlet (7) and the gas inlet (8) in any of its positions； a valve body (10) that can be moved against the gas inlet (8) in order to close the gas inlet (8)； a second restoring element (11) that transitions the valve body (10) into the closed position； at least one pestle (12) that is arranged such as to be mobile in axial direction within the housing (1, 2) between the working piston (5) and the valve body (10), whereby upon a motion of the working piston (5) in the direction of the rear side of the internal space (4), the valve body (10) can be moved against the force of the second restoring element (11) and thus the gas inlet (8) can be opened, and whereby the free cross-section of the opened gas inlet (8) is at least equal in size to the free cross-section of the gas outlet (7). The invention also relates to a surgical drive system comprising said vacuum motor, a medical lavage system for the debridement of soft tissue and/or bone tissue comprising said vacuum motor, and a medical device for brushing, rasping or sawing of soft tissue and/or bone tissue compris
