The invention provides a driving device comprising a tubular housing (2) and a moving unit (4) which is positioned on the housing (2) in such a way that it can be moved lengthwise therein. Said moving unit (4) comprises an internal part which is located in the housing (2) and an external part which is located outside the housing (2), both parts being magnetically coupled. The magnetic coupling creates a coupling device which produces at least one closed magnetic circuit (13) via the outer part (6) and which fully traverses the inner part (5) and the housing (2).