Abstract: An external gear pump and/or motor of floating-shaft type comprising a front cover, a back cover and a housing forming a cavity in which a pair of meshed gears are mounted, characterized in that the gear shafts are brought toward the high-pressure side by means of a sleeve which can float radially under the pressure of the hydraulic oil and meanwhile said sleeves are pushed against the ends of the gears under the pressure of the hydraulic oil so that radial floating is achieved without any additional floating means in an external gear pump and/or motor. Therefore, the size of high-pressure zone and thereby, the inherent radial force are reduced in the gear pump and/or motor according to the present invention. Furthermore, its structure is simplified and reliable and its production cost is reduced.