Abstract: In a pump drive for a motor vehicle automatic gearbox, a hollow shaft (6) secured in rotation to a primary part (3) of a torque converter (1) projects into the inside of a pump housing (7) and bears an impeller (10) of the pump. The hollow shaft (6) is borne in a bore (12) in the pump housing (7) via a rolling bearing, whereby, in order to seal the pump housing, there is a radial sealing ring (18) on one side of the rolling bearing and a sealing ring (14) on the other. The latter ring (14) is designed to enclose a uniform sealing gap (25) with the hollow shaft (6) and it is guided freely both radially and axially in the bore (12) so that the sealing gap (25) may automatically set itself.