Abstract: The gear unit for a delivery pump installed in a deep borehole has a toothed gear unit with a pinion located on input shaft (2) and a gear wheel engaged with the pinion, which gear wheel is located on a vertical output shaft (5) driving the delivery pump. The gear unit is designed as a right-angle unit with a conical pinion gear (3) located on the input shaft (2) and a bevel gear (6) located on the output shaft (5). Located on the input shaft (2) is a gearwheel (10) which together with a second gearwheel (11) forms a gear pump which conveys fluid in a direction opposite the operational direction of rotation of the gear unit.