Planetary gear train, gearbox and industrial robot

A gearbox for an industrial robot, the gearbox comprising a planetary gear train including:

• a ring gear defining a central axis;
• a plurality of planet gears, each planet gear being rotatable about a respective planet axis and meshing with the ring gear, and each planet gear including a conical and helical planet gear toothing defining a conical direction;
• a planet carrier rotationally supporting the planet gears for rotation about the planet axes, the planet carrier being axially displaceable along the central axis;
• and
• a carrier forcing device arranged to force the planet carrier along the central axis in the conical direction.

An industrial robot comprising a planetary gear train or a gearbox, including:

• a ring gear defining a central axis;
• a plurality of planet gears, each planet gear being rotatable about a respective planet axis and meshing with the ring gear, and each planet gear including a conical and helical planet gear toothing defining a conical direction;
• a planet carrier rotationally supporting the planet gears for rotation about the planet axes, the planet carrier being axially displaceable along the central axis;
• and
• a carrier forcing device arranged to force the planet carrier along the central axis in the conical direction.