Fixture for machining planetary gear of gearbox

The utility model relates to a fixture for machining a planetary gear of a gearbox. The die is characterized by comprising a cylindrical base, upper protrusions integrally connected with the base are evenly distributed on the upper end of the base in the circumferential direction, and a die holder is arranged on the upper protrusions. The die holder is a circular ring, and the outer side of the die holder is sleeved with an annular cover plate. The outer diameter of the annular cover plate is not larger than that of the base, and the annular cover plate is connected with the upper protrusion. A tooth die is connected to the upper end of the die holder and is a short cylinder, and the upper end face of the tooth die is a conical face conveniently matched with the conical end of the planetary gear. An oil cylinder and a rotating oil cylinder are arranged between every two adjacent upper protrusions, and cylinder bodies of the oil cylinders and cylinder bodies of the rotating oil cylinders are fixed to the annul