High-reliability cylinder type second-gear planetary wheel gearbox

The invention discloses a high-reliability cylinder type second-gear planetary wheel gearbox. The high-reliability cylinder type second-gear planetary wheel gearbox comprises a box body, wherein a left cylinder end cover and a right cylinder end cover are respectively connected to the left and right sides of the box body; an input shaft is connected to the left side of the box body, and a tumbler output shaft is connected to the right side of the box body; the tumbler output shaft is connected with the input shaft; a planetary wheel shaft is connected to the tumbler output shaft; a combined planetary wheel is connected to the planetary wheel shaft, and a small planetary wheel is connected to the planetary wheel shaft; the small planetary wheel is connected with a right gear ring; the combined planetary wheel is connected with a left gear ring; a small sun wheel and a large sun wheel are connected to the right side of the input shaft; the small sun wheel is engaged with the combined planetary wheel; the large sun wheel is engaged with the small planetary wheel; a left cylinder pushing plate device is arranged on the left cylinder end cover, a right cylinder pushing plate device is arranged on the right cylinder end cover, and a low-gear brake structure and a high-gear brake structure are arranged in the box body. The high-reliability cylinder type second-gear planetary wheel gearbox has the advantages of simple structure and cost reduction, and lubricating oil can be cooled and circulated, so that the service life of the lubricating oil is prolonged.