Gearbox adapter and gearbox

A gearbox comprising:

• a gearbox body;
• and
• an adapter body with an internal cavity, a first end having a gearbox connection structure connecting the adapter body to a gearbox body, a first shaft hole in an end face of the first end providing communication between the internal cavity and an outside of the adapter body, and a second end having an opening in communication with the internal cavity;
• a transmission shaft configured to extend from the outside into the internal cavity via the opening and then out of the adapter body through the first shaft hole;
• an opening cover with a second shaft hole, the opening cover fitted at the second end to block the opening but allow the transmission shaft to pass out of the internal cavity through the second shaft hole;
• and
• a rotating bearing arranged in the internal cavity and fitted to the transmission shaft to support the transmission shaft;
• wherein the adapter body is connected to the gearbox body via the gearbox connection structure;
• one end of the transmission shaft protruding from the first shaft hole is inserted into the gearbox body and fitted to a high-speed gear in the gearbox body;
• a first step in the internal cavity with an end face of the first step facing the opening;
• wherein the rotating bearing comprises a first bearing with an outer ring nested on an inner wall of the adapter body and an inner ring fitted round the transmission shaft;
• a first end of the first bearing abuts the first step;
• and
• a second end of the first bearing is locked by a first locking ring installed on the adapter body to prevent the first bearing from moving in the direction of the first locking ring.