Gear box of gear lubricating type automobile auxiliary brake device

The utility model discloses a gear box of a gear lubricating type automobile auxiliary brake device. The gear box comprises a box body and a transmission component, wherein the transmission component comprises an input shaft, an upper output shaft and a lower output shaft; the upper output shaft and the lower output shaft are connected with a driving shaft through couplings respectively; a secondary driven gear sleeves the upper output shaft and the lower output shaft respectively, and is engaged with a secondary driving gear; the secondary driving gear is arranged on a secondary transmission shaft; the secondary transmission shaft is also provided with a primary driven gear; the primary driven gear is engaged with a primary driving gear; the primary driving gear is arranged on the input shaft; the secondary driven gears, the secondary driving gear, the primary driven gear and the primary driving gear are all of heat dissipation type gear structures; the heat dissipation type gear structures comprise gear bodies, gear teeth, tooth sockets and heat dissipation members. The gear box has the advantages of simple structure, rational structure, high bearing capacity and low noise.