Worm and gear speed reducer

The utility model relates to a worm and gear speed reducer, including speed reducer main part and heat radiation protection cover, the speed reducer main part includes the casing, the inside working chamber that is of casing. Be equipped with the worm wheel in the working chamber, still be equipped with in the working chamber with the worm of worm wheel cooperation work, the cooperation of the casing outside is installed the heat radiation protection cover, the heat radiation protection cover is including the protective housing, the protective housing is hollow structure, install the hinge on the protective housing, the change door is observed to articulated installing on the hinge, be close to in the protective housing observe the one end of changing the door and install the oil pump, install in the protective housing and lead oil pipe, the speed reducer main part install oil inlet and oil -out on the both sides face of casing, it is connected to by the oil -out to lead oil pipe the oil pump, again by it is