Speed reducer

Provided is a speed reducer. The problems that an existing speed reducer pin is small in cross sectional area, prone to breakage and low in bearing capacity are mainly solved. The utility model is characterized in that the output disc is provided with a first connecting end face (21), the output pipe is provided with a second connecting end face (31), the first connecting end face is provided with a sinking groove (211), the second connecting end face is provided with a boss (311) with a rectangular cross section, the boss is arranged in the sinking groove, and the boss is connected with the output disc. When the output disc rotates, the output disc drives the output pipe to rotate through the sinking groove and the boss which are matched with each other. According to the speed reducer, torque is transmitted through the rectangular protruding blocks, the rectangular grooves and the matched fasteners, the contact area is large, the structural rigidity is good, and the bearing capacity is larger. 一种减速机。主要解决目前的减