High-precision heavy-load speed reducer used for transmission of servo press

The invention discloses a high-precision heavy-load speed reducer used for transmission of a servo press. The high-precision heavy-load speed reducer comprises a speed reducer box, a servo motor, a first connecting sleeve, an input gear shaft and an output gear shaft, the speed reducer box is mounted above a cross beam body, the servo motor is mounted on the speed reducer box and connected with the input gear shaft of the speed reducer through the first connecting sleeve, the input gear shaft transmits high-speed rotary motion of the servo motor onto the output gear shaft through a gear mechanism, the output gear shaft is meshed with a middle big gear in the cross beam body to transmit power to a main transmission gearbox in the cross beam body, and a brake is assembled on the input gear shaft and used for braking of a movement mechanism when the servo press stops. By the high-precision heavy-load speed reducer, transmission efficiency and transmission stability are improved greatly, transmission accuracy and running stability are improved, noise is lowered effectively, forming capability of the servo press is improved, and leaking of lubricating oil in a high-speed state is prevented.