Gear reducer with balanced output of very large torque from plurality of motors

A reducer, comprising a first motor shaft, a second motor shaft, a third motor shaft and a fourth motor shaft, each configured to be drivingly connected to a motor, wherein an upper left vertically positioned transmission gear and a lower left vertically positioned transmission gear which are mutually driven are disposed in a top-down orientation each between the first motor shaft and the second motor shaft, an upper right vertically positioned transmission gear and a lower right vertically positioned transmission gear mutually driven are disposed in a top-down orientation each between the third motor shaft and the fourth motor shaft (4), the upper left vertically positioned transmission gear and the upper right vertically positioned transmission gear are drivingly connected by a first horizontally positioned transmission shaft, and the lower left vertically positioned transmission gear and the lower right vertically positioned transmission gear are drivingly connected by a second horizontally positioned transmission shaft, adjustable motor transmission assemblies are assembled on exterior lateral surfaces of the first motor shaft, the second motor shaft, the third motor shaft and the fourth motor shaft, and torque adjustment assemblies are axially mounted on right side walls of the upper left vertically positioned transmission gear, the lower left vertically positioned transmission gear, the upper right vertically positioned transmission gear and the lower right vertically positioned transmission gear;

• wherein horizontally positioned transmission links are provided between upper and lower ends of the first motor shaft and the torque adjustment assemblies on the upper left vertically positioned transmission gear and the lower left vertically positioned transmission gear, between upper and lower ends of the second motor shaft and the torque adjustment assemblies on the upper left vertically positioned transmission gear and the lower left vertically positioned transmission gear, between upper and lower ends of the third motor shaft and the torque adjustment assemblies on the upper right vertically positioned transmission gear and the lower right vertically positioned transmission gear, and between upper and lower ends of the fourth motor shaft and the torque adjustment assemblies on the upper right vertically positioned transmission gear and the lower right vertically positioned transmission gear;
• wherein the torque adjustment assemblies comprise first fixation holders and second fixation holders fixed on right side surfaces of the upper left vertically positioned transmission gear, the lower left vertically positioned transmission gear, the upper right vertically positioned transmission gear and the lower right vertically positioned transmission gear, first adjustment struts fixedly mounted to outer side surfaces of the first fixation holders, second adjustment struts fixedly mounted to the second fixation holders and toothed gear heads axially fixed to outer telescopic sections of the first adjustment struts and the second adjustment struts;
• wherein:
• when the toothed gear heads of the first adjustment struts and the toothed gear heads of the second adjustment struts engage with the horizontally positioned transmission links, the upper left vertically positioned transmission gear, the lower left vertically positioned transmission gear, the upper right vertically positioned transmission gear and the lower right vertically positioned transmission gear are driven to rotate through a rotation of the horizontally positioned transmission links, and when the toothed gear heads of the first adjustment struts and the toothed gear heads of the second adjustment struts are disengaged from the horizontally positioned transmission links, the upper left vertically positioned transmission gear, the lower left vertically positioned transmission gear, the upper right vertically positioned transmission gear and the lower right vertically positioned transmission gear separate from the first motor shaft, the second motor shaft, the third motor shaft and the fourth motor shaft.