Inner gear wheel with impact absorption structure and reducer using same

A reducer, comprising:

• an input shaft arranged along an axial direction and configured to receive a power input;
• an outer gear plate comprising an outer ring surface, a central shaft hole and a plurality of outer gears, wherein the central shaft hole penetrates the outer gear plate along the axial direction and is passed through by the input shaft, and the plurality of outer gears are disposed on the outer ring surface along a circumferential direction;
• an inner gear wheel sleeved on the outer gear plate, and comprising:
• a body wheel comprising an inner ring surface and a plurality of inner gears, wherein the inner ring surface is disposed around the input shaft, the plurality of inner gears are disposed around the inner ring surface, and each of the plurality of inner gears is partially connected to and engaged with the outer gear plate in a radial direction;
• a plurality of fixing holes disposed on the body wheel and penetrating the body wheel along the axial direction;
• and
• a plurality of impact absorption structures spatially corresponding to the plurality of fixing holes and penetrating the body wheel along the axial direction, wherein each of the plurality of impact absorption structures comprises a pair of buffer grooves, a connecting slit and a pair of buffer elements, the pair of buffer grooves are disposed at two sides of a corresponding one of the plurality of fixing holes along the circumferential direction, the connecting slit is arranged between the inner ring surface and the corresponding one of the plurality of fixing holes, extended along the circumferential direction and in communication between the pair of buffer grooves, and the pair of buffer elements are made of elastic high-damping materials and disposed in the pair of buffer grooves respectively to absorb a stress transmitted from the outer gear plate engaged with the inner gear wheel;
• and
• an output plate arranged along the axial direction, disposed on an outer side of the inner gear wheel along the radial direction, and connected to the outer gear plate through an output pin, wherein when the power input is inputted through the input shaft, the input shaft drives the plurality of outer gears of the outer gear plate to engaged with the plurality of inner gears of the inner gear wheel, and the outer gear plate is rotated with the output pin, so that the output pin drives the output plate to perform a rotational motion and output a torque.