SPEED REDUCER

The present invention relates to a speed reducer, comprising a box body (1), an input shaft (2), a circular spline (3), an output member, and a flex spline (5). The flex spline (5) is located in an accommodation cavity (10) of the box body (1) and is sleeved on the periphery of the input shaft (2), and the outer periphery of the flex spline (5) is fixedly connected to the box body (1); the flex spline (5) is located between the circular spline (3) and the output member, and is driven by the circular spline (3) to partially elastically deform towards the output member along the axial direction of the input shaft (2), so as to drive the output member to rotate around the axis of the input shaft (2). According to the speed reducer of the present invention, compared with the prior art, the flex spline deforms along the axial direction of the output shaft, so that the power outputted by the output member is balanced relative to the input shaft, thereby ensuring the bearing capacity of the speed reducer. La présent