A structure for mounting a Hall effect sensor, the structure including: a mounting bracket, a mounting plate, a left supporting column, a right supporting column, and a first supporting column. The left supporting column and the right supporting column are protruded upwards from top surfaces of two adjacent teeth at the inner side of a certain winding slot, respectively. The first supporting column is protruded upwards from the top surface of the circular yoke at the outer side of the winding slot. The mounting plate is disposed on top surfaces of the first supporting column, the left supporting column, and the right supporting column. The mounting bracket is installed at the bottom of the mounting plate. The Hall effect sensor is installed in the mounting bracket.