Steering device

A steering device comprising:

• a rack bar which includes a rack teeth portion, and which is arranged to turn steered wheels;
• a pinion shaft including a pinion teeth portion arranged to be engaged with the rack teeth portion of the rack bar;
• a worm wheel which is arranged to rotate as a unit with the pinion shaft, and which includes a wheel teeth portion;
• a worm shaft including a worm teeth portion arranged to be engaged with the wheel teeth portion of the worm wheel;
• an electric motor which includes a motor shaft, and which is arranged to rotate the worm shaft;
• a coupling including a first coupling member, a second coupling member, and an elastic member,
• a first shaft member being one of the worm shaft and the motor shaft;
• a second shaft member being the other of the worm shaft and the motor shaft;
• a first shaft member assembly including the first shaft member and the first coupling member;
• a second shaft member assembly including the second shaft member and the second coupling member;
• the first coupling member including a first coupling base portion, a first outer blade portion, a second outer blade portion, and a third outer blade portion,
• the first coupling base portion provided to the first shaft member,
• the first outer blade portion which is provided to the first coupling base portion, and which protrudes in a radially outward direction with respect to a first axis which is a rotation axis of the first shaft member,
• the second outer blade portion which is provided to the first coupling base portion, and which protrudes in the radially outward direction with respect to the first axis,
• the third outer blade portion which is provided to the first coupling base portion, and which protrudes in the radially outward direction with respect to the first axis,
• the second coupling member including a second coupling base portion, a first inner blade portion, and a second inner blade portion,
• the second coupling base portion provided to the second shaft member,
• the first inner blade portion which is provided to the second coupling base portion, which protrudes in a radially inward direction with respect to a second axis that is a rotation axis of the second shaft member, and which is provided between the first outer blade portion and the second outer blade portion in a circumferential direction with respect to the first axis,
• the second inner blade portion which is provided to the second coupling base portion, which protrudes in the radially inward direction with respect to the second axis, and which is provided between the second outer blade portion and the third outer blade portion in a circumferential direction with respect to the second axis,
• the elastic member which is made from a resin, and which includes an elastic member base portion, a first rotation direction elastic portion, a second rotation direction elastic portion, a third rotation direction elastic portion, a fourth rotation elastic portion, and an axial elastic portion,
• the elastic member base portion which is provided between the first shaft member assembly and the second shaft member assembly in a direction of the first axis,
• the first rotation direction elastic portion which is provided to the elastic member base portion, and which is provided between the first outer blade portion and the first inner blade portion in the circumferential direction with respect to the first axis,
• the second rotation direction elastic portion which is provided to the elastic member base portion, and which is provided between the second outer blade portion and the first inner blade portion in the circumferential direction with respect to the first axis,
• the third rotation direction elastic portion which is provided to the elastic member base portion, and which is provided between the second outer blade portion and the second inner blade portion in the circumferential direction with respect to the first axis,
• the fourth rotation direction elastic portion which is provided to the elastic member base portion, and which is provided between the third outer blade portion and the second inner blade portion in the circumferential direction with respect to the first axis, and
• the axial elastic portion which is provided to the elastic member base portion, which protrudes in the direction of the first axis from the first shaft member toward the second shaft member, which includes an axial elastic portion base portion adjacent to the elastic portion base portion, and an axial elastic portion tip end portion abutted on the second shaft member assembly, and a line connecting the axial elastic portion base portion and the axial elastic portion tip end portion being inclined with respect to the first axis.