In-wheel motor unit

1. An in-wheel motor unit comprising:

a rim member having a tire installed along an outer circumference thereof;

a spoke connected to the rim member and configured to rotated with the rim member;

a motor part located in a mounting space formed by the rim member and the spoke, and configured to generate rotational power through power supplied thereto, and rotate the spoke, wherein the motor part further comprises:

a rotor member fixed to the spoke; and

a rotor fixed to the rotor member and having magnetism;

a knuckle part connected to the motor part and configured to support a suspension part; and

a hub part having one side fixed to the spoke and the other side connected to the knuckle part, and configured to rotatably support the spoke, wherein the in-wheel motor unit is unimpeded by the suspension part.

2. The in-wheel motor unit of claim 1 , wherein the spoke comprises:

a core member installed at a position facing the hub part; and

an extension member extended radially from the core member, and connected to the circumference of the rim member.

3. The in-wheel motor unit of claim 1 , wherein the motor part further comprises:

a stator installed at a position facing the rotor, and having magnetism; and

a motor housing configured to support the stator, and connected to the knuckle part and constrained from rotating.

4. The in-wheel motor unit of claim 3 , further comprising:

the rotor member fixed to the motor housing by a first fixing connection member, wherein the first fixing connection member is removed after the rotor member is fixed to the spoke; and

the spoke fixed to the motor housing, wherein a second fixing connection member is removed after the hub part is fixed to the spoke and wherein an increased degree of freedom in a configuration of the motor is determined based on the first fixing connection member and the second fixing connection member.

5. The in-wheel motor unit of claim 1 , wherein the hub part comprises:

a hub inner race connected to the spoke, and rotated with the spoke; and

a hub outer race located outside the hub inner race with a hub bearing interposed therebetween, and connected to the knuckle part and constrained from rotating.

6. The in-wheel motor unit of claim 5 , further comprising:

a resolver installed at a position facing the hub inner race, and configured to measure the position of the hub inner race; and

an inverter configured to receive the measurement value of the resolver, and installed inside the motor part.

7. The in-wheel motor unit of claim 1 , further comprising a brake part located inside the motor part, and configured to constrain the rotation of the spoke according to a control signal.

8. The in-wheel motor unit of claim 7 , wherein the brake part comprises:

a disk member fixed to the spoke, and rotated with the spoke; and

a caliper located inside the motor part, and moved in a direction to abut on the disk member in order to form a braking force.

9. The in-wheel motor unit of claim 1 , wherein a degree of freedom in design of the in-wheel motor unit is increased with respect to the suspension part.

10. The in-wheel motor unit of claim 1 , further comprising:

a first fixing connection member configured to fix the rotor member to the motor housing, wherein the first fixing connection member is removable after the rotor member is fixed to the spoke; and

a second fixing connection member configured to fix the spoke to the motor housing, wherein is the second fixing connection member is removable after the spoke is fixed to the motor housing.

11. An in-wheel motor unit comprising:

a rim member having a tire installed along an outer circumference thereof;

a spoke connected to the rim member and rotated with the rim member;

a motor part located in a mounting space formed by the rim member and the spoke, and configured to generate rotational power through power supply, and rotate the spoke, wherein the motor part comprises a motor housing and a first fixing connection member configured to fix a rotor member to the motor housing, and removed after the rotor member is fixed to the spoke; and

a hub part having one side fixed to the spoke and configured to rotatably support the spoke, wherein the in-wheel motor unit is unimpeded by the suspension part.

12. The in-wheel motor unit of claim 11 , further comprising a second fixing connection member configured to fix the spoke to the motor housing, and removed after the hub part is fixed to the spoke.

13. A method of forming an in-wheel motor unit comprising:

installing a tire along an outer circumference of a rim member;

connecting a spoke to the rim member, wherein the spoke is configured to be rotated with the rim member;

disposing a motor part in a mounting space formed by the rim member and the spoke, wherein the motor part is configured to generate rotational power through power supply, and rotate the spoke, wherein the disposing the motor part further comprises:

fixing a rotor member fixed to the spoke

removing a first fixing connection member; and

fixing a rotor to the rotor member;

connecting a knuckle part to the motor part, wherein the knuckle part is configured to support a suspension part; and

fixing one side of a hub part to the spoke and connecting the other side of hub part to the knuckle part, wherein the hub part is configured to rotatably support the spoke, and the in-wheel motor unit is unimpeded by the suspension part.