Rack-assist-type electric power steering apparatus
A rack-assist-type electric power steering apparatus may include: a motor pulley provided on or coupled to a shaft of a motor; a nut pulley provided on or coupled to an outer circumferential surface of a ball nut coupled to a rack bar via a ball; a belt coupled to the motor pulley and the nut pulley, the belt comprising provided with one or more first magnetic bodies; and a rack housing enclosing or housing at least a portion of the motor pulley, the nut pulley and the belt are housed. The rack housing may comprise one or more second magnetic bodies provided on an inner circumferential surface thereof facing or opposite to the belt. Alternatively, the rack housing may comprise a support portion protruding from an inner surface of the rack housing, and one or more second magnetic bodies may be provided on a surface of the support portion.
1. An electric power steering apparatus comprising:
a motor pulley provided on a shaft of a motor;
a nut pulley provided on an outer surface of a ball nut coupled to a rack bar via a ball;
a belt coupled to the motor pulley and the nut pulley, the belt comprising at least one first magnetic body; and
a rack housing enclosing at least a portion of the motor pulley, the nut pulley and the belt, the rack housing comprising at least one second magnetic body, wherein the at least one second magnetic body is provided on a surface of the rack housing facing the belt.
2. The electric power steering apparatus of claim 1 , wherein the at least one first magnetic body and the at least one second magnetic body facing each other have different magnetisms.
3. The electric power steering apparatus of claim 1 , wherein the at least one first magnetic body is provided over an entire outer surface of the belt.
4. The electric power steering apparatus of claim 1 , wherein the at least one first magnetic body comprises a plurality of first magnetic bodies, and the plurality of first magnetic bodies are provided along an outer surface of the belt and spaced apart from each other.
5. The electric power steering apparatus of claim 1 , wherein the at least one second magnetic body is provided on an inner surface of the rack housing between the motor pulley and the nut pulley.
6. The electric power steering apparatus of claim 5 , wherein the at least one second magnetic body comprises a plurality of second magnetic bodies, and the plurality of second magnetic bodies are disposed symmetrically with respect to a plane connecting center axes of the motor pulley and the nut pulley.
7. The rack-assist-type electric power steering apparatus of claim 1 , wherein the at least one second magnetic body is positioned in a middle between a first contact portion, in which the outer surface of the motor pulley starts to come into contact with an inner surface of the belt, and a second contact portion, in which the outer surface of the nut pulley and the inner surface of the belt start to come into contact with each other.
8. The electric power steering apparatus of claim 7 , wherein the at least one second magnetic body comprises a plurality of second magnetic bodies, and the plurality of second magnetic bodies are disposed symmetrically with respect to a plane connecting center axes of the motor pulley and the nut pulley.
9. An electric power steering apparatus comprising:
a motor provided on a shaft of a motor;
a nut pulley provided on an outer surface of a ball nut coupled to a rack bar via a ball;
a belt coupled to the motor pulley and the nut pulley, the belt comprising at least one first magnetic body; and
a rack housing enclosing at least a portion of the motor pulley, the nut pulley and the belt, the rack housing comprising a support portion protruding from an inner surface of the rack housing between the motor pulley and the nut pulley, the support portion comprising at least one second magnetic body, wherein the second magnetic body is provided on a surface of the support portion of the rack housing facing the belt.
10. The electric power steering apparatus of claim 9 , wherein the at least one first magnetic body and the at least one second magnetic body facing each other have a same magnetism.
11. The electric power steering apparatus of claim 9 , wherein the first magnetic body is provided over an entire outer surface of the belt.
12. The electric power steering apparatus of claim 9 , wherein the least one first magnetic body comprises a plurality of first magnetic bodies, and the plurality of first magnetic bodies are provided along an outer surface of the belt and spaced apart from each other.
13. The electric power steering apparatus of claim 9 , wherein the support portion is positioned in a middle between the motor pulley and the nut pulley.
14. The electric power steering apparatus of claim 9 , wherein the support portion has a symmetrical shape with respect to a plane connecting center axes of the motor pulley and the nut pulley.
15. The electric power steering apparatus of claim 9 , wherein the at least one second magnetic body is provided in a middle between a first contact portion, in which an outer surface of the motor pulley starts to come into contact with an inner surface of the belt, and a second contact portion, in which an outer surface of the nut pulley and the inner surface of the belt start to come into contact with each other.