Reducer including planetary gear and steering apparatus for vehicle including the same

1. A reducer for a steering apparatus of a vehicle comprising:

a sun gear coupled to a hollow motor shaft;

a plurality of first planet gears circumscribed about the sun gear and inscribed in a first ring gear that is coupled and fixed to an inner peripheral surface of a housing;

a plurality of second planet gears inscribed in a second ring gear to which a pinion shaft, which is inserted into the hollow motor shaft, is coupled, the plurality of second planet gears being connected to the first planet gears via connecting shafts;

a carrier, through which the pinion shaft passes, having coupling holes such that the connecting shafts pass through and are coupled to the coupling holes, in which a distance from the center of the carrier to the center of a first coupling hole of the coupling holes and a distance from the center of the carrier to the centers of the remaining coupling holes are different; and

a first resilient member coupled between a first connecting shaft among the connecting shafts and the first coupling hole,

wherein the first connecting shaft is inserted into the first coupling hole.

2. The reducer of claim 1 , further comprising a second resilient member coupled between a second connecting shaft among the connecting shafts and a second coupling hole of the coupling holes,

wherein the second connecting shaft is inserted into the second coupling hole.

3. The reducer of claim 2 , wherein a plurality of protrusions protruding radially to the outside are formed on an outer surface of one or both of the first resilient member and the second resilient member.

4. The reducer of claim 3 , wherein the protrusions are circumferentially spaced apart from each other at an equal separation.

5. The reducer of claim 2 , wherein the carrier has a plurality of protrusion supports protruding radially and circumferentially formed on an outer peripheral surface thereof, and the coupling holes are formed in the protrusion supports, respectively.

6. The reducer of claim 5 , wherein a cutaway portion is formed in the protrusion supports to be opened to a radial outer side and opposite circumferential sides, and the second planet gear may be provided in the cutaway portion.

7. A reducer for a steering apparatus of a vehicle, the reducer comprising:

a sun gear coupled to a hollow motor shaft;

a plurality of first planet gears circumscribed about the sun gear and inscribed in a first ring gear that is coupled and fixed to an inner peripheral surface of a housing;

a plurality of second planet gears inscribed in a second ring gear to which a pinion shaft, which is inserted into the hollow motor shaft, is coupled, the plurality of second planet gears being connected to the first planet gears via connecting shafts;

a carrier, through which the pinion shaft passes, having coupling holes such that the connecting shafts pass through and are coupled to the coupling holes; and

a first resilient member coupled between a first connecting shaft of the connecting shafts and a first coupling hole among the coupling holes inside the first coupling hole, for providing a resilient support force in a radial direction of the carrier,

wherein a thickness of the first resilient member facing an inside of the carrier is different from a thickness in an opposite direction such that the first resilient member provides a resilient support force to the first connecting shaft inside the first coupling hole in a radial direction.

8. The reducer of claim 7 , wherein a second resilient member coupled between a second connecting shaft of the connecting shafts and a second coupling hole among the coupling holes, for providing a resilient support force in a circumferential direction of the carrier.

9. The reducer of claim 8 , wherein the carrier has a plurality of protrusion supports protruding radially and circumferentially formed on an outer peripheral surface thereof, and the coupling holes are formed in the protrusion supports, respectively.

10. The reducer of claim 9 , wherein a cutaway portion is formed in the protrusion supports to be opened to a radial outer side and opposite circumferential sides, and the second planet gears are provided in the cutaway portion.

11. The reducer of claim 7 , wherein a thickness of one of opposite sides of a second resilient member facing a circumferential direction of the carrier is different from a thickness of the other side such that the second resilient member provides a resilient support force to the second connecting shaft inside a second coupling hole circumferentially.

12. A steering apparatus of a vehicle, comprising:

a motor comprising a motor housing and a hollow motor shaft;

an input shaft connected to a steering shaft and connected to a pinion shaft via a torsion bar; and

a reducer including a planetary gear set in a housing which is coupled to the motor housing to transfer rotation power of the motor to the pinion shaft,

wherein the reducer comprises:

a sun gear coupled to the hollow motor shaft;

a plurality of first planet gears circumscribed about the sun gear and inscribed in a first ring gear that is coupled and fixed to an inner peripheral surface of the housing;

a plurality of second planet gears inscribed in a second ring gear to which the pinion shaft, which is inserted into the hollow motor shaft, is coupled, the plurality of second planet gears being connected to the first planet gears via connecting shafts;

a carrier, through which the pinion shaft passes, having coupling holes such that the connecting shafts pass through and are coupled to the coupling holes, in which a distance from the center of the carrier to the center of a first coupling hole of the coupling holes and a distance from the center of the carrier to the centers of the remaining coupling holes are different; and

a first resilient member coupled between a first connecting shaft among the connecting shafts and the first coupling hole,

wherein the first connecting shaft is inserted into the first coupling hole.