Actuator for shift-by-wire system

An actuator for a shift-by-wire system comprising:

• a drive motor installed inside a motor housing, the drive motor having comprising:
• a rotor;
• a drive shaft comprising a driving part having a central axis of rotation, an eccentric part and an elongated part,
• wherein the driving part is fixed to the rotor,
• wherein the eccentric part is integrally connected to the driving part at a position off the central axis of rotation, and
• wherein the elongated part is elongated with respect to the central axis of rotation from the eccentric part;
• and
• a decelerator inside a decelerator housing coupled with the motor housing, the decelerator eccentrically coupled to the drive shaft , the decelerator and including:
• a sun gear rotatably connected to a first side of an the eccentric part of the drive shaft;
• a ring gear engaged with the sun gear and fixed to the decelerator housing;
• an output shaft rotatably connected to a second side of the eccentric part the elongated part, wherein the output shaft integrally forms a flange part orthogonal to a shaft direction;
• and
• radial groove parts radially formed arranged along a radial direction at an edge part of one side surface of the sun gear corresponding to the output shaft and radial protrusions formed to be protruded protruding along a radial direction at an edge part of the output shaft and coupled to the radial groove parts with a predetermined gap and ,
• wherein the sun gear further includes a supporting part connected to the radial groove parts and supporting the flange part of the output shaftand
• a lubricant filled part filled with a lubricant and arranged between the flange part and the supporting part,
• wherein the sun gear further includes crown parts arranged between the radial groove parts,
• wherein a lubricant flow groove connected with the lubricant filled part is arranged in the crown parts and sealed by a cover part of the output shaft,
• wherein the lubricant flow groove is arranged on upper surfaces of the crown parts along a rotational direction of the sun gear, and
• wherein, during a phase movement of the sun gear, the lubricant filled in the lubricant filled part is circulatable through the lubricant flow groove to an adjacent radial groove part.

An actuator for a shift-by-wire system comprising:

• a drive motor installed inside a motor housing, the drive motor having comprising:
• a drive shaft comprising a driving part having a central axis of rotation, an eccentric part and an elongated part,
• wherein the driving part is fixed to a rotor,
• wherein the eccentric part is integrally connected to the driving part at a position off the central axis of rotation, and
• wherein the elongated part is elongated with respect to the central axis of rotation from the eccentric part;
• and
• a decelerator inside a decelerator housing coupled with the motor housing, the decelerator eccentrically coupled to the drive shaft , the decelerator and including:
• a sun gear rotatably connected to a first side of an the eccentric part of the drive shaft;
• a ring gear engaged with the sun gear and fixed to the decelerator housing;
• an output shaft rotatably connected to a second side of the eccentric partthe elongated part;
• and
• radial groove parts radially formed arranged along a radial direction at an edge part of one side surface of the sun gear corresponding to the output shaft and radial protrusions formed to be protruded protruding along a radial direction at an edge part of the output shaft and coupled to the radial groove parts with a predetermined gap;,
• wherein the sun gear further includes crown parts radially formed arranged along a radial direction between the radial groove parts of the sun gear;,
• wherein the radial groove forms a first circular arc of a first predetermined curvature extending from an inner wall to an end side of the crown parts;
• and
• wherein the crown parts form a second circular arc of a second predetermined curvature from the end side toward an edge end side of the sun gear
• wherein a lubricant filled part is filled with a lubricant and arranged between a flange part of the output shaft and a supporting part of the sun gear,
• wherein a lubricant flow groove connected with the lubricant filled part is arranged in the crown parts and sealed by a cover part of the output shaft,
• wherein the lubricant flow groove is arranged on upper surfaces of the crown parts along a rotational direction of the sun gear, and
• wherein, during a phase movement of the sun gear, the lubricant filled in the lubricant filled part is circulatable through the lubricant flow groove to an adjacent radial groove part.