Actuator for shift-by-wire system

Patent metadata

Field	Value
Publication number	US-RE50673-E
Application number	US-202418584507-A
Country	US
Kind code	E1
Filing date	Feb 22, 2024
Priority date	Dec 12, 2019
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

An acuator for a shift-by-wire system includes a drive motor installed inside a motor housing, the drive motor having a drive shaft, and a decelerator inside a decelerator housing coupled with the motor housing, the decelerator coupled to the drive shaft. The decelerator includes a sun gear connected to a first side of an eccentric part of the drive shaft, a ring gear engaged with the sun gear and fixed to the decelerator housing, an output shaft connected to a second side of the eccentric part, a first bearing coupled to one side of the eccentric part and supporting the sun gear, a second bearing coupled to the other side of the eccentric part and supporting the output shaft, and a power delivery unit coupled to the sun gear and the output shaft in a center region between the first and second bearings.In an embodiment an actuator includes a drive motor installed inside a motor housing, wherein the drive motor includes a drive shaft having a driving part fixed to a rotor of the drive motor, an eccentric part integrally connected to the driving part at a position off a shaft center of the driving part, and an elongated part elongated from the eccentric part with respect to the shaft center, and a decelerator inside a decelerator housing coupled with the motor housing. The decelerator is eccentrically coupled to the drive shaft and includes a sun gear rotatably connected to the eccentric part, a ring gear engaged with the sun gear and fixed to the decelerator housing, an output shaft rotatably connected to the elongated part, a first bearing coupled to the eccentric part and supporting the sun gear, a second bearing coupled to the elongated part and a power delivery unit coupled to the sun gear and the output shaft in a center region between the first bearing and the second bearing.

First claim

What is claimed is:

1 . An actuator for a shift-by-wire system comprising:
a drive motor installed inside a motor housing, the drive motor having comprising:
a rotor, and
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;
a first bearing coupled to one side of the eccentric part and supporting the sun gear;
a second bearing coupled to another side of the eccentric part the elongated part and supporting the output shaft; and
a power delivery unit coupled to the sun gear and the output shaft in a center region between the first bearing and the second bearing, wherein the power delivery unit includes radial groove parts radially formed arranged along a radial direction at an edge part of one 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 flange 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 shaft; and
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.

2 . The actuator for the shift-by-wire system of claim 1 , wherein the radial groove parts and the radial protrusions are disposed to be mutually overlapped overlap in the center region between the first bearing and the second bearing.

3 . The actuator for the shift-by-wire system of claim 1 , wherein the power delivery unit further includes crown parts formed radially along a radial direction between the radial groove parts of the sun gear.

4 . The actuator for the shift-by-wire system of claim 3 1 , further comprising arc surfaces of predetermined curvatures, wherein the crown parts form aneach arc surface of a predetermined curvature at a part in contact with the radial protrusion in thethe arc surfaces connects a respective crown part of the crown parts to a respective radial groove part of the radial groove parts.

5 . The actuator for the shift-by-wire system of claim 4 , wherein theeach radial protrusion of the radial protrusions is in contact in a normal direction to thewith a respective arc surface of the arc surfaces along a rotating direction of the output shaft.

6 . The actuator for the shift-by-wire system of claim 5 , wherein the respective radial groove part and thea respective radial protrusion of the radial protrusions are configured to transmit a rotation torque of a normal direction to the output shaft through the sun gear in the center region between the first bearing and the second bearing.

7 . The actuator for the shift-by-wire system of claim 1 , wherein a lubricant filled part filled with a lubricant is provided between the flange part and the supporting part.

8 . The actuator for the shift-by-wire system of claim 7 , wherein:
the sun gear includes crown parts formed between the radial groove parts; and a lubricant flow groove connected with the lubricant filled part is formed in the crown parts.

9 . The actuator for the shift-by-wire system of claim 1 , wherein the output shaft further includes a cover part is integrally connected with the flange part and the radial protrusion protrusions.

10 . 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.

11 . The actuator for the shift-by-wire system of claim 10 , wherein the radial groove parts and the radial protrusions are provided to be in contact along a rotating direction of the output shaft in a normal direction.

12 . The actuator for the shift-by-wire system of claim 10 , wherein the sun gear further includes crown parts radially formed along a radial direction between the radial groove parts of the sun gear.

13 . The actuator for the shift-by-wire system of claim 12 , 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 the crown parts form a second circular arc of a seco

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp
• Kyung Chang Ind Co Ltd

Inventors

• Cho Yang Rae
• Lee Byoung Hyuk
• Jeong Wonjin
• Kim Kyu-Jung
• Hyun Ki Cheol
• Kim Dae Yeon

Classifications

• F16H57/08

  of gearings with members having orbital motion · CPC title

• F16H2061/323

  for power assistance, i.e. servos with follow up action · CPC title

• F16H2001/327

  with the orbital gear having internal gear teeth · CPC title

• F16H57/021 Primary

  Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings · CPC title

• F16H2057/085

  Bearings for orbital gears · CPC title