KR20150123533A - Motor coupling for electric power steering apparatus - Google Patents

Abstract

A motor coupling, which connects a motor output shaft and a worm shaft of an electric power steering apparatus, comprises: a first member formed to be connected to the motor output shaft to be rotated along with the motor output shaft, and having a body unit and a plurality of coupling protrusions protruding radially outward from the body unit; a second member formed to be connected to the worm shaft to be rotated along with the worm shaft, forming an accommodating space to accommodate the body unit, and having an accommodating groove into which the coupling protrusions are individually inserted; a first damping member installed in the body unit; and a plurality of second damping members individually installed in the coupling protrusions.

Description

[0001] The present invention relates to a motor coupling for an electric power steering apparatus,

The present invention relates to a motor coupling for connecting a motor and a worm shaft of an electric power steering device.

There is known an electric power steering apparatus that assists a steering force of a vehicle by using a driving force of a motor. An electric power steering device of a column type has been disclosed in which an electric power of a motor is transmitted to a steering shaft such as a steering column in an electric power steering device to assist a steering force.

An electric power steering device generally operates to drive a motor according to vehicle driving conditions such as a vehicle speed sensor and a steering torque sensor to assist a steering force and improve a steering feeling.

In a column type electric power steering apparatus, a worm gear is provided on a worm shaft connected to an output shaft of a motor, and a worm wheel is provided on a steering shaft so that the worm wheel is gear-meshed with each other so that the driving force of the motor can be transmitted to the steering shaft.

At this time, a motor coupling is provided between the warm shaft and the output shaft of the motor to transmit the power. Generally, the motor coupling is required to have a damping function for shock absorption and a function for preventing the shift of the shaft center. Conventional motor coupling has a problem in that it can not sufficiently satisfy these required functions.

Patent Document 1: JP-A-10-0030199

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a motor coupling of an electric power steering device having an excellent shock absorbing and anti-shaft deviation prevention function.

The motor coupling for connecting the motor output shaft and the warm shaft of the electric power steering apparatus according to the embodiment of the present invention is formed to be connected to the motor output shaft so as to rotate together with the motor output shaft and includes a body portion, A first member including a plurality of fastening protrusions projecting outwardly, a receiving space formed to be connected to the warm shaft so as to rotate together with the warm shaft, and a receiving space for accommodating the body portion is formed, and the plurality of fastening protrusions A second member including a receiving groove, a first damping member provided on the body portion, and a plurality of second damping members provided on the plurality of fastening protrusions.

The first damping member may be provided so as to be in contact with the inner surface forming the accommodation space in a circumferential direction so as to allow radial damping.

The receiving groove may be formed by being recessed from the side facing the first member, and the second damping member may be formed in an inner surface forming the receiving groove so as to be circumferentially damped and axially damped, Respectively.

The second damping member may have a ring shape covering only a part of the fastening protrusion in a radial direction.

According to the present invention, by providing a first damping member that provides radial damping and a second damping member that provides axial and circumferential damping, the motor coupling is capable of axial and circumferential damping action, The center shift can be effectively compensated.

1 is a schematic perspective view of an electric power steering apparatus to which motor coupling of an electric power steering apparatus according to an embodiment of the present invention is applied.
2 is a partial cross-sectional view showing a state in which a motor coupling of an electric power steering device according to an embodiment of the present invention is mounted.
3 is a perspective view of a motor coupling of an electric power steering device according to an embodiment of the present invention.
4 is a perspective view of a first member of a motor coupling of an electric power steering device according to an embodiment of the present invention.
5 is a perspective view of a second member of a motor coupling of an electric power steering device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The motor coupling 100 according to the embodiment of the present invention can be applied to an electric power steering apparatus of a vehicle.

1 and 2, an electric power steering apparatus is formed so that power of the motor 20 can be transmitted to the steering shaft 1. [

The electric power steering apparatus has a worm shaft 10 that is rotated by the power of the motor 20. [ The worm shaft 10 is engaged with the worm wheel 3 including the worm gear 11 and formed on the steering shaft 1. [ At this time, the worm shaft 10 is installed in the housing 40.

The motor coupling 100 according to the embodiment of the present invention connects the motor output shaft 21 and the worm shaft 10. The motor coupling 100 is coupled to the output shaft 21 of the motor 20 and the worm shaft 10 to transmit the power of the motor 20 to the worm shaft 10. The worm shaft 10 can be connected to the output shaft 21 of the motor 20 through the motor coupling 100 in a concentric manner.

The motor coupling 100 according to the embodiment of the present invention includes first and second members 110 and 130 fastened to each other to transmit power.

The first member 110 is formed so as to be connected to the motor output shaft 21 so as to rotate together with the motor output shaft 21. For example, a through hole 111 is formed in the first member 110 in the axial direction, and a motor output shaft 21 is inserted into the through hole 111 and is splined to the first member 110, The output shafts 21 can be connected to each other to rotate together.

Referring to FIGS. 3 and 4, the first member 110 may include a body portion 113 and a plurality of fastening protrusions 115. The body portion 113 is a portion where the through hole 111 described above is formed and the plurality of fastening protrusions 115 may protrude radially outward from the outer surface of the body portion 113. The fastening protrusions 115 may be four as shown in the figure, but the number is not limited thereto. The plurality of fastening protrusions 115 may be radially arranged so as to be equally spaced along the circumferential direction. At this time, the plurality of fastening protrusions 115 may be arranged at different intervals.

The second member 130 is formed to be connectable to the worm shaft 10 to rotate with the worm shaft 10. For example, the through hole 131 is formed in the second member 130 in the axial direction, and the worm shaft 10 is inserted into the through hole 131 and spline coupled to the second member 130 and the worm shaft 10 Can rotate together.

Referring to FIGS. 3 and 5, the second member 130 defines a receiving space 133 for receiving the body portion 113 of the first member 110. The accommodation space 133 may be formed by being recessed from the side facing the motor 20 toward the side facing the warm shaft 10. 3, the first member 110 and the second member 130 are inserted into the receiving space 133 of the second member 130 so that they can be fastened to each other.

The second member 130 includes a plurality of receiving grooves 135 into which the plurality of fastening protrusions 115 of the first member 110 are inserted, respectively. The receiving groove 135 may be formed in a position and size corresponding to the fastening protrusion 115.

As shown in the figure, the second member 130 may be composed of two portions 132, 134 having a substantially cylindrical shape. At this time, the through hole 131 may be formed in the small diameter portion 132 in the axial direction, and the receiving space 133 and the receiving groove 135 may be formed in the large diameter portion 134.

The rotational force of the motor 20 is transmitted to the first member 110 by the fastening protrusions 115 of the first member 110 being inserted into the receiving grooves 135 of the second member 130, To the second member (130).

As shown in FIG. 4, the first damping member 117 may be installed on the body portion 113. For example, the first damping member 117 may have a ring shape surrounding the body portion 113 and may be formed of an elastic material such as a rubber.

At this time, the first damping member 117 is installed so as to make contact with the inner surface 136 forming the receiving space 133 of the second member 130 in the circumferential direction so as to allow radial damping. Here, the radial direction means a direction perpendicular to the axial direction of the motor output shaft 21 and the warm shaft 10. When the axis of the motor output shaft 21 and the shaft of the worm shaft 10 are displaced due to the radial damping by the first damper member 117, it can be returned to the predetermined original position, It is possible to absorb the rotational force and compensate the shift of the transmission shaft center.

3 and 4, a plurality of second damping members 119 may be installed on the plurality of fastening protrusions 115, respectively. For example, the second damping member 119 may have a ring shape surrounding the fastening protrusion 115, and may be formed of an elastic material such as rubber.

At this time, the second damping member 119 is installed so as to be in contact with the inner surfaces 135a and 135b forming the receiving groove 135 in the circumferential direction and the axial direction, respectively, so that the damping member 119 can be circumferentially do. 5, the second damping member 119 is in contact with the axially-disposed inner surface 135a of the receiving groove 135 and at the same time the inner surface 135b of the receiving groove 135 disposed in the circumferential direction of the receiving groove 135 As shown in Fig. Circumferential and axial damping can be achieved by this second damping member 119.

At this time, when the second damping member 119 is formed in a ring shape that only partially covers the fastening protrusion 115 in the radial direction, when the relative rotation or movement between the first member 110 and the second member 130 is small The damping is performed by the second damping member 119. When the relative rotation or movement between the first member 110 and the second member 130 is large, The inner surfaces 135a and 135b forming the receiving grooves 135 of the inner tube 135 directly bump into each other. Accordingly, damping by the damping member 119 or shock absorption by the direct contact between the first member 110 and the second member 130 can be selectively performed according to the magnitude of the rotational impact transmitted.

By providing the first member 110 with the first and second damping members 117 and 119, axial and circumferential damping is possible, and it is possible to compensate for displacement of the axis center.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And all changes and modifications to the scope of the invention.

1: Steering shaft
10: Worm shaft
20: Motor
21: Motor output shaft
100: Motor coupling
110: first member
111: Through hole
113:
115: fastening projection
130: second member
131: Through hole
133: accommodation space
135: receiving groove
117: first damping member
119: second damping member

Claims (4)

A motor coupling coupling a motor output shaft and a warm shaft of an electric power steering device,
A first member including a body portion and a plurality of fastening protrusions protruding radially outward from the body portion, the first member being connectable to the motor output shaft so as to rotate together with the motor output shaft,
A second member including a receiving groove formed in a receiving space for receiving the body portion and connected to the worm shaft so as to rotate together with the worm shaft,
A first damping member installed on the body portion, and
And a plurality of second damping members respectively installed on the plurality of fastening protrusions. The method of claim 1,
Wherein the first damping member is installed so as to be in contact with the inner surface forming the accommodation space in the circumferential direction so as to allow radial damping. 3. The method according to claim 1 or 2,
Wherein the receiving groove is recessed from a side facing the first member,
And the second damping member is installed so as to be in contact with the inner surface forming the receiving groove in the circumferential direction and the axial direction, respectively, so that circumferential damping and axial damping can be effected. The method of claim 1,
And the second damping member has a ring shape covering only a part of the fastening projection in a radial direction.

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