KR20190104806A - A Motor-Driven Power Steering Apparatus - Google Patents

Abstract

The present invention provides a motor-driven power steering device, capable of preventing noise due to a gap between a worm wheel and a worm shaft from being transferred to a housing when large reaction is transferred to a steering shaft when rapidly changing the direction of a steering wheel of a vehicle. According to the present invention, the motor-driven power steering device comprises: the housing (140); the worm wheel (3) connected to the steering shaft (1) by being installed to rotate in the housing (140); the worm shaft (110) installed in the housing (140) to rotate and including a worm (111) engaged with the worm wheel (3); a support bearing (113) and a tilt bearing (115), supporting the worm shaft (110) to rotate on the housing (140) by being installed in the housing (140) by being installed on both sides of the worm (111); and a driving motor (120) connected to the housing (140), wherein a rotation shaft (121) is connected to the worm shaft (110) by a coupling (130). The tilt bearing (115) is installed between the worm (111) and the coupling (130), and the support bearing (113) is installed on an opposite side of the tilt bearing (115) across the worm (111). The tilt bearing (115) comprises: a ring-shaped inner wheel (115-1) having an inner wheel track on the outer circumference, wherein the worm shaft (110) is inserted into the inner wheel (115-1); a ring-shaped outer wheel (115-2) having an outer wheel track on the inner circumference and installed on the outer side in a radial direction of the inner wheel (115-1); and multiple motor-driven bodies (115-3) arranged in a circumferential direction between the inner wheel track and the outer wheel track. A tilting shock absorbing unit is installed in the housing (140) on the outer wheel (115-2), and the outer wheel (115-2) is inserted into the tilting shock absorbing unit.

Description

Electric Power Steering Apparatus {A Motor-Driven Power Steering Apparatus}

The present invention relates to an electric power steering device, which can sufficiently absorb the axial flow of the worm shaft and the vertical flow of the worm shaft with respect to the worm wheel, and the reaction force between the worm wheel and the worm shaft is generated to prevent noise caused by play. felled It relates to an electric power steering device.

The electric power steering apparatus assists the steering force of the vehicle by using the driving force of the motor.

In general, the electric power steering device operates to assist the steering power and improve the steering feeling by driving the motor according to the driving conditions of the vehicle such as a vehicle speed sensor and a steering torque sensor. Among the electric power steering devices, the column type electric power steering device transmits the driving force of the motor to the steering shaft by installing a worm gear on the worm shaft connected to the output shaft of the motor and installing a worm wheel on the steering shaft so that both are geared together. To be possible. Such a column type electric power steering device may increase backlash due to play due to wear of gears, manufacturing tolerances, and the like, and thus vibration or noise may occur. In order to solve this problem, an electric power steering device having a tilting structure for compensating play due to wear by tilting the worm shaft in the direction of the worm wheel has been introduced.

1 is a perspective view showing a conventional electric power steering apparatus, Figure 2 is a partial cross-sectional view of a conventional electric power steering apparatus. 1 and 2, the drive motor 20 of the electric power steering device generates a steering assistance force, and is formed to transmit the power of the drive motor 20 to the steering shaft (1).

The worm shaft 10 is rotated by the power of the drive motor 20 is provided. The worm shaft 10 includes a worm 11, and the worm 11 meshes with a worm wheel 3 provided in the steering shaft 1. At this time, the worm shaft 10 is installed in the housing 40.

The coupling 30 connects the rotation shaft 21 and the worm shaft 10. The coupling 30 is coupled to the rotation shaft 21 and the worm shaft 10 of the motor 20, respectively, and performs a function of transmitting the power of the driving motor 20 to the worm shaft 10. The worm shaft 10 may be concentrically connected to the rotation shaft 21 of the motor 20 through the coupling 30.

A tilting structure 50 is provided to provide the worm shaft 10 with a force for tilting the worm shaft 10 in the direction of the worm wheel 3 so that the play between the worm 11 and the worm wheel 3 can be absorbed. . For example, the tilting structure 50 may be formed to support the outer surface of the bearing supporting one end of the worm shaft 10. At this time, the worm shaft 10 may be supported in a rotatable state by two bearings disposed at both ends thereof, and the tilting structure 50 supports a bearing farther from the driving motor 20 among these two bearings. Can be installed.

By elastically supporting the bearing supporting the worm shaft 10 in the direction toward the worm wheel 3, the tilting structure 50 can compensate for the play between the worm 11 and the worm wheel 13.

However, the conventional electric power steering device has a problem in that it installs a separate damping device for tilting absorption, but cannot sufficiently absorb the axial flow of the worm shaft and the up and down flow of the worm shaft with respect to the worm wheel. To this end, when the steering wheel is sharply rotated, when a large reaction force is transmitted to the steering shaft, there is a problem in that a reaction force is generated between the worm wheel and the worm shaft to generate noise due to play.

Korean Patent Publication No. 10-2013-0003312

The present invention has been proposed to solve the above problems, and when the direction of the car handle is sharply changed, noise caused by play between the worm wheel and the worm shaft can be prevented from being transmitted to the housing when a large reaction force is transmitted to the steering shaft. An object of the present invention is to provide an electric power steering apparatus.

To this end, the present invention provides a housing, a worm shaft rotatably provided in the housing and a worm wheel coupled to a steering shaft, and a worm shaft rotatably provided in the housing and engaged with the worm wheel. It is composed of a support bearing and a tilt bearing which is provided in the housing and located on both sides of the worm to rotatably support the worm shaft with respect to the housing, and a driving motor connected to the worm shaft by a rotation shaft and coupled to the housing. ; The tilt bearing is located between the worm and the coupling, and the support bearing is located opposite the tilt bearing with the worm in between; The tilt bearing has a ring-shaped inner ring in which a worm shaft is inserted and an inner ring raceway is formed on an outer diameter surface, and a ring-shaped outer ring formed on an outer diameter of the inner ring and formed with an outer ring raceway on an inner diameter surface, between the inner ring track and the outer ring track. It consists of a plurality of rolling elements arranged along the circumferential direction; The outer ring is provided to the outside of the outer ring is provided with an electric power steering device further comprises a tilting buffer installed in the housing.

In the above, the tilting buffer portion is a ring-shaped ring of the outer ring is inserted, the ring-shaped buffer member is inserted into the outer ring surface of the ring is inserted, the outer surface of the buffer member and the outer surface of both sides of the width surrounding the buffer member A ring-shaped support member; The outer surface of the outer ring is formed in a curved shape in which the outer diameter decreases toward both sides from the center of the width direction to form a spherical surface, the inner surface of the ring is concave curved formed along the width direction to form a spherical surface; The radius of curvature of the inner surface of the guard ring is formed larger than the radius of curvature of the outer ring outer surface, characterized in that the outer surface of the outer ring is in contact with the inner surface of the guard ring.

In the above, the ring is formed on both sides in the width direction outwardly and has a radially outwardly projecting outwardly projecting portion, the buffer member is provided on the outer diameter surface of the outwardly projecting portion; The support member is characterized by consisting of a cylindrical support body surrounding the outer diameter surface of the shock absorbing member and an annular side support portion bent radially inward from both sides of the support body to cover the side portion of the shock absorbing member and a side portion of the outward protrusion. .

In the above, the ring is formed on both sides in the width direction outwardly and has a radially outwardly projecting outwardly projecting portion, the support member is a cylindrical support body surrounding the outer diameter surface of the outwardly projecting portion and one side in the width direction of the support body An annular side support portion bent inwardly to cover one side surface of the outward protrusion, and an annular first side support portion bent outwardly from the other side in the width direction of the support body; The buffer member surrounds the outer diameter surface of the support body and has one end portion in the width direction in contact with the first side support portion; The outer diameter of the shock absorbing member is larger than the first side support, characterized in that the contact with the inner surface of the housing.

In the above, the tilting shock-absorbing portion is formed of a ring-shaped ring member in which the outer ring is inserted, and a ring-shaped buffer member provided on the outer diameter surface of the ring ring in which the ring is inserted. The widthwise sides of the cushioning member and the guard ring are provided in contact with the jaw surface of the housing; The outer surface of the outer ring is formed in a curved shape in which the outer diameter decreases toward both sides from the center of the width direction to form a spherical surface, the inner surface of the ring is concave curved formed along the width direction to form a spherical surface; The radius of curvature of the inner surface of the guard ring is formed larger than the radius of curvature of the outer ring outer surface, characterized in that the outer surface of the outer ring is in contact with the inner surface of the guard ring.

In the above, the guard ring forms a jaw surface outwardly on both sides in the width direction, and an outwardly projecting portion projecting outward in the radial direction and a jaw surface outwardly extending on both sides in the width direction of the outward protrusion and extending outwardly in the radial direction from the outwardly projecting portion. With; The support member and the buffer member are provided symmetrically on both sides in the width direction with the outward protrusion and the second outward protrusion interposed therebetween; The buffer member is composed of a buffer body which is inserted into the jaw surface of the outward projection portion and is in contact with the width surface of the second outward projection portion, and a buffer body extending radially inward in the width direction outside of the buffer body to contact the width surface of the outward projection portion; The support member is positioned between the buffer member and the watch ring is coupled to the buffer member and provided with a cylindrical support body provided in contact with the jaw surface of the outward protrusion, and radially inwardly bent at the widthwise outer end of the support body to the width surface of the outward protrusion. The side support portion is in contact with the radially outward bending at the inner side of the width direction of the support body is inserted into the buffer member, characterized in that consisting of a support protrusion parallel to the width of the outward protrusion.

In the above, the ring is formed with a jaw surface outwardly on both sides in the width direction and provided with an outwardly projecting portion projecting outward in the radial direction; The support member and the buffer member are provided symmetrically on both sides in the width direction with the outward protrusion therebetween; The buffer member includes a cylindrical buffer body into which the outward protrusion is inserted, and a side buffer part radially inwardly extending from the outer end in the width direction of the buffer body to contact the width face of the outward protrusion; The support member is positioned between the buffer member and the watch ring is coupled to the buffer member and provided with a cylindrical support body provided in contact with the outer diameter surface of the outward projection portion, the radially inwardly bent at the outer end in the width direction from the support body to the width surface of the outward projection portion Characterized in that it consists of a side support portion in contact with.

In the above, the ring is formed with a jaw surface outwardly on both sides in the width direction and provided with an outwardly projecting portion projecting outward in the radial direction; The support member and the buffer member are provided symmetrically on both sides in the width direction with the outward protrusion therebetween; The buffer member includes a cylindrical buffer body into which the outward protrusion is inserted, and an annular side buffer portion extending radially inward from the width direction outside of the buffer body to contact the width surface of the outward protrusion; The support member is composed of a cylindrical support body that surrounds the outer diameter surface of the buffer member in a bent form, and a side support portion that is bent radially inward in the widthwise outer end of the support body to surround the width surface of the buffer member; The side buffer portion is provided to surround the end portion and the outer surface portion of the side support portion is characterized in that the width surface of the portion surrounding the side support portion protrudes outward than the width surface of the ring.

According to the electric power steering apparatus according to the present invention, it is possible to sufficiently absorb the axial flow of the worm shaft and the vertical flow of the worm shaft with respect to the worm wheel, and a large reaction force generated while the automobile steering wheel is rapidly rotated is transmitted to the steering shaft. At this time, there is an effect that can prevent the occurrence of play noise by the reaction force between the worm wheel and the worm shaft.

1 is a perspective view showing a conventional electric power steering device,
2 is a partial cross-sectional view of a conventional electric power steering apparatus,
3 is a partial cross-sectional view of the electric power steering apparatus of the present invention,
4 is an enlarged partial cross-sectional view of a portion A of FIG.
5 is an enlarged partial cross-sectional view of portion A of FIG. 3 according to a modification of the present invention;
6 is an enlarged partial cross-sectional view of a portion A of FIG. 3 according to a second modified example of the present invention;
7 is an enlarged partial cross-sectional view of a portion A of FIG. 3 according to a third modified example of the present invention;
8 is an enlarged cross-sectional view of a portion A of FIG. 3 according to a fourth modified example of the present invention;
9 is an enlarged cross-sectional view of a portion A of FIG. 3 according to a fifth modified example of the present invention.

Hereinafter, an electric power steering apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In the detailed description, description of the contents described in the prior art will be omitted.

3 is a partial cross-sectional view of the electric power steering apparatus of the present invention, FIG. 4 is a partial cross-sectional view showing an enlarged portion A of FIG. 3, and FIG. 5 is an enlarged view of a portion A of FIG. 3 according to a modification of the present invention. 6 is an enlarged cross-sectional view of a portion A of FIG. 3 according to a second modified example of the present invention, and FIG. 7 is an enlarged cross-sectional view of a portion A of FIG. 3 according to a third modified example of the present invention. 8 is an enlarged partial cross-sectional view of part A of FIG. 3 according to a fourth modified example of the present invention, and FIG. 9 is an enlarged partial cross-sectional view of part A of FIG. 3 according to a fifth modified example of the present invention.

As shown in FIG. 3, the electric power steering apparatus 100 includes a housing 140, a steering shaft 1, a worm wheel 3, a worm shaft 110, a drive motor 120, and a coupling. 130, the support bearing 113, and the tilt bearing 115 are included. The steering shaft 1 is rotatably provided in the housing 140. The worm wheel 3 is coupled to the steering shaft 1.

The worm shaft 110 is rotatably provided in the housing 140. The worm shaft 110 is rotated by the power of the drive motor 120. The worm shaft 110 includes a worm 111. The worm 111 is engaged with the worm wheel 3 formed on the steering shaft 1.

The drive motor 120 is provided coupled to the housing 140. The drive motor 120 generates a steering assistance force, the power of the drive motor 120 is transmitted to the steering shaft (1). The rotating shaft 21 of the drive motor 120 is connected to the worm shaft 110 by a coupling 130.

The coupling 130 connects the rotation shaft 121 and the worm shaft 110. The coupling 130 is fastened to the rotation shaft 121 and the worm shaft 110 of the drive motor 120, respectively, and performs a function of transmitting the power of the drive motor 120 to the worm shaft 110.

The electric power steering apparatus 100 according to the present invention may have a tilting structure. The tilting structure is formed to support an outer surface of the support bearing 113 located at one end of the worm shaft 110. The tilting structure is provided to provide the worm shaft 110 with a force for tilting the worm shaft 110 in the worm wheel 3 direction. Due to the tilting structure, the support bearing 130 is elastically supported to push in the direction toward the worm wheel 13. Therefore, the tilting structure compensates for the gap between the worm 110 and the worm wheel 130. Gaps are compensated between the worm 110 and the worm wheel 130 to minimize tolerances and assembly tolerances of the electric power steering device 100 to improve performance.

The support bearing 113 is positioned at one end of the worm 111 to support the worm shaft 110 to be rotatable with respect to the housing 140. The support bearing 113 is made of a deep groove ball bearing. The support bearing 113 is formed by being located opposite to the tilt bearing 115 with the worm 111 therebetween.

The tilt bearing 115 is located on the other side of the worm 111 and the worm shaft 110 is supported to be rotatable with respect to the housing 140. The tilt bearing 115 is provided between the worm 111 and the coupling 130. The tilt bearing 115 is formed of a ball bearing having a structure with improved tilt stability.

The tilt bearing 115 is provided with a worm shaft 110 is inserted into the inner ring 115-1 of the ring-shaped inner ring raceway formed on the outer diameter surface, the outer ring in the radial direction of the inner ring 115-1 and the outer ring on the inner diameter surface A ring-shaped outer ring 115-2 having a track, and a plurality of rolling elements 115-3 which are arranged in the circumferential direction between the inner ring track and the outer ring track.

The electric power steering apparatus 100 according to the present invention further includes a tilting shock absorbing portion which is inserted into the outer ring 115-2 and installed in the housing 140 to the outside of the outer ring 115-2. The housing 140 is provided with an annular jaw surface that is provided with both sides of the inner surface having a circular cross section into which the tilting buffer part is inserted and supports the tilting buffer part. The outer diameter surface of the tilting buffer portion is in contact with the inner surface, and the width surfaces of both sides of the tilting buffer portion are in contact with the jaw surface.

The tilting buffer part is a ring ring ring (5) -5-5 into which the outer ring 115-2 is inserted, and the ring ring 115-5 is inserted into the outer ring surface of the ring ring 115-5. It consists of a buffer member 115-6 of the form, and a ring-shaped support member 115-7 surrounding the outer surface of the buffer member 115-6 and the width surface of both sides.

The support member 115-7 is made of a metal such as steel, and the buffer member 115-6 is made of an elastomeric material such as rubber. The guard ring 115-5 is made of a metal such as bearing steel.

The outer surface 115-2a of the outer ring 115-2 is formed in a curved shape in which the outer diameter decreases toward both sides from the center in the width direction to form a spherical surface, and the inner surface 115-5a of the ring ring 115-5. Is concavely curved along the width direction to form a spherical surface. The radius of curvature of the inner surface 115-5a of the guard ring 115-5 is formed to be larger than the radius of curvature of the outer ring outer surface 115-2a, and the outer surface 115-2a of the outer ring 115-2 is formed of the guard ring ( 115-5a is provided in contact with the inner surface 115-5a.

The width of the guard ring 115-5 is larger than the width of the outer ring 115-2, and the outer surface 115-2a of the outer ring 115-2 is connected to the inner surface 115-5a of the guard ring 115-2. The contact surface is provided in contact with the outer surface 115-2a of the outer ring and the contact surface is moved when the tilt bearing 115 is tilted.

As shown in FIG. 4, the guard ring 115-5 has a jaw surface outwardly formed at both sides in the width direction and includes an outward protrusion 115-5b protruding outward in the radial direction. The buffer member 115-6 is provided on an outer diameter surface of the outward protrusion 115-5b. The buffer member 115-6 is formed in a cylindrical shape.

The support member 115-7 is bent inward in the radial direction from both sides of the cylindrical support body 115-7a and the support body 115-7a surrounding the outer diameter surface of the buffer member 115-6. And an annular side support portion 115-7b that covers a side of 115-6 and a portion of the side of the outward protrusion 115-5b. The width surface of the side support portion 115-7b is coplanar with the width surface of the ring ring 115-5, and is installed in contact with the jaw surface of the housing 140 together with the width surface of the ring ring 115-5.

The support body 115-7b constituting the support member 115-7 is inserted into an inner surface of the housing 140. When the tilting occurs, the external force transmitted from the outer ring 115-2 to the guard ring 115-5 is transmitted to the support member 115-7 through the buffer member 115-6 to form the worm wheel 3 and the worm shaft 110. Absorption generated between them is absorbed and noise is prevented from occurring.

As shown in Figure 5, the watch ring (115-5) is the support member 115-7 is a cylindrical support body (115-7a) surrounding the outer diameter surface of the outward projection (115-5b), and support An annular side support portion 115-7b that is bent inward from one side of the main body 115-7a in the width direction and covers one side surface of the outward protrusion 115-5b and outward from the other side in the width direction of the support body 115-7a. It consists of an annular 1st side support part 115-7c formed by bending.

The buffer member 115-6 surrounds the outer diameter surface of the support body 115-7a and has one end portion in the width direction contacting the first side support portion 115-7c; The outer diameter of the shock absorbing member 115-6 is larger than the first side support part 115-7c so as to contact the inner surface of the housing 140.

Since the shock absorbing member 115-6 directly contacts the inner surface of the housing 140, and at one side, the first side support part 115-7c supports the width surface of the shock absorbing member 115-6 so that the outer ring 115-2 when tilting occurs. The external force transmitted from) to the guard ring 115-5 is transmitted to the shock absorbing member 115-6 via the support member 115-7, so that the play is absorbed and is between the worm wheel 3 and the worm shaft 110. Noise generation due to play can be prevented.

The width surface of the side support portion 115-7b and the first side support portion 115-7c is located inward of the width surface of the alert ring 115-5, and both side width surfaces of the alert ring 115-5 are provided in the housing 140. The width of the side support portion 115-7b and the first side support portion 115-7c is spaced apart from the jaw surface of the housing 140.

As shown in FIG. 6, the tilting buffer part has a ring-shaped ring ring 115-5 into which the outer ring 115-2 is inserted and the ring ring 115-5 are inserted into the ring ring 115-5. It consists of a ring-shaped buffer member 115-6 provided on the outer diameter surface of the.

The outer diameter surface of the shock absorbing member (115-6) is in contact with the inner surface of the housing 140, and both side width surfaces of the shock absorbing member (115-6) and the watch ring (115-5) is provided in contact with the jaw surface of the housing 140. . Since both of the external force components in the axial direction and the radial direction are transmitted through the shock absorbing member 115-6, the shock absorbing effect can be remarkably improved.

As shown in FIG. 7, the guard ring 115-5 has a jaw surface that is outwardly formed on both sides in the width direction and has a width of the outward protrusion 115-5b and the outward protrusion 115-5b protruding outward in the radial direction. The outwardly facing second projections 115-5c are formed on both sides of the jaw surface and extend radially outwardly from the outward projections 115-5b.

The support member 115-7 and the buffer member 115-6 are provided symmetrically on both sides of the width direction with the outward protrusion 115-5b and the outward second protrusion 115-5c interposed therebetween.

The buffer member 115-6 is a buffer body 115-6b and a buffer body 115-6b which are inserted in contact with the width of the outwardly projecting portion 115-5b and the jaw face of the outwardly projecting portion 115-5b. It consists of a buffer body (115-6a) extending radially inward from the width direction outer side of the c) in contact with the width surface of the outward projection (115-5b).

The support member 115-7 is positioned between the buffer member 115-6 and the watch ring 115-5, coupled to the buffer member 115-6, and provided in contact with the jaw surface of the outward protrusion 115-5b. A cylindrical support body 115-7a and a side support portion 115-7b which are bent radially inward at the widthwise outer end of the support body 115-7a to be in contact with the width surface of the outward protrusion 115-5b, A radially outward bent at the widthwise inner end of the support body 115-7a is inserted into the buffer member 115-6 and includes a support protrusion 115-7d parallel to the width surface of the outward protrusion 115-5c.

In the above, the width surface of the shock absorbing member 115-6 is coplanar with the outermost width surface of the alert ring 115-5, or protrudes outward from the outermost width surface of the alert ring 115-5, and the buffer body. The outer diameter of the 115-6b is larger than the outer diameter of the outward second protrusions 115-5c.

As shown in FIG. 8, the watch ring 115-5 has a jaw surface outwardly formed at both sides in the width direction, and includes an outward protrusion 115-5b protruding outward in the radial direction, and the support member 115-7. And the buffer member 115-6 are provided with symmetry on both sides in the width direction with the outward protrusions 115-5b interposed therebetween.

The shock absorbing member 115-6 extends radially inward at an outer end in the width direction of the cylindrical shock absorbing body 115-6b into which the outward projecting portions 115-5b are inserted, and the shock absorbing body 115-6b. It consists of a side buffer part 115-6a which contacts the width surface of 115-5b.

The support member 115-7 is positioned between the buffer member 115-6 and the watch ring 115-5 to be coupled to the buffer member 115-6 and in contact with the outer diameter surface of the outward protrusion 115-5b. The cylindrical support body 115-7a provided and the side support part 115-7b which are bend | folded radially inward from the outer side of the width direction from the support body 115-7a, and contact the width surface of the outward protrusion 115-5b. Is done.

The width surface of the shock absorbing member 115-6 is coplanar with the outermost width surface of the alert ring 115-5, or protrudes outward from the outermost width surface of the alert ring 115-5. The widthwise inner ends of the buffer member 115-6 are provided to be spaced apart from each other.

While the shock absorbing member 115-6 is in direct contact with the housing 140, the support member 115-7 coupled to the inner side of the shock absorbing member 115-6 is provided, so that the shock absorbing member 115-6 is reduced from external force due to tilting. ) Is prevented from being locally deformed, so that the external force due to tilting is absorbed as a whole without a partial large deformation in the buffer member 115-6.

As shown in FIG. 9, the watch ring 115-5 has a jaw surface outwardly formed at both sides in the width direction, and includes an outward protrusion 115-5b protruding outward in the radial direction, and the support member 115-7. ) And the buffer member 115-6 are provided symmetrically on both sides in the width direction with the outward protrusion 115-5b interposed therebetween.

The shock absorbing member 115-6 extends radially inward from the outer side in the width direction of the cylindrical shock absorbing body 115-6b into which the outward projecting part 115-5b is inserted, and the shock absorbing body 115-6b. An annular side buffer portion 115-6a in contact with the width surface of 115-5b);

The support member 115-7 has a cylindrical support body 115-7a that surrounds the outer diameter surface of the buffer member 115-6 in a bent form, and a radius at a widthwise outer end of the support body 115-7a. It is made of a side support portion (115-7b) that is bent inwardly to surround the width surface of the buffer member (115-6). The side buffer portion 115-6b is provided to surround an end portion and an outer surface portion of the side support portion 115-7b so that the width of the portion surrounding the side support portion 115-7b is greater than the width of the caution ring 115-5. It protrudes outward.

During installation, the outer side of the side buffer portion 115-6b is deformed in contact with the jaw face of the housing 140, and the support member 115-7 is supported from the outside, so that deformation by tilting is applied to the support member 115-7. Controlled by the

The tilt bearing 115 prevents the tilting force from being increased by increasing the tilt absorbing force, and a large reaction force is transmitted from the road surface to the steering shaft 1 as the vehicle travels on the rough road or uneven road. The noise generated by the play between the 3) and the worm shaft 11 can be suppressed.

The electric power steering apparatus according to the present invention has been described with reference to the embodiments shown in the drawings, but this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope should be defined by the technical spirit of the appended claims.

1: steering shaft 3: worm wheel
110: worm shaft 111: worm
113: support bearing 115: tilt bearing
120: drive motor 130: coupling
115-1: Inner Ring 115-2: Outer Ring
115-3: Rolling element 115-4: Cage
115-5: Watch ring 115-6: Shock absorbing member
115-7: support member

Claims (8)

A housing 140, a worm wheel 3 rotatably provided in the housing 140 and coupled to the steering shaft 1, and rotatably provided in the housing 140 and engaged with the worm wheel 3; Worm shaft 110 provided with a worm 111 and support bearings which are disposed on both sides of the worm 111 and provided in the housing 140 to rotatably support the worm shaft 110 with respect to the housing 140. (113) and the tilt bearing 115, the drive shaft 120 is connected to the worm shaft 110 by a coupling 130 to the coupling shaft 130 is coupled to the housing 140 is provided; The tilt bearing 115 is located between the worm 111 and the coupling 130, and the support bearing 113 is located opposite the tilt bearing 115 with the worm 111 interposed therebetween;
The tilt bearing 115 is provided with a worm shaft 110 is inserted into the inner ring 115-1 of the ring-shaped inner ring raceway formed on the outer diameter surface, the outer ring in the radial direction of the inner ring 115-1 and the outer ring on the inner diameter surface A ring-shaped outer ring 115-2 and a plurality of rolling elements 115-3 arranged in a circumferential direction between the inner ring track and the outer ring track;
Electric power steering device 100, characterized in that the outer ring 115-2 is inserted into the outer side of the outer ring 115-2 and further comprises a tilting buffer installed in the housing 140. According to claim 1, wherein the tilting buffer portion of the ring-shaped ring ring (115-5) is inserted into the outer ring (115-2), and the ring ring (115-5) is inserted into the ring of the ring ring (115-5) A ring-shaped buffer member 115-6 provided on the outer diameter surface, and a ring-shaped support member 115-7 surrounding the outer diameter surface of the buffer member 115-6 and the width surface of both sides;
The outer surface 115-2a of the outer ring 115-2 is formed in a curved shape in which the outer diameter decreases toward both sides from the center in the width direction to form a spherical surface, and the inner surface 115-5a of the ring ring 115-5. Is concavely curved along the width direction to form a spherical surface; The radius of curvature of the inner surface 115-5a of the guard ring 115-5 is formed to be larger than the radius of curvature of the outer ring outer surface 115-2a, and the outer surface 115-2a of the outer ring 115-2 is formed of the guard ring ( The electric power steering apparatus 100 which contact | connects the inner surface 115-5a of 115-5). The method of claim 2, wherein the ring 115-5 has a jaw surface outwardly on both sides in the width direction and has a radially outwardly projecting outward projection (115-5b), the buffer member 115-6 is It is provided in the outer diameter surface of the outward protrusion part 115-5b; The support member 115-7 is a cylindrical support body 115-7a surrounding the outer diameter surface of the buffer member 115-6, and the buffer member is bent radially inward from both sides of the support body 115-7a. The electric power steering apparatus 100 characterized by consisting of the annular side support part 115-7b which covers the side of 115-6 and the side part of the outward protrusion 115-5b. The method of claim 2, wherein the ring 115-5 has a jaw surface outwardly on both sides in the width direction and has a radially outwardly projecting outward projection (115-5b), the support member (115-57) outward Cylindrical support body 115-7a surrounding the outer diameter surface of the protrusion 115-5b and an annular shape bent inward in one width direction side of the support body 115-7a to cover one side surface of the outward protrusion 115-5b. The upper side support portion 115-7b and the annular first side support portion 115-7c formed by bending outward at the other side in the width direction of the support body 115-7a; It wraps around the outer diameter surface of the support body 115-7a and has one end portion in the width direction contacting the first side support portion 115-7c; The outer diameter of the buffer member 115-6 is the first side support portion 115-7c. Electric power steering device 100, characterized in that larger than the contact with the inner surface of the housing (140). According to claim 1, wherein the tilting buffer portion of the ring-shaped ring ring (115-5) is inserted into the outer ring (115-2), and the ring ring (115-5) is inserted into the ring of the ring ring (115-5) It is made of a ring-shaped buffer member (115-6) provided on the outer diameter surface, the outer diameter surface of the buffer member (115-6) abuts the inner surface of the housing 140, the buffer ring 115-6 and the watch ring Both side width surfaces of the 115-5 are provided in contact with the jaw surface of the housing 140;
The outer surface 115-2a of the outer ring 115-2 is formed in a curved shape in which the outer diameter decreases toward both sides from the center in the width direction to form a spherical surface, and the inner surface 115-5a of the ring ring 115-5. Is concavely curved along the width direction to form a spherical surface; The radius of curvature of the inner surface 115-5a of the guard ring 115-5 is formed to be larger than the radius of curvature of the outer ring outer surface 115-2a, and the outer surface 115-2a of the outer ring 115-2 is formed of the guard ring ( The electric power steering apparatus 100 which contact | connects the inner surface 115-5a of 115-5). The width of both sides of the guard ring 115-5 is a radially outwardly projecting outward protrusion 115-5b and an outward protrusion 115-5b. An outward second projection 115-5c extending outwardly from the outward projection 115-5b and defining a jaw surface facing outwardly;
The support member 115-7 and the buffer member 115-6 are provided symmetrically on both sides in the width direction with the outward protrusion 115-5b and the outward second protrusion 115-5c interposed therebetween;
The buffer member 115-6 includes a buffer main body 115-6b which is inserted into the jaw face of the outward protrusion 115-5b and abuts on the width surface of the outward second protrusion 115-5c, and the buffer main body 115-b. It consists of a buffer body (115-6a) extending radially inward from the width direction outside of 6b) in contact with the width surface of the outward projection (115-5b);
The support member 115-7 is positioned between the buffer member 115-6 and the watch ring 115-5, coupled to the buffer member 115-6, and provided in contact with the jaw surface of the outward protrusion 115-5b. A cylindrical support body 115-7a and a side support portion 115-7b which are bent radially inward at the widthwise outer end of the support body 115-7a to be in contact with the width surface of the outward protrusion 115-5b, It is bent in the radially outward end at the width direction inner end of the support body (115-7a) is inserted into the buffer member (115-6), characterized in that consisting of a support protrusion (115-7d) parallel to the width of the outward projection (115-5c) Electric power steering apparatus 100 to be used. 3. The device according to claim 2, wherein the watch ring (115-5) forms a jaw surface on both sides in the width direction and has an outward protrusion (115-5b) projecting outward in the radial direction;
The support member 115-7 and the buffer member 115-6 are provided symmetrically on both sides in the width direction with the outward protrusion 115-5b interposed therebetween;
The shock absorbing member 115-6 extends radially inward at an outer end in the width direction of the cylindrical shock absorbing body 115-6b into which the outward projecting portions 115-5b are inserted, and the shock absorbing body 115-6b. A side buffer portion 115-6a in contact with the width surface of the surface 115-5b;
The support member 115-7 is positioned between the buffer member 115-6 and the watch ring 115-5 to be coupled to the buffer member 115-6 and in contact with the outer diameter surface of the outward protrusion 115-5b. The cylindrical support body 115-7a provided and the side support part 115-7b which are bend | folded radially inward from the outer side of the width direction from the support body 115-7a, and contact the width surface of the outward protrusion 115-5b. Electric power steering device 100, characterized in that made. 3. The device according to claim 2, wherein the watch ring (115-5) forms a jaw surface on both sides in the width direction and has an outward protrusion (115-5b) projecting outward in the radial direction;
The support member 115-7 and the buffer member 115-6 are provided symmetrically on both sides in the width direction with the outward protrusion 115-5b interposed therebetween;
The shock absorbing member 115-6 extends radially inward from the outer side in the width direction of the cylindrical shock absorbing body 115-6b into which the outward projecting part 115-5b is inserted, and the shock absorbing body 115-6b. An annular side buffer portion 115-6a in contact with the width surface of 115-5b);
The support member 115-7 has a cylindrical support body 115-7a that surrounds the outer diameter surface of the buffer member 115-6 in a bent form, and a radius at a widthwise outer end of the support body 115-7a. A side support portion 115-7b that is bent inwardly and wraps around the width surface of the buffer member 115-6;
The side buffer portion 115-6b is provided to surround an end portion and an outer surface portion of the side support portion 115-7b so that the width of the portion surrounding the side support portion 115-7b is greater than the width of the caution ring 115-5. Electric power steering device 100, characterized in that provided to protrude outward.

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