KR20210092891A - Steering apparatus for vehicle - Google Patents

Abstract

The present invention relates to a vehicle steering apparatus. According to the present embodiments, in a coupling structure of a worm shaft and a motor shaft, the number of parts required for coupling is reduced, which simplifies an assembly process, makes it easy to secure an installation space, increases durability of the parts, and improves noise performance. The vehicle steering apparatus of the present invention comprises: the worm shaft; and a motor.

Description

Steering system for automobiles {STEERING APPARATUS FOR VEHICLE}

The present embodiments relate to a steering apparatus for a vehicle, and more particularly, the number of parts required for coupling in the coupling structure of the worm shaft and the motor shaft is reduced, thereby simplifying the assembly process and securing the installation space, increasing the durability of the parts and increasing the noise It relates to a steering system of an automobile with improved performance.

The steering system of a car uses a motor to assist the driver in operating the steering wheel or to steer the wheel correspondingly, or to perform the tilt or teles operation of the steering column. In order to amplify the torque of the motor, the worm shaft- A worm wheel reducer can be used.

In particular, the worm shaft-worm wheel reducer is used in an electric power-assisted steering device. The electric power-assisted steering device is a device for assisting the driver in operating the steering wheel. The worm wheel coupled to the steering shaft and the worm shaft coupled to the motor are engaged and the vehicle An electronic control device provided in the control unit controls the motor based on the driver's steering wheel manipulation information, etc. to generate an auxiliary torque on the steering shaft to assist the driver in manipulating the steering wheel.

When assembling, the worm shaft is coupled to the housing so that it is provided coaxially with the motor shaft, but when driven by a clearance compensation mechanism to compensate for the flow caused by the road impact of the vehicle and the clearance caused by the wear of the worm wheel, it is rotated at a predetermined angle with respect to the motor shaft. It flows and rotates in a tilted state.

In the conventional steering system, a damping coupler is provided so that power can be transmitted even if the worm shaft is inclined with respect to the motor shaft, but it is complicated to assemble due to the large number of parts, and it is difficult to secure an installation space due to an increase in the size of the housing. There was a problem in that it was difficult to secure the durability of the damping coupler, and the driver's steering feeling was deteriorated by noise generated from the damping coupler.

The present embodiments have been devised in the background described above, and the number of parts required for coupling in the coupling structure of the worm shaft and the motor shaft is reduced, so that the assembly process is simplified, the installation space is easily secured, the durability of the parts is increased, and the noise performance is improved. It relates to the steering system of a car.

According to the present embodiments, a worm shaft including a first coupling part coupled to a housing by a gear part and a bearing engaged with the worm wheel and having a coupling hole that is opened to one side in the axial direction is formed, and a motor shaft meshing with the worm shaft is provided, and a motor is provided. The shaft is inserted into the coupling hole, and the steering apparatus of a vehicle including a motor including a second coupling part coupled to the first coupling part from the inside of the bearing may be provided.

According to the present embodiments, the number of parts required for coupling in the coupling structure of the worm shaft and the motor shaft is reduced, thereby simplifying the assembly process, facilitating the securing of an installation space, increasing the durability of the parts, and improving the noise performance.

1 is a front view of a steering apparatus for a vehicle according to the present embodiments.
FIG. 2 is a perspective view of a part of FIG. 1 ;
3 to 4 are exploded perspective views and cross-sectional views of a part of a steering system for a vehicle according to the present embodiments.
5 to 7 are exploded perspective views and cross-sectional views of a part of a steering system for a vehicle according to the present embodiments.
8 to 9 are exploded perspective views and cross-sectional views of a part of a steering system for a vehicle according to the present embodiments.
10 to 12 are exploded perspective views and cross-sectional views of a part of a steering system for a vehicle according to the present embodiments.

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present embodiments, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present technical idea, the detailed description thereof may be omitted. When "includes", "having", "consisting of", etc. mentioned in this specification are used, other parts may be added unless "only" is used. When a component is expressed in a singular, it may include a case in which the plural is included unless otherwise explicitly stated.

In addition, in describing the components of the present disclosure, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms.

In the description of the positional relationship of the components, when two or more components are described as being "connected", "coupled" or "connected", the two or more components are directly "connected", "coupled" or "connected" ", but it will be understood that two or more components and other components may be further "interposed" and "connected," "coupled," or "connected." Here, other components may be included in one or more of two or more components that are “connected”, “coupled” or “connected” to each other.

In the description of the temporal flow relation related to the components, the operation method, the manufacturing method, etc., for example, a temporal precedence relationship such as "after", "after", "after", "before", etc. Or, when a flow precedence relationship is described, it may include a case where it is not continuous unless "immediately" or "directly" is used.

On the other hand, when numerical values or corresponding information (eg, level, etc.) for a component are mentioned, even if there is no explicit description, the numerical value or the corresponding information is based on various factors (eg, process factors, internal or external shock, Noise, etc.) may be interpreted as including an error range that may occur.

1 is a front view of a steering apparatus for a vehicle according to the present embodiments, FIG. 2 is a perspective view of a part of FIG. 1, and FIGS. 3 to 4 are an exploded perspective view of a part of a steering apparatus for a vehicle according to the present embodiments and a cross-sectional view, FIGS. 5 to 7 are an exploded perspective view and a cross-sectional view of a part of a steering system for a vehicle according to the present embodiments, and FIGS. 8 to 9 are an exploded perspective view of a part of a steering system for a vehicle according to the present embodiments and cross-sectional views, FIGS. 10 to 12 are exploded perspective views and cross-sectional views of a part of a steering apparatus for a vehicle according to the present embodiments.

The steering apparatus 100 for a vehicle according to the present embodiments is coupled to the housing 101 by a gear part 111 and a bearing 120 engaged with the worm wheel 104 and a coupling hole ( A worm shaft 110 including a first coupling portion 112 on which 201 is formed, a motor shaft 130 engaged with the worm shaft 110 is provided, and the motor shaft 130 is inserted into the coupling hole 201 , and a motor 102 including a second coupling part 131 coupled to the first coupling part 112 on the inside of the bearing 120 .

The drawings show embodiments in which the present embodiments are applied to an electric power-assisted steering system in which the worm wheel 104 is coupled to the steering shaft 105 and the driver's steering wheel operation is assisted by the torque of the motor 102, The present embodiments are not necessarily limited to being applied to the electric power assist steering system.

Since the worm shaft-worm wheel reducer is a structure commonly used to amplify the torque of the motor in the steering system, for example, the reducer coupled to the motor that performs the tilt or teles operation of the steering column, or the driver by rotating the pinion bar engaged with the rack bar It should be understood that the present embodiments can also be applied to a reducer coupled to a motor that assists in the operation of the steering wheel or correspondingly slides the rack bar.

Referring to FIGS. 1 and 2 , the worm shaft 110 includes a gear part 111 and a first coupling part 112 , and a worm is formed in the gear part 111 to engage the worm wheel 104 and first One coupling part 112 is provided at one end of the worm shaft 110 and is coupled to the motor shaft 130 of the motor 102 .

The first coupling part 112 is coupled to the housing 101 by the bearing 120 , and a coupling hole 201 that is opened to one side in the axial direction is formed.

The motor shaft 130 of the motor 102 is engaged with the worm shaft 110 , the motor shaft 130 is inserted into the coupling hole 201 and the second coupling part 131 coupled to the first coupling part 112 . ) is included.

That is, the first coupling part 112 and the second coupling part 131 are coupled inside the bearing 120 .

On the other hand, the support member 121 supported by the bearing 120 from the opposite side of the gear part 111 may be coupled to the outer peripheral surface of the first coupling part 112 .

That is, the first coupling part 112 partially protrudes from the inside of the bearing 120 to one side in the axial direction, and the support member 121 is supported by the bearing 120 and coupled to the outer circumferential surface of the protruding portion, thereby bearing 120 . The rotation of the worm shaft 110 can be supported.

Subsequently, the worm shaft 110 and the motor shaft 130 are assembled to be provided coaxially, but the other end of the worm shaft 110 is pressed to compensate for the flow caused by the road impact of the vehicle and the play caused by the wear of the worm wheel 104 . When driven by the clearance compensation mechanism 103 and the like, the worm shaft 110 flows and rotates in a state inclined at a predetermined angle with respect to the motor shaft 130 .

The worm shaft 110 is inclined with respect to the motor shaft 130 around the first coupling part 112 coupled to the bearing 120 so that the outer ring of the bearing 120 is formed in a two-stage structure in contact with a curved surface. there is. Alternatively, a damper may be provided between the outer ring of the bearing 120 and the housing 101 as shown in the drawings.

The conventional steering device is also rotated in a tilted state with respect to the motor shaft centering on the portion where the worm shaft is coupled to the bearing. In the conventional steering device, the end of the worm shaft protrudes from the bearing to the motor, and the protruding end is the motor As a structure coupled to the shaft, the coupling between the worm shaft and the motor shaft is not made inside the bearing, but at a position spaced apart from it in the axial direction.

Therefore, when flow occurs in the worm shaft, a flow of a magnitude proportional to the distance between the center of the bearing and the coupling part occurs in the coupling part of the worm shaft and the motor shaft.

Therefore, when the flow occurs in the worm shaft, the flow also occurs in the coupling portion of the worm shaft and the motor shaft, and as the distance between the center of the bearing and the coupling portion of the worm shaft and the motor shaft increases, the size of the flow generated in the coupling portion also increases.

Therefore, the durability of the motor shaft and the damping coupler is reduced by the coupling part of the worm shaft and the motor shaft, noise is generated, and a damping coupler must be provided so that power can be transmitted even if a flow occurs in the coupling part of the worm shaft and the motor shaft. There was a problem with the number of parts and the cumbersome assembly.

However, according to the steering apparatus of a vehicle according to the present embodiments, since the coupling of the worm shaft 110 and the motor shaft 130 is made inside the bearing 120 which is the center of the worm shaft 110 flow, the worm shaft 110 . Even if the flow occurs in the worm shaft 110 and the motor shaft 130, the flow does not occur in the coupling portion.

Therefore, since there is no need to provide a damping coupler, etc., the number of parts is reduced and the assembly process is simplified, the distance between the motor and the worm shaft can be further narrowed, so the size of the reducer is small, so it is easy to secure the installation space, and the flow of the worm shaft is reduced by the motor Since it is not transmitted to the shaft, the durability of the part can be increased and the noise performance can also be improved.

Hereinafter, the coupling structure of the worm shaft 110 and the motor shaft 130 will be described.

Referring to FIGS. 3 to 4 , a serration engaged with each other may be formed in the first coupling part 112 and the second coupling part 131 .

That is, serrations are formed on the inner circumferential surface of the first coupling part 112 and the outer circumferential surface of the second coupling part 131 , respectively, so that the second coupling part 131 is inserted into the coupling hole 201 and the serrations are aligned with each other. Bit and the worm shaft 110 and the motor shaft 130 are fixed in the circumferential direction, the power of the motor 102 can be transmitted to the worm shaft (110).

Referring to FIGS. 5 to 7 , a support part 501 is protruded from the inner circumferential surface of the first coupling part 112 , and a groove part 513 in which the support part 501 is seated on the outer circumferential surface of the second coupling part 131 . can be formed.

That is, when the serration is formed on the worm shaft 110 and the motor shaft 130, it is difficult to process to a precise dimension, and the problem that the serration collides during rotation and noise occurs often occurs. 513), by combining the worm shaft 110 and the motor shaft 130, it is possible to lower the machining difficulty and improve the noise performance.

The support part 501 and the groove part 513 are spaced apart in the circumferential direction and may be provided in two or more, and the figure shows an embodiment in which four are provided each so that the second coupling part 131 is formed in a substantially cross shape.

In addition, the second coupling portion 131 may include a large-diameter portion 511 provided with the groove portion 513 and a small-diameter portion 512 provided on one side in the axial direction of the large-diameter portion 511 .

As shown in the drawing, the other end of the motor shaft 130 may include a large diameter portion 511 and a small diameter portion 512 connecting the large diameter portion 511 and the motor shaft 130 body.

Even if flow occurs in the worm shaft 110, the support part 501 is preferably formed longer in the axial direction than the large diameter part 511 so that the worm shaft 110 and the motor shaft 130 can maintain a supported state in the circumferential direction. (See FIG. 7 ), as the small diameter portion 512 is formed, the contact surface where the second coupling portion 131 comes into contact with the support portion 501 is narrowed in the axial direction, and thus the motor shaft by the flow of the worm shaft 110 ( 130) can be further reduced.

Referring to FIGS. 8 to 9 , the large-diameter portion 511 is formed so that the boundary between the outer circumferential surface and one side in the axial direction is rounded, or the boundary between the outer circumferential surface and the other side in the axial direction is formed to be round, similarly of the worm shaft 110 . It is possible to further reduce the flow of the motor shaft 130 due to the flow.

That is, since the outer surface of the large diameter portion 511 is formed to be round, the worm shaft 110 can flow with respect to the motor shaft 130 around the first coupling portion 112 without a sense of being caught, so the worm shaft 110 . It is possible to prevent the flow of the motor shaft 130 from being transmitted.

The drawing shows an embodiment in which all of the axial boundaries of the outer peripheral surface of the large-diameter portion 511 are rounded, and an embodiment in which only one of the boundaries with one side or the other side is rounded can be easily derived from the drawing. There will be.

Meanwhile, referring to FIGS. 10 to 12 , the motor shaft 130 includes a first shaft part 1001 having a second coupling part 131 and a second shaft part 1002 coupled to the first shaft part 1001 ). may include.

That is, the motor shaft 130 includes a first shaft portion 1001 and a second shaft portion 1002, and the first shaft portion 1001 includes a second coupling portion 131 and is coupled to the worm shaft 110, The second shaft part 1002 is rotated by being coupled to the rotor of the motor 102 .

When the motor shaft 130 is provided as a single entity, it is difficult to process the large diameter part 511 , the small diameter part 512 , etc., so the motor shaft 130 is divided into the first shaft part 1001 and the second shaft part 1002 . It may be simpler to separate and process the second coupling part 131 to the first shaft part 1001 and to couple it to the second shaft part 1002 .

10 shows an embodiment in which the second coupling part 131 including the large diameter part 511 whose outer circumferential surface is not rounded as in FIG. 5 is provided in the first shaft part 1001, and in FIG. An embodiment in which the second coupling portion 131 including the large-diameter portion 511 whose outer circumferential surface is rounded as shown is provided in the first shaft portion 1001 is illustrated.

In addition, an insertion hole 1011 that is opened in the axial direction is formed in any one of the first shaft portion 1001 and the second shaft portion 1002 , and an insertion portion 1012 inserted into the insertion hole 1011 is formed in the other one. Thus, the first shaft portion 1001 and the second shaft portion 1002 are coupled.

As shown in the drawing, a serration engaged with each other is formed in the insertion hole 1011 and the insertion part 1012 and can be fixed in the circumferential direction, or although not shown in the drawing, the insertion hole 1011 and the insertion part 1012 are formed. ) is formed in a cross shape rather than a cylindrical shape, and may be fixedly coupled in the circumferential direction.

According to the steering system of a vehicle having such a shape, the number of parts required for coupling in the coupling structure of the worm shaft and the motor shaft is reduced, thereby simplifying the assembly process, making it easier to secure an installation space, increasing the durability of the parts, and improving the noise performance. can

The above description is merely illustrative of the technical spirit of the present disclosure, and various modifications and variations will be possible without departing from the essential characteristics of the present disclosure by those skilled in the art to which the present disclosure pertains. In addition, the present embodiments are not intended to limit the technical spirit of the present disclosure, but rather to explain, so the scope of the present technical spirit is not limited by these embodiments. The protection scope of the present disclosure should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present disclosure.

100: steering system of a vehicle 101: housing
102: motor 103: gap compensation mechanism
104: worm wheel 105: steering shaft
110: worm shaft 111: gear unit
112: first coupling portion 120: bearing
121: support member 130: motor shaft
131: second coupling part 201: coupling hole
501: support 511: large-gyeongbu
512: small diameter part 513: groove part
1001: 1st shaft part 1002: 2nd shaft part
1011: insertion hole 1012: insertion part

Claims (11)

a worm shaft including a first coupling part coupled to the housing by a gear part and a bearing engaged with the worm wheel and having a coupling hole that is opened to one side in the axial direction;
a motor having a motor shaft engaged with the worm shaft, the motor shaft including a second coupling part inserted into the coupling hole and coupled to the first coupling part from the inside of the bearing;
A steering system of a vehicle comprising a. The method of claim 1,
A support member supported by the bearing on the opposite side of the gear part is coupled to an outer peripheral surface of the first coupling part. The method of claim 1,
A steering apparatus for a vehicle, characterized in that the first coupling portion and the second coupling portion are formed with serrations engaged with each other. The method of claim 1,
A support portion is formed protruding from the inner circumferential surface of the first coupling portion,
A steering apparatus for a vehicle, characterized in that a groove portion in which the support portion is seated is formed on an outer circumferential surface of the second coupling portion. 5. The method of claim 4,
The support part and the groove part are spaced apart in the circumferential direction, and two or more steering devices are provided. 5. The method of claim 4,
The second coupling portion may include a large-diameter portion provided with the groove portion and a small-diameter portion provided on one axial direction of the large-diameter portion. 7. The method of claim 6,
The large-diameter portion is a steering device for a vehicle, characterized in that the boundary between the outer peripheral surface and one side in the axial direction is formed to be rounded. 7. The method of claim 6,
The large-diameter portion is a steering device for a vehicle, characterized in that the boundary between the outer peripheral surface and the other axial side is formed to be rounded. 5. The method of claim 4,
The motor shaft includes a first shaft portion provided with the second coupling portion and a second shaft portion coupled to the first shaft portion. 10. The method of claim 9,
An insertion hole opening in the axial direction is formed in one of the first shaft portion and the second shaft portion, and an insertion portion inserted into the insertion hole is formed in the other one. 11. The method of claim 10,
A steering apparatus for a vehicle, characterized in that the insertion hole and the insertion part are formed with serrations engaged with each other.

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