KR20120042087A - Electric power steering apparatus for vehicle - Google Patents

Electric power steering apparatus for vehicle Download PDF

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Publication number
KR20120042087A
KR20120042087A KR1020100103577A KR20100103577A KR20120042087A KR 20120042087 A KR20120042087 A KR 20120042087A KR 1020100103577 A KR1020100103577 A KR 1020100103577A KR 20100103577 A KR20100103577 A KR 20100103577A KR 20120042087 A KR20120042087 A KR 20120042087A
Authority
KR
South Korea
Prior art keywords
worm shaft
housing
support member
guide
electric power
Prior art date
Application number
KR1020100103577A
Other languages
Korean (ko)
Inventor
김태식
Original Assignee
주식회사 만도
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 만도 filed Critical 주식회사 만도
Priority to KR1020100103577A priority Critical patent/KR20120042087A/en
Publication of KR20120042087A publication Critical patent/KR20120042087A/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D3/00—Steering gears
    • B62D3/02—Steering gears mechanical
    • B62D3/04—Steering gears mechanical of worm type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0421—Electric motor acting on or near steering gear
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H57/00—General details of gearing
    • F16H57/02—Gearboxes; Mounting gearing therein
    • F16H57/021—Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings
    • F16H2057/0213—Support of worm gear shafts

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)

Abstract

The present invention relates to a speed reducer of an electric power assisted steering device. According to the present invention, when a load is transmitted from a worm shaft to a worm shaft bearing in a speed reducer of an electric power assisted steering device, the worm shaft is centered regardless of the direction in which the load is transmitted. Maintained in the position, the support force for supporting the worm shaft in the center direction is generated constantly so that the worm shaft is eccentric to either side, or there is an effect that can prevent the departure and deformation of the worm shaft support member due to excessive uneven load.

Description

Electric Power Steering Apparatus for Vehicle

The present invention relates to a speed reducer of an electric power assisted steering device. More specifically, when the load is transmitted from the worm shaft to the worm shaft bearing in the reduction gear of the electric power assisted steering device, the worm shaft is maintained at the center position and the bearing force for supporting the worm shaft in the center direction is constant even if the load is transmitted in any direction. It is generated so that the worm shaft is eccentric to any one side, or the reducer of the electric power assist steering device that can prevent the departure and deformation of the worm shaft support member due to excessive bias load.

In general, the electric power assist steering device assists the driver's steering torque by driving the motor in the electronic control device according to the driving conditions of the vehicle detected by the vehicle speed sensor and the steering torque sensor, thereby providing a light and comfortable steering state at low speed driving. In addition, it provides a heavy and stable steering state at high speeds, and provides steering performance to maintain the optimal steering feeling for the driver, such as enabling rapid steering operation in response to sudden emergency situations.

1 is a cross-sectional view showing a speed reducer of a conventional electric power assisted steering apparatus.

As shown in the figure, the reducer is provided with a worm shaft 104 having a worm 102 formed at an intermediate portion thereof, and worm shaft bearings 106 are installed at both ends of the worm shaft 104 to support the worm shaft 104, and the worm shaft 104 ) And the motor shaft 108 is connected to the worm shaft 104 is rotated by the drive of the motor (110).

A worm wheel 114 is provided at one side of the outer diameter of the worm 102 so that the worm 102 can be engaged with the worm 102 formed in the middle of the worm shaft 104. The worm wheel 114 is a steering wheel (not shown) operated by a driver. It is mounted on the steering shaft 112 for transmitting the rotational force of, so that the rotational force of the worm shaft 104 by the drive of the motor 110 is transmitted to the steering shaft (112). These worm wheels 114 and worm shafts 104, which are engaged in a worm gear manner, are mounted inside the housing 116 for protection from the outside.

Accordingly, the driving force of the motor 110 is controlled by the electronic control device provided in the vehicle according to the vehicle driving condition, and the rotational force of the worm shaft 104 by the driving of the motor 110 is dependent on the rotational force of the steering wheel operated by the driver. By being added to the steering shaft 112, the steering driving state of the driver can be smoothly and stably maintained.

By the way, in the speed reducer of the conventional electric power assisted steering apparatus, when a load is transmitted from the worm shaft or the housing, the worm shaft is not maintained at the center position of the housing, and the worm shaft and the housing cause interference or generate rattle noise. Or there was a problem of breaking the housing.

In addition, since the bearing force supporting the worm shaft in the center direction is not generated constantly, the worm shaft is eccentric to either side of the housing, or the worm shaft support member is dislodged and deformed due to excessive unloading, resulting in frequent replacement of the worm shaft support member. There was a problem that the replacement cost is increased due to the damage of the worm shaft or housing.

SUMMARY OF THE INVENTION The present invention has been devised in this background. When a load is transmitted from a worm shaft to a worm shaft bearing in a speed reducer of an electric power assisted steering apparatus, the worm shaft is maintained at the center position even if the load is transmitted in any direction, and the worm shaft is centered. The support force is constantly generated so that the worm shaft is eccentric to any one side, or the excessive axial load is to prevent the departure and deformation of the worm shaft support member.

In order to achieve the above object, the first embodiment of the present invention includes a worm shaft in which a worm shaft groove is formed in the circumferential direction on an outer circumferential surface portion to which the worm shaft bearing is coupled, and the one side is opened to prevent the worm shaft bearing from being separated. An electric motor comprising a worm shaft support member having a worm shaft support member coupled to a groove, an axial guide coupled between the worm shaft bearing and the worm shaft, and a radial guide coupled between the worm shaft bearing and the worm shaft support member. Provides a reducer for power assisted steering.

In addition, the second embodiment of the present invention, the housing groove is formed in the circumferential direction on the inner circumferential surface portion to which the worm shaft bearing is coupled, and one side is coupled to the groove to prevent the worm shaft bearing from being separated in an annular opening And a housing guide including a housing support member, an axial guide coupled between the worm shaft bearing and the housing, and a radial guide coupled between the worm shaft bearing and the housing support member. To reducer.

According to the present invention, when a load is transmitted from the worm shaft to the worm shaft bearing in the reduction gear of the electric power assisted steering apparatus, the worm shaft is maintained at the center position and the worm shaft is supported in the center direction even if the load is transmitted in any direction. The bearing force is constantly generated so that the worm shaft is eccentric to either side, or due to excessive bias load, there is an effect of preventing the departure and deformation of the worm shaft support member.

1 is a cross-sectional view showing a reducer of an electric power assisted steering apparatus conventionally used;
2 is a cross-sectional view showing an electric power assisted steering device according to a first embodiment of the present invention;
3 is a perspective view showing the worm shaft support member of FIG.
4 is a cross-sectional view showing a reducer of the electric power assisted steering apparatus according to the second embodiment of the present invention;
5 is a perspective view illustrating the housing support member of FIG. 4.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

2 is a cross-sectional view showing the electric power assisted steering apparatus according to the first embodiment of the present invention, Figure 3 is a perspective view showing a worm shaft support member of FIG.

As shown in these drawings, in the reduction gear 200 of the electric power assisted steering apparatus according to the first embodiment of the present invention, a worm shaft groove 203 is formed in the circumferential direction on an outer circumferential surface portion to which the worm shaft bearing 106 is coupled. The worm shaft 104 and the worm shaft support member 210 coupled to the worm shaft groove 203 to prevent the worm shaft bearing 106 from being separated in an annular shape of one side, and the worm shaft bearing 106 and the worm shaft ( And a worm shaft guide 205 having an axial guide 205a coupled between the 104 and a radial guide 205b coupled between the worm shaft bearing 106 and the worm shaft support member 210. .

The reducer is provided with a worm shaft 104 having a worm 102 formed inside the housing 116, and bearings are installed at both ends of the worm shaft 104 to support the worm shaft 104, and the worm shaft 104 includes the motor 110. The worm shaft 104 is rotated by the driving of the motor 110 is connected to the.

In addition, a worm wheel 114 is provided at an outer circumferential side of the worm 102 so that the worm 102 can be engaged with the worm 102 formed on the worm shaft 104. The worm wheel 114 transmits rotational force of a steering wheel operated by a driver. Mounted on the steering shaft 112 is a structure in which the rotational force of the worm shaft 104 by the drive of the motor 110 is transmitted to the steering shaft.

Here, the worm shaft support member 210 and the worm shaft guide 205 are coupled to a portion of the bearings installed at both ends of the worm shaft 104 to be connected to the shaft 108 of the motor to prevent the worm shaft bearing 106 from being separated.

The worm shaft guide 205 has an axial guide 205a into which the worm shaft 104 is press-fitted, and a radial guide 205b formed in the outer diameter direction at the end of the axial guide 205a. The axial guide 205a of the worm shaft 104 is pressed between the worm shaft 104 and the worm shaft bearing 106, and the radial guide 205b of the worm shaft guide 205 is disposed between the worm shaft support member 210 and the worm shaft bearing 106. Coupled to transmit the axial load transmitted from the worm shaft bearing 106 to the worm shaft support member 210 when the worm shaft 104 is rotated.

In addition, the worm shaft 104 is provided with a worm shaft groove 203 formed in the circumferential direction on the outer circumferential surface portion to which the worm shaft bearing 106 is coupled, so that the worm shaft support member 210 is coupled to the worm shaft groove 203. .

The worm shaft support member 210 is provided with openings 213 spaced apart from each other so that a gap is formed in the circumferential direction of the body, so that elastic support force that is radially retracted when coupled to the worm shaft 104 is generated.

And, the worm shaft support member 210 is formed in a wedge shape in which the thickness of the inner circumferential surface inserted into the worm shaft groove 203 is smaller than the thickness of the outer circumferential surface, the taper inclined toward the inner circumferential surface on the opposite side of the surface supported by the worm shaft guide 205. The surface 215 is formed, and the worm shaft groove 203 is also formed in a shape corresponding thereto.

Accordingly, when the worm shaft support member 210 is inserted into the worm shaft groove 203 and seated on the worm shaft groove 203 by the elastic support force that is retracted in the radial direction, the worm shaft support member 205 supports the radial guide 205b of the worm shaft guide 205. As a result, the position of the worm shaft bearing 106 is fixed, and at the same time, the load transmitted in the axial direction is supported.

That is, the axial guide 205a of the worm shaft guide 205 supports the inner ring 106a of the worm shaft bearing 106, and the radial guide 205b of the worm shaft guide 205 has an inner ring of the worm shaft bearing 106. 106a) and the outer ring 106b are supported from the side, so that when the load in the axial direction is transmitted, the worm shaft support member 210 is bent by being transferred to the worm shaft support member 210 through the entire surface of the radial guide 205b. Or to be prevented from falling off.

4 is a cross-sectional view illustrating a reducer of the electric power assisted steering apparatus according to the second embodiment of the present invention, and FIG. 5 is a perspective view illustrating the housing supporting member of FIG. 4.

As shown in these drawings, in the reduction gear 400 of the electric power assisted steering apparatus according to the second embodiment of the present invention, the housing groove 403 is formed in the circumferential direction on the inner circumferential surface portion to which the worm shaft bearing 106 is coupled. A housing 116, a housing support member 410 coupled to the housing groove 403 to prevent the worm shaft bearing 106 from being detached in an annular shape having an opening at one side thereof, and the worm shaft bearing 106 and the housing ( And a housing guide 405 having an axial guide 405a coupled between the 116 and a radial guide 405b coupled between the worm shaft bearing 106 and the housing support member 410. .

The difference from the first embodiment in the second embodiment of the present invention is that the housing support member 410 is coupled to the housing 116 instead of the worm shaft support member to support the worm shaft bearing 106, Hereinafter, the same or similar contents as those of the first embodiment of the present invention will be omitted.

The housing guide 405 has an axial guide 405a into which the worm shaft bearing 106 is press-fitted and a radial guide 405b formed in the inner diameter direction at the end of the axial guide 405a. The housing guide 405 The axial guide 405a of the housing 116 and the worm shaft bearing 106 is press-fitted, the radial guide 405b of the housing guide 405 between the housing support member 410 and the worm shaft bearing 106 Coupled to transmit the axial load transmitted from the worm shaft bearing 106 to the housing support member 410 during rotation of the worm shaft 104.

In addition, the housing 116 is provided with a housing groove 403 formed in the circumferential direction at an outer circumferential surface portion to which the worm shaft bearing 106 is coupled, such that the housing support member 410 is coupled to the housing groove 403. .

The housing support member 410 is provided with openings 413 spaced apart from each other so as to form a gap in the circumferential direction of the body, so that the elastic support force that occurs in the radial direction when coupled to the housing 116 is generated.

In addition, the housing support member 410 is formed in a wedge shape in which the thickness of the outer circumferential surface inserted into the housing groove 403 is smaller than the thickness of the inner circumferential surface, and the taper is inclined toward the outer circumferential surface on the surface opposite to the surface supported by the housing guide 405. The surface 415 is formed, and the housing groove 403 is also formed in a shape corresponding thereto.

Therefore, when the housing support member 410 is inserted into the housing groove 403 and seated on the housing groove 403 by an elastic support force that extends in the radial direction, the housing supporting member 410 supports the radial guide 405b of the housing guide 405. The position of the worm shaft bearing 106 is fixed, and at the same time, the load transmitted in the axial direction is supported.

That is, the axial guide 405a of the housing guide 405 supports the outer ring 106b of the worm shaft bearing 106, and the radial guide 405b of the housing guide 405 has an inner ring of the worm shaft bearing 106. 106a) and the outer ring 106b are supported from the side, so that when the load in the axial direction is transmitted, the housing support member 410 is bent through the entire surface of the radial guide 405b. Or to be prevented from falling off.

According to the present invention having such a structure and shape, when a load is transmitted from the worm shaft to the worm shaft bearing in the reduction gear of the electric power assisted steering apparatus, the worm shaft is maintained at the center position even if the load is transmitted in any direction. The support force to be supported in the center direction is constantly generated, so that the worm shaft is eccentric to any one side, or there is an effect of preventing departure and deformation of the worm shaft support member due to excessive eccentric load.

In the above description, all elements constituting the embodiments of the present invention are described as being combined or operating in combination, but the present invention is not necessarily limited to the embodiments. In other words, within the scope of the present invention, all of the components may be selectively operated in combination with one or more.

In addition, the terms "comprise", "comprise" or "having" described above mean that the corresponding component may be included, unless otherwise stated, and thus excludes other components. It should be construed that it may further include other components instead. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

104: worm shaft 106: worm shaft bearing
203: warm shaft groove 205: warm shaft guide
210: worm shaft support member 403: housing groove
405: housing guide 410: housing support member

Claims (6)

A worm shaft in which a worm shaft groove is formed in the circumferential direction on an outer circumferential surface portion to which the worm shaft bearing is coupled;
A worm shaft support member coupled to the worm shaft groove to prevent detachment of the worm shaft bearing in an annular shape in which one side is opened; And
A worm shaft guide having an axial guide coupled between the worm shaft bearing and the worm shaft, and a radial guide coupled between the worm shaft bearing and the worm shaft support member;
Reducer of the electric power assisted steering apparatus comprising a. The method of claim 1,
The worm shaft support member is a reduction gear of the electric power assist steering device characterized in that the thickness of the inner peripheral surface inserted into the worm shaft groove is formed in a wedge shape smaller than the thickness of the outer peripheral surface. The method of claim 2,
The worm shaft support member is a reduction gear of the electric power assist steering device characterized in that the tapered surface inclined toward the inner peripheral surface is formed on the opposite side of the surface supported by the radial guide of the worm shaft guide. A housing in which a housing groove is formed in a circumferential direction on an inner circumferential surface portion to which the worm shaft bearing is coupled;
A housing support member coupled to the housing groove to prevent detachment of the worm shaft bearing in an annular shape of which one side is opened; And
A housing guide having an axial guide coupled between the worm shaft bearing and the housing, and a radial guide coupled between the worm shaft bearing and the housing support member;
Reducer of the electric power assisted steering apparatus comprising a. The method of claim 4, wherein
The housing support member is a reducer of the electric power assist steering device characterized in that the thickness of the outer peripheral surface inserted into the housing groove is formed in a wedge shape smaller than the thickness of the inner peripheral surface. The method of claim 5, wherein
The housing support member is a reducer of the electric power assist steering device characterized in that the tapered surface inclined toward the outer peripheral surface is formed on the surface opposite to the surface supported by the radial guide of the housing guide.
KR1020100103577A 2010-10-22 2010-10-22 Electric power steering apparatus for vehicle KR20120042087A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020100103577A KR20120042087A (en) 2010-10-22 2010-10-22 Electric power steering apparatus for vehicle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020100103577A KR20120042087A (en) 2010-10-22 2010-10-22 Electric power steering apparatus for vehicle

Publications (1)

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KR20120042087A true KR20120042087A (en) 2012-05-03

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Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020100103577A KR20120042087A (en) 2010-10-22 2010-10-22 Electric power steering apparatus for vehicle

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180089691A (en) * 2017-02-01 2018-08-09 주식회사 만도 Reducer of Electric Power Steering Apparatus
KR20190070024A (en) * 2017-12-12 2019-06-20 현대자동차주식회사 Reducer support device of MDPS

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180089691A (en) * 2017-02-01 2018-08-09 주식회사 만도 Reducer of Electric Power Steering Apparatus
KR20190070024A (en) * 2017-12-12 2019-06-20 현대자동차주식회사 Reducer support device of MDPS

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