KR20070116328A - Electrical power steering apparatus and manufacturing method thereof - Google Patents

Abstract

An electrical power steering apparatus and its manufacturing method are provided to reduce vibration and noise by compensating for clearance between a worm gear and a worm wheel gear due to screw rotation of an eccentric housing connected with a first bearing supporting a first shaft unit of the worm gear. An electrical power steering apparatus comprises: a gear box housing(200) including a worm gear mounting unit(201) and a worm wheel gear mounting unit(202), which receive rotation power from an electric motor(100) and transmit steering torque, a worm gear(203) installed to the worm gear mounting unit, a worm wheel gear(204) installed to the worm wheel gear mounting unit, which is engaged with the worm gear, a second bearing(220) connected with the gear box housing, which supports to rotate the worm gear including a first shaft(203a) and a second shaft(203b), an eccentric housing(300) equipped with a bearing connection unit(301) so as to connect a first bearing(210) pivoted to the first shaft of the worm gear, and a screw fastening hole(207) formed in one side of the gear box housing, which is screwed with the eccentric housing.

Description

ELECTRICAL POWER STEERING APPARATUS AND MANUFACTURING METHOD THEREOF

1 is a cross-sectional view of an electrically driven steering apparatus according to the prior art,

2 is a cross-sectional view for explaining an electric steering apparatus according to an embodiment of the present invention;

Figure 3 is an exploded perspective view showing a coupling relationship of the eccentric housing shown in FIG.

4 is a right side view of the electric steering apparatus shown in FIG. 2;

FIG. 5 is a schematic view for explaining a method of correcting a clearance amount between a worm gear and a worm wheel gear by the eccentric housing shown in FIG. 3;

6 is a right side view of a state in which the eccentric housing shown in FIG. 3 is fixed to the gearbox housing;

FIG. 7 is a block diagram illustrating a method of manufacturing the electric steering apparatus illustrated in FIG. 2.

<Description of the symbols for the main parts of the drawings>

100: electric motor 200: gearbox housing

201: Worm gear mounting portion 202: Worm wheel gear mounting portion

203: worm gear 204: worm wheel gear

207: screwing hole 210: first bearing

220: second bearing 300: eccentric housing

301: bearing coupling portion 306: clearance adjustment groove

The present invention relates to an electric steering apparatus and a method of manufacturing the same, and more particularly, to an electric steering apparatus and a method of manufacturing the same used to adjust the steering force or steering force of the steering wheel mounted on the vehicle.

In general, the power steering corresponding to the steering device has been in most cases playing a role of reducing the driver's operating force or steering power by using the hydraulic pressure of the engine power.

Recently, the electric steering device, ie, electric power steering or electronic control, which obtains power by using an electric motor that generates rotational power by using electric power which is more environmentally friendly and economically advantageous than hydraulic type that uses the power of a conventional engine. Power Steering is spreading to large-sized cars, especially light and small cars.

To help understand the EPS, we will look at the prior art based on the configuration of the C-EPS. As shown in FIG. 1, the electric steering apparatus according to the related art includes a steering assist electric motor 17 mounted to the motor flange 16 to provide assistance; A worm gear (5: worm gear) having a shaft (5a, 5b) mounted inside the reduction gear casing and axially coupled via the shaft coupler (11) with the rotary shaft of the electric motor (17); A worm wheel gear (4: worm wheel gear) having an output shaft (3) geared with such a worm gear (5) and having a torsion bar (2) inserted in an axial position; It consists of a torque sensor, a potentiometer, a harness, a convolute tube and the like.

By the worm reduction gear structure or the worm gear coupling structure, the worm gear 5 and the worm wheel gear 4 are engaged so that the teeth engage with each other in the state in which the axial directions of their shafts 5a, 5b, and 3 are arranged at right angles to each other. It is. At this time, the worm gear 5 has a single or several rows of twisted teeth in the shape of a screw, and the worm wheel gear 2 corresponding to these teeth has a cylindrical or a long tooth, such as a reduction gear. It will have a reduction ratio of 1/100.

The worm gear 5 and the worm wheel gear 4 correspond to movable parts, and maintain the distance H between the axial directions of the shafts 5a, 5b, 3. Where each tooth is engaged in the worm gear 5 and the worm wheel gear 4, there is a clearance amount B such as a kind of backlash.

The clearance amount, such as backlash (B), is a geometric tolerance between the pitch plane or the distal end of the tooth, and has a significant influence on noise quality such as vibration and noise.

The shaft 5a located at one side of the worm gear 5 is inserted into the bushing-shaped elastic portion 13.

The elastic part 13 is fastened to the ball bearing 12 which consists of the outer ring 12a, the inner ring 12b, and the some ball 12c, but is inserted in the inner diameter of the inner ring 12b.

The inner ring 12b of the ball bearing 12 is in contact with the outer surface of the elastic portion 13, and the outer ring 12a is in contact with the bearing mounting hole 14 of the reduction gear casing.

A screw hole 15 is formed in the reduction gear casing with respect to the outer periphery of the bearing mounting hole 14. The screw ring 18 is coupled to this screw hole 15 to press the outer ring 12a of the ball bearing 12 by screwing.

Here, the outer ring 12a forms a tubular outer wall on the outside of the disk-shaped portion, and forms a shaft coupler passage hole in the shaft center of the disk-shaped portion. For this reason, the space A exists along the axial direction of the shafts 5a and 5b of the worm gear 5 in the inner space of the outer ring 12a.

On the other hand, the shaft 5b located on the other side of the worm gear 5 is inserted into the pushing portion 9 with the sliding bearing 10 interposed therebetween.

The pushing part 9 is attached to the guide hole 19 formed in the direction perpendicular to the axial direction of the shafts 5a and 5b of the worm gear 5.

An elastic body 8 and an elastic plate 7 are mounted in the upper space inside the pushing portion 9.

A movable screw 6 coupled to the upper portion of the elastic plate 7 to be movable up and down by screwing is coupled.

The screw rotation of the movable screw 6 generates a pressing force for moving the elastic plate 7 and the elastic body 8 in the vertical direction.

This pressing force moves the shaft 5b located on the other side of the worm gear 5 with the shaft 5a located on one side of the worm gear 5 as a center point, thereby reducing the clearance between the worm gear 5 and the worm wheel gear 4. Used to adjust.

That is, the electric steering apparatus according to the related art uses a play force to apply a force by using elastic means such as an elastic plate 7, an elastic body 8, an elastic portion 13, etc. coupled to the worm gear 5 to compensate for the play amount. It has a quantity correction configuration.

However, the clearance correction structure of the electric steering apparatus according to the prior art has a fatal disadvantage that the elastic means or some bearings are not constrained to the reduction gear casing.

For example, the elastic portion 13 of the elastic means may be constrained by the ball bearings 12 in the radial direction of the shafts 5a and 5b of the worm gear 5, but the shafts 5a and 5b of the worm gear 5 may be restricted. Since it is not constrained in the same direction as the spacing space A, resonance may occur in the elastic portion 13, which causes vibration and noise between the worm gear 5 and the worm wheel gear 4 pitch face or tooth end face. This may occur.

Resonance means that the object vibrates according to the frequency when a wave having the same frequency as the natural frequency that each object has is applied from the outside. When the object exceeds the limit of the amplitude that can vibrate for each object by the resonance, It means you can destroy it.

For this reason, the electric steering apparatus according to the prior art has a disadvantage in that the worm reducer structure has a structure that is vulnerable to vibration and noise, even if the worm reducer structure corrects the amount of play before its operation, even though the worm reducer structure corrects the amount of play. have.

In addition, the electric steering apparatus according to the related art mounts the movable screw 6, the elastic plate 7, the elastic body 8, the pushing part 9, and the sliding bearing 10 through the guide hole 19. , Has a complex coupling structure such as the shaft 5b of the worm gear 5 to the sliding bearing 10, there is a disadvantage that the assembly is very inconvenient and takes a relatively long time.

In addition, the electric steering apparatus according to the related art has a structure in which the header portion of the movable screw 6 protrudes outwardly of the reduction gear casing in order to rotate the movable screw 6, so that the layout of the electric steering apparatus as a whole is improved. By extension, the space utilization is relatively low when the electric steering device is mounted on a vehicle.

In addition, the electric steering apparatus according to the prior art should further include an auxiliary nut 6a for the movable screw 6, and in order to keep the movable screw 6 fixed in the reduction gear casing, the movable screw 6 is provided. Since the auxiliary nut 6a needs to be rotated without rotating, there is an inconvenience and complexity in assembling work at the time of fixing the movable screw 6 after adjusting the flow rate.

An object of the present invention devised to solve such a problem is to compensate for the clearance between the worm gear and the worm wheel gear according to the screw rotation of the eccentric housing in which the first bearing for supporting the first shaft portion of the worm gear is coupled, thereby providing vibration and noise. It is to provide an electric steering apparatus that can reduce the.

In addition, another object of the present invention is to mount the eccentric housing to the gearbox housing in the screw-mounted type to easily adjust the clearance between the worm gear and the worm wheel gear, produced by fixing the eccentric housing to the gearbox housing by the caulking method And it provides a method of manufacturing an electric steering apparatus that can increase the workability.

Objects of the present invention as described above in the electric steering apparatus having a gearbox housing having a worm gear mounting portion with a worm gear mounting portion and a worm wheel gear mounting portion with a worm gear gear that receives the rotational force from the electric motor, the first shaft portion and the worm gear portion A second bearing assembled to the gearbox housing to rotatably support the worm gear including a second shaft portion; An eccentric housing in which a bearing engaging portion is formed such that the first bearing assembled to the first shaft portion of the worm gear is engaged with respect to the opposite side of the second bearing; And a screwing hole formed at one side of the gearbox housing to screw the eccentric housing, wherein the eccentric housing is different from a first center of the bearing coupling portion and a second center of one end surface of the eccentric housing. It is achieved by an electric steering device having an eccentric structure in position and fixed to the gearbox housing to have at least one caulking portion.

In addition, an object of the present invention is a method of manufacturing an electric steering apparatus, comprising: a coupling step of coupling a first bearing to a bearing coupling portion of an eccentric housing in a fitting coupling manner; A mounting step of mounting the eccentric housing in a screwing manner at a screwing hole of the gearbox housing; An assembling step of assembling a second bearing, a worm gear and a worm wheel gear to the gearbox housing; After the assembling step, when the eccentric housing is rotated by a finite rotation angle while the gearbox housing is fixed, the first bearing coupled to the bearing coupling part of the eccentric housing by a finite sized moving distance A correction step of correcting a clearance between the worm gear and the worm wheel gear by performing a center movement; After the correcting step, it is possible to achieve by the manufacturing method of the electric steering apparatus, characterized in that it comprises a fixing step of fixing the eccentric housing to the gearbox housing by a caulking method.

In the electric steering apparatus according to the present invention, since the other parts controlled by the controller for EPS (not shown) are the same as the general components, when the user operates the handle, the torque sensor recognizes a value corresponding to the handle operation, The detailed configuration and the coupling relationship for supplying the current and voltage corresponding to the result of the control to the rotating shaft of the electric motor by performing the corresponding control are omitted in the detailed description of the present invention.

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

In the accompanying drawings, Figure 2 is a cross-sectional view for explaining the electric steering apparatus according to an embodiment of the present invention, Figure 3 is an exploded perspective view showing a coupling relationship of the eccentric housing shown in Figure 2, Figure 4 is a Right side view of the electric steering apparatus shown. In addition, Figure 5 is a schematic diagram for explaining a method for correcting the amount of play between the worm gear and the worm wheel gear by the eccentric housing shown in Figure 3, Figure 6 is a eccentric housing shown in Figure 3 is fixed to the gearbox housing FIG. 7 is a block diagram illustrating a method of manufacturing the electric steering apparatus illustrated in FIG. 2.

First, as shown in FIG. 2, the electric steering apparatus of the present invention receives a worm gear mounting portion 201 and a worm wheel gear mounting portion 202 to receive a rotational force from the electric motor 100 to transmit a steering force corresponding to the reduction ratio. A gearbox housing 200 having; A worm gear 203 installed in the worm gear mounting unit 201; The worm wheel gear mounting portion 202 is provided with a worm wheel gear 204 geared with the worm gear 203.

The worm gear 203 includes a first shaft portion 203a and a second shaft portion 203b formed at both ends of the worm gear portion.

A motor flange 204 for mounting the electric motor 100 is formed at the other side (left side in FIG. 2) of the gearbox housing 200, and inwardly coincides with the shaft center of the rotation shaft of the electric motor 100. The fixing ring screw hole 205 is formed with respect to the imaginary extension line L. As shown in FIG.

The second bearing 220 is placed on the other side of the worm gear mounting portion 201 corresponding to the inside of the fixing ring screw hole 205, and the bearing fixing ring 206 is screwed into the fixing ring screw hole 205, The outer ring of the second bearing 220 is constrained to the gearbox housing 200.

Here, the second bearing 220 is preferably self-aligning type bearings. For example, the self-aligning bearing corresponding to the second bearing 220 may be any one selected from self-aligning ball bearings, spherical roller bearings, and the like. In the case of having the self-monitoring function, it can be applied and used in the present invention.

On the other hand, one side (in FIG. 2, right side) of the gearbox housing 200 corresponding to the opposite side of the electric motor 100 as the worm gear mounting portion 201, the eccentric housing screwing holes (207: hereinafter referred to as 'screwing holes') ) Is formed.

Here, the screwing hole 207 is used to screw the eccentric housing 300 to the gear box housing 200 to be mounted.

As the screwing hole 207 and the eccentric housing 300 are simultaneously mounted and adjusted through screwing, the screw fastening hole 207 and the eccentric housing 300 have features of the present invention that do not require a separate fastener.

The hole center of the screwing hole 207 coincides with the second center of the one end surface 302 of the eccentric housing 300, which will be described later, while the first of the bearing engaging portion 301 of the eccentric housing 300 is formed. It is preferable that the center or one of the bearing centers of the first bearing 210 coupled to the bearing coupling part 301 is eccentric.

Here, the first bearing 210 is disposed on one side of the worm gear mounting portion 201, and is coupled to and seated on the bearing coupling portion 301 of the eccentric housing 300.

In addition, the screw fastening hole 207 includes a screw hole portion 207a which is screwed in correspondence with the screw portion of the eccentric housing 300 to be described later; It is preferable that the fitting hole portion 207b is formed to be hermetically inserted corresponding to the circular fitting portion of the eccentric housing to be described below.

The bearing coupling part 301 of the eccentric housing 300 is a circular groove having an inner diameter equivalent to the outer ring of the first bearing 210 and is used to couple the first bearing 210.

In addition, the one end surface 302 of the eccentric housing 300 formed on the opposite side of the bearing coupling portion 301 is a hexagon wrench structure that hardly protrudes out of the gearbox housing 200 by the clearance adjustment groove 306. Since the layout of the electric steering apparatus is hardly expanded as a whole, the space utilization when mounting the electric steering apparatus is relatively large.

Here, the first bearing 210 is preferably a general ball bearing.

For example, the ball bearing corresponding to the first bearing 210 may be any one selected from a deep groove ball bearing, a magneto ball bearing, an angular ball bearing, a double row angular ball bearing, a combination angular ball bearing as a radial type, and any bearing may be a rotating shaft. In the case of a radial type capable of supporting the present invention can be applied and used.

Of the both ends of the worm gear 203, the first bearing 210 is assembled to the first shaft portion 203a, and the second bearing 220 is assembled to the second shaft portion 203b by a fitting coupling method.

The second bearing 220 is supported and restrained by the gearbox housing 200, and the first bearing 210 is supported and restrained by the bearing coupling part 301 of the eccentric housing 300.

Accordingly, the worm gear 203 and its first and second shaft parts 203a and 203b are rotatable in the worm gear mounting part 201 by the first and second bearings 210 and 220.

Referring to FIGS. 3 and 4, the inner surface of the bearing coupling part 301 is constrained only by the outer ring of the first bearing 210 by pressing, and is circular in recessed contact with the retainer and the inner ring of the first bearing 210. It is preferable that the recessed groove 305 is further formed.

The eccentric housing 300 to which the first bearing 210 is coupled is screwed in the screwing hole 207 to be mounted to the gearbox housing 200.

To this end, the eccentric housing 300 includes a screw 303 in which a screw line is formed on an outer circumferential surface of one side of the housing and a clearance adjusting groove 306 is formed on one end surface 302; The bearing coupling portion 301 having a uniform surface on the outer peripheral surface of the housing formed integrally with the screw portion 303 and having an inner diameter and a fitting depth of fitting equivalent to the outer ring of the first bearing 210 at the other end surface. Is formed of a circular fitting portion 304 is formed.

Here, the clearance adjusting groove 306 preferably has a hexagonal groove shape so that an adjustment tool such as a hexagon wrench can be inserted therein. In addition, the center of the clearance adjusting groove 306 preferably coincides with the second center C2 of the one end surface 302 of the eccentric housing 300.

The eccentric housing 300 has an eccentric structure in which the first center C1 of the bearing coupling part 301 and the second center C2 of one end surface 302 of the eccentric housing 300 are different from each other. .

Here, the first center C1 of the bearing coupling part 301 may coincide with the bearing center of the first bearing 210.

As described above, the axial direction of the first and second shaft portions of the worm gear 203 axially coupled to receive the rotational force from the rotating shaft of the electric motor 100 is the first bearing by the fastening with the first bearing 210. Through the center of the bearing of 210, it can eventually coincide with the first center C1 of the bearing engagement portion 301 of the eccentric housing 300, while the one end surface 302 of the eccentric housing 300 is It is inconsistent with the second center C2, that is, eccentric.

A method of correcting the clearance between the worm gear 203 and the worm wheel gear 204 by the eccentric housing 300 will be understood with reference to FIG. 5.

As shown in FIG. 5, the first center C1 of the bearing coupling portion of the eccentric housing and the second center C2 of one end surface of the eccentric housing have the first and second centers C1 and C2 in a straight line. The connected eccentric distance S is maintained.

The operator for correcting the backlash and the like measure the amount of play through a predetermined reduction gear play amount measuring equipment, such as a backlash measuring device that has been filed by the present applicant.

Thereafter, the operator inserts a predetermined adjustment tool such as a hexagon wrench into the clearance adjusting groove 306 at the position M at which the initial clearance amount is to be corrected, thereby reducing the basic clearance amount when the initial worm gear and the worm wheel gear are assembled. To rotate the eccentric housing by the first rotation angle r1.

In this case, as the eccentric housing is rotated based on the second center C2 and the eccentric distance S, the first center C1 is moved by the first movement distance h1 to firstly correct the first. Reach the center C1 '.

As a result, the first bearing and the first shaft portion of the worm gear assembled to the bearing engagement portion of the eccentric housing are moved toward the center of the worm wheel gear in proportion to the movement ratio of the first travel distance h1 to compensate for the reduction in the reference clearance amount. The second shaft portion of the worm gear is automatically adjusted in the axial twist of the first and second shaft portions of the worm gear by the self-aligning bearing, that is, the second bearing.

Further, if necessary, the operator may move the eccentric housing by the second rotation angle r2 in the direction of increasing the basic flow amount by using a predetermined adjustment tool and the clearance adjustment groove at the position M where the initial flow amount correction starts if necessary. Can be reversed.

In this case, as the eccentric housing is reversely rotated based on the second center C2 and the eccentric distance S, the first center C1 is moved by the second movement distance h2 to compensate for the second correction. Reach one center (C1 ").

As a result, the first bearing coupled to the bearing engagement portion of the eccentric housing and the first shaft portion of the worm gear are moved away from the center of the worm wheel gear in proportion to the movement ratio of the second travel distance h2 to increase the reference clearance amount. The second shaft portion of the worm gear is also automatically adjusted in the axial twist of the first and second shaft portions of the worm gear by the self-aligning bearing, that is, the second bearing.

Here, the first travel distance h1 or the second travel distance h2 is calculated by multiplying the eccentric distance S by the sine of each of the first rotation angle r1 or the second rotation angle r2. As such, precise and simple clearance adjustment may be performed based on the first rotation angle r1 or the second rotation angle r2.

Thus, the electric steering apparatus of the present invention, in which the clearance adjustment is completed, does not cause resonance by conventional elastic means, and the seating state of the first bearing or the second bearing is moved in the radial direction or the axial direction passing through the center of the inner ring of the bearing. By constraining, vibration and noise generation are significantly reduced.

Then, as shown in Figure 6, after the clearance adjustment as described above the eccentric housing 300 has a gearbox housing 200 to have at least one caulking portion 400 by a caulking method using a conventional caulking (caulking) equipment. It is fixed to).

Hereinafter, a manufacturing method of the electric steering apparatus will be described with reference to FIG. 7.

As illustrated in FIG. 7, in the cooking method of the electric steering apparatus of the present invention, a coupling step of coupling the first bearing to the bearing coupling portion of the eccentric housing by fitting coupling is performed (S10).

Thereafter, the mounting step in which the eccentric housing is mounted in a screwing manner at the screwing hole of the gearbox housing is performed (S20).

Then, an assembly step of assembling the second bearing and the worm gear and the worm wheel gear to the gearbox housing is performed (S30).

At this time, by the fitting coupling method, one of the first shaft portion of both ends of the worm gear is assembled to the inner ring of the first bearing coupled to the eccentric housing, and the second shaft portion of the other side is assembled to the inner ring of the second bearing. Then, the outer ring of the second bearing is fixed to the gearbox housing by engaging the fixing ring to the fixing ring screw hole.

After the assembling step (S30), the amount of play such as backlash is measured by a predetermined play amount measuring equipment. When the eccentric housing is rotated by a finite rotation angle (for example, the first rotation angle or the second rotation angle) while the gearbox housing is fixed based on the result of the clearance measurement, the eccentric housing by the finite moving distance. The first bearing coupled to the bearing coupling portion of the bearing performs a center movement to correct the amount of play between the worm gear and the worm wheel gear (S40).

After the correction step (S40), a fixing step (S50) of fixing the eccentric housing to the gearbox housing by a caulking method by a predetermined caulking equipment is performed.

As described above, the electric steering apparatus of the present invention configured as described above is mounted to the gearbox housing after being coupled to the eccentric housing without using the elastic means, or as directly assembled to the gearbox housing. By constraining the seating state of all bearings in the radial direction or the axial direction passing through the center of the inner ring of the bearing has the advantage that vibration and noise generation can be significantly reduced.

In addition, the electric steering apparatus of the present invention has an advantage of simply adjusting and correcting the amount of clearance by simply rotating the eccentric housing by a finite angle range corresponding to the amount of clearance such as the measured backlash.

In addition, the electric steering apparatus of the present invention uses a self-aligning bearing for the second bearing, instead of lowering the manufacturing cost by using a general ball-type bearing for the first bearing, and without using an elastic means capable of generating resonance. Even if it is corrected, there is an advantage of automatically adjusting the distortion of the shaft core, which may be caused by the amount of play of the worm gear and its shaft.

In addition, the electric steering apparatus of the present invention has a hexagonal wrench use structure, so that the eccentric housing hardly protrudes out of the gearbox housing, and the layout of the electric steering apparatus as a whole does not extend substantially, so that the electric steering apparatus is used as a vehicle. Space utilization has a relatively big advantage when mounted on the.

In addition, the manufacturing method of the electric steering apparatus of the present invention can compensate and fix the play amount through the assembly method and the caulking method for screwing the eccentric housing combined with the first bearing for supporting the first shaft portion of the worm gear to the gearbox housing. Therefore, there is an advantage that can increase the workability and productivity of the corresponding products such as the electric steering device.

In addition, the manufacturing method of the electric steering apparatus of the present invention corresponds to a direct method in which the rotation of the hexagon wrench directly corrects the clearance amount of the worm gear and the worm wheel gear, and the accuracy of the plurality of components together with the ease of correction work. Compared with the prior art made of a remarkably excellent assembly is very easy and there is an advantage that can reduce the work time relatively.

In addition, the preferred embodiment of the present invention is disclosed for the purpose of illustration, those skilled in the art will be able to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (6)

In the electric steering apparatus having a gearbox housing having a worm gear mounting portion equipped with a worm gear and a worm wheel gear mounting portion provided with a worm wheel gear receiving rotational force from an electric motor, A second bearing assembled to the gearbox housing to rotatably support the worm gear including a first shaft portion, a worm gear portion and a second shaft portion; An eccentric housing in which a bearing engaging portion is formed such that the first bearing assembled to the first shaft portion of the worm gear is engaged with respect to the opposite side of the second bearing; And a screwing hole formed in one side of the gearbox housing to screw the eccentric housing, The eccentric housing has an eccentric structure in which the first center of the bearing coupling portion and the second center of one end surface of the eccentric housing are in different positions, and are fixed to the gearbox housing to have at least one caulking portion. Electric steering apparatus, characterized in that. The method of claim 1, The inner surface of the bearing coupling portion is limited to the outer ring of the first bearing by pressing, and further comprises a circular recessed groove recessed to be in contact with the retainer and the inner ring of the first bearing. The method of claim 1, The eccentric housing may include a screw portion having a screw line formed at one outer circumferential surface of the housing and a clearance adjusting groove having a hexagonal groove shape at one end surface thereof; It includes a circular fitting portion formed with the bearing coupling portion having a uniform surface formed on the outer peripheral surface of the housing integrally formed with the screw portion and has an inner diameter of a size equal to the outer ring of the first bearing on the other end surface; An electric steering apparatus characterized by the above. In the manufacturing method of the electric steering apparatus, A coupling step of coupling the first bearing to the bearing coupling portion of the eccentric housing in a fitting coupling manner; A mounting step of mounting the eccentric housing in a screwing manner at a screwing hole of the gearbox housing; An assembling step of assembling a second bearing, a worm gear and a worm wheel gear to the gearbox housing; After the assembling step, when the eccentric housing is rotated by a finite rotation angle while the gearbox housing is fixed, the first bearing coupled to the bearing coupling part of the eccentric housing by a finite sized moving distance A correction step of correcting a clearance between the worm gear and the worm wheel gear by performing a center movement; And a fixing step of fixing the eccentric housing to the gearbox housing by caulking. The method of claim 4, wherein The assembling step of the electric steering apparatus manufacturing method, characterized in that for rotating the eccentric housing forward or reverse to correspond to the flow rate measurement results, such as backlash. The method of claim 4, wherein The moving distance is calculated by multiplying the sine value (sine) of the rotation angle by the eccentric distance (S) connecting the first center of the bearing coupling portion and the second center of one end surface of the eccentric housing in a straight line. Method of manufacturing an electric steering device.

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