KR20070018336A - Electric Power Steering System Equipped with Clearance Compensator for Use in Worm Gear - Google Patents

Abstract

The present invention relates to an electric power assisted steering apparatus having a worm gear clearance compensation device.

The present invention provides an electric power assisted steering device in which a worm wheel is mounted on a steering shaft and a worm shaft having a worm which is entangled with the worm wheel is driven by a motor, wherein the worm wheel and the steering shaft and the steering shaft bearing are installed. A worm wheel housing formed to be fixed and open at one side; A worm housing connected to the motor and configured to have the worm shaft and the worm shaft bearing internally fixed and having an open side surface coupled or separated from the open side surface of the worm wheel housing; An elastic member inserted into an engagement surface between the worm wheel housing and the worm housing; And a fastening means for coupling the worm wheel housing and the worm housing to an electric power assisted steering apparatus having a worm gear play compensation device.

According to the present invention, the worm gear housing is formed by dividing the worm wheel housing and the worm housing, and the worm wheel by the coupling force of the worm wheel housing and the worm housing by inserting and engaging an elastic member between the coupling surface of the worm wheel housing and the worm housing. By preventing the bite play of the worm and the worm, it is possible to prevent the vibration and noise caused by the worm gear bite play during steering operation of a vehicle equipped with an electric power assisted steering device and to provide a smooth and comfortable steering feeling to the driver. There is.

Worm wheel, worm, worm wheel housing, worm housing, tension device

Description

Electric Power Steering System Equipped with Clearance Compensator for Use in Worm Gear}

1 is a perspective view briefly showing the shape of a worm gear housing of a conventional column type electric power assisted steering device;

Figure 2 is a horizontal cross-sectional view showing the internal structure of a conventional column type electric power assist steering device,

3 is an exploded perspective view briefly illustrating a structure of a worm gear play compensation device of a column type electric power assisted steering device according to an embodiment of the present invention;

4 is a horizontal cross-sectional view showing the structure of a worm gear clearance compensation device of a column type electric power assisted steering device according to an embodiment of the present invention;

5 is an exploded perspective view briefly illustrating a structure of a worm gear play compensation device of a column type electric power assisted steering device according to another embodiment of the present invention;

6 is a horizontal cross-sectional view showing the structure of a worm gear clearance compensation device of a column type electric power assisted steering device according to another embodiment of the present invention;

7 is an exploded perspective view briefly showing a structure of a worm gear play compensation device of a column type electric power assisted steering device according to another embodiment of the present invention;

8 is a horizontal cross-sectional view showing the structure of a worm gear clearance compensation device of a column type electric power assisted steering device according to another embodiment of the present invention;

9 is an exploded perspective view briefly showing the structure of a worm gear play compensation device of a column type electric power assisted steering device according to another embodiment of the present invention;

10 is a horizontal cross-sectional view showing the structure of a worm gear clearance compensation device of a column type electric power assisted steering device according to another embodiment of the present invention.

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

100: worm gear housing 102: worm wheel

104: worm 106: steering shaft

108: worm shaft 110: motor

202: worm shaft bearing 204: motor shaft

310: worm housing 312: third protrusion

314: fourth protrusion 320: worm wheel housing

322: first protrusion 324: second protrusion

330: sealing elastic member 332: bonding elastic member

334: coupling bolt 336: coupling nut

338: hole 340: motor

410: worm shaft 412: worm

414: worm shaft bearing 416: bush

420: steering shaft 422: worm wheel

510: hinge axis 710: tension device

712: flat washer 714: coil spring

The present invention relates to an electric power assisted steering apparatus having a worm gear clearance compensation device. More specifically, in an electric power assisted steering device in which a worm shaft is mounted on a steering shaft and a worm shaft having a worm that is bitten by a worm wheel is driven by a motor, the worm wheel and the worm gear portion formed by the worm are protected. The worm gear housing is formed by dividing the worm gear housing into a worm wheel housing and a worm housing, and the elastic member is inserted between the worm wheel housing and the worm housing by inserting an elastic member between the worm wheel housing and the worm housing coupling surface, thereby increasing the coupling force between the worm wheel housing and the worm housing. The present invention relates to an electric power assisted steering device having a worm gear play compensation device for preventing the play between the worm wheel and the worm.

Recent technical trends of the vehicle steering apparatus have been researched and developed in the direction of pursuing the convenience of the driver along with safety such as the stability of the steering state and the smooth and comfortable steering feeling. In accordance with this development trend, various power assist steering devices, such as hydraulic or electric, are being developed as a way to improve the driver's steering feeling. Electric power is advantageous due to the lighter electric, less energy consumption, and improved fuel economy. The use of auxiliary steering devices is increasing.

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 speeds. It provides a heavy and stable steering condition during operation, and provides steering performance to maintain the optimal steering feeling for the driver by coping with it in case of emergency and enabling rapid steering operation.

 The electric power assisted steering device can be divided into various types according to the mounting position. The column-type electric power assisted steering device (C-EPS) is used in the driver's steering wheel and under the vehicle. A power assist steering device equipped with an electric motor is installed in the steering column part for fixing the steering shaft connecting the gearbox to the vehicle body so that the rotational force of the steering wheel operated by the driver can be transmitted to the gearbox by the power assist steering device. Device.

1 is a perspective view briefly showing the shape of a worm gear housing of a conventional column type electric power assist steering device, and FIG. 2 is a horizontal sectional view showing the internal structure of a conventional column type electric power assist steering device.

A worm shaft 108 having a worm 104 formed in the middle thereof is provided, and worm shaft bearings 202 are installed at both ends of the worm shaft 108 to support the worm shaft 108. The worm shaft 108 is a motor The worm shaft 108 is connected to the shaft 204 to rotate by the driving of the motor 110.

The worm wheel 102 is provided at one side of the outer diameter of the worm 104 so that the worm 104 can be separated from the worm 104 formed in the middle of the worm shaft 108. The worm wheel 102 is a steering wheel operated by a driver ( It is mounted on the steering shaft 106 for transmitting the rotational force of the (not shown), the rotational force of the worm shaft 108 by the drive of the motor is transmitted to the steering shaft 106.

Accordingly, a steering wheel (not shown) in which the driving 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 108 driven by the driving of the motor 110 is manipulated by the driver. In addition to the rotational force of), it is transmitted to the steering shaft 106, so that the steering operation state of the driver can be smoothly and stably maintained.

The worm gear portion in which the worm wheel 102 and the worm 104 are driven by being bitten off is fixedly mounted inside the integral worm gear housing 100 for protection from the outside, but in the worm gear tooth enlarged view of FIG. As shown by the dotted line, a gap occurs in the bite of the worm wheel 102 and the worm 104 due to wear or deformation of the gear according to use. When such a play occurs, vibration and noise are generated when the worm gear is driven, thereby hindering smooth and comfortable steering operation.

Therefore, the present invention is to solve this problem, the worm gear housing is formed by dividing the worm wheel housing and the worm housing and the worm wheel housing and the worm by inserting the elastic member between the coupling surface of the worm wheel housing and the worm housing As the coupling force between housings increases, the elastic members between the coupling surfaces can be compressed to reduce the play between the worm wheel and the worm's bite. Also, by combining the worm wheel housing and the worm housing with the tension of the tension device, It is an object of the present invention to provide an electric power assisted steering apparatus having a worm gear clearance compensation device capable of preventing a bite clearance.

In order to achieve the above object, the present invention provides an electric power assisted steering device in which a worm shaft is mounted on a steering shaft and a worm shaft having a worm bited by the worm wheel is driven by a motor. A worm wheel housing having a shaft and a steering shaft bearing formed therein and fixed at one side thereof; A worm housing connected to the motor and configured to have the worm shaft and the worm shaft bearing internally fixed and having an open side surface coupled or separated from the open side surface of the worm wheel housing; An elastic member inserted into an engagement surface between the worm wheel housing and the worm housing; And a fastening means for coupling the worm wheel housing and the worm housing to an electric power assisted steering apparatus having a worm gear play compensation device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

3 is an exploded perspective view briefly illustrating a structure of a worm gear play compensation device of a column type electric power assisted steering device according to an embodiment of the present invention, and FIG. 4 is a column type electric power assisted device according to an embodiment of the present invention. A horizontal cross-sectional view showing the structure of a worm gear play compensation device of a steering device.

Worm with a worm wheel 422 mounted on a steering shaft 420 that transmits the rotational force of a steering wheel (not shown) operated by the driver to the lower universal joint, and a worm 412 that is engaged with the worm wheel 422 is formed. It has a shaft 410. A worm 412 is formed in the middle of the worm shaft 410, and worm shaft bearings 414 are installed at both ends of the worm shaft 410 to support the worm shaft 410, and one end of the worm shaft 410 is provided. The worm shaft 410 is rotated by the driving of the motor 340 is connected to the motor shaft.

Since the worm 412 formed on the worm shaft 410 is rotated by the worm shaft 410 rotated by the driving of the motor 340, the worm wheel 422 is rotated so that the worm shaft 410 rotates. The rotational force of the worm shaft 410 is transmitted to the steering shaft 420 which is perpendicular to the axial direction of the worm shaft 410. Therefore, the rotational force of the steering wheel (not shown) operated by the driver and the rotational force of the driving of the motor 340 are synthesized to perform steering operation.

The worm gear housing for protecting the worm gear, which is formed by the worm wheel 422 and the worm 412 being bitten away from the outside, is a steering shaft supporting the worm wheel 422, the steering shaft 420, and the steering shaft 420. The worm wheel housing 320 and the worm shaft 410 and the worm shaft bearing 414 are formed to be internally fixed and are connected to the worm shaft 410 driving motor 340. The structure is formed by dividing into a worm housing 310. The worm wheel housing 320 and the worm housing 310 are formed in the worm wheel housing 320 and the worm housing 310 by forming portions of the worm wheel 422 and the worm 412 in the open surface, respectively. The worm wheel 422 and the worm 412 may be bitten by combining the open surfaces with each other.

The worm wheel housing 320 and the worm housing 310 has the same shape of the open side of the worm wheel housing 320 and the worm housing 310 of the same shape as the open face of the worm sealing member 330 It is inserted between the coupling surface of the wheel housing 320 and the worm housing 310 to be a seal for the gear oil.

The first protrusion 322 and the second protrusion 324 are formed in parallel with the open face on both sides of the open face of the worm wheel housing 320 and the face also open on both sides of the open face of the worm housing 310. The third protrusion 312 and the fourth protrusion 314 are formed in parallel with each other. When the worm wheel housing 320 and the worm housing 310 are coupled so that the worm wheel 422 and the worm 412 may be bitten, the first protrusion 322 and the third protrusion 312 may be bolted to each other. The holes 338 are formed on the same axis so that the centers are located on the same axis, and the second protrusions 324 and the fourth protrusions 314 may be bolted to each other. ). The combination of the worm wheel housing 320 and the worm housing 310 is a structure that is coupled by bolting of each corresponding protrusion. It also includes inserting an annular engagement elastic member 332 of the same thickness and material as the sealing elastic member 330 between each corresponding protrusion that engages.

Coupling bolt inserting the sealing elastic member 330 and the coupling elastic member 332 between the coupling surface of the worm wheel housing 320 and the worm housing 310, and coupling the worm wheel housing 320 and the worm housing 310 As the tightening force of the 334 is increased, the sealing elastic member 330 and the coupling elastic member 332 are compressed, and the gap between the worm wheel housing 320 and the coupling surface of the worm housing 310 becomes smaller. And the bite play of the worm 412 becomes small. Therefore, in the case of the foreign matter clearance caused by the deformation or wear of the worm wheel 422 and the worm 412 may increase the fastening force of the coupling bolt 334 can compensate for the clearance.

The sealing elastic member 330 and the coupling elastic member 332 inserted between the worm wheel housing 320 and the coupling surface of the worm housing 310 are preferably made of a rubber material, but there is no particular limitation thereto.

In addition, the present invention inserts a bush 416 having elastic force to the outer circumferential surface of the worm shaft bearing 414 is fixed to the worm housing 310 in accordance with an embodiment of the worm wheel 422 and the worm 412 It includes a structure that absorbs vibration caused by the bite play.

5 is an exploded perspective view briefly illustrating a structure of a worm gear play compensation device of a column type electric power assisted steering device according to another embodiment of the present invention, and FIG. 6 is a column according to another embodiment of the present invention. A horizontal cross-sectional view showing the structure of a worm gear clearance compensation device of a type electric power assisted steering device.

According to another embodiment of the present invention, the present invention has a structure formed by dividing the worm wheel housing 320 and the worm housing 310 as shown in FIGS. 3 and 4, and the worm wheel housing 320. And the worm wheel housing 320 and the worm housing 310 are connected to each other in a hinged structure for convenience of coupling and assembly of the worm housing 310.

One side of the open surface of the worm wheel housing 320 and the worm housing 310 is formed with a first protrusion 322 and a third protrusion 312 having holes 338, respectively, and on the opposite side of the worm housing 310. The hinge shaft 510 which is a rotation center of the insert is connected to the hinge structure. The worm wheel housing 320 is fixed and the worm housing 310 is rotatable about the hinge axis 510 so that the open face of the worm wheel housing 320 and the open face of the worm housing 310 are coupled to each other. The first protrusion 322 and the third protrusion 312 are coupled by bolting. In addition, a sealing elastic member 330 and a coupling elastic member 332 are inserted between the worm wheel housing 320 and the coupling surface of the worm housing 310, according to the same principle as the exemplary embodiment illustrated in FIGS. 3 and 4. By increasing the fastening force of the coupling bolt 334 it is possible to compensate for the clearance gap of the worm wheel 422 and the worm 412.

7 is an exploded perspective view briefly illustrating a structure of a worm gear play compensation device of a column type electric power assisted steering device according to another embodiment of the present invention, and FIG. 8 is a column according to another embodiment of the present invention. A horizontal cross-sectional view showing the structure of a worm gear clearance compensation device of a type electric power assisted steering device.

According to another embodiment of the present invention, the present invention is formed by dividing the worm wheel housing 320 and the worm housing 310 as shown in Figs. The structure, but including the tension device 710 in the bolt fastening portion.

The tension device 710 is configured in such a manner that the worm wheel housing 320 and the worm housing 310 are coupled by inserting the flat washer 712 and the coil spring 714 into the coupling bolt 334. The sealing elastic member 330 and the engaging elastic member 332 are inserted between the worm wheel housing 320 and the engaging surface of the worm housing 310, and the first protrusion 322, the third protrusion 312, and the second protrusion are inserted. When fastening the 324 and the fourth protrusion 314 to the coupling bolt 334, the flat washer 712 and the coil spring 714 are attached to the coupling bolt 334 as shown in FIGS. 7 and 8. By inserting and fastening, the worm wheel housing 320 and the worm housing 310 are coupled by the elastic force of the coil spring 714.

Therefore, when there is play in debris due to deformation or wear of the worm wheel 422 and the worm 412, the sealing elastic member 330 may be formed by the elastic force of the tension device 710 even without increasing the tightening force of the coupling bolt 334. And the coupling elastic member 332 are compressed and the gap between the coupling surface of the worm wheel housing 320 and the worm housing 310 is smaller, so that the clearance gap between the worm wheel 422 and the worm 412 becomes smaller.

FIG. 9 is an exploded perspective view briefly illustrating a structure of a worm gear play compensation device of a column type electric power assisted steering device according to another embodiment of the present invention, and FIG. 10 is a column according to another embodiment of the present invention. A horizontal cross-sectional view showing the structure of a worm gear clearance compensation device of a type electric power assisted steering device.

According to another embodiment of the present invention, the present invention is formed by dividing the worm wheel housing 320 and the worm housing 310 as shown in Figures 5 and 6 and connected in a hinge structure, the first protrusion ( And a tension device 710 at the bolt coupling portion of the 322 and the third protrusion 312.

The tension device 710 inserts the flat washer 712 and the coil spring 714 into the coupling bolt 334 to the first protrusion 322 of the worm wheel housing 320 and the third protrusion of the worm housing 310. 312). When the worm housing 310 is rotatable about the hinge shaft 510 to bolt the first protrusion 322 and the third protrusion 312, as illustrated in FIGS. 9 and 10, the coupling bolt ( The worm wheel housing 320 and the worm housing 310 are coupled by the elastic force of the coil spring 714 by inserting and fastening the flat washer 712 and the coil spring 714 into the 334.

Therefore, according to the same principle as the exemplary embodiment illustrated in FIGS. 7 and 8, the bite play between the worm wheel 422 and the worm 412 is reduced by the elastic force of the tension device 710.

The tension device 710 described above is set to insert the flat washer 712 and the coil spring 714 to the coupling bolt 334, but there is no particular limitation thereon and has a greater elastic force than the sealing elastic member 330 An elastic member (not shown) can also be used.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes 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.

As described above, according to the present invention, the worm gear housing is formed by dividing the worm wheel housing and the worm housing, and the elastic member is inserted between the worm wheel housing and the coupling surface of the worm housing to engage the worm wheel housing and the worm housing. It prevents the bite play of the worm wheel and the worm by the coupling force to prevent vibration and noise caused by the worm gear bite play during steering operation of a vehicle equipped with an electric power assisted steering device. There is an effect that can be provided.

Claims (6)

In the electric power assisted steering apparatus in which a worm wheel is mounted on a steering shaft and a worm shaft having a worm bited by the worm wheel is driven by a motor. A worm wheel housing formed so that the worm wheel and the steering shaft and the steering shaft bearing are internally fixed and open at one side thereof; A worm housing connected to the motor and configured to have the worm shaft and the worm shaft bearing internally fixed and having an open side surface coupled or separated from the open side surface of the worm wheel housing; An elastic member inserted into an engagement surface between the worm wheel housing and the worm housing; And Fastening means for coupling the worm wheel housing and the worm housing An electric power assisted steering device having a worm gear play compensation device, characterized in that it comprises a. The method of claim 1, The worm wheel housing and the worm housing are connected by a hinge structure is an electric power having a worm gear gap compensation device, characterized in that the rotatable structure so that each of the one open side can be mutually coupled or separated around the hinge axis Auxiliary Steering Device. The method according to claim 1 or 2, An electric power assisted steering device having a worm gear play compensation device, characterized in that a cylindrical bush having an elastic force is inserted between an outer circumferential surface of the worm shaft bearing and an inner surface of the worm housing. The method according to claim 1 or 2, The fastening means is an electric power assisted steering apparatus having a worm gear play compensation device, characterized in that it comprises a tension device for generating a coupling force of the worm wheel housing and the worm housing by the elastic force. The method of claim 4, wherein The tension device is an electric power assisted steering device having a worm gear play compensation device, characterized in that by inserting the flat washer and the coil spring to the coupling bolt. The method of claim 4, wherein An electric power assisted steering device having a worm gear play compensation device, characterized in that a cylindrical bush having an elastic force is inserted between an outer circumferential surface of the worm shaft bearing and an inner surface of the worm housing.

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