DESC:TECHNICAL FIELD
The present disclosure relates to an electric power steering system of an automobile and more particularly the present disclosure relates to backlash compensation for reduction gear mechanism.
BACKGROUND
Generally, an electric power steering comprises of reduction gear unit and mechanical gear unit, wherein reduction gear unit transmit the torque from electric motor to mechanical gear. Mechanical gear provides torque transmission between steering hand wheel to road wheel through steering linkage mechanism.
CN111692318A discloses an invention provides a worm and gear gap adjusting structure. The structure is used in a worm and gear speed reducer for an electric power steering device. A worm gear mounting cavity and a worm mounting cavity are formed in a speed reducer shell, a worm gear and a worm gear shaft are mounted in the worm gear mounting cavity through bearing supporting, the two ends of the worm are supported in a worm through deep groove ball bearings, the worm and the worm gear are engaged, through an adjusting nut, the axial backlash of the deep groove ball bearings can be adjusted, the axial gap between the worm and the worm gear can be adjusted, through a pressing block nut and an arc pressing block, the radial backlash of the deep groove ball bearings can be adjusted, the radial gap between the worm and the worm gear can be adjusted, the idea is created, the axial backlash and the radial backlash of the deep groove ball bearings are adopted for achieving gap adjusting of the worm and the worm gear, the tangent force influences can be overcome, the noise can be reduced in the worm and gear motion process, a car ECU signal can be collected more precisely, and the reliability of the worm and gear operation can be effectively improved.
KR20220155515A discloses an electric power steering device for vehicles and prevents play due to backlash between a worm wheel and a worm shaft by using a bearing-integrated damper bush made of steel coupled to an end of a worm shaft. And preventing the flow of the worm shaft, and supplying the lubricant between the worm shaft and the bearing-integrated damper bush when the worm shaft rotates to promote lubrication and cooling.
US20040149512A1 discloses an electric power steering apparatus having a reduction mechanism in which an inner peripheral face of a fitting hole provided to a gear housing is formed into an inclined face inclined with respect to a worm shaft so as to fit with and hold a bearing to which a worm shaft for transmitting rotating force of a steering assisting motor to a steering shaft provided with a worm wheel, an inclined contact surface in contact with the inclined face is provided on an outer periphery of the bearing, and the inclined contact surface of the bearing is moved along the inclined face of the fitting hole to adjust a distance between a shaft center of the worm shaft and a rotation center of the worm wheel.
The following are the deficiencies in the existing prior art: Controlling tooth gap of reduction gear without disassembling the steering gear is not provided or complicated. Accessibility for setting and resetting of reduction gear preload is difficult.
Accordingly, there exists need for a simple and cost effective backlash compensation assembly for reduction gear gap arrest in electric power steering gear.
SUMMARY
In some aspects of the present disclosure, an integrated backlash adjuster assembly within an electric power steering box.
The backlash adjuster assembly includes an inner bush exhibiting a taper profile at outer periphery.
The backlash adjuster assembly further includes an outer bush demonstrating a taper profile at inner peripheral surface, ensuring constant contact with said inner bush taper.
The backlash adjuster assembly further includes a spring positioned coaxially along the axis of the reduction input gear, the outer periphery of a bearing guided by the inner peripheral surface of said inner bush. The outer bush cooperates with the inner bush, supporting the bearing and facilitating movement of a reduction input gear towards a reduction output gear to mitigate tooth gap via the force exerted by the spring. Adjustment of the end plug loads or unloads the spring, facilitating the setting or resetting of preload between the reduction input gear and reduction output gear.
In some aspects of the present disclosure, the integrated backlash adjuster assembly for an electric power steering gear system further includes one or more main housings configured to house components of the electric power steering gear system.
In some aspects of the present disclosure, the integrated backlash adjuster assembly for an electric power steering gear system further includes an input shaft that is positioned in the one or more main housings and configured to receive the input power from the input.
In some aspects of the present disclosure, the integrated backlash adjuster assembly for an electric power steering gear system further includes a screw shaft, that is positioned on length of the input shaft and configured to rotate along with the input shaft.
In some aspects of the present disclosure, the integrated backlash adjuster assembly for an electric power steering gear system further includes a rack nut that is operatively coupled with the screw shaft and adapted to move in a substantial horizontal direction when the screw nut rotates in clockwise and counter-clockwise direction.
In some aspects of the present disclosure, the integrated backlash adjuster assembly for an electric power steering gear system further includes an output shaft that is communicatively coupled with the rack nut and adapted to rotate upon the rack nut moves in horizontal direction.
In some aspects of the present disclosure, the spring includes a variable compression spring allowing for adjustable tension between the reduction input gear and reduction output gear.
In some aspects of the present disclosure, the adjustment of the end plug includes a threaded interface providing fine-tuning of the preload between the reduction input gear and reduction output gear.
In some aspects of the present disclosure, the inner bush and outer bush are composed of materials with low friction coefficients to ensure smooth movement and contact between the components.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawing,
Figure 1 illustrates a cross-sectional view of the actuator, in accordance with an aspect of the present disclosure;
Figure 2 illustrates the cross-sectional view of the actuator with motor, in accordance with an aspect of the present disclosure;
Figure 3 illustrates the cross-sectional view of the backlash adjuster assembly, in accordance with an aspect of the present disclosure; and
Figure 4 illustrates the exploded view of the backlash adjuster assembly, in accordance with an aspect of the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. Thus, the following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, known details are not described in order to avoid obscuring the description.
References to one or an embodiment in the present disclosure can be references to the same embodiment or any embodiment; and, such references mean at least one of the embodiments.
Reference to "one embodiment", "an embodiment", “one aspect”, “some aspects”, “an aspect” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others.
The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Alternative language and synonyms may be used for any one or more of the terms discussed herein, and no special significance should be placed upon whether or not a term is elaborated or discussed herein. In some cases, synonyms for certain terms are provided.
A recital of one or more synonyms does not exclude the use of other synonyms.
The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any example term. Likewise, the disclosure is not limited to various embodiments given in this specification. Without intent to limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, technical and scientific terms used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the disclosure will become more fully apparent from the following description and appended claims or can be learned by the practice of the principles set forth herein.
One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention. It is the primary object of the present invention to provide simple and cost effective backlash compensation assembly for reduction gear tooth gap arrest in electric power steering gear. It is the primary object of the present invention to provide easy in setting and resetting of reduction gear preload.
Figure 1 illustrates a cross-sectional view of the actuator, in accordance with an aspect of the present disclosure. Figure 2 illustrates a cross-sectional view of the actuator with motor, in accordance with an aspect of the present disclosure, Figure 3 illustrates the cross-sectional view of the backlash adjuster assembly, in accordance with an aspect of the present disclosure and Figure 4 illustrates the exploded view of the backlash adjuster assembly, in accordance with an aspect of the present disclosure.
An electric power steering actuator with backlash adjuster comprising of one or more main housings (1), an input shaft (2), a screw shaft (3), a rack nut (4), an output shaft (5), one or more drop housings (6), a motor (7), a coupler (8), a reduction input gear (9), a reduction output gear (10), one or more bearings (11), an inner bush (12), an outer bush (13), one or more springs (14), and an end plug (15) with thread.
The one or more main housings (1) configured to house components of the electric power steering gear system.
The input shaft (2) may be positioned in the one or more main housings (1) and configured to receive the input power from the input.
The screw shaft (3) may be positioned on length of the input shaft (2) and configured to rotate along with the input shaft (2).
The rack nut (4) may be operatively coupled with the screw shaft (3) and adapted to move in a substantial horizontal direction when the screw nut (3) rotates in clockwise and counter-clockwise direction.
The output shaft (5) may be communicatively coupled with the rack nut (4) and adapted to rotate upon the rack nut (4) moves in horizontal direction.
The one or more drop housings (6) may be adapted to house the reducing input gear (9).
In some aspects of the present disclosure, the motor (7) may be adapted to generate torque. The motor (7) may be adapted to provide input to the reducing input gear (9).
In some aspects of the present disclosure, the reduction input gear (9) may be adapted to transmit torque from the motor (7) to a reduction output gear (10).
In some aspects of the present disclosure, the reduction output gear (10) may be adapted to multiplies the torque from the motor (7) thru a reduction input gear (9) to screw shaft (3)
The variable compression spring allowing for adjustable tension between the reduction input gear (9) and reduction output gear (10).
The inner bush (12) may exhibit a taper profile at outer periphery.
The outer bush (13) may demonstrate a taper profile at inner peripheral surface, ensuring constant contact with said inner bush taper.
The spring (14) may be positioned coaxially along the axis of the reduction input gear (9).
The outer periphery of a bearing (11) may be guided by the inner peripheral surface of said inner bush (12). The outer bush (13) may cooperates with the inner bush (12), supporting the bearing (11) and facilitating movement of a reduction input gear (9) towards a reduction output gear (10) to mitigate tooth gap via the force exerted by the spring (14). The adjustment of the end plug (15) may load or unload the spring (14), facilitating the setting or resetting of preload between the reduction input gear (9) and reduction output gear (10).
The adjustment of the end plug (15) includes a threaded interface providing fine-tuning of the preload between the reduction input gear (9) and reduction output gear (10).
The inner bush (12) and outer bush (13) may be composed of materials with low friction coefficients to ensure smooth movement and contact between the components.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein the inner bush has a taper profile at its outer peripheral.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein the outer bush has a taper profile at its inner peripheral.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein the taper of inner and outer bush is always in contact with each other.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein the spring is positioned along the axis of reduction input gear.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein outer periphery of the bearing is guided by inner peripheral of the inner bush.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein spring provides a lever force on support bush to act on a bearing so as to ensure meshing of a reduction input gear and the reduction output gear.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein the backlash adjuster assembly compensates the wearing and tearing clearance between reduction input gear and the reduction output gear.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein backlash adjuster assembly provides ease accessibility in controlling tooth gap of reduction gear without disassembling the steering gear.
It is another object of the present invention to provide electric power steering actuator with backlash adjuster, wherein backlash adjuster assembly provides easy in setting and resetting of reduction gear preload without disassembling the steering gear.
In an embodiment, the backlash adjuster assembly is integrated with an electric power steering box as shown in Fig. 2 and Fig.3. The backlash adjuster assembly comprises of inner bush (12), outer bush (13), spring (14) and an end plug (15). The inner bush (12) has a taper profile at its outer peripheral. The outer bush (13) has a taper profile at its inner peripheral. The taper of inner bush (12) and outer bush (13) is always in contact with each other. Spring (14) is positioned along the axis of reduction input gear (9). The outer periphery of the bearing (11) is guided by the inner peripheral of the inner bush (12).
The outer bush (13) is taper and has contact with the inner bush (12) taper works together and supports the bearing (11). The bearing (11) moves the reduction input gear (9) tooth towards reduction output gear (10) tooth leads to arrest the tooth gap between them due to spring force acting on the outer bush (13). The system provides a provision for adjusting and controlling the backlash between the reduction input gear (9) and reduction output gear (10).
The spring (14) has its own stiffness (spring force) provides a lever force on support/outer bush (13) to act on a bearing (11) so as to ensure meshing of a reduction input gear (9) and the reduction output gear (10).
The backlash adjuster assembly compensates the wearing and tearing clearance between reduction input gear (9) and the reduction output gear (10), provides ease accessibility in controlling tooth gap of the reduction input gear (9) and reduction output gear (10) without disassembling the steering gear.
In an embodiment, the backlash adjuster assembly set and reset the reduction input gear (9) and reduction output gear (10) preload without disassembling the steering gear by adjusting the end plug (15), the spring (14) is loaded or unloaded by either compression or tensile in the spring (14), this leads to set and reset the reduction input gear (9) and reduction output gear (10) preload.
Advantages:
• Ease in assemble.
• Compensates the wearing and tearing clearance between reduction gears.
• Ease accessibility in controlling tooth gap of reduction gear without disassembling the steering gear.
• Easy in setting and resetting of reduction gear preload without disassembling the steering gear.
The implementation set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detain above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementation described can be directed to various combinations and sub combinations of the disclosed features and/or combinations and sub combinations of the several further features disclosed above.
In addition, the logic flows depicted in the accompany figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations may be within the scope of the following claims.

,CLAIMS:1. An integrated backlash adjuster assembly (100) within an electric power steering box, said backlash adjuster assembly comprises:
an inner bush (12) exhibiting a taper profile at outer periphery;
an outer bush (13) demonstrating a taper profile at inner peripheral surface, ensuring constant contact with said inner bush taper;
a spring (14) positioned coaxially along the axis of the reduction input gear (9);
wherein outer periphery of a bearing (11) guided by the inner peripheral surface of said inner bush (12), wherein the outer bush (13) cooperates with the inner bush (12), supporting the bearing (11) and facilitating movement of a reduction input gear (9) towards a reduction output gear (10) to mitigate tooth gap via the force exerted by the spring (14), wherein adjustment of the end plug (15) loads or unloads the spring (14), facilitating the setting or resetting of preload between the reduction input gear (9) and reduction output gear (10).

2. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising one or more main housings (1) configured to house components of the electric power steering gear system.

3. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising an input shaft (2) that is positioned in the one or more main housings (1) and configured to receive the input power from the input.

4. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising a screw shaft (3), that is positioned on length of the input shaft (2) and configured to rotate along with the input shaft (2).

5. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising a rack nut (4) that is operatively coupled with the screw shaft (3) and adapted to move in a substantial horizontal direction when the screw nut (3) rotates in clockwise and counter-clockwise direction.

6. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising an output shaft (5) that is communicatively coupled with the rack nut (4) and adapted to rotate upon the rack nut (4) moves in horizontal direction.

7. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising one or more drop housing (6) that is adapted to house the reduction input gear (9).

8. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising a motor (7) that is adapted to generate torque.

9. The integrated backlash adjuster assembly (100) for an electric power steering gear system as claimed in claim 1, further comprising reduction input gear (9), that is adapted to transmit torque from the motor (7) to a reduction output gear (10).

10. In some aspects of the present disclosure, the reduction output gear (10) may be adapted to multiplies the torque from the motor (7) thru a reduction input gear (9) to screw shaft (3)

11. The integrated backlash adjuster assembly (100) as claimed in claim 1, wherein the spring (14) comprises a variable compression spring allowing for adjustable tension between the reduction input gear (9) and reduction output gear (10).

12. The integrated backlash adjuster assembly (100) as claimed in claim 1, wherein the adjustment of the end plug (15) includes a threaded interface providing fine-tuning of the preload between the reduction input gear (9) and reduction output gear (10).

13. The integrated backlash adjuster assembly (100) as claimed in claim 1, wherein the inner bush (12) and outer bush (13) are composed of materials with low friction coefficients to ensure smooth movement and contact between the components.