Non-return spring device

Abstract

A check spring device includes a body having an annular shape extending between an outer diameter and an inner diameter, the body including a first axial side and a second axial side, the second axial side including a flat extending from the inner diameter toward the outer diameter. The check spring device further includes a plurality of spring elements integrally formed with the body, each of the plurality of spring elements including a tab portion extending radially inward from the inner diameter.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a no-back spring device, and in particular to a no-back spring device for a bearing assembly in a vehicle steering system. BACKGROUND

[0002] Vehicles, such as cars, trucks, crossovers, SUVs, vans, boats, airplanes, ATVs, recreational vehicles, or other suitable vehicles, include various steering system schemes, e.g., steer-by-wire and driver interface steering. These steering system schemes generally include a steering column for converting a steering input into an output, which interacts with steering links to ultimately turn the wheels (or other elements) of the vehicle.

[0003] The steering column generally includes a boot assembly (i.e., one or more jackets operatively interconnected) having a steering shaft located within it. The steering shaft is operatively connected to a steering input (e.g., a steering wheel) on a first end and to an output (e.g., a pinion shaft assembly or a device as part of a steer-by-wire system) on a second end. When the steering wheel is turned, the steering shaft rotates within the boot assembly to interact with the steering links (either mechanically directly or indirectly). Typically, the boot assembly is mounted to a component of the vehicle such that it cannot rotate, and a bearing assembly allows the steering shaft to rotate relative to the boot assembly.

[0004] Depending on the requirements and preferences of the end use, there are generally maximum rotational torque requirements that can be satisfied with a traditional bearing assembly. However, as technology continues to advance, there have also been requirements and preferences that set minimum rotational torque requirements. To meet this growing demand, torque adjustment devices have been developed for a narrow range between the maximum and minimum torque requirements.

[0005] There are many conventional bearing assembly configurations that generally include an inner race and an outer race separated by ball bearings, the inner race operably connected to a steering shaft, and the outer race operably connected to a boot assembly. Current torque adjustment devices use a plastic bearing sleeve that is sandwiched between the inner race and a splined portion of the steering shaft. The plastic bearing sleeve defines a friction surface and an axial spring is preloaded on the friction surface and axially retained by a no-back washer that interfaces with the boot assembly. The no-back washer is generally configured to be inserted in one direction, but difficult to remove in the opposite direction, thereby axially retaining the adjacent components. In use, the axial spring will remain stationary while the steering shaft rotates due to the different friction interfaces (i.e., dry steel-on-steel between the no-back washer and the axial spring versus lubricated steel of the axial spring on the friction surface of the plastic bearing sleeve). This relative rotation between the plastic bearing sleeve and the axial spring creates friction, thereby increasing the torque to establish the minimum torque requirement.

[0006] While the above-described torque adjustment devices provide improvements over conventional steering shafts, they are not without drawbacks. For example, over time, the friction surface of the bearing sleeve changes. Additionally, the axial spring sometimes partially rotates and winds up before the plastic bearing sleeve begins to slide relative to the friction surface. As a result, durability of the control, as well as increasing spring geometry distortion and preloading, remains an issue. Moreover, these issues are more pronounced with higher torque requirements and preferences.

[0007] Accordingly, improvements to torque adjustment devices continue to be of interest, particularly improvements in weight, simplicity of design, consistency of operation, and durability of service life. SUMMARY

[0008] According to one aspect of the present disclosure, a bearing retention assembly for a vehicle steering system includes a housing structure. The bearing retention assembly further includes a steering shaft disposed within a bore of the housing structure. The bearing retention assembly further includes a bearing sleeve surrounding a portion of an outer surface of the steering shaft. The bearing retention assembly still further includes a bearing assembly including an inner race and an outer race, wherein a plurality of balls are disposed between the inner race and the outer race, wherein the inner race is located between the bearing sleeve and the outer race. The bearing retention assembly still further includes a no-back spring device having a main body formed in an annular shape extending between an outer diameter and an inner diameter. The no-back spring device further includes at least one spring element integrally formed with the main body and extending axially therefrom and in contact with a friction surface of the bearing sleeve.

[0009] According to another aspect of the present disclosure, a check spring device includes a body having an annular shape extending between an outer diameter and an inner diameter, the body including a first axial side and a second axial side, the second axial side including a flat extending from the inner diameter toward the outer diameter. The check spring device further includes a plurality of spring elements integrally formed with the body, each of the plurality of spring elements including a tab portion extending radially inward from the inner diameter.

[0010] These and other aspects of the present disclosure are disclosed in the following detailed description of embodiments, the appended claims, and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0011] The present disclosure can best be understood by reading the following detailed description together with the accompanying drawings, in which:

[0012] Figure 1 FIG. 1 is a partial cross-sectional view generally illustrating a steering column assembly including a check spring device according to the principles of the present disclosure;

[0013] Figure 2 FIG. 2 is a partial cross-sectional view generally illustrating a steering column assembly according to the principles of the present disclosure;

[0014] Figure 3 FIG. 3 is a perspective view of a first axial side of a check spring device according to the principles of the present disclosure; and

[0015] Figure 4 FIG. 4 is a perspective view of a second axial side of a check spring device according to the principles of the present disclosure. DETAILED DESCRIPTION

[0016] The following discussion is directed to various embodiments of the present disclosure. While one or more embodiments can be preferred as described herein, the disclosed embodiments should not be interpreted, or otherwise used, to limit the scope of the present disclosure, including claims, to that described in only these embodiments. Additionally, one skilled in the art will understand that the description set forth herein has broad application and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the present disclosure, including claims, is limited to that embodiment.

[0017] As described, features of the subject disclosure can be incorporated into vehicles such as cars, trucks, sport utility vehicles, crossovers, minivans, watercraft, aircraft, all-terrain vehicles, recreational vehicles, or other suitable vehicles, which include various steering system schemes, such as steer-by-wire and driver interface steering. These steering system schemes can include a steering column assembly for converting a steering input into an output, which interacts with a steering linkage to ultimately turn the wheels (or other elements) of the vehicle. These steering systems can further include a construction that allows the steering column assembly to be axially adjusted or angularly (tilted) adjusted.

[0018] Reference is now made to the drawings, where the various embodiments are shown and described, without limitation. Figures 1 to 4 A check spring device for a steering column assembly in a vehicle steering system is shown. The check spring device combines both axial spring and check washer functionality into an integrally formed thin profile body that provides improvements in weight, simplicity of design, consistency of operation, and durability of service life.

[0019] Reference is first made to Figure 1 and Figure 2 A steering column assembly 10 is shown, and is generally referred to by the numeral 10. The steering column assembly 10 includes a check spring device 12 for establishing at least one of a minimum torque requirement and a maximum torque requirement of the steering column assembly 10. The steering column assembly 10 includes a housing structure 14, which can be part of a column shroud assembly. For example, the housing structure 14 can be a shroud that is part of a shroud assembly having one or more shrouds that radially surround a steering shaft 16. Regardless of the particular housing structure 14, the housing structure 14 defines a cavity that extends along an axis A, and the steering shaft 16 is located within the cavity. The steering shaft 16 is configured to rotate during a steering maneuver, and at the same time the housing structure 14 is rotationally stationary relative to the steering shaft 16. A bearing assembly 18 facilitates the relative rotational motion between the steering shaft 16 and the housing structure 14.

[0020] The bearing assembly 18 can include an outer race 20 and an inner race 22, with the inner race 22 being radially inward of the outer race 20. A plurality of bearing elements (not shown) can be located between the outer race 20 and the inner race 22 and facilitate relative rotation therebetween. In some embodiments, the bearing elements can have a spherical shape. In some embodiments, the outer race 20 is operatively and statically connected to the housing structure 14, while the inner race 22 is operatively and statically connected to the steering shaft 16. In some embodiments, the steering shaft 16 can include an upper portion and a lower portion, and the bearing assembly 18 and the check spring device 12 can be located in the lower portion. In embodiments where the steering shaft 16 has an upper portion and a lower portion, these portions can be joined via a spline connection (not shown).

[0021] In some embodiments, at least a portion of the radially outer surface of the steering shaft 16 defines a series of splines 26 that are circumferentially arranged about the axis A and axially extend along the axis A. In some embodiments, the portion of the steering shaft 16 that defines the splines 26 also includes a retention region 28 that is annular about the steering shaft 16. The retention region 28 extends axially between a first edge 30 and a second edge 32. The bearing assembly 18 and the check spring device 12 are located at the retention region 28 between the first edge 30 and the second edge 32. Specifically, a bearing sleeve 34 is keyed to the shaft splines 26 and has an interference fit with the inner race 22. The steering shaft 16 is splined below the bearing sleeve 34. A pair of retention grooves 29 are formed in the shaft splines 26 to accommodate a pair of retention rings 48, 50 that assist in axially retaining the position of the bearing assembly 18.

[0022] With continued reference to Figure 1 and Figure 2A bearing sleeve 34 is positioned between the inner race 22 and the steering shaft 16 in the retaining region 28. The bearing sleeve 34 includes a frayed portion 36 adjacent the first edge 30 and a flanged portion 38 adjacent the second edge 32. The frayed portion 36 extends to a tapered edge 40 and includes a series of axially extending slots 42. The axially extending slots 42 allow for the circumferential expansion and contraction of the frayed portion 36. The flanged portion 38 extends radially outward and defines a bearing surface 44 facing the bearing assembly 18 and a friction surface 46 facing the check spring device 12. A pair of retaining rings axially retain the bearing assembly 18 and the bearing sleeve 34 within the retaining groove 29. The pair of retaining rings includes a first retaining ring 48 positioned in the retaining groove 29 adjacent the first edge 30 and a second retaining ring 50 positioned in the retaining groove 29 adjacent the second edge 32. In some embodiments, both the first retaining ring 48 and the second retaining ring 50 include an inner diameter positioned radially inward of an outer diameter of the splines (ODsplines). In some embodiments, both the first retaining ring 48 and the second retaining ring 50 include an inner diameter positioned radially outward of an outer diameter of the steering shaft 16 (ODshaft).

[0023] The housing structure 14 includes an inner surface 52 to which the outer race 20 is press fit. In some embodiments, the housing structure defines an annular protrusion 54 for positioning the outer race 20 during assembly. More specifically, the annular protrusion 54 is annular in shape and projects radially inward for defining a first surface 56 that contacts an outer diameter of the outer race 20 for radially retaining the outer race 20. The annular protrusion 54 further includes a step 58 that extends further radially inward from the first surface 56 for contacting a side of the outer race 20 facing the first edge 30 to axially retain the outer race 20 during assembly while the outer race 20 is press fit to the housing 14. The first surface 56 can include a taper 60 opposite the step 58 to facilitate insertion of the bearing assembly 18.

[0024] Figure 2 A perspective view of the steering column assembly 10 is generally shown with the housing structure 14 being cut away and various features of the check spring device 12 are shown. The check spring device 12 includes a body 62 having a generally annular shape extending between an inner diameter and an outer diameter. The body 62 includes a flat portion 64 extending from the inner diameter and an angled portion 66 extending from the outer diameter to the flat portion 64. The check spring device 12 includes a first surface 68( Figure 3 ) and a second surface 70( Figure 4The first surface 68 faces away from the bearing assembly 18, while the second surface 70 faces toward the bearing assembly 18. A series of retention fingers 72 extend from the angled portion 66 radially outward and away from the second surface 70 and the bearing assembly 18 to an outer retention finger diameter that can be equal to or slightly greater than the diameter defined by the inner surface 52 of the outer shroud 14.

[0025] A series of spring elements 74 extend radially inward from the inner diameter away from the first surface 68 and toward the bearing assembly 18. The retention fingers 72 and the spring elements 74 are circumferentially arranged relative to the body 62. The spring elements 74 include a tab portion 76 that extends radially inward from the inner diameter. In some embodiments, the tab portion 76 is coplanar with the flat portion 64. A pair of spring fingers 78 extend circumferentially from opposite sides of the tab portion 76. Each spring finger 78 includes an angled spring portion 80 that extends toward the bearing assembly 18 and a leaf spring portion 82 that is in contact with the friction surface 46. In some embodiments, the check spring device 18 is made of spring steel, while the bearing sleeve 34 is made of plastic. In some embodiments, lubrication 83 is located on the friction surface 46. In some embodiments, at least one of the spring elements 74 is circumferentially aligned with at least one of the retention fingers 72. In some embodiments, each of the spring elements 74 is circumferentially aligned with at least one of the retention fingers 72. In some embodiments, there are fewer spring elements 74 than retention fingers 72. In some embodiments, each of the tab portion 76 and the leaf spring portion 82 is circumferentially aligned with at least one of the retention fingers 72.

[0026] Figure 3 is a perspective view of the first axial surface 68 of the check spring device 12 isolated from other components of the column assembly 10. Figure 4 is a perspective view of the second axial surface 70 of the check spring device 12 isolated from other components of the column assembly 10.

[0027] The above discussion is meant to be illustrative of the principles and various embodiments of the present disclosure. Many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. The following claims are intended to cover all such variations and modifications.

[0028] The words “example” or “exemplary” are used herein to mean “serving as an example, instance, or illustration.” Any aspect or design described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word example is intended to present concepts in a concrete manner. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or clear from context, “X includes A or B” is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then “X includes A or B” is satisfied under any of the foregoing instances. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Moreover, use of the term “an implementation” or “one implementation” throughout is not intended to mean the same implementation or implementation unless described as such.

[0029] The foregoing embodiments, implementations and aspects have been described in order to easily understand the present disclosure and are not intended to limit the present disclosure. On the contrary, the present disclosure is intended to cover various modifications and equivalent arrangements included in the scope of the appended claims, which should be afforded the broadest interpretation so as to encompass all such modifications and equivalent structures legally allowed.

Claims

1. A bearing retaining assembly for a vehicle steering system, comprising: Shell structure; A steering shaft, wherein the steering shaft is disposed within a hole in the housing structure; A bearing sleeve that surrounds a portion of the outer surface of the steering shaft; A bearing assembly including an inner ring and an outer ring, wherein a plurality of balls are disposed between the inner ring and the outer ring, wherein the inner ring is located between the bearing sleeve and the outer ring; and A check spring device, the check spring device comprising: The main body is formed in an annular shape extending between the outer diameter and the inner diameter; At least one retaining finger, said retaining finger being integrally formed with the body and extending radially outward from the outer diameter, to axially retain the check spring device within the housing structure; and At least one spring element, the at least one spring element being integrally formed with the body and extending axially from the body and contacting the friction surface of the bearing sleeve; The main body includes a first axial side and a second axial side, wherein the first axial side faces away from the bearing sleeve, and the second axial side faces the bearing sleeve, wherein the second axial side includes a flat portion extending from the inner diameter toward the outer diameter; Wherein, the at least one spring element extends radially inward from the inner diameter of the body of the check spring device; Wherein, the at least one spring element includes a tab portion extending radially inward from the inner diameter; The at least one spring element includes a pair of spring fingers, each of which extends circumferentially from opposite sides of the tab portion; Each of the spring fingers includes an angled spring portion extending axially toward the bearing sleeve, and each of the spring fingers includes a leaf spring portion that contacts the friction surface of the bearing sleeve.

2. The bearing retaining assembly according to claim 1, wherein, At least one retaining finger comprises a plurality of fingers spaced circumferentially from each other.

3. The bearing retaining assembly according to claim 2, wherein, The plurality of fingers are angled away from the bearing.

4. The bearing retaining assembly according to claim 1, wherein, The steering shaft has a splined outer surface and a retaining region, and the bearing assembly is arranged within the retaining region.

5. The bearing retaining assembly according to claim 1, wherein, The check spring device is made of spring steel, and the bearing sleeve is made of plastic.

6. The bearing retaining assembly according to claim 1, wherein, Lubrication is present on the friction surface of the bearing sleeve.

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