GB2568693A

GB2568693A - Diametrically adaptive polymeric rolling element

Info

Publication number: GB2568693A
Application number: GB1719434.1A
Authority: GB
Inventors: Terence Goldsmith Mark
Original assignee: BNL UK Ltd
Current assignee: BNL UK Ltd
Priority date: 2017-11-23
Filing date: 2017-11-23
Publication date: 2019-05-29
Also published as: GB201719434D0

Abstract

There is disclosed a diametrically adaptive polymeric rolling bearing that can be used to provide radial rotation and resistance to radial, axial and torsional loading within an automotive steering column system or other similar applications. Inner rings 100, 107 are retained on the shaft via grab ring 112. Track wrap 123 forms an outer race and has an angled split 127 (Fig.1F) which allows the diametric clearance to be altered. An overload feature 126 contacts the inner ring during high load to reduce loading through the balls 103. An impact band 105 is made from elastomeric polymers to provide impact resistance, and may form a seal 128 (Fig.1F). Outer case 106 has flexible clips 108 for easy insertion within a jacket/housing. The clips may also provide torsional dampening. The outer case may also have crush ribs 109, 110, as well as rib formations 111 to hold the impact band 105. The outer case may further include poka-yoke fail-safe location features 115 (Fig.1C), as well as location pads 113 (Fig.1C) and a gaps 114 to provide axial dampening.

Description

FIELD OF THE INVENTION

The present invention relates to material and design technology for the introduction of adaptive diametrical clearance in polymeric radial and thrust bearings. The invention relates to a novel rolling element which increases application system efficiency whilst also reducing overall cost and operations required in installation of applications. Such an invention provides advantages in such operations as motion, reduced noise, reduced system weight, reduced maintenance, corrosion resistance to chemical attack and longer operating life.

BACKGROUND TO THE INVENTION

High quality polymeric rolling element assemblies are used in the replacement or as an alternative to steel bearings for many applications. These applications fit into many sectors of industry including automotive, medical, aerospace, food processing, consumer goods, white goods and water systems to name a few. The applications demand different requirements for the polymeric rolling elements to address, with the automotive sector being amongst the most demanding. However, all the characteristics and properties used in the solution for the automotive sector by polymeric rolling elements are directly transferrable to all other market sectors. The automotive sector typically calls for a polymeric rolling element to address the following requirements: resistance to changing environments that can include a range of temperatures from 40deg C to +85deg C, dry to wet to humid conditions either in air or submerged in a neutral, alkali or acidic solution, low to high operating loads in a radial and or axial plane that can be static, dynamic or can be oscillating between either, shock loading or aggressive impacts can be applied to the polymeric rolling element as part of the greater automotive assembly in its final location. This may result as a force driving the polymeric rolling elements against or away from mating components. Transference of vibration through the polymeric rolling elements must be controlled to aid the full system frequency and harmonics with its classification against noise, vibration and harshness (NVH). Polymeric rolling elements are also required to aid system efficiency by providing a reduction in weight, operating torque and smoothness throughout the defined operating environments. Finally, the requirements for the fitment of the polymeric rolling elements to mating parts is constrained by small space envelopes requiring the need for integration of bespoke elements, features and members.

SUMMARY OF THE INVENTION

The invention relates to a polymeric rolling element which is like a plastic bearing but incorporates addition novel functionality used in the steering systems of passenger and or commercial vehicles yet can be used in other applications as earlier stated. The polymeric rolling elements located in four main but not exclusive positions within the steering system. The positions include the upper bearing position, the mid bearing position, the lower bearing position and the firewall bearing position. The polymeric rolling element is different to a standard bearing due to the additional functionality it provides. The extra functionality is provided due to integration of mating components and novel bespoke features, these include: shock absorption for impact loading, dampening for blocking, reducing and or tuning noise, vibration and harshness (NVH), with adaptive multiple bearing surfaces that will contract and or expand to suit environmental conditions whilst retaining a targeted range of diametrical clearance, with rolling elements that withstand radial and or axial loads. A retaining member that has features integrated to provide strength and stability with a method of attaching permanently or temporarily to final system components, the features include clips, crush ribs, flexible fingers, complex ribbing, retention rings, flanges, brackets, spigots, gears, mechanical seals and pegs. The materials of the polymeric rolling elements can be adapted to withstand high and low temperatures therefore providing a solution for the product placement in the engine compartment as well as the passenger compartment or other varied environments.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figures la to If illustrate a first embodiment of a diametrically adaptive polymeric rolling element with the invention.

DETAILED DESCRIPTION OF EMBODIMENT(S)

Figure 1A shows the first embodiment of a diametrically adaptive polymeric rolling element to the invention. The polymeric rolling element is exploded to show all its nine components split axially. The assembly consists of seven different embodiments. Embodiment 103 the ball array is categorised as one body even though the ball array can consist of three or more ball bearings. Body 100 the male inner may be a polymeric and or alloy material and contains several features primarily providing the rotation of the assembled element, the identification of the assembled embodiment, the location and retention feature press fits on the centre shaft of the automotive steering column shaft, the grab ring that prevents back lash on the centre shaft of the steering column in this particular application of the invention and the connection method to body 107 the female inner. Body 102 polymer cage or spacer consists of multiple spherical pockets that retain and space the ball array element 103. Body 104 adaptive outer contains several features primarily providing the rotation of the assembled element with a single or multiple raceway integrated within its bore adjacent to the anti-crush post (figure IE 126). The outer diameter of body 104 features location grooves and or keys for body 105 the impact band to connect. Body 104 the adaptive outer also contains the adaptive split feature that is orientated at between 15 and 75 degrees’ to the integrated raceways. The split feature is angled in relation to the ball spacing in the 102 polymer cage ensuring that ball array/s 103 do not multiple balls rolling over the split at the same time. Body 105 the impact band is located between body 104 the adaptive outer and body 106 the outer case. Body 105 the impact band is made from elastomeric polymers which can be manufactured in a range of shore hardness to provide the required impact resistance for the given application. The thickness and profile of the impact band not only functions as a mechanical key, but is also tuned relatively to the section or area of the polymeric rolling element that is subjected to impact or load. Body 107 the female inner is a polymeric and or alloy embodiment containing several features, primarily providing the rotation of the assembled element, the location and retention surface to press fit on the centre shaft of the steering column. Body 107 the female inner also contains the other half of the retention clip that temporally locks onto Body 100 the male inner, and permanently locks the assembly when the centre shaft of the automotive steering column assembly is inserted through the diametrically adaptive polymeric rolling element. The experienced reader will understand that many similar applications exist with other central shafts from many different machine types.

Figure IB shows the polymeric rolling element fully assembled before installation in the automotive steering column assembly. The polymeric rolling element differs from a conventional steel bearing via the integration of supporting features. Body 106 the outer casing has the following features integrated to aid with the retention of the diametrically adaptive polymeric rolling element within the automotive steering column jacket/housing: 1. Multiple clips 108 that can be flexed for easy of insertion and removal for inspection but also lock when fitted to retain the assembly under shock/crash testing. 2. Primary crush ribs 109 that deform during insertion into the steering column to absorb tolerance and concentricity deviations of mating parts. 3. Secondary crush ribs 110 that support the outer casing when inserted into the steering column jacket /housing. Body 106 outer casing also provides a solid structure via rib formations 111. The rib formations are strategically placed to provide the most effective solution to absorb and displace general and abuse loading throughout the assembly’s life. The rib formation also provides a mechanical key for body 105 the impact band. The rib formation is also used to limit the impact zone preventing body 105 impact band from introducing excessive movement. Figure IB clearly depicts the diametrically adaptive polymeric rolling element main retaining feature element 112 the grab ring located at the perimeter of the body 101 male inner and or body 107 female inner. Positioned to suit the assembly method and direction of insertion of the steering column shaft. The sectioned grab ring a polymeric or alloy element dependent on what loading the diametrically adaptive polymeric rolling element is required withstand in operation. When the sectioned grab ring 112 is pushed from inside its bore via body 107 the female inner element 112 expands to let the steering column shaft pass through the bore of the polymeric rolling element. However, if the steering column shaft is retracted in the opposing direction element 112 will contract and bury into the surface of the steering column shaft, the interaction can be greatly improved with the addition of a grove cut into the surface of the steering column shaft. Either method locks the diametrically adaptive polymeric rolling element in place with in the final assembly.

Figure 1C shows the reverse view of figure IB. This depicts the presence of pokeyoke features 115 integrated into the body 106 outer case, features being integrated but not exclusive to the element 106 providing a fail-safe location for fitment into the steering column system for ease of assembly and reduction of location errors. When the polymeric rolling element loaded into the automotive steering column jacket / housing the location pads 113 contact the mating face of the automotive steering column jacket / housing, thus creating a temporary crumple zone for resistance against high loading during operation and or crash testing. Under high axial loading the location pads 113 compress allowing the impact bands 105 side wall to engage. When engaged, it compresses and spills over into the gap 114 created from body 106 the outer cases rib formation 111. When gap 114 starts to be closed in it acts as a secondary dampener between the rib formation 111 and the automotive steering columns jacket / housing. Whist this interaction occurs, the stability of the distance of the diametrically adaptive polymeric rolling element raceways is retained by the inners self-adjusting under axial loading, limited by the adjustment / expansion gap situated between body 101 the male inner and body 107 the female inner.

Figure ID presents the front view of the diametrically adaptive polymeric rolling element. The grab ring 112 located on body 101 male inner is shown with a bladed edge 122 and land between teeth 119. These features work in conjunction to bury into the steering column shaft retaining the diametrically adaptive polymeric rolling element. The diametrically adaptive polymeric rolling element is also exposed to torsional loading to the body 106 outer case. To resist the loading the diametrically adaptive polymeric rolling element must be able to flex before reaching a stop. This action occurs when the multiple clips 108 flex closing the gap 118 between the rib formation 111 and the multiple clips 108 in the direction of rotation. This allows the polymeric rolling element to dampen the inertia of the initial torsional loading.

Figure IE shows diametrically adaptive polymeric rolling element sectioned. The sectioned area allows all elements to be seen in location as required for application. Body 104 the adaptive outer contains additional track wrap 123 to increase operating load resistance on one or multiple raceways while retaining the position of the ball arrays 103 during the assembly of the polymeric rolling element. Body 104 adaptive outer combined with body 100 male inner and body 107 female inner, form the raceways for a multiple row angular contact diametrically adaptive polymeric rolling element. Body 104 adaptive outer also contains an over load feature 126 that activates if the adaptive outer race reaches the limit of its stroke/expansion or contraction. The overload feature when activated contacts the connected male inner 101 and female inner 107 reducing the loading through the ball array or arrays 103. When engaged the diametrically adaptive polymeric rolling element operates as a bush for the duration of the time the high radial loading is applied, thus preventing permeant plastic deformation of the adaptive outer 106.

Figure IF the polymeric rolling element is sectioned and exploded to show the adaptive outer 104 in more detail. The angled split through the element allows the polymeric raceways to expand and or contract. This expansion and contraction could be activated either by loading or environmental conditions, thus allowing the diametrically adaptive polymeric rolling element to adapt to the required conditions during application. By adapting, the bearing raceways can be preloaded to provide specified torque to rotate values for the full life of the assembly. The diametrically adaptive polymeric rolling element may also be set with a negative, neutral or positive diametric clearance, on one or multiple raceways of the same value or a combination dependent on the application. The effectiveness of the body 106 the adaptive outer is dependent on the hardness and thickness of the body 105 the impact band. A softer, thinner elastomer allows a greater adaptive diametric range, likewise, a harder, thicker elastomer reduces the adaptive diametric range. The grade / hardness of the elastomer in body 105 also directly influences the sealing strips 128 of the raceways and how they compress and ware against body 101 the male inner and body 107 the female inner.

Claims

1. An alignment and rotational device for aligning and rotating a shaft and a housing, comprising an alignment and rotational assembly, the alignment and rotational assembly comprising:

A or multiple radial and or axial rolling elements encapsulated in an adaptive polymeric housing.

2. An alignment and rotational device according to claim 1, wherein, the device can be distinguished from a standard alloy or plastic bearing due to the integration that provides extra novel functionality.

3. An alignment and rotational device according to claim 1 or claim 2, wherein, the device can be retained within or on the surface of a shaft, housing, plate and or other assembly via the integration of novel features, the novel features comprising: clips, crush ribs, flexible fingers, complex ribbing, retention rings, flanges, brackets, spigots, gears and pegs that have been designed and moulded it to any or all of the members in the polymeric rolling element assembly.

4. An alignment and rotational device according to any of the preceding claims, wherein, the device is capable of self-adjustment within the operating temperature range and loading, dependent on environmental conditions to retain a desired diametrical clearance.

5. An alignment and rotational device according to any of the preceding claims, wherein, when encapsulating a member that functions as a shock absorbing unit to absorb shock or impact forces to the device and final system without resulting in permeant damage to the device.

6. An alignment and rotational device according to any of the preceding claims, wherein, when encapsulating a selection of composite polymeric, alloy, and or ceramic materials designed for dampening or blocking, reducing and or tuning noise, vibration and harshness (NVH) of the final system.

7. An alignment and rotational device according to any of the preceding claims, wherein, which is assembled and retained through novel methods of plastic deformation of polymeric materials in either a pre-hardened or hardened state.

8. An alignment and rotational device according to any of the preceding claims, wherein, provides a mechanical seal from the ingress of liquids and or the differential temperatures between final system compartments or areas.

9. An alignment and rotational device according to any of the preceding claims, wherein, that the assembly is resistant to chemical attack.

10. An alignment and rotational device according to any of the preceding claims, wherein, provides weight reduction to alterative alignment and rotational devices via the integration of novel features, the novel features comprising: clips, crush ribs, flexible fingers, complex ribbing, retention rings, flanges, brackets, spigots, gears and pegs that have been designed and moulded to any or all of the members in the polymeric rolling element assembly reducing the final assembly part count.

11. An alignment and rotational device according to any of the preceding claims, wherein, provides a torque reduction or tuneable torque output in comparison with alterative alignment and rotational devices, via the integration of adaptive track profile and novel polymeric material processing.

12. An alignment and rotational device according to any of the preceding claims, wherein, provides a smooth consistent rotation with or without the addition of lubricants.

13. An alignment and rotational device according to any of the preceding claims, wherein, provides a low to high load bearing solution in a radial and or axial plane via the integration of composite polymeric materials.

14. An alignment and rotational device according to any of the preceding claims, wherein, provides a stable rotation over a wide range of speed via the ability to self-adjust adaptive track profiles allowing the dissipation of running heat generated from ball bearings and or needle rollers through the assembly’s’ composite polymeric materials.

15. An alignment and rotational device according to any of the preceding claims, wherein, provides accurate alignment, rotation and or linear travel via the use of single and or multiple track profiles that can be adaptive or fixed in a radial and or axial plane.

16. An alignment and rotational device according to any of the preceding claims, wherein, provides accurate alignment, rotation and or linear travel via the use of alloy, polymer and or ceramic ball bearings and needle roller, in various sizes that may or may not be match or balanced in size across different track profiles within the device.

17. An alignment and rotational device according to any of the preceding claims, wherein, provides accurate alignment, rotation and or linear travel via the use of caged or full complement track profile with ball bearing and or needle rollers

Intellectual Property Office

Application No:

Claims searched:

GB 1719434.1

Examiner:

Date of search:

Mr Christian GibsonFaux

27 February 2019

Patents Act 1977: Search Report under Section 17

Documents considered to be relevant:

Category Relevant to claims Identity of document and passage or figure of particular relevance X 1 at least DE 102004018900 Al (SKF) See figures 1-5. X 1 at least US 2014/345414 Al (ERHARDT) See abstract and figures 1-5. X 1 at least DE 102009051107B3 (THYSSENKRUPP) See abstract and figures 6-9. X 1 at least US 3813102 A (DERMAN) See figures 9 and 10. A - US 2014/153855 Al (ADANE) See paragraphs [0030] and [0031], as well as figures 2, 3, 5, and 6. A - JP 2006170420 A (JTEKT) See abstract and figures 1-5. A - DE 202005007904 U (STARRAGHE) See description and figure 4. A - DE 19634877 Al (SCHAEFFLER) See abstract and figures. A - US 2008/258540 Al (HICKS) See figures. A - DE 102014224130 Al (SCHAEFFLER) See figures. A - US 2004/175066 Al (CHADWICK) See figures.