DE102011081881A1 - Steering shaft bearing for vertically adjustable steering column of vehicle i.e. motor car, has pressure ring element axially clamping bearing rings against supporting sing portion such that ring portion is displaced within housing ring - Google Patents

Abstract

The bearing (11) has two annular end rings (12b, 12c) comprising an outer jacket (12a) of a housing ring (12), where outer diameter of a supporting ring portion (13b) is smaller than internal diameter of the outer jacket of the housing ring. Two bearing rings (14a, 14b) are mounted on two running surfaces (S1, S2) of the supporting ring portion. A pressure ring element (16) axially clamps the two bearing rings against the supporting ring portion such that the supporting ring portion is displaced within the housing ring. The pressure ring element is manufactured by an elastomer, plastic or steel material. The annular end rings are made of plastic.

Description

Field of the invention

The invention relates to a steering shaft bearing for rotatably supporting a steering shaft which is coupled as such with a vehicle steering wheel, with a housing ring, an inner sleeve seated on the steering shaft and a bearing means for supporting the inner bush in said housing ring.

Out DE 100 58 491 A1 a steering shaft bearing is known which has a manufactured as a sheet metal forming inner sleeve with a groove formed between two circumferential grooves. This groove limits the interior of a substantially vollkugelig filled with balls annulus in which the balls can rotate. These balls are guided axially and radially by outer races, these outer races are supported by elastomeric rings in a housing ring. In this steering shaft bearing, the outer races can slightly shift axially and radially and also allow a slight tilting of the inner ring relative to the housing ring.

Steering wheel bearings are generally designed as relatively high load bearing bearings, as in particular for special loads of the steering wheel z. B. when a driver uses the steering wheel as a handle and loaded when entering and exiting, or in a change in the seat position, if necessary, with its total weight, attack large forces on the steering wheel bearing. Furthermore, especially in bearings of steering columns in suspension structures which allow an angular or vertical adjustment of the steering wheel, setting conditions occur in which the center of rotation of the adjusting mechanism does not agree exactly with the joint center of a steering shaft joint. In these cases, there is the problem that arise due to the coupling of the steering column with the steering gear to individual bearings high bearing forces.

The invention has for its object to provide a steering shaft bearing, by which a steering shaft bearing can be realized, which is characterized by a cost-effective and robust construction, as well as an advantageous mechanical performance.

• – einem Gehäusering der einen Außenmantel, sowie einen ersten Stirnring und einen zweiten Stirnring aufweist,
• – einem Innenbuchsenring mit einem Innenmantel und einem radial nach außen abragenden Stützringabschnitt der eine erste und eine zweite, jeweils im wesentlichen plane, ringartige Lauffläche bildet,
• – wobei der Stützringabschnitt einen Außendurchmesser aufweist der kleiner ist als der Innendurchmesser des Außenmantels des Gehäuseringes, und
• – einer Lagereinrichtung mit einem ersten Lagerring der auf der ersten Lauffläche des Stützringabschnitts aufsitzt, einem zweiten Lagerring der auf der zweiten Lauffläche des Stützringabschnitts aufsitzt, und einem Druckringelement zur axialen Spannung der beiden Lagerringe gegen den Stützringabschnitt derart, dass der Stützringabschnitt innerhalb des Gehäuseringes radial verlagerbar ist.

This object is achieved by a steering shaft bearing with:

• A housing ring having an outer shell, and a first end ring and a second end ring,
• An inner sleeve ring having an inner jacket and a radially outwardly projecting support ring portion forming a first and a second, each substantially planar, annular tread,
• - Wherein the support ring portion has an outer diameter which is smaller than the inner diameter of the outer shell of the housing ring, and
• - A bearing device with a first bearing ring which rests on the first running surface of the support ring portion, a second bearing ring which rests on the second running surface of the support ring portion, and a pressure ring member for axial tension of the two bearing rings against the support ring portion such that the support ring portion radially displaceable within the housing ring is.

This makes it possible in an advantageous manner, a steering shaft coupled as such is substantially rigidly coupled to a steering wheel in its lower, adjacent steering shaft joint adjacent end portion axially and thereby to a limited extent and substantially free of radial restoring forces a radial displacement of this Steering shaft range to allow.

The steering shaft bearing according to the invention can be designed as a pure slide bearing, as a pure rolling bearing, or in a particularly advantageous manner as a combined sliding / rolling bearings. In the case of the embodiment as a plain sliding bearing, both the first bearing ring and the second bearing ring are preferably formed from a plastic material which offers the corresponding sliding properties. In the case of the embodiment as a pure rolling bearing, the two bearing rings are preferably formed as equipped with rolling elements, in particular balls cage structures. In the aforementioned mixed form one of the bearing rings may be designed as a sliding bearing ring and the other bearing ring as equipped with rolling elements structure. The support ring portion extends between the bearings and is axially supported on both sides.

According to a particularly preferred embodiment of the invention, the pressure ring element is made of an elastomer material, in particular a silicone rubber material. The pressure ring element is preferably integrated into the steering shaft bearing in such a way that it receives a prestress in the installed state and thus biases the bearing rings against the support ring section. The bias can be brought about in the production of the steering shaft bearing by a forming, pressing or upsetting step. Thus, for example, one of the end rings of the housing ring can be made by plastic deformation integral with the outer shell and thereby radially compressed inwardly or crimped. However, it is also possible to manufacture the steering shaft bearing as a demountable composite assembly, in which For example, one of the end ring sections is designed as inserted into the shell section spring ring.

In particular, in the embodiment of the steering shaft bearing as a plain bearing, it is possible to manufacture the bearing rings of a self-lubricating material, in particular a filled with lubricant plastic material. In the formation of at least one of the bearing rings as a rolling element-bearing structure, however, the steering shaft bearing is preferably filled with a lubricant, in particular a high-viscosity grease.

The steering shaft bearing according to the invention is preferably structurally designed such that it forms an inner radial stop by which the maximum radial displaceability of the support ring portion relative to the housing ring is limited. Those structures causing these radial abutment function can be designed to provide a substantially smooth contact over sliding surfaces so that the contacting structures do not cause a significant increase in bearing moment nor force each other hard, thus causing noise.

The steering shaft bearing according to the invention is preferably designed as a sealed system, so that on the one hand the access of contaminants in the tread area difficult and any retained in the steering shaft bearing lubricant is retained in this steering shaft bearing.

The steering shaft bearing according to the invention can be embodied as a component whose function is essentially only in the relatively rigid axial and radial provision of provision of a radial displacement bearing a steering shaft. This steering shaft bearing can also be used advantageously as a support structure for a steering angle sensor, or as a connecting element for creating an electrically conductive connection in the steering wheel system and this may optionally be equipped with other components.

The bearing according to the invention is installed in a motor vehicle steering column for positioning the lower steering shaft. The bearing of the invention supports the lower shaft up against the adjustment of the driver when adjusting the steering wheel and the lower steering shaft down against the displacement forces of the intermediate steering shaft and the forces coming through the deflection angle of this intermediate steering shaft. In addition, in the event of a vehicle collision, the crash forces are received coming from the steering gear above. Also occurring angle errors and radial offsets between the upper and lower bearing are compensated, which may occur due to technology-dependent manufacturing process of the items in the steering column.

The steering shaft bearing according to the invention can deflect radially at high axial support effect advantageously without significant radial forces applied to the shaft in a dimensioning-relevant displacement region, which could lead to tension of the sliding partners between the lower and upper shaft.

By inventively designed steering shaft bearing sufficient compensation of any radial inaccuracies is achieved in an advantageous manner. The inventive concept can thus be prevented from exceeding the radial forces.

In the context of the present description, the term bearing ring is to be understood as meaning a ring structure which transmits axial forces between the inner bushing and the housing ring. Any rolling elements received in this ring structure, in particular balls, form part of the bearing ring. The term bearing ring thus fall in particular also equipped with rolling elements ring-like cages.

The bearing of the invention allows for a small and non-increasing force a radial displacement of the inner sleeve relative to the housing ring. The possibly occurring at the bearing rings wear can be taken into account by appropriate choice of material and pad thickness dimensioning in the design of the bearing for a corresponding life. Also, a radial end stop can be achieved by the steering shaft bearing according to the invention. The bearing can be designed so that it is free of play over its entire service life. The external dimensions and load capacity can be adapted to the constructional specifications of the customer with great freedom in design. The bias of the raceways over life can be generated by a spring element of an elastomeric material, plastic, or steel. Life cycle requirements can still be met by selecting wear resistant raceways with associated grease types. The storage can be designed as a plain bearing solution, but also as a rolling bearing solution. The steering shaft bearing according to the invention preferably consists of an optionally hardened by heat treatment outer sleeve, and one or more spring biasing elements made of elastomeric material, plastic or steel. The inner bearing may further comprise one or more raceway rings for sliding contact, as well as one or more cages with rolling elements. The contact with the inner ring is adapted to the necessary movements of the inner ring (swivel angle, radial / axial movements) one or more Raceways for a rolling contact or one or more Axialkugelkränze for a radial as well as circumferential movement. The bearing further comprises an inner ring in non-cutting or cutting geometry made of steel or plastic. Possibly. Grease introduced into the bearing is preferably matched specifically to the material pairings and a required sliding friction function.

Brief description of the figures

Further details and features of the invention will become apparent from the following description taken in conjunction with the drawings. It shows:

1 a system representation for illustrating a preferred installation position for a steering shaft bearing according to the invention;

2 an axial sectional view illustrating a sliding ring variant of a steering shaft bearing according to the invention;

3 an axial sectional view illustrating a variant of a steering shaft bearing according to the invention with a pair of bearing rings which are equipped with rolling elements;

4 an axial sectional view to illustrate a further variant of a steering shaft bearing according to the invention in which the axial support via a Gleitführungsring and a Axialwälzlager, wherein the Axialwälzlager comprises a fitted with rolling elements ring element which is centered on the support ring portion;

5 an axial sectional view for illustrating a further variant of a steering shaft bearing according to the invention in which axial spring elements are mounted on the plastic cage.

Detailed description of the figures

In 1 a steering shaft assembly for a motor vehicle is shown, which is a vehicle steering wheel 1 coupled with a steering gear not shown here. The steering shaft assembly includes an upper steering shaft 2 which rigid with the vehicle steering wheel 1 is coupled, and a lower steering shaft A. This steering shaft 2 is in an inner steering housing 3 stored. The inner steering housing 3 in turn is about a hinge device 4 pivotable with an outer steering housing 5 coupled and via a clamping device 6 on the outer steering housing 5 fixable.

In a the vehicle steering wheel 1 turned away end portion is on the steering shaft A a universal joint head of a universal joint 6 attached. In a the cardan joint 6 further downstream area is the steering shaft in further steering shaft members 7 . 8th subdivided. The lowest steering shaft link 8th is about a universal joint 9 with a steering pin 10 coupled.

In the steering system shown here, when releasing the clamping device 6 the inner steering housing 3 opposite the outer steering housing 5 be pivoted. This is for the steering wheel 1 given a height and Längsverstellfunktion.

The steering shaft A is about two here not closer to each other rolling bearings in the inner steering housing 3 stored. In her the lower cardan joint 6 adjacent end portion is the steering shaft A via another, according to the invention designed according to the steering shaft bearing 11 supported. The structure of this steering shaft bearing 11 will be described below in connection with the 2 . 3 and 4 described.

This in 2 illustrated steering shaft bearing 11 includes a housing ring 12 the one outer jacket 12a , a first end ring 12b and a second end ring 12c having. The steering shaft bearing 11 further includes an inner sleeve ring 13 with an inner jacket 13a and a radially outwardly projecting support ring portion 13b , The support ring section 13b forms a first and a second, each substantially planar, and also ring-like tread S1, S2. The support ring section 13b is designed in terms of its outer diameter such that it is significantly smaller than the inner diameter of the outer shell 12a of the housing ring 12 ,

Inside the housing ring 12 is a storage facility 14 intended. This includes a first bearing ring 14a on the first running surface S1 of the support ring section 13b seated, as well as a second bearing ring 14b seated on the second tread S2 of the support ring portion. Furthermore, a pressure ring element 16 provided that the axial stress of the two bearing rings 14a . 14b against the support ring section 13b serves. The bearing arrangement 14 as well as the housing ring 12 and the support ring portion are configured such that the support ring portion 13b and thus the inner sleeve ring 13 in itself within the housing ring 12 are radially displaceable. By this special bearing design, it is possible to support the steering shaft axially and still provide a certain amount of radial freedom of movement for the steering shaft in the area corresponding to the bearing point. As a result, both component tolerances and adjustment-related misalignment can be compensated.

In the embodiment shown here, both the first bearing ring 14a , as well as the second bearing ring 14b as Gleitführungsringe educated. These Gleitführungsringe are made of a bearing material, in particular a plastic material and each have a circumferential nose N1, N2, which rests on the running surfaces S1, S2. The bearing rings 14a . 14b are designed so that these with a sufficient radial play in the outer jacket 12a sit the housing ring and possibly in the housing ring 12 in the circumferential direction, ie can wander around the bearing axis X.

The two bearing rings 14a . 14b be axially by a pressure ring element 16 against the support ring section 13b curious; excited. The pressure ring element 16 is made of an elastomeric material and is seated in an inner corner ring portion of the inner circumferential surface of the outer shell 12a and the radially inwardly projecting first end ring 12b is formed.

In the embodiment shown here are both end rings 12b . 12c by plastic deformation integral with the outer shell 12a manufactured. Preferably, this component is manufactured as a drawn and thus seamless component. However, it is also possible to manufacture this component as a rolled component, or as a multi-part, possibly composed of two half-shells structure. The second bearing shown here 14b can be attached to the outer casing 12 be fixed so that it is neither pronounced in the circumferential direction, nor in the axial direction pronounced.

In the embodiment shown here, the first bearing ring 14a . 14b designed so that it provides a radial stop function by which the radial displacement of the inner sleeve 13 is limited. The inner dimensions of the first bearing ring 14a are dimensioned so that the outer peripheral surface of the inner sleeve 13 on the inner peripheral surface of the first bearing ring 14a is present before the peripheral surface of the support ring portion 13 on the inner peripheral surface of the housing ring 12 pending. As a result, a gentle radial support of the inner sleeve 13 achieved and a direct start of the inner sleeve on the inner surface of the housing ring 12 avoided.

In the construction shown here is the inner sleeve 13 inside the outer casing 12 by a measure radially displaceable that is substantially the difference between the inner diameter of the first bearing ring 14a and the outer diameter of the inner shell 13a equivalent. The radial displaceability can also be limited by other design concepts.

In the embodiment shown here, the two bearing rings 14a . 14b as identical parts. It is also possible to design these components as structurally different structures.

The through the two bearing rings 14a . 14b on the support ring section 13b applied biasing force is essentially due to the axial compression, the cross-section and the material properties of the pressure ring element 16 certainly. This compression results in this embodiment, after the assembly of the components in the order shown here, the second end ring section 12c is formed by a forming step. The compression condition of the pressure ring element 16 This is due to the component geometries of the internal components, as well as the axial distance of the end ring sections 12b . 12c certainly.

The steering shaft bearing shown here is further loaded with a lubricant filling by which in the area of the contact surfaces between the bearing rings 14a . 14b With the corresponding running surfaces S1, S2 of the support ring portion, a lubricating film is generated.

For the in 3 embodiment shown apply to the versions of the variant 2 analogous. The main difference to the variant 2 is that here the bearing rings 14a . 14b as with rolling elements 17a . 17b equipped rings are executed.

The rolling elements 17b of the second bearing ring 14b are axially supported on the inner surface of the second Stirnringabschnitts 12c , as well as on the second tread S2 of the support ring portion 13b from. The rolling elements 17a of the first bearing ring 14a are supported on the first running surface S1 of the support ring section 13b as well as on a lid ring 18 from. The lid ring 18 becomes axially through the pressure ring element 16 against the rolling elements of the first bearing ring 14a curious; excited.

Both bearing rings 14a . 14b can in the housing ring 12 move radially. Also in this embodiment is about the first bearing ring 14a given a certain radial stop function, ie the outer peripheral surface of the inner sleeve 13 is on the inner peripheral surface of the first bearing ring 14a before, the peripheral surface of the support ring portion 13b on the inner peripheral wall of the shell portion 12a pending.

In the embodiment shown here are the rolling elements 17a . 17b executed as balls. The rolling elements 17a . 17b However, they can also have other geometries, in particular as cylindrical rollers, or be executed tons.

In 4 is shown a further variant of a steering shaft bearing according to the invention, in which one of the two bearing rings - here the first bearing ring 14a - as plain bearing ring and the other bearing ring - here the second bearing ring 14b - as with rolling elements 17b fitted bearing ring or cage is executed. The second bearing ring 14b is also designed so that it smoothly through the inner sleeve 13 is centered. For this purpose, on the second bearing ring 14b a circumferential shoulder S3 is formed, which optionally on the outer peripheral surface of the support ring portion 13b starts. This variant offers a special operating behavior in that a assumed axis position of the inner axis of the inner bush 13 opposite the bearing axis X of the housing ring 12 tends to be maintained. The positioning of the inner bush 13 opposite the housing ring 12 results, for example, in a setting process in which the steering wheel height is adjusted. The second bearing ring 14b is here by the support ring section 13b radially positioned accordingly, since the support ring section 13b in this case temporarily pending on the peripheral shoulder S3. Due to the radial guidance of the second bearing ring 14b on the inner bush 13 and the rolling contact of the rolling elements 17b with the support ring section 13b or the radial inner surface of the second Stirnringabschnitts 12c There is a tendency to retain the new axle positions. This effect is all the more pronounced, the higher the axial stress of the bearing and the narrower the second bearing ring 14b on the inner bush 13 is centered. Also by a minimal radial clearance of the rolling elements 17b in the ring element 14b this effect is further supported.

The axial tension of the axial bearing device 14 is also in this embodiment by a pressure ring element 16 causes this between the first end ring section 12b and the first bearing ring 14a sitting.

This pressure ring element can be formed in particular by an O-ring. It is also possible, as indicated in the lower half of the section, to realize by this pressure ring element a sealing device by which the interior, in particular if it is filled with lubricant, is sealed. The sealing device is preferably designed so that this the radial displacement of the inner sleeve 13 opposite the housing ring 12 sufficiently permitting.

Also on the side of with rolling elements 17b equipped second Lageringes is - although not shown here - preferably provided a lip seal as such, the rolling bearing seals against the environment. This lip seal can be attached to the second bearing ring 14b be connected and in installed condition on the inserted steering shaft and the second end ring section 12b start. This seal can be structurally accomplished otherwise, for example by a to the inner sleeve 13 Tailored sealing lip ring structure.

The pressure ring element can also be made of a metal material and designed, for example, as a ring element with a U-shaped cross-section or as a plate or wave spring.

In 5 a fourth embodiment of a steering shaft bearing according to the invention is shown. This steering shaft bearing comprises a housing ring 12 the one outer jacket 12a , as well as a first end ring 12b and a second end ring 12c having. In the housing ring is an inner sleeve ring 13 stored. This inner sleeve ring comprises an inner sheath 13a and a radially outwardly projecting support ring portion 13b which forms a first and a second, ring-like, here also in each case substantially planar tread S1, S2. The support ring section 13b has an outer diameter that is smaller than the inner diameter of the outer shell 12a of the housing ring 12 , The bearing of the inner sleeve ring 13 in the housing ring 12 is about a storage facility 11 accomplished. This includes a first bearing ring 14a on the first running surface S1 of the support ring section 13b seated, as well as a second bearing ring 14b on the second running surface S2 of the support ring section 13b seated. In the two bearing rings 14a . 14b is a pressure ring element 16 integrated in the installed state shown here, a certain axial tension of the two bearing rings 14a . 14b against the respective support ring section 13b brought about, the storage facility 11 is designed in such a way that the support ring section 13b within the housing ring 12 is radially displaceable. By the integration of the pressure ring element 16 into the bearing rings 14a . 14b they receive a certain axial elasticity and can thus be axially biased on the support ring section 13b seated. Also in this embodiment, it is possible Zentrierstrukturen to the bearing rings 14a . 14b form the - similar to the annular shoulder S3 in the embodiment according to 4 the bearing rings 14a . 14b radially on the support ring portion 13b to lead. The bearing rings 14a . 14b are made of a plastic material that offers the appropriate sliding properties. The balls 17a . 17b as such part of the bearing rings 14a . 14b form are preferably made of a steel material. In particular, in the construction shown here, however, these can also be made of a high-strength plastic material. The balls can also sit in pockets which give the balls within the cage acting as a bearing ring a certain axial position. For example, sitting in a bearing ring balls alternately the support ring section 13b and then the lid ring again 18 or the inner surface of the Stirnringabschnitts 12c to contact. The respective bearing ring 18a . 18b is then loaded axially in the manner of a shaft ring and in this case provides a corresponding axial elasticity.

The bearing rings 14a . 14b can be formed overall as a wave rings which are compressible in the axial direction and installed under bias.

In the embodiment shown here, the two bearing rings 14a . 14b each as with balls 17a respectively. 17b equipped bearing rings 14a . 14b educated. From a certain axial compression or deformation degree of the pressure ring elements 16 Then there is an axial force transmission via the balls 17a . 17b the storage facility 11 then both the treads S1 and S2 of the support ring section 13b , as well as the inner wall of the end ring 12c or the cover ring 18 to contact. The lid ring 18 is supported in the axial direction on the inner wall of the end ring 12b from. On the lid ring 18 is a ring collar 18a educated. The inner diameter of this annular collar is dimensioned such that one for the required radial displaceability of the inner stud ring 13 sufficient annular gap between the inner circumferential surface of the annular collar 18a and the adjacent outer peripheral surface of the inner shell 13a given is. On the inner jacket 13a of the inner sleeve ring 13 is a cone section 13c educated. This cone section 13c facilitates the assembly of the inner sleeve ring 13 on the corresponding shaft A.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10058491 A1 [0002]

Claims (10)

Steering shaft bearing with: - a housing ring ( 12 ) of an outer jacket ( 12a ), and a first end ring ( 12b ) and a second end ring ( 12c ), - an inner sleeve ring ( 13 ) with an inner jacket ( 13a ) and a radially outwardly projecting support ring portion ( 13b ) which forms a first and a second, ring-like running surface (S1, S2), - wherein the support ring portion ( 13b ) has an outer diameter which is smaller than the inner diameter of the outer jacket ( 12a ) of the housing ring ( 12 ), and - a storage facility ( 11 ) with a first bearing ring ( 14a ) on the first running surface (S1) of the support ring portion (S1) 13b ), a second bearing ring ( 14b ) on the second running surface (S2) of the support ring section (FIG. 13b ), and a pressure ring element ( 16 ) to the axial tension of the two bearing rings ( 14a . 14b ) against the support ring section ( 13b ) such that the support ring portion ( 13b ) within the housing ring ( 12 ) is radially displaceable. Steering shaft bearing according to claim 1, characterized in that the first bearing ring ( 14a ) than with rolling elements ( 17a ) equipped ring structure is formed. Steering shaft bearing according to claim 1 or 2, characterized in that the second bearing ring ( 14b ) than with rolling elements ( 17b ) equipped ring structure is formed. Steering shaft bearing according to claim 1 or 3, characterized in that the first bearing ring ( 14a ) is designed as Gleitführungsring. Steering shaft bearing according to claim 2 or 4, characterized in that the second bearing ring ( 14b ) is designed as Gleitführungsring. Steering shaft bearing according to claim 4 or 5, characterized in that the respective Gleitführungsring ( 14a . 14b ) is made of a plastic material. Steering shaft bearing according to at least one of claims 1 to 6, characterized in that the pressure ring element ( 16 ) is made of an elastomer, plastic, or steel material. Steering shaft bearing according to at least one of claims 1 to 7, characterized in that at least one of the end rings ( 12b . 12c ) by plastic deformation integral with the outer shell ( 12a ) is made. Steering shaft bearing according to at least one of claims 1 to 8, characterized in that in the region of the support ring portion ( 13b ) A lubricant filling is provided. Steering shaft bearing according to at least one of claims 1 to 9, characterized in that a Radialendanschlag is provided to limit the radial displacement of the support ring portion ( 13b ), and that one of the end rings ( 12b . 12b ) is retracted radially inwardly during the assembly of the bearing device, and that the compression state of the pressure ring element ( 16 ) by the axial distance of the end rings ( 12b . 12c ).

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