Steering shaft bearings and intermediate steering shaft

Abstract

Steering shaft bearing (1) for an intermediate steering shaft (2) of a motor vehicle, which is designed to support an inner hollow shaft (10) of the intermediate steering shaft (2) in an outer hollow shaft (12) of the intermediate steering shaft (2), comprising a bearing bushing (14) which can be arranged on an outer surface (10a) of an inner hollow shaft (10) of the intermediate steering shaft (2), wherein the bearing bushing (14) is circular with a circumferential interruption (14a) provided at a predetermined section; and comprising a circular flexible sealing element (16) arranged on the bearing bushing (14) for sealing the outer hollow shaft (12) against the inner hollow shaft (10). characterized by that the flexible sealing element (16) is arranged along the circumference of the bearing bushing (14) and in the area of ​​the interruption (14a) of the circumference of the bearing bushing (14); that the bearing bushing (14) has a plurality of first sections (18) and second sections (20) arranged alternately in the circumferential direction, wherein the bearing bushing (14) has a first diameter (D1) in the region of the first sections (18) and a second diameter (D2) in the region of the second sections (20); and that the flexible sealing element (16) is arranged in the area of ​​the first sections (18) of the bearing bushing (14) on its outer surface (14c) and in the area of ​​the second sections (20) of the bearing bushing (14) on its inner surface (14b).

Description

[0001] The invention relates to a steering shaft bearing for an intermediate steering shaft of a motor vehicle. The invention further relates to an intermediate steering shaft for a steering system of a motor vehicle. State of the art

[0002] Conventional steering shaft bearings allow the inner hollow shaft of the intermediate steering shaft to be mounted within an outer hollow shaft of the intermediate steering shaft. Furthermore, steering shaft bearings of this type typically have a sealing function to seal the outer hollow shaft from the inner hollow shaft of the intermediate steering shaft.

[0003] DE 10 2011 081 881 A1 discloses a steering shaft bearing with a housing ring having an outer shell, as well as a first end ring and a second end ring, an inner bushing ring with an inner shell and a radially outwardly projecting support ring section which forms a first and a second, annular running surface, wherein the support ring section 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 sits on the first running surface of the support ring section, a second bearing ring which sits on the second running surface of the support ring section, and a pressure ring element for axially tensioning the two bearing rings against the support ring section in such a way that the support ring section is radially displaceable within the housing ring.

[0004] US 2008 / 0 231 003 A1 deals with a dust cover for a steering shaft, wherein the cover has several bellows for sealing. Furthermore, the cover includes a bushing made of a low-friction material to reduce the generation of disturbing noise.

[0005] DE 197 81 693 B4 deals with a shock absorber in which a piston rod is guided by a sealing member and a piston rod bearing unit at one end of a cylinder in such a way that it can slide freely. The piston rod bearing unit is formed in one piece from a base material by pressing or deep drawing.

[0006] DE 42 25 556 A1 discloses a rod guide supported between radially inwardly facing projections of a cylindrical surface.

[0007] DE 199 09 922 A1 proposes a bearing seal assembly with a bearing element. The bearing element has a bearing area and a sealing area, with the sealing area being preloaded against a sealing surface with a clamping element sealing element for sealing purposes.

[0008] The above-mentioned conventional steering shaft bearings have the disadvantage that a sealing element of the steering shaft bearing cannot be mounted on bearing bushes which have a larger diameter than an inner diameter of the sealing element, but this results in a reduced sealability or sealing performance by the sealing element.

[0009] The invention is therefore based on the object of providing a steering shaft bearing for an intermediate steering shaft of a motor vehicle, which enables good sealing properties by a good fit on the inner hollow shaft of the intermediate steering shaft.

[0010] The object is achieved with a steering shaft bearing for an intermediate steering shaft of a motor vehicle having the features of patent claim 1. The invention is further achieved with an intermediate steering shaft for a steering system of a motor vehicle having the features of patent claim 10. Disclosure of the invention

[0011] The present invention provides a steering shaft bearing for an intermediate steering shaft of a motor vehicle, which is designed to support an inner hollow shaft of the intermediate steering shaft in an outer hollow shaft of the intermediate steering shaft, with a bearing bush which can be arranged on an outer surface of an inner hollow shaft of the intermediate steering shaft, wherein the bearing bush is substantially circular in shape with an interruption of a circumference provided at a predetermined section, and with a substantially circular sealing element arranged on the bearing bush for sealing the outer hollow shaft with respect to the inner hollow shaft, wherein the sealing element is arranged along the circumference of the bearing bush and in the region of the interruption of the circumference of the bearing bush.

[0012] The bearing bushing has a plurality of first sections and second sections arranged alternately in the circumferential direction, wherein the bearing bushing has a first diameter in the region of the first sections and a second diameter in the region of the second sections. Thus, a flexible connection between the inner hollow shaft and the outer hollow shaft of the intermediate steering shaft can be advantageously provided.

[0013] The flexible sealing element is arranged on the outer surface of the bearing bushing in the area of ​​the first sections and on the inner surface of the bearing bushing in the area of ​​the second sections. Such an alternating arrangement of the sealing element on the bearing bushing can advantageously ensure a solid connection between the sealing element and the bearing bushing. Furthermore, it can ensure a good seal against the inner hollow shaft of the intermediate steering shaft.

[0014] The present invention further provides an intermediate steering shaft for a steering system of a motor vehicle, having an outer hollow shaft and an inner hollow shaft guided in the outer hollow shaft by the steering shaft bearing according to the invention.

[0015] One idea of ​​the present invention is that by forming the bearing bush with an interruption of its circumference provided at the predetermined section and providing the flexible sealing element along the circumference of the bearing bush and in the region of the interruption of the circumference of the bearing bush, it can be made possible that the steering shaft bearing is expandable in the region of the flexible sealing element such that the steering shaft bearing has flexibility in the region of the interruption of the circumference of the bearing bush and the steering shaft bearing can thus be mounted on an inner hollow shaft of the intermediate steering shaft, which has a larger diameter than the inner diameter of the bearing bush. Thus, the flexible sealing element enables improved sealing of the outer hollow shaft against the inner hollow shaft of the steering shaft bearing.

[0016] Advantageous embodiments and further developments emerge from the subclaims and from the description with reference to the figures.

[0017] According to a preferred development, the bearing bushing is overmolded along its inner surface and / or its outer surface with a flexible sealing element, wherein the bearing bushing is formed from a non-elastic plastic material, preferably from a hard plastic material, and wherein the flexible sealing element is formed from an elastic plastic material, preferably from a rubber material. Thus, a two-component steering shaft bearing can advantageously be provided, the flexible sealing element of which has the elastic or flexible properties preferred according to the invention.

[0018] Furthermore, such a steering shaft bearing can compensate for tolerances or dimensional deviations of the components of the intermediate steering shaft, such as the inner hollow shaft and the outer hollow shaft.

[0019] According to a further preferred development, a respective first section is connected to a respective second section of the bearing bush by a connecting section that bridges a diameter difference between the first section and the second section of the bearing bush. Thus, the bearing bush can advantageously be provided in one piece, even though it has a plurality of sections with a first diameter and a plurality of sections with a second diameter.

[0020] According to a further preferred development, it is provided that the plurality of first sections of the bearing bush are arranged axially offset from the plurality of second sections of the bearing bush, wherein the plurality of first sections of the bearing bush and the plurality of second sections of the bearing bush have a substantially equal axial length.

[0021] The axially offset arrangement of the first sections and the second sections preferably allows the first sections and / or the second sections, depending on the arrangement, to be overmolded with the flexible sealing element to a greater extent. For example, the first sections of the bearing bush can be arranged axially offset from the second sections of the bearing bush, so that the first sections of the bearing bush are overmolded with the flexible sealing element to a greater extent than the second sections of the bearing bush.

[0022] According to a further preferred development, the flexible sealing element comprises a first sealing lip arranged adjacent to the bearing bush and a second sealing lip arranged axially offset from the first sealing lip, which can be applied to the outer surface of the inner hollow shaft. The first sealing lip and the second sealing lip are designed to seal the outer hollow shaft from the inner hollow shaft. Thus, improved sealing can be advantageously achieved by providing two axially spaced-apart sealing lips.

[0023] According to a further preferred development, the first sealing lip and the second sealing lip are formed circumferentially along a circumference of the flexible sealing element and have a waviness formed in the circumferential direction of the flexible sealing element. Due to the waviness of the sealing lips, the sealing lips can advantageously withstand high elongation or stretching that occurs during assembly or operation of the steering shaft bearing. Furthermore, a sealing element designed in this way is capable of providing very good dirt-repellent properties and of fitting precisely against the inner hollow shaft of the intermediate steering shaft.

[0024] According to a further preferred development, a volume formed between the first sealing lip and the second sealing lip can be filled with a lubricant. This allows for an improved sealing function and a reduction in sliding friction of the steering shaft bearing.

[0025] According to a further preferred development, it is provided that the flexible sealing element has an outer ring which can be inserted into a first groove formed in an inner surface of the outer hollow shaft, and wherein the flexible sealing element can be axially fixed by a retaining ring which can be inserted into a second groove formed in the inner surface of the outer hollow shaft.

[0026] By providing the first groove as well as the second groove in the inner surface of the outer hollow shaft as well as forming the flexible sealing element with the outer ring and providing the retaining ring, the flexible sealing element can thus advantageously be axially fixed to the outer hollow shaft of the intermediate steering shaft.

[0027] According to a further preferred development, the flexible sealing element has a web arranged between the first sealing lip and the second sealing lip, extending in the axial direction, and the flexible sealing element has a radial surface formed adjacent to the web, which has a stop for the retaining ring. The flexible sealing element is thus advantageously designed such that it has a stop or a contact surface for the retaining ring for axially fixing the sealing element.

[0028] According to a further preferred development, the first material is made of a non-elastic plastic material, preferably a hard plastic material, and the second material is made of an elastic plastic material, preferably a rubber material. Thus, a two-component steering shaft bearing can advantageously be provided, the flexible sealing element of which has the elastic or flexible properties preferred according to the invention.

[0029] The described designs and further training courses can be combined as desired.

[0030] Further possible embodiments, further developments and implementations of the invention also include combinations of features of the invention described previously or below with regard to the exemplary embodiments that are not explicitly mentioned. Short description of the drawings

[0031] The accompanying drawings are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention.

[0032] Other embodiments and many of the aforementioned advantages will become apparent upon review of the drawings. The elements illustrated in the drawings are not necessarily drawn to scale.

[0033] They show: Fig. 1 is a longitudinal sectional view of an intermediate steering shaft for a steering system of a motor vehicle according to a preferred embodiment of the invention; Fig. 2 is a cross-sectional view of a bearing bush of a steering shaft bearing according to the preferred embodiment of the invention; Fig. 3 is a schematic representation of the bearing bush of the steering shaft bearing according to the preferred embodiment of the invention; Fig. 4 is a schematic representation of the bearing bush of the steering shaft bearing according to the preferred embodiment of the invention; Fig. 5 a cross-sectional view of the bearing bush of the steering shaft bearing overmolded with a flexible sealing element according to the preferred embodiment of the invention; Fig. 6 is a longitudinal sectional view of a portion of the steering shaft bearing according to the preferred embodiment of the invention; Fig. 7 is a schematic representation of the steering shaft bearing according to the preferred embodiment of the invention; and Fig. 8 is a flowchart of a method for manufacturing a steering shaft bearing for an intermediate steering shaft of a motor vehicle according to the preferred embodiment of the invention.

[0034] In the figures of the drawings, the same reference symbols designate the same or functionally equivalent elements, parts or components, unless otherwise stated.

[0035] Fig. 1 shows a longitudinal sectional view of an intermediate steering shaft for a steering system of a motor vehicle according to a preferred embodiment of the invention.

[0036] The intermediate steering shaft 2 for the steering system of the motor vehicle has an inner hollow shaft 10, an outer hollow shaft 12, and a steering shaft bearing 1 arranged between the inner hollow shaft 10 and the outer hollow shaft 12. The steering shaft bearing 1 is designed to support and axially guide the inner hollow shaft 10 in the outer hollow shaft 12.

[0037] The steering shaft bearing 1 has a bearing bush 14 and a flexible sealing element 16. The bearing bush 14 is arranged on an outer surface 10a of the inner hollow shaft 10. The bearing bush 14 is substantially circular and extends along an outer circumference of the inner hollow shaft 10 and an inner circumference of the outer hollow shaft 12 of the intermediate steering shaft 2.

[0038] Furthermore, the steering shaft bearing 1, in particular the flexible sealing element 16 of the steering shaft bearing 1, has a first sealing lip 24 and a second sealing lip 26 for sealing the outer hollow shaft 12 from the inner hollow shaft 10. Furthermore, the flexible sealing element 16 has an outer ring 28. The outer ring 28 is inserted into a first groove 30 formed in an inner surface of the outer hollow shaft 12.

[0039] The flexible sealing element 16 can also be fixed in the axial direction by a retaining ring 34 inserted into a second groove 32 formed in the inner surface of the outer hollow shaft 12.

[0040] Fig. 2 shows a cross-sectional view of a bearing bush of a steering shaft bearing according to the preferred embodiment of the invention.

[0041] The bearing bush 14 is substantially circular in shape with a circumferential interruption 14a provided at a predetermined portion. The bearing bush 14 has a plurality of first portions 18 and second portions 20 arranged alternately in the circumferential direction. The bearing bush 14 has a first diameter D1 in the region of the first portions 18 and a second diameter D2 in the region of the second portions 20. The first diameter D1 is smaller than the second diameter D2.

[0042] A respective first section 18 of the bearing bush 14 is connected to a respective second section 20 of the bearing bush 14 by a connecting section 22 bridging a diameter difference between the first section 18 and the second section 20 of the bearing bush 14.

[0043] Fig. Figure 3 shows a schematic representation of the bearing bush of the steering shaft bearing according to the preferred embodiment of the invention. The plurality of first sections 18 of the bearing bush 14 are arranged axially offset from the plurality of second sections 20 of the bearing bush 14. The plurality of first sections 18 of the bearing bush 14 and the plurality of second sections 20 of the bearing bush 14 preferably have substantially the same length.

[0044] Alternatively, for example, an inverse arrangement to the embodiment shown can be provided. As a result, for example, the second sections 20 of the bearing bush 14 can be arranged axially in the direction of the (in Fig. 3 not shown) sealing element.

[0045] Fig. Figure 4 shows a schematic representation of the bearing bush of the steering shaft bearing according to the preferred embodiment of the invention. Due to the schematic representation of the bearing bush 14, the diameter difference between the first sections 18 and the second sections 20 of the bearing bush 14 is clearly visible. Also clearly visible is a respective connecting section 22, which is arranged at respective end sections of the first sections and the second sections.

[0046] Fig. 5 shows a cross-sectional view of the bearing bush of the steering shaft bearing overmolded with a flexible sealing element according to the preferred embodiment of the invention.

[0047] In the Fig. 5, the bearing bush 14 is overmolded with the flexible sealing element 16. The interruption 14a of the circumference of the bearing bush 14 is in Fig. 5 above. The flexible sealing element 16 is essentially circular and bears against the bearing bush 14 along its circumference. Furthermore, the flexible sealing element 16 is also arranged in the region of the interruption 14a in the circumference of the bearing bush 14, thereby providing an elastic expansion property of the steering shaft bearing.

[0048] The bearing bush 14 is as in Fig. 5, the bearing bush 14 is overmolded with the flexible sealing element 16 along its inner surface 14b and its outer surface 14c. The bearing bush 14 is formed from a non-elastic plastic material, preferably a hard plastic material. The flexible sealing element 16 is formed from an elastic plastic material, preferably a rubber material.

[0049] The flexible sealing element 16 is arranged in the region of the first sections 18 of the bearing bush 14 on its outer surface 14c and in the region of the second sections 20 of the bearing bush 14 on its inner surface 14b.

[0050] Fig. 6 shows a longitudinal sectional view of a portion of the steering shaft bearing according to the preferred embodiment of the invention.

[0051] The flexible sealing element 16 has a first sealing lip 24 arranged adjacent to the bearing bush 14 and a second sealing lip 26 arranged axially offset from the first sealing lip. The first sealing lip 24 and the second sealing lip 26 are connected to the (in Fig. 6 not shown) outer surface of the inner hollow shaft. Furthermore, the first sealing lip 24 and the second sealing lip 26 are designed to Fig. 6 not shown) outer hollow shaft against the inner hollow shaft.

[0052] A volume formed between the first sealing lip 24 and the second sealing lip 26 can be filled with a lubricant.

[0053] Furthermore, the flexible sealing element 16 has an outer ring 28 which fits into a recess formed in an inner surface of the (in Fig. 6 not shown) outer hollow shaft. Furthermore, the flexible sealing element 16 has a web 36 arranged between the first sealing lip 24 and the second sealing lip 26 and extending in the axial direction. The flexible sealing element 16 also has a radial surface 38 formed adjacent to the web 36, which forms a stop or a contact surface for the (in Fig. 6 not shown) retaining ring.

[0054] Fig. Figure 7 shows a schematic representation of the steering shaft bearing according to the preferred embodiment of the invention. The first sealing lip 24 and the second sealing lip 26 are formed circumferentially along a circumference of the flexible sealing element 16. Furthermore, the first sealing lip 24 and the second sealing lip 26 have a waviness formed in the circumferential direction of the flexible sealing element. The waviness can be determined accordingly depending on requirements and can, for example, have a sinusoidal shape.

[0055] Fig. 8 shows a flow chart of a method for manufacturing a steering shaft bearing for an intermediate steering shaft of a motor vehicle according to the preferred embodiment of the invention.

[0056] The method comprises injection molding S1 of a bearing bush 14 of the steering shaft bearing 1 using a first material such that the bearing bush 14 is formed substantially circular with an interruption 14a of a circumference provided at a predetermined portion.

[0057] The method further comprises overmolding S2 of the bearing bush 14 using a second material such that a flexible sealing element 16 is arranged on the bearing bush 14, which is formed substantially circular for sealing the outer hollow shaft 12 with respect to the inner hollow shaft 10, wherein the flexible sealing element 16 is arranged along the circumference of the bearing bush 14 and in the region of the interruption 14a of the circumference of the bearing bush 14.

[0058] The first material is made of a non-elastic plastic material, preferably a hard plastic material. The second material is made of an elastic plastic material, preferably a rubber material.

Claims

[1] Steering shaft bearing (1) for an intermediate steering shaft (2) of a motor vehicle, which is designed to support an inner hollow shaft (10) of the intermediate steering shaft (2) in an outer hollow shaft (12) of the intermediate steering shaft (2), with a bearing bush (14) which can be arranged on an outer surface (10a) of an inner hollow shaft (10) of the intermediate steering shaft (2), wherein the bearing bush (14) is circular in shape with an interruption (14a) of a circumference provided at a predetermined portion; and with a circularly shaped flexible sealing element (16) arranged on the bearing bush (14) for sealing the outer hollow shaft (12) relative to the inner hollow shaft (10), characterized by , that the flexible sealing element (16) is arranged along the circumference of the bearing bush (14) and in the region of the interruption (14a) of the circumference of the bearing bush (14); that the bearing bush (14) has a plurality of first sections (18) and second sections (20) arranged alternately in the circumferential direction, wherein the bearing bush (14) has a first diameter (D1) in the region of the first sections (18) and a second diameter (D2) in the region of the second sections (20); and that the flexible sealing element (16) is arranged in the region of the first sections (18) of the bearing bush (14) on its outer surface (14c) and in the region of the second sections (20) of the bearing bush (14) on its inner surface (14b). [2] Steering shaft bearing according to claim 1, characterized by that the bearing bush (14) is overmolded with the flexible sealing element (16) along its inner surface (14b) and / or its outer surface (14c), wherein the bearing bush (14) is formed from a non-elastic plastic material, and wherein the flexible sealing element (16) is formed from an elastic plastic material. [3] Steering shaft bearing according to claim 1 or 2, characterized by that a respective first section (18) is connected to a respective second section (20) of the bearing bush (14) by a connecting section (22) bridging a diameter difference between the first section (18) and the second section (20) of the bearing bush (14). [4] Steering shaft bearing according to one of claims 1 to 3, characterized by that the plurality of first sections (18) of the bearing bush (14) are arranged axially offset from the plurality of second sections (20) of the bearing bush (14), wherein the plurality of first sections (18) of the bearing bush (14) and the plurality of second sections (20) of the bearing bush (14) have the same axial length. [5] Steering shaft bearing according to one of the preceding claims, characterized byin that the flexible sealing element (16) has a first sealing lip (24) arranged adjacent to the bearing bush (14) and a second sealing lip (26) arranged axially offset from the first sealing lip (24), which can be placed on the outer surface (10a) of the inner hollow shaft (10), wherein the first sealing lip (24) and the second sealing lip (26) are designed to seal the outer hollow shaft (12) relative to the inner hollow shaft (10). [6] Steering shaft bearing according to claim 5, characterized by that the first sealing lip (24) and the second sealing lip (26) are formed circumferentially along a circumference of the flexible sealing element (16) and have a waviness formed in the circumferential direction of the flexible sealing element (16). [7] Steering shaft bearing according to claim 5 or 6, characterized by that a volume formed between the first sealing lip (24) and the second sealing lip (26) can be filled with a lubricant. [8] Steering shaft bearing according to one of the preceding claims, characterized by in that the flexible sealing element (16) has an outer ring (28) which can be inserted into a first groove (30) formed in an inner surface of the outer hollow shaft (12), and wherein the flexible sealing element (16) can be axially fixed by a retaining ring (34) which can be inserted into a second groove (32) formed in the inner surface of the outer hollow shaft (12). [9] Steering shaft bearing according to claim 8, characterized by in that the flexible sealing element (16) has a web (36) arranged between the first sealing lip (24) and the second sealing lip (26) and extending in the axial direction, and wherein the flexible sealing element (16) has a radial surface (38) formed adjacent to the web (36) which has a stop for the retaining ring (34). [10] Steering intermediate shaft (2) for a steering system of a motor vehicle, with an outer hollow shaft (12) and an inner hollow shaft (10) guided in the outer hollow shaft (12) by a steering shaft bearing according to one of claims 1 to 9.

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