Bearing ring with retaining rim

Abstract

Induction-hardened bearing ring (2) of a rolling bearing, which has a running surface (4) for rolling elements and at least one rim (8; 10) which merges into a bearing ring shoulder (6) and which rises with a height (H) above the running surface (4), characterized in that the running surface (4) is induction-hardened and the bearing ring shoulder (6) and the rim (8; 10) which merges into the bearing ring shoulder (6) are unhardened, wherein a recess (12) is further formed between the bearing ring shoulder (6) and the rim (8; 10), the depth (T) of which recess is selected such that the unhardened rim (8; 10) is free-standing over its entire height (H).

Description

The present invention relates to a bearing ring according to claim 1, and to a rolling bearing having such a bearing ring.In general, bearing inner and bearing outer rings of a rolling bearing each have a running surface for arranging rolling bodies. The bearing rings can have axially arranged rims, so-called holding and / or guide rims, wherein the holding rim plays a role in bearing assembly and / or during transport for supporting the rolling bodies, and the guide rim serves for axial rolling body guidance, in particular during operation of the bearing.Bearing rings are known, inter alia, from the following documents.JP 2014 / 1 800 A discloses a bearing device including an inner ring having an inner ring extraction part at an end in the direction of the rotation axis, an outer ring, and a rolling element. The inner ring extraction part includes an inner ring extraction groove formed from a surface on a radially outer side toward a radially inner side.WO 2006 / 094 661 A1 discloses a rolling bearing having an inner ring which has an inner raceway which is designed in the manner of a truncated cone and is bounded laterally by a first rim and a second rim, an outer ring which has an outer raceway which is designed in the manner of a truncated cone, rolling bodies which roll between the inner raceway and the outer raceway, and cage segments which are arranged in a row one next to the other in the circumferential direction and are fitted with the rolling bodies. The cage segments equipped with the rolling bodies are secured to the inner ring in a captive manner in the region of the first rim by the cage segments and in the region of the second rim by the rolling bodies.US 2 071 628 A discloses a rolling bearing having inner and outer races and rollers mounted therebetween, the rollers being frusto-conical and the outer race having a co-operating frusto-conical bearing surface, one portion of the bearing surface of the inner race co-operating with the frusto-conical surfaces of the rollers and another portion gradually diverging to reduce the concentration of load from the frusto-conical surface at a steadily increasing angle.DE 10 2011 086 925 A1 discloses a double-row spherical roller bearing having a multiplicity of rolling bodies rolling around a bearing axis on a raceway of an inner ring in two bearing rows, wherein a pressure angle of a first row of layers is different from a pressure angle of a second row of bearings and / or wherein a roller length of rolling bodies of a first row of bearings is different from a roller length of rolling bodies of a second row of bearings.DE 69 00 506 U discloses a seal, in particular for rolling bearings, by means of a sealing disk made of rubber-elastic material, which is locked in a rotationally fixed manner in a receiving groove of a bearing ring and which rests slidingly with axial residual stress on the other bearing ring, wherein the sealing disk has an essentially disk-spring-shaped cross section in the relaxed state.It is known from the prior art to inductively harden the running surface of the bearing rings in order to impart sufficient hardness and strength to them with respect to mechanical stresses, such as deformations due to tension or pressure. In this case, induction hardening as a method for setting certain edge layer properties is based on a structure transformation as a result of material-specific thermal treatments and can generally be divided into heating above the austenitizing temperature and optionally into subsequent quenching below the martensite start temperature. As a result, in an outer layer, for example the running surface of a bearing ring, a transformation into an austenite structure occurs, while the initial initial structure remains in the inner region. Owing to the machining of only partial surfaces and to a good control of the hardness values and the hardness profile, induction hardening is used more and more frequently.However, it is disadvantageous that a thermal expansion of the material occurs during the induction process, which is critical in particular in the region of the retaining rim, since the retaining rim is generally not cured and is accordingly not heated, so that particularly high stresses occur in this region, which can lead to undesired crack formations.It is therefore the object of the present invention to provide a bearing ring in which it is possible to subject the running surfaces of the bearing ring to an induction hardening method without problems and a rolling bearing with such a bearing ring.This object is achieved by a bearing ring according to claim 1 and by a rolling bearing according to claim 11.In the following, a bearing ring of a rolling bearing is presented, which has a running surface for rolling bodies and at least one rim which merges into a bearing ring shoulder and rises above the running surface with a height H. The rim is preferably a retaining rim. Since the retaining rim serves only for assembly purposes and / or as a transport securing means, the retaining rim generally remains uncured. Although preferred for the retaining rim, all the features mentioned below can likewise also be used in the case of a guide rim. In the following, therefore, a bearing ring is described in which the running surface is inductively hardened and the bearing ring shoulder and the rim merging into the bearing ring shoulder are uncured.In order to prevent crack formation during induction hardening due to thermal stresses in the region of the in particular non-inductively treated rim, it is proposed to form between the bearing ring shoulder and the rim a depression whose depth T is selected such that the rim is formed free-standing over its entire height H. The free-standing rim according to the invention makes it possible for the free-standing rim to expand thermally during induction hardening, as a result of which cracking is counteracted.In this case, the depression is not only formed as a undercut, but preferably extends clearly into a region below the running surface and the bearing ring shoulder, such that the bearing ring shoulder has a first radial distance from an axis of rotation of the bearing ring, and the depression has a deep point which has a second radial distance from the axis of rotation, wherein a difference between the first radial distance and the second radial distance is greater than the height H of the rim. In this case, in the case of a configuration of the bearing ring as a bearing inner ring, the second radial distance is formed to be smaller than the first radial distance, while in the case of a configuration of the bearing ring as a bearing outer ring, the second radial distance is formed to be larger than the first radial distance. It is furthermore advantageous if the depth T, measured perpendicularly to the running surface from a deepest point of the depression up to the maximum height H of the rim, is more than one and a half times, preferably more than twice, the height H. This allows a particularly good thermal expansion of the rim.According to a further preferred exemplary embodiment, the depression extends substantially perpendicularly to the running surface of the bearing ring. As a result, the thermal stresses generated during the induction method can be reduced particularly effectively, since the depression enables a thermal expansion of the rim in the direction of the annular bearing shoulder.In a further advantageous exemplary embodiment, the depression has a first and a second depression wall which are formed substantially parallel to one another. The depression can thereby be worked into the bearing ring in a simple manner, for example by means of rotation. In general, however, the first and the second recess wall can also not be formed parallel to one another, but can have a conical shape, for example.According to a further advantageous exemplary embodiment, the depression is designed as a circumferential groove. As a result, the depression can be worked into the bearing ring in a simple manner.Alternatively or additionally, as already mentioned above, a guide flange can also be provided on the bearing ring in addition to the retaining flange. Instead of or in addition to the retaining rim, the guide rim can also be formed free-standing, as described above. As a result, inductors can be used which only cure the running surface of the bearing ring.A further aspect relates to a rolling bearing having at least one bearing ring which has the features described above.Further advantages and advantageous embodiments are specified in the dependent claims, the description and the drawing. A combination of the features in the description and in the drawing is purely exemplary and it is clear to the person skilled in the art that the features need not necessarily be present in the specified combination, but can also be present individually or differently combined with one another without thereby exceeding the scope of the invention.The principle of the invention is described in more detail below with reference to an exemplary embodiment shown in the drawing. The exemplary embodiment is purely exemplary in nature and is not intended to define the scope of the invention. This applies in particular to features shown in combination, which can also be realized as individually standing features within the scope of the present invention. The scope of the application is defined solely by the appended claims.It shows: FIG. 1 : a schematic cross-sectional view through a bearing ring according to an embodiment of the invention.In the following, identical or similar elements are identified by the same reference numerals.FIG. 1 shows a schematic cross-sectional view through a bearing ring 2 which has a running surface 4 on which rolling bodies (not shown) can be arranged. Furthermore, the bearing ring 2 has a retaining rim 8 merging into a bearing ring shoulder 6 and a guide rim 10, wherein in particular the retaining rim 8 rises with a height H above the running surface 4 of the bearing ring 2. The bearing ring shoulder 6 and the retaining rim 8 can be edge regions of the bearing ring 2 that are not to be hardened, whereas the running surface 4 and the guide rim 10 are preferably hardened inductively.As FIG. 1 further shows, the retaining rim 8 is formed free-standing and has, between the bearing shoulder 6 and the retaining rim 8, a depression 12 preferably formed as a circumferential groove, having a depth T and a width B. The depth T of the depression 12 is determined perpendicular to the running surface from the maximum height H to a deepest point of the depression 12 and, as can be seen from FIG. 1, is dimensioned such that it extends clearly into a region below the running surface 4 and the bearing ring shoulder 6. It is particularly preferred here if the depth T is selected such that it is formed approximately twice as large as the height H. Due to the free-standing configuration resulting from this, the retaining rim 8 can thermally expand during an induction method, so that stresses in this region can be reduced and crack formation can be avoided. It is thus possible to inductively harden the running surface 4 and / or the starboard 10 and to utilize the advantages associated with the induction method.Furthermore, FIG. 1 shows that the bearing ring shoulder 6 has a first radial distance R 1 and the depression 12 has a second radial distance R 2 from an axis of rotation D of the bearing ring 2, wherein preferably a difference X between the first radial distance R 1 and the second radial distance R 2 is greater than the height H of the retaining rim 8, so that a particularly extended clearance of the retaining rim and thus a particularly effective thermal expansion can be made possible.Furthermore, FIG. 1 shows that the depression 12 extends substantially perpendicularly to the running surface 4 of the bearing ring 2. As a result, the voltages generated during the induction method can also be reduced particularly effectively.As is also shown in FIG. 1, the depression 12 has a first and a second depression wall 14; 16, which are formed substantially parallel to one another. As a result, the depression can be worked into the bearing ring 2 in a simple manner, for example by means of rotation. In general, however, it is also possible to design the recess walls 14; 16 differently, for example conically.Alternatively or additionally, instead of the retaining rim 8, the guide rim 10 can also have the features listed above. As a result, inductors can be used which only cure the running surface 4 of the bearing ring 2.Overall, due to the formation of a depression between a bearing ring shoulder and a rim, in particular a retaining rim, a bearing ring for a rolling bearing can be provided, which bearing ring has a rim which is free-standing with respect to the bearing ring shoulder. As a result, a thermal expansion of the rim occurring in the course of an induction method is possible, so that stresses and crack formations resulting therefrom can be reduced in this region.List of reference characters2 Bearing ring 4 running surface 6 bearing ring shoulder 8 retaining rim 10 guide rim 12 depression 14, 16 depression wall T depth of the depression H height of the retaining rim D axis of rotation R 1, R 2 radial distance X difference between the radial distances B distance bearing ring shoulder - rim

Claims

Inductively hardened bearing ring (2) of a rolling bearing, which has a running surface (4) for rolling bodies and at least one rim (8; 10) which merges into a bearing ring shoulder (6) and rises above the running surface (4) with a height (H), characterized in that the running surface (4) is inductively hardened and the bearing ring shoulder (6) and the rim (8; 10) merging into the bearing ring shoulder (6) are uncured, wherein furthermore a depression (12) is formed between the bearing ring shoulder (6) and the rim (8; 10), the depth (T) of which depression is selected such that the uncured rim (8; 10) is formed free-standing over its entire height (H).The inductively hardened bearing ring (2) according to claim 1, wherein the uncured rim is a retaining rim (8).The inductively hardened bearing ring (2) according to claim 1 or 2, wherein the unhardened rim is a guide rim (10).Inductively hardened bearing ring (2) according to one of the preceding claims, wherein the bearing ring (2) is a bearing ring for a tapered roller bearing.Inductively hardened bearing ring (2) according to one of the preceding claims, wherein the bearing ring (2) has a retaining rim (8) and a guide rim (10), wherein the retaining rim (8) is uncured and the guide rim (10) and the running surface (4) are cured, and wherein the depression (12) is formed only between the uncured bearing ring shoulder (6) and the uncured retaining rim (8).Inductively hardened bearing ring (2) according to one of the preceding claims, wherein the depression (12) extends as far as a region significantly below the running surface (4) and the bearing ring shoulder (6).Inductively hardened bearing ring (2) according to one of the preceding claims, wherein the depth (T), measured perpendicularly to the running surface (4) from a deepest point of the depression (12) to the maximum height (H) of the rim (8), is more than one and a half times, preferably more than twice, the height (H).Inductively hardened bearing ring (2) according to one of the preceding claims, wherein the depression (12) extends substantially perpendicularly to the running surface (4) of the bearing ring (2).Inductively hardened bearing ring (2) according to one of the preceding claims, wherein the depression (12) has a first and a second depression wall (14; 16) which are formed substantially parallel to one another.Inductively hardened bearing ring (2) according to one of the preceding claims, wherein the depression (12) is formed as a circumferential groove.Rolling bearing, in particular tapered roller bearing, having at least one inductively hardened bearing ring (2) according to one of the preceding claims.

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