DE102017222921A1 - Method for producing a bearing ring - Google Patents

Abstract

Disclosed is a method for producing a bearing ring (1) with a raceway (2) and at least one arranged on an end face of the track board (6), wherein the vehicle opening angle is substantially 90 °, comprising the steps of: a) providing a bearing ring ( 1) having at least one shelf (6) extending in a direction away from the track (2), the transition between the track (2) and the shelf (6) having a radius of curvature, b) heat treating the bearing ring (1) along the raceway (2) and the board (6); and c) reworking the bearing ring (1) to a board opening angle of substantially 90 °.

Description

The present invention relates to a method for producing a bearing ring with a raceway and at least one arranged on an end side of the track board according to the preamble of claim 1.

Bearing rings made of steel are often subjected to a hardening process during production. This can have a (for example inductive) heat treatment, in which the bearing rings are heated and then cooled by cooling water. In particular, in large camps, which have a diameter of more than Im, in particular 1.5 to 4 m, normally inductors are used, which introduce the heat in the ring locally when passing on the ring. Immediately after heating by the inductor, the ring is locally quenched with large amounts of water.

If the bearing ring now has a board, the heat is introduced locally by the inductor also on the ring-board shoulder surface. However, the transition between the raceway and the ribs is a critical area for inductive heat treatment. Due to the geometry, it is difficult to provide sufficient energy for heating the material. Furthermore, when cooling with water, it may become problematic if the cooling water flows into this heating area, that is, into the transition between the raceway and the board, or accumulates on the board. As a result, the heat input is made more difficult. A tilting of the ring to drain the water is usually not possible, especially with very large bearing rings.

It is therefore an object of the present invention to provide a method for producing a bearing ring, in which the abovementioned disadvantages are reduced or avoided.

This object is achieved by a method for producing a bearing ring with a track and at least one arranged on an end face of the track board, wherein the board opening angle is substantially 90 °, according to claim 1.

First, a bearing ring is provided, which has at least one board, which extends in a direction away from the track, wherein the transition between the track and the board has a radius of curvature.

Subsequently, the bearing ring is heat treated along the track and the board. The smooth transition between track and board, on the one hand, the heat input can be improved, and on the other hand, the cooling water, which is used during the heat treatment, better drain. There is thus no area on the board where the water collects. The radius of curvature between the track and the board can be realized, for example, by an opening angle of more than 90 °.

Finally, the bearing ring is reworked to an in-board opening angle of substantially 90 °. Under the board opening angle while the angle between the track and the board is understood. An in-flight opening angle of substantially 90 ° may be required, for example, in cylindrical roller bearings or tapered roller bearings. The production of the on-board opening angle of substantially 90 ° can be done for example by means of an undercut.

According to one embodiment, the step of heat treating b) comprises introducing heat into the surface of the bearing ring along the raceway and the board and cooling the surface of the bearing ring along the raceway and the board. The cooling of the surface can be carried out for example by means of cooling water.

Since the bearing ring during the heat treatment has a smooth transition between career and board, the cooling water used can flow better, since there is no area on which the cooling water can collect. Furthermore, the obtuse angle makes it easier to bring the element used for heating up to the surface of the areas to be heated. As a result, the case hardening depth profile along the heat treated surface can be made more uniform.

The heat treatment may be induction heat treatment. By using an inductor for heating the surfaces of the bearing ring large bearing rings with a diameter of more than Im, in particular 1.5 to 4 m can be very easily heat treated, since the inductor can be moved past the bearing ring and not the bearing ring in a Heat source must be moved.

The post-processing c) may include a hard machining of the heat-treated bearing ring.

A hard machining can be understood, for example, as a chip removal process. Due to the hard machining, the on-board opening angle is changed to substantially 90 °. Through hard machining and the adaptation of the in-board opening angle, the case-hardening depth profile changes along the transition between the raceway and the board. In this area, although the case hardening depth is reduced, but this can be accepted, if it is a non-loaded board. Furthermore, the geometry of the bearing ring can be adjusted to limit the load to areas with higher case depth. In the transition region between the raceway and the board with a lower case depth, the load can thus be reduced.

According to one embodiment, the on-board opening angle in step a) is greater than 95 °. In particular, the on-board opening angle in step a) is between 100 ° and 120 °. A larger opening angle can improve the outflow of cooling water.

According to one embodiment, the bearing ring has two shelves, wherein at least one of the transitions between the raceway and a shelf has a radius of curvature, wherein in particular the opening angle of this transition in step a) is greater than 90 ° degrees. The large board opening angle can be used both on one side and on both sides.

According to a further embodiment, a bearing ring is provided with a raceway and at least one arranged on an end face of the raceway board, wherein the bearing ring has been prepared according to a method as described above.

According to a further embodiment, the track is inductively hardened and reworked such that a case hardening depth profile of the bearing ring along the transition between the raceway and the board has a reduced case hardening depth. The rework can be done, for example, by a hard machining process. By hard machining, in which the on-board opening angle can also be adjusted, the case hardening depth profile changes along the transition between the raceway and the board, so that the case hardening depth in this area is reduced.

By the described method of manufacturing a bearing ring, improved hardenability of the bearing rings can be provided, which is less critical for heat treatment errors. Due to the special geometry of the bearing ring during the heat treatment, lower process optimizations may be required because the improved heat input and the improved outflow of cooling water already takes place through the geometry of the bearing ring.

Further advantages and advantageous embodiments are given in the description, the drawings and the claims. In particular, the combinations of features given in the description and in the drawings are purely exemplary, so that the features can also be present individually or otherwise combined.

In the following, the invention will be described in more detail with reference to embodiments illustrated in the drawings. Here, the embodiments and the combinations shown in the embodiments are purely exemplary and are not intended to define the scope of the invention. This is defined solely by the appended claims.

• 1: eine Schnittansicht eines Lagerrings mit einem Bordöffnungswinkel von 90° während einer Wärmebehandlung;
• 2: eine Schnittansicht eines Lagerrings mit einem Bordöffnungswinkel von mehr als 90° während einer Wärmebehandlung; und
• 3: eine Schnittansicht eines Lagerrings nach einem Hartbearbeitungsschritt.

Show it:

• 1 FIG. 4 is a sectional view of a bearing ring having an in-flight angle of 90 degrees during a heat treatment; FIG.
• 2 FIG. 1 is a sectional view of a bearing ring having an in-flight angle greater than 90 ° during a heat treatment; FIG. and
• 3 : A sectional view of a bearing ring after a hard machining step.

In the following, the same or functionally equivalent elements are identified with the same reference numerals.

1 shows a bearing ring 1 , which is a career 2 and at each end of the track 2 a board 4 . 6 having. Around the bearing ring 1 or the career path 2 and the board surfaces 4 . 6 to cure, becomes an inductor 10 at the track 2 and the Borden 4 . 6 guided along. Through the inductor 10 Heat is transferred to the surface of the track 2 and the shelves 4 . 6 brought in.

Subsequently, the heated surface of the raceway 2 and the shelves 4 . 6 cooled by cooling water. Due to the geometry of the bearing ring 1 that is, by the right angle between the track 2 and the board 6 It can happen that on the board 6 , especially in an undercut, collects cooling water. This is in 1 by the reference numeral 8th characterized.

To such an accumulation of cooling water 8th To avoid, it is intended to provide a bearing ring with a changed geometry. This is in 2 shown. Unlike the in 1 shown bearing ring 1 shows the bearing ring 1 in 2 between the career 2 and the board 6 a radius of curvature, ie a smooth transition without undercut. In this case, the transition has an increased board opening angle greater than 90 °.

Will now be the inductor 10 at the track 2 and the board 6 Guided along, becomes the surface of the raceway 2 and the board 6 warmed, which is indicated by the dotted line 12 is displayed, showing the case depth. Subsequently, the heated surface of the raceway 2 and the board 6 cooled by cooling water. Unlike the in 1 shown bearing ring 1 can at the bearing ring 1 from 2 drain the cooling water, as indicated by the reference numeral 8th and the arrow is displayed.

Will now be in the final bearing ring 1 a geometry with a right angle between the raceway 2 and the board 6 If required, the smooth transition with a radius of curvature can be adapted or the rim opening angle reduced in a post-processing step, for example a hard machining operation. In the area of transition between career 2 and board 6 the case depth is reduced as indicated by reference numerals 14 is displayed. However, this is preferably an area with reduced load, so that the reduced case hardening depth can be tolerated.

The proposed method makes it possible in a simple manner to provide an improved heat treatment of the bearing ring. For this purpose, only a changed geometry of the bearing ring in the transition area between the track and board is required. This geometry can be adapted for the final use of the bearing ring in a post-processing step.

LIST OF REFERENCE NUMBERS

1

bearing ring

2

career

4, 6

shelf

8th

accumulated water

10

inductor

12

Case depth course

Claims (10)

Method for producing a bearing ring (1) with a track (2) and at least one board (6) arranged on an end face of the track (2), wherein the board opening angle is substantially 90 °, with the steps: a) providing a bearing ring (1) having at least one board (6) which extends in a direction away from the raceway (2), wherein the transition between the raceway (2) and the board (6) has a radius of curvature . b) heat treating the bearing ring (1) along the raceway (2) and the board (6); and c) reworking of the bearing ring (1) to a board opening angle of substantially 90 °. Method according to Claim 1 , wherein the opening angle in step a) is greater than 90 ° degrees. Method according to Claim 1 or 2 wherein the step of heat treating b) introducing heat into the surface of the bearing ring (1) along the raceway (2) and the board (6) and cooling the surface of the bearing ring (1) along the raceway (2) and the Bords (6). Method according to Claim 3 , wherein the cooling is done by means of cooling water. The method of any one of the preceding claims, wherein the heat treating comprises induction heat treating. Method according to one of the preceding claims, wherein the reworking c) comprises a hard machining of the heat-treated bearing ring (1). Method according to one of the preceding claims, wherein the angle between the track (2) and the board (6) in step a) is greater than 95 °, in particular between 100 ° and 120 °. Method according to one of the preceding claims, wherein the bearing ring (1) has two shelves (4, 6), wherein at least one of the transitions between the raceway (2) and one of the shelves (4, 6) has a radius of curvature, wherein in particular the angle between the track (2) and one of the shelves (4, 6) in step a) is greater than 90 ° degrees. Bearing ring (1) with a track (2) and at least one on a front side of the track (2) arranged board (6), wherein the bearing ring (1) is made according to a method according to one of the preceding claims. Bearing ring (1) after Claim 9 wherein the raceway (2) is inductively hardened and post-processed such that a case hardening depth profile (12) of the bearing ring (1) along the transition between raceway (2) and rim (6) has a reduced case hardening depth.

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