DEVICE FOR PRODUCING A RELEASABLE CLEARANCE-FREE POSITION OF A ROLLING BEARING AND A CORRESPONDING METHOD

Abstract

A device for producing a releasable clearance-free position of a rolling bearing, having a rolling bearing which has an outer ring, an inner ring mounted on a shaft and a plurality of rolling elements arranged between the inner ring and the outer ring, and having a tensioning device mounted on the circumference of the rolling bearing outer ring for generating a radial preload which is uniform over the outer circumference of the rolling bearing outer ring between the tensioning device and the rolling bearing outer ring, wherein the tensioning device has an axially adjustable tensioning element which can be brought into a first alignment in which the rolling bearing has play, and which can be brought into a second alignment in which the rolling bearing is free of play. A corresponding method is also described.

Claims

1-15. (canceled)

16. A device for producing a releasable clearance-free position of a rolling bearing, comprising: a roller bearing having an outer ring, an inner ring mounted on a shaft, and a plurality of rolling elements arranged between the inner ring and the outer ring, and with a tensioning device mounted on the circumference of the rolling bearing outer ring for generating a radial and uniform preload over the outer circumference of the rolling bearing outer ring between the tensioning device and the rolling bearing outer ring, wherein the tensioning device has an axially adjustable tensioning element which can be brought into a first alignment in which the rolling bearing has play, and which can be brought into a second alignment in which the rolling bearing is free of play, wherein the tensioning device has a closed cavity which extends axially and at least in sections, preferably over the entire circumference of the tensioning device in an annular manner and tapers in the axial direction, in which cavity the tensioning element is received in the form of a sleeve in an axially displaceable manner.

17. The device according to claim 16, wherein the tensioning element is adjustable within the second alignment in such a way that a defined bearing preload is adjustable.

18. The device according to claim 16, wherein the sleeve has a sleeve outer surface extending conically at least in sections in the axial direction and the cavity has a cavity outer surface extending conically at least in sections in the axial direction and pointing inwardly in the radial direction and cooperating with the sleeve outer surface, wherein the conical section of the sleeve outer surface and the conical section of the cavity outer surface are aligned parallel to one another.

19. The device of claim 18, wherein the sleeve has a sleeve inner surface and the cavity has a cavity inner surface abutting the sleeve inner surface and facing radially outward, wherein the sleeve inner surface and the cavity inner surface are aligned parallel to the axial direction of the rolling bearing.

20. The device according to claim 16, wherein furthermore an actuator is connected to the tensioning device, which is set up for continuous axial adjustment of the tensioning element.

21. The device according to claim 20, which further comprises means for continuously monitoring the bearing clearance of the rolling bearing.

22. The device according to claim 21, which further comprises a control loop for setting a predefinable desired bearing preload, wherein in the control loop the desired bearing preload is compared continuously or at predefined time intervals with the actual bearing preload measured by the device for continuous monitoring of the bearing clearance and in response thereto the actuating device is actuated with a corresponding manipulated variable.

23. The device according to claim 16, wherein the rolling bearing is a cylindrical roller bearing or a needle roller bearing.

24. A method for adjusting the preload of a rolling bearing mounted on a shaft by means of a device according to claim 16, comprising the steps: Detecting the preload of a bearing arrangement while it is in operation; Comparing the detected actual preload with a target preload and calculating a difference value; Using the difference value, outputting a manipulated variable to an actuator for adjusting the bearing preload, wherein the actuator controls the axially adjustable tensioning device arranged in the tensioning device, which, depending on the axial adjustment position, generates a predefined bearing preload.

25. The method of claim 24, wherein said detecting of the preload comprises measuring an electrical contact resistance and/or measuring mechanical loads and/or measuring thermal operating conditions of the bearing.

26. The method according to claim 24, wherein the tensioning element is axially adjusted hydraulically or pneumatically by the actuator.

27. The method according to claim 26, wherein, for axial adjustment, the tensioning element is subjected to different pressures at opposite end faces, wherein, for increasing the pretension, a first pressure on a first face of the tensioning element is increased relative to a second pressure on a second face of the tensioning element opposite the first face, and wherein, for decreasing the pretension, the second pressure is increased relative to the first pressure.

28. The method of claim 27, wherein the tensioning element is axially adjustably disposed in a cavity that tapers in the axial direction, wherein the tensioning element is adjusted in the direction of the tapered cavity end to increase the preload.

Description

DRAWINGS

[0038] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure.

[0039] Further details of the invention are explained with reference to the figures below. Thereby shows:

[0040] FIG. 1 a cross-sectional view of an embodiment of the device according to the invention in a preload-free first position;

[0041] FIG. 2 a cross-sectional view of an embodiment of the device according to the invention in a preload-generating second position.

DETAILED DESCRIPTION

[0042] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0043] The device 1 shown in FIG. 1 for producing a releasable clearance-free position of a rolling bearing has a rolling bearing 2 mounted on a shaft 6 in the form of a needle bearing with a bearing inner ring 5, rolling elements 4 and a bearing outer ring 3. A tensioning device 7 for generating a radial circumferential stress is pushed axially onto the bearing outer ring 3 and has an annular cavity 11 with a tensioning element 8 axially adjustable therein. The cavity 11 has a radially outwardly facing cavity inner surface 15, which is aligned parallel to the bearing axis. The cavity 11 further has an inwardly facing cavity outer surface 13, which does not run parallel to the cavity inner surface 15, but runs at an angle as shown, so that the cavity 11 tapers from right to left or has a lower height on the left than on the right in the illustration. The tensioning element 8 has contact surfaces corresponding to the cavity shape, with a radially inwardly facing tensioning element inner surface 14 and an outwardly facing tensioning element outer surface 12. The tensioning element inner surface 14, like the cavity inner surface 15, is aligned parallel to the bearing axis, and the tensioning element outer surface 12, like the cavity outer surface 13, extends obliquely thereto. Here, the angle of the conical course of the tensioning element outer surface 12 corresponds to the angle of the cavity outer surface 13, relative to the bearing axis. The tensioning element 8 has an axial width that is smaller than the axial width of the cavity 11, so that the tensioning element 8 is axially adjustable in the cavity 11. To generate a preload, it is crucial that the smallest height of the cavity 11 is smaller than the smallest height of the tensioning element 8. On the left and right of the tensioning element 8, the latter has end faces aligned essentially perpendicular to the bearing axis, which each delimit a fluid-tight chamber between themselves and the respective opposite wall of the cavity 11. Thus, the tensioning element 8 forms a hydraulically axially adjustable actuator which causes a predefined shrinkage of the bearing outer diameter depending on the axial position. For this purpose, a first fluid line 21 opens into a first fluid-tight chamber 23 and a second fluid line 22 opens into a second opposite fluid-tight chamber 24, via which the chambers can each be pressurized with a specific hydraulic pressure p.sub.1, p.sub.2. The two fluid lines 21 and 22 can be controlled via an electrically controllable 4/2-way valve, so that either the first fluid line 21 or the second fluid line 22 is pressurized depending on the valve position. A pump 20 is connected to the valve 19 for generating a desired pressure. The valve 19 or the pump 20 are controlled by a control unit (PLCProgrammable Logic Controller) 18, which receives measurement data continuously or at predetermined intervals from a monitoring device for detecting the bearing clearance or a resistance measuring device 17, which measures the electrical contact resistance measured between the shaft 6 and the tensioning device 7. In the illustration, the negative pole is connected to the shaft and the positive pole of the resistance measuring device 17 is connected to the tensioning device 7. The pump 20, the valve 19, the control device 18 and the resistance measuring device are part of a control device 16, by means of which a control loop for setting a predetermined target preload is implemented.

[0044] FIG. 1 shows the tensioning element 8 in a first orientation 9, in which the tensioning element 8 is positioned in such a way that no pretension is generated in the cavity 11. The arrows on the tensioning element 8 indicate its direction of movement to the right, i.e. in the direction of the expanded cavity section. Accordingly, the rolling bearing 2 has bearing play. As can be seen in FIG. 1, there is a clearance between the rolling elements 4 and the outer bearing ring 3. For this purpose, the valve 19 has a position in which the pump 20 applies a signal pressure p.sub.1 to the fluid-tight chamber 23 via the first fluid line 21 to lower the preload. FIG. 2 shows the tensioning element 8 in a second orientation 10, in which the tensioning element 8 is positioned in such a way that a preload is generated in the cavity 11, by means of which the bearing 2 is set free of play. The direction of movement, indicated by the arrows on the tensioning element 8, shows that the tensioning element moves to the left, that is, in the direction of the tapered cavity section. In the course of this, the chamber volume of the first fluid-tight chamber 23 decreases and the chamber volume of the second fluid-tight chamber 24 increases. For this purpose, the valve 19 is adjusted by the control unit 18 in such a way that now the second fluid line 22 is pressurized with a pressure p.sub.2 for increasing the pretension in the second fluid-tight chamber 24 by the pump 20. As a result, the tensioning device 7 produces a shrinkage on the bearing outer ring 3 so that it is in full contact with the rolling elements 3. Beyond the clearance release, a predefined preload can now be generated in the bearing 2, which is necessary for the particular application. By continuously monitoring the electrical contact resistance and processing the measurement data in the control unit 18, it is possible for the preload to be readjusted continuously and during operation, for example if a change in preload occurs in the event of thermal fluctuations.

[0045] The features of the invention disclosed in the foregoing description, in the drawings as well as in the claims may be essential to the realization of the invention both individually and in any combination.

[0046] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.