Method of mounting bearings with a taper bore

Abstract: Method and device for establishing correct amount a bearing ring (3) has to be driven up a shaft (2) or the like, at mounting of bearing (1) with taper bore, whereby a measuring of the strain in at least one of the side faces (5, 6) of the bearing ring (3) is effected by means of a sensor (7) arranged on said side face during the driving up, whereupon the instantaneous clearance reduction in the bearing is calculated from the measured instantaneous strain and the value for the known initial clearance of the bearing.

Description: The present invention refers to a method according to the preamble of claim 1. Bearings with taper bore are always mounted with an interference fit on shaft or adapter sleeve. The driving up of the inner race ring is preferably effected by means of a hydraulic nut. The reduction of the radial bearing clearance or the overall axial distance the inner ring shall be driven up on the taper seat, is used as a measure of the size of the fit. The procedure at mounting, particularly of big bearings, is that the new bearings in a washing process first are relived from the anti-corrosive layer, they usually have been provided with prior to delivery from the bearing manufacturer. Thereupon the bearing is usually placed on a base and the radial clearance in the bearing is measured with aid of thickness gauges. This measurement however is subjective and uncertain, which might lead to malfunction of the bearing. Such a mounting is known from FR 2 619 428 A1. When measuring the axial distance a bearing ring has been driven up, it is of course important for obtaining a satisfactory result, to know where the starting position for the driving up is, and this might be difficult as the bearing in practice is positioned loosely on the shaft journal and is pressed up thus that it has metallic contact around the entire bore of the bearing inner ring. This procedure is laborious as the bearings concerned are often heavy, and furthermore might have a certain out-of-roundness, which might also be valid for the shaft journal. The uncertainty, which therefore rules regarding the starting position for the driving up therefore can amount to several millimetres and this means certainly that a satisfactory and reliable result is not obtained even at accurate measuring of the length of the driving up with aid of a dial indicator. Measuring of the clearance reduction is a method, which ought to be reliable, but which by experience has proven itself to give different results depending on which person who is performing the measurement, and thus different persons can obtain variations of 0.1 mm at measurement of the same clearance. Therefore the purpose of the invention now is to provide a method for establishing at mounting of a bearing with taper bore, a correct amount a bearing ring shall be driven up on a shaft or the like, whereby correct mounting of the bearing is highly facilitated, at the same time as the above mentioned problems are eliminated, and this is obtained by the steps of the method defined in the second part of claim 1. Hereinafter the invention will be further described with reference to an embodiment schematically shown in the accompanying drawing. The drawing shows in cross section a spherical roller bearing 1 which is driven up a taper shaft journal 2. The bearing inner ring 3 has a taper bore and the driving up is effected in usual manner with aid of a hydraulic nut 4. At least at one side face 5, 6 of the inner ring 3 is arranged at least one sensor 7, by means of which the strain of the inner ring may be established. The sensors might be common strain gauges, but it is also possible to use other types of sensors, whereby it is essential that they in a simple and reliable manner can present the instantaneous strain of the inner ring. The strain on one or both side faces then can be converted into a very accurate estimation of the current clearance reduction in the bearing by means of a simple calculation. This calculation of the clearance reduction can be estimated with good accuracy as the strain measured by the sensors in circumferential direction multiplied with twice the radial distance between the centre line of the supported shaft and the sensor. The accuracy in this calculation can be increased in that the radial distance between the centre line of the supported shaft and the sensor is substituted for an equivalent radial distance, which pays attention to the local deformation of the ring in dependency of the axial position within the studied section of the bearing ring. By connecting the or those sensor(s) 7 arranged at the bearing to a simple instrument 8, which performs the above mentioned calculation, it is possible to obtain a numerical value for the instantaneous clearance in the bearing directly on the display of the instrument, whereby a continuous, safe indication is obtained over the actual amount the bearing ring is driven up and of the fit, no matter if the starting position for the driving up is known or not. The method according to the invention thus incorporates continuous measuring of the strain in one or both side faces of the bearing inner ring and with a simple calculation continuously calculating a numerical value representing the instantaneous clearance reduction in the bearing. In order to be able to establish the strain desired for a certain clearance reduction it is of course also necessary to know the original clearance of the bearing, but as this is known for each individual bearing, already at the manufacture, it is simple to provide the bearing with a relevant marking, e.g. in form of an engraved numerical value for the original clearance. At measurement with the instrument during the time the ring is driven up, the current value for the bearing in question is fed into the instrument in every specific case. By the steps referred to above a bearing equipped in accordance with the invention will be more easy to mount in a correct manner than a bearing without said device. Furthermore the requirement of washing away corrosion protection from the bearings prior to mounting, and finally the mounting can be accomplished without problems with a simple instruction and the instrument described also by personnel, that is not particularly trained. The invention is not limited to the embodiment intimated in the drawing and described in connection thereto but modifications are possible within the scope of the accompanying claims.

Claims: A method of mounting a bearing having a bearing ring (3) with tapered bore, on a shaft (2), whereby the ring (3) is positioned on the shaft (2) and the bearing is moved axially along the shaft by a correct amount characterized that strain is measured at at least one side face (5, 6) of the bearing ring (3), during the time the ring is driven up axially, that the instantaneous clearance reduction in the bearing is calculated based upon the instantaneous measured strain and upon the initial bearing clearance, and that the reduction of the internal bearing clearance is used for determining the amount the bearing should be driven along the shaft. A method as claimed in claim 1, characterized in using sensors (7) arranged on said side face for measurement of the strain in at least one side face (5, 6) of the bearing ring (3). A method as claimed in claim 2, characterized in using strain gauges as sensors (7). A method as claimed in anyone of claims 2 or 3, characterized in that signals representative of changes in the strain in the side faces of said bearing ring (3) are supplied from said sensors (7) to a calculator (8), that the known value of the initial internal clearance of the bearing is fed into the calculator (8), whereupon the calculator is caused to calculate the instantaneous nominal clearance reduction on basis of the the signals from the sensors (7) and the value of the said initial clearance.

Inventors: BANKESTROEM JAN OLOF, GOETHBERG SVEN, BANKESTROEM, JAN OLOF, GOETHBERG, SVEN, Bankeström, Jan Olof, Göthberg, Sven
Applicants: SKF AB, AKTIEBOLAGET SKF
Application year: 1995
Main classification: F16C35
IPC codes: F16C35, B23Q17, F16D1, F16C25, B23P21