DE102016224598A1 - Rolling bearing and method of its operation - Google Patents

Abstract

The invention relates to a rolling bearing (1), comprising at least one inner ring (2) and at least one outer ring (3), wherein between the inner ring (2) and the outer ring (3) rolling elements (4) are arranged. In order to obtain information about the lubricating state of the rolling bearing in an improved manner, the invention provides that a recess (5) is arranged in at least one of the rolling bodies (4), wherein in the recess (5) a transmitting element (6) for emitting a acoustic signal and a receiving element (7) are arranged for receiving an acoustic signal. Furthermore, the invention relates to a method for operating a rolling bearing.

Description

The invention relates to a roller bearing comprising at least one inner ring and at least one outer ring, wherein between the inner ring and the outer ring rolling elements are arranged. Furthermore, the invention relates to a method for operating a rolling bearing.

The lubrication status in a rolling bearing is a crucial factor when it comes to the question of the service life of the bearing. Therefore, various efforts have already been made to detect the lubrication situation that results in the operation of a rolling bearing.

Capacitive measuring methods or the evaluation of acoustic emissions in the rolling bearing are known in this context. The latter solution is used for example in the WO 2012/035169 A1 described. Another solution reveals the US 6,360,610 B1 ,

The achievable with the previously known solutions results are partially not yet satisfactory. In particular, it is difficult to accurately detect and monitor the lubrication conditions of the bearing.

The invention is therefore based on the object to train a generic rolling bearing so and to propose a method for its operation, so that an improved monitoring of the lubrication condition of the bearing is possible. It should therefore be able to obtain information about the lubricating state of the rolling bearing in an improved manner.

The solution of this problem by the invention is characterized in that a recess is arranged in at least one of the rolling elements, wherein in the recess a transmitting element for emitting an acoustic signal and a receiving element for receiving an acoustic signal are arranged.

The recess is preferably formed as a cylindrical recess. This recess is preferably arranged coaxially to the axis of rotation of the rolling body. It is preferably provided that the transmitting element and the receiving element are diametrically opposite to each other with respect to the axis of rotation of the rolling body in the recess.

The transmitting element is preferably designed as a piezoelectric element; The same applies advantageously also for the receiving element.

1. a) Aussenden eines akustischen Signals vom Sendeelement;
2. b) Empfangen des im Wälzlager reflektierten akustischen Signals vom Empfangselement;
3. c) Ermittlung des Status der Schmiermittelversorgung im Wälzlager anhand einer vorher empirisch ermittelten Korrelationsfunktion zwischen dem empfangenen reflektierten Signal und dem Schmiermittelstatus.

The proposed method for operating such a rolling bearing comprises the steps:

1. a) emitting an acoustic signal from the transmitting element;
2. b) receiving the reflected in the rolling bearing acoustic signal from the receiving element;
3. c) Determining the status of the lubricant supply in the rolling bearing on the basis of a previously empirically determined correlation function between the received reflected signal and the lubricant status.

In the aforementioned steps a), b) and / or c), the time profile of the received reflected signal over a predetermined time can be taken into account.

When receiving the received reflected signal by the receiving element, the angular position of the rolling element relative to at least one of the bearing rings is preferably taken into account.

The signal received by the receiving element is preferably transmitted wirelessly to an evaluation unit outside the rolling bearing.

The proposed solution is therefore based on the determination of the lubricating situation and in particular on the measurement of the lubricating film in a rolling bearing, wherein preferably a first piezoelectric element for the emission of an acoustic signal and a second piezoelectric element for the detection of the reflected acoustic signal are used ; Both sensors are placed in a rolling element of the bearing. Thus, the thickness of the lubricating film can be measured in a relatively accurate manner.

Accordingly, a piezo element is used to generate an acoustic signal, that is, a sound wave, wherein the reflected signal is received by another piezo element (acting as a sensor).

The sensor signal corresponds to the relative angular position of the rolling element in the bearing, ie to the bearing rings and the lubricant film thickness. By means of an algorithm in the evaluation of the received reflected acoustic signal can thus be concluded taking into account the angular position of the rolling element on the lubricating situation. Details on this procedure are in the WO 2012/035169 A1 mentioned, to which reference is expressly made. Here you will find details on the procedure for the evaluation of measured acoustic signals, so that no repetition of the procedure is necessary at this point.

The proposed rolling bearing can be used in any applications. Examples include paper machines, shipbuilding, wind turbines, rolling mills and vehicles called. Also, as far as the construction of the rolling bearing, any applications are conceivable, ie in particular single or multi-row bearings with arbitrary cages.

Advantageously, can be observed improved in the rolling bearing with the proposed embodiment of a rolling bearing and with the described method, the lubricating film. Accordingly, there is the possibility of improved monitoring of storage conditions.

Problematic operating conditions as a result of insufficient lubrication can advantageously be detected in good time before bearing damage occurs in this regard.

• 1 schematisch den Radialschnitt durch ein erfindungsgemäßes Wälzlager,
• 2 schematisch einen Wälzkörper des Wälzlagers, der zwischen einer Laufbahn des Innenrings und einer Laufbahn des Außenrings des Wälzlagers angeordnet ist,
• 3 schematisch den Verlauf von erfassten Signalen des reflektierten Schalls über der Zeit für drei unterschiedliche Schmierzustände des Wälzlagers und
• 4 ein Blockdiagramm mit Angaben zum Ablauf des Verfahrens zum Ermitteln des Schmierzustands des Wälzlagers.

In the drawing, an embodiment of the invention is shown. Show it:

• 1 schematically the radial section through an inventive rolling bearing,
• 2 schematically a rolling element of the rolling bearing, which is arranged between a raceway of the inner ring and a raceway of the outer ring of the rolling bearing,
• 3 schematically the course of detected signals of the reflected sound over time for three different lubrication conditions of the bearing and
• 4 a block diagram with information on the procedure of the method for determining the lubricating condition of the rolling bearing.

In 1 is schematically a rolling bearing 1 shown, which is an inner ring 2 and an outer ring 3 between which rolling elements 4 are arranged (here in the form of cylindrical rollers). During operation, the rolling elements rotate 4 around its axis of rotation a ,

In 2 is hinted that the inner ring 2 an inner ring raceway 8th has and that the outer ring 3 an outer ring raceway 9 Has. Between the rolling elements 4 and the tracks 8th . 9 a lubricating film forms, namely once a lubricating film 10 on the inner ring 2 and once a lubricating film 11 on the outer ring 3 , The thickness of the lubricating film is critical to the lubrication condition of the bearing and, as a consequence, the service life of the same.

It is essential that in the rolling elements 4 (And that concerns at least one of the rolling elements of the rolling bearing 1 ) a recess 5 - Here in the form of a cylindrical recess - is incorporated, wherein a transmitting element 6 and a receiving element 7 (both in the form of one piezo element each) in the recess 5 are placed.

As it is in 2 is indicated (see the arrows), which spreads from the transmitting element 6 generated sound wave through the metallic material of the rolling body 4 out. The sound wave is partially reflected at the interface between the rolling element and the bearing ring.

The thinner the lubricant film in the rolling contact between the rolling elements and raceways, the lower the intensity of the reflected signal. Accordingly, the intensity of the reflection of the sound wave corresponds to the lubrication status in the rolling bearing.

Furthermore, the intensity of the reflection of the sound wave is dependent on the phase of the sound wave. The location of the contact between the rolling element and the track moves with rotation of the bearing, so that the signal changes with the relative angular position of the rolling element to the raceways.

Accordingly, this corresponds to the receiving element 7 (Sensor) received signal to the angular position of the rolling element 4 relative to the bearing rings as well as to the lubricating film thickness. By means of a suitable algorithm, the angular position can be determined and then - based on the detected signal - closed on the lubricating film quality.

This is schematically in 3 illustrated. Here is about time t for three different lubrication conditions of the bearing the course of the receiving element 7 received signal recorded.

In the case of a first correlation function M1 results in an amplitude A1 whose size suggests that there are good lubrication conditions in the bearing.

In the case of a second correlation function M2, the amplitude has A2 opposite to the amplitude A1 reduced, so that now only borderline lubrication conditions are present.

Finally, the case of a third correlation function M3 is outlined, only with a reduced amplitude A3 can come up with; Accordingly, there is now a lack of lubrication in the rolling bearing 1 in front.

For the basic procedure in the context of the described method can be found in 4 a block diagram illustrating the individual measures.

A signal generator 16 provides a signal to a driver circuit 17 , which in turn is the transmitting element 6 activated. This emits an acoustic signal S (ie a sound wave).

The reflected portions of the signal are received by the receiving element 7 captured and connected to a preamplifier 12 passed.

After passing a band filter 13 the signal reaches an envelope detector 14 and finally to a signal processor 15 ,

The latter provides a signal based on the processing by means of a stored algorithm L that corresponds to the lubrication condition of the bearing.

Thus, a conclusion on the lubrication situation in the rolling bearing 1 possible, so that in case of unfavorable lubrication conditions appropriate measures can be taken in time to improve the lubrication situation.

LIST OF REFERENCE NUMBERS

1

roller bearing

2

inner ring

3

outer ring

4

rolling elements

5

Recess (recess)

6

Transmitting element (piezoelectric element)

7

Receiving element (piezoelectric element)

8th

Inner ring raceway

9

Outer ring raceway

10

Lubricating film on the inner ring

11

Lubricating film on the outer ring

12

preamplifier

13

band filter

14

Envelope detector

15

Signal processor

16

Signal generator

17

driver circuit

a

Rotary axis of the rolling element

M

correlation function

A1

Amplitude with good lubrication

A2

Amplitude for marginal lubrication

A3

Amplitude in case of insufficient lubrication

t

Time

S

acoustic signal (wave)

L

Signal corresponding to the lubrication condition

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2012/035169 A1 [0003, 0015]
• US 6360610 B1 [0003]

Claims (10)

Rolling bearing (1), comprising at least one inner ring (2) and at least one outer ring (3), between the inner ring (2) and the outer ring (3) rolling elements (4) are arranged, characterized in that in at least one of the rolling elements ( 4) a recess (5) is arranged, wherein in the recess (5) a transmitting element (6) for emitting an acoustic signal and a receiving element (7) for receiving an acoustic signal are arranged. Rolling bearings after Claim 1 , characterized in that the recess (5) is a cylindrical recess. Rolling bearings after Claim 2 , characterized in that the cylindrical recess (5) coaxial with the axis of rotation (a) of the rolling body (4) is arranged. Rolling bearings after Claim 2 or 3 , characterized in that the transmitting element (6) and the receiving element (7) with respect to the axis of rotation (a) of the rolling body (4) in the recess (5) are diametrically opposite. Rolling bearings according to one of Claims 1 to 4 , characterized in that the transmitting element (6) is designed as a piezoelectric element. Rolling bearings according to one of Claims 1 to 5 , characterized in that the receiving element (7) is designed as a piezo element. Method for operating a roller bearing (1), comprising at least one inner ring (2) and at least one outer ring (3), between the inner ring (2) and the outer ring (3) rolling elements (4) are arranged, wherein in at least one of the rolling elements (4) a recess (5) is arranged, wherein in the recess (5) a transmitting element (6) for emitting an acoustic signal and a receiving element (7) for receiving an acoustic signal are arranged, the method comprising the steps: a) emitting an acoustic signal from the transmitting element (6); b) receiving the in the rolling bearing (1) reflected acoustic signal from the receiving element (7); c) Determining the status of the lubricant supply in the rolling bearing (1) based on a previously empirically determined correlation function (M) between the received reflected signal and the lubricant status. Method according to Claim 7 , characterized in that in step a), step b) and / or step c) according to Claim 7 the time profile of the received reflected signal over a predetermined time is taken into account. Method according to Claim 7 or 8th , characterized in that when recording the received reflected signal by the receiving element (7), the angular position of the rolling element (4) relative to at least one of the bearing rings (2, 3) is taken into account. Method according to one of Claims 7 to 9 , characterized in that the signal received by the receiving element (7) is transmitted wirelessly to an evaluation unit outside the rolling bearing (1).

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