DE102010020759B4 - Sensed rolling elements - Google Patents

Abstract

Rolling elements (2, 22, 32, 42, 62, 72, 82, 92, 102) having an outer surface for forming a first rolling contact with an outer race of an inner rolling bearing part (5, 25, 35, 65, 75, 85, 95, 105 ) and for simultaneously forming a second rolling contact with an inner raceway of an outer rolling bearing part (1), wherein the rolling bearing parts (5, 25, 35, 65, 75, 85, 95, 105; 1) are rotatable relative to each other, wherein the rolling elements (2 , 22, 32, 42, 62, 72, 82, 92, 102) at least one measuring element (6, 23, 36, 37, 38, 39, 43, 64, 74, 84, 94, 104) and at least one transmission means ( 7, 26, 34, 41) for the wireless transmission of a signal, characterized in that the measuring element (64, 74, 84, 94, 104) at a recess (63, 73, 83, 93, 103) in the rolling body (62 , 72, 82, 92, 102) and for the optical detection of light radiation (87, 107) is provided.

Description

Field of the invention

The invention relates to a rolling body having an outer surface for forming a first rolling contact with an outer race of an inner rolling bearing part and for simultaneously forming a second rolling contact with an inner race of an outer rolling bearing part, wherein the rolling bearing parts are rotatable relative to each other. Furthermore, the invention relates to a rolling bearing assembly, in particular wheel bearing assembly having such rolling elements.

State of the art

Background of the invention

In recent years, sensors in rolling bearings have concerned measured quantities, such as temperature, force distribution or rotational speeds. On the basis of the measured variables measured at different points of the rolling bearing, operating states or defects of the rolling bearing could be ascertained and, in addition, statements about devices that were connected to the rolling bearing could be made.

For example, in wheel bearings a sophisticated speed sensor in combination with a force measurement could be used to detect the driving dynamics of the vehicle.

In the past, in particular, the rotating part of the rolling bearing or the rolling bearing assembly has been made accessible to sensors other than just the rotational speed sensors by wirelessly transmitting the measurement signal from a rotatable rolling bearing part to a stationary rolling bearing part or the wheel carrier wirelessly. A particular problem in this case is the power supply of the measuring element, which could not be readily provided with a rotatable rolling bearing part available. For this purpose, the generator principle was used, wherein a static part of the rolling bearing assembly was made the stator and a rotatable part of the rolling bearing assembly to a rotor. During operation of the rolling bearing, the measuring element or the entire sensor was supplied with electrical energy in this way.

Out DE 10 2007 061279 A1 a device for detecting operating data is known. The current operating situation is measured locally by a measuring element which is supplied with power by a power supply unit, a transmitter-side receiving unit being supplied with operating power wirelessly. The energy transfer and the signal transmission takes place between the bearing rings.

task

Summary of the invention

The object of the invention is therefore to provide antifriction bearing arrangements which allow new measuring arrangements to be developed in the context of rolling bearing sensor technology which permit more comprehensive statements about the operating state of the rolling bearing or its surroundings, or at least improve the signal strength of previously measured measured variables.

The object is achieved by a wheel bearing unit of the type mentioned above in that the rolling element has at least one measuring element and at least one transmission means for wireless transmission of a signal.

According to the invention it is provided that the rolling elements of a rolling bearing assembly forms with its outer surface a first rolling contact with an outer race of an inner rolling bearing part and at the same time a second rolling contact with an inner race of an outer rolling bearing part. This means that the rolling element rolls both in the outer race, as well as on the inner race. It is not absolutely necessary to carry a load. The rolling element may be provided only for supporting one or more measuring elements to collect operating data of the rolling bearing, which are then transmitted wirelessly. Wearing a load is thus an optional feature.

The inner rolling bearing part is, for example, an inner ring or a hub. The outer rolling bearing part may be an outer ring, which is optionally integrated in a hub, or is also provided for other functions, that is, for example, fastening elements, sealing elements or other rolling bearing components. Alternatively, the inner rolling bearing part or the outer rolling bearing part may be a stationary rolling bearing part.

In the outer surface of the rolling body is the area which is provided for transmitting a contact force or dynamic forces between the mutually supported, inner and outer rolling bearing parts. The rolling contact with the inner race moving on the outer surface of the rolling element is diametrically opposed to the second rolling contact with the outer race with respect to the rotational axis of the rolling element. Thus, the outer surface of the rolling element forms together with the raceways both Wälzkontakte alike.

For the rolling contact a certain amount of friction is basically necessary, so that the rolling element continuously performs its own movement about its own axis of rotation. If this minimum dimension is not present, the self-rotation is prevented, that is, there is slippage between the relatively rotatable inner and outer rolling bearing parts.

According to the invention, it is provided that the rolling element has at least one measuring element and at least one transmission means for the wireless transmission of a signal. In this case, the signal goes back in some form to the measuring signal of the measuring element or is formed by means of this. Thus, measured variables in or on the rolling elements, in particular in the rolling contact, can be measured and read out wirelessly.

In an advantageous embodiment, the rolling elements are preferably load-bearing rolling elements, which include both measuring elements, as well as load transferred between the mutually mounted rolling bearing parts. It must be prevented if necessary, that the measuring elements require larger cavities within the rolling elements, whereby the arrangement of the measuring element and the transmission means within the rolling body is to be determined taking into account the diametrical force transmission. In this case, the other outer surfaces, such as side surfaces of the rolling element for the attachment of the transmission means and possibly also for the measuring element offer. The arrangement of the measuring element further depends on the measured variable to be measured, which should optionally be measured in the vicinity of the load-transmitting outer surface or also on a side surface which, for example, also serves as a guide surface.

In an advantageous embodiment, the measuring element is arranged on a side surface of the rolling body. Here, both the measuring element, as well as the transmission means may have been applied only on the side surface of a conventional rolling element, taking into account that no unnecessary friction points with the Wälzkörperkäfig arise. Alternatively, it is conceivable that a bulge or a recess is provided on the side surface, which can be introduced, for example, in a conventional rolling element by a subsequent drilling. This makes it possible to subsequently form a normal rolling element within a rolling bearing as sensed rolling elements without having to accept losses in the load bearing. It is also advantageous that the rolling bearing can be retrofitted by a rolling element is replaced by a sensed rolling elements.

Advantageously, a sensed rolling element can also be used as an analysis means, which allows a detailed examination of a rolling bearing. So it is conceivable, for example, that a continuous failure of a slewing bearing is examined in that a rolling element is temporarily replaced by a sensed rolling element and thus can collect data at a time when a supposed malfunction occurs. After troubleshooting, the sensed rolling element must be removed again.

In an advantageous embodiment, the transmission means is a first coil, an antenna or a telemetry ring. The transmission means is primarily intended to transmit a signal which goes back to the measuring signal generated by the measuring element or even images or contains this measuring signal. Depending on the application, it is thus possible that an unprocessed measurement signal is passed as a signal to a signal sensor. Alternatively, a processing or only a pre-processing of the measuring signal take place within the rolling body, after which, for example, a processed signal or a data-optimized signal is transmitted wirelessly. For example, the measurement signal can be processed by an amplifier and transmitted wirelessly as an amplified processed signal. A data-optimized signal is preprocessed to the extent that only in a very specific case, a wirelessly transmitted signal is generated. If, for example, an end-of-life function of the sensor is desired, in particular such signals will be forwarded, which actually indicate a life end of the rolling bearing. The signal does not have to be generated from the measuring signal until the user has to be warned before the approaching end of life of the rolling bearing.

In addition to a first coil, which is provided for transmitting information, a second coil for transmitting the operating energy can be provided or the first coil assumes both functions, whereby the first coil is also provided for wireless energization of the measuring element and optionally an evaluation unit. The evaluation unit processes the measurement signal in any form, that is, amplifies it, converts the measurement signal and / or evaluates it otherwise to generate the wirelessly transmitted signal.

The signal does not necessarily have to be transmitted from the first coil to the signal receiver, but can also be transmitted to the signal receiver by means of an antenna. Thus, the signal pickup no longer puts in the near field, but in far field. This is advantageous when the signal sensor is far away from the transmission means and, for example, a wheel bearing accommodating wheel carrier or at another location of the chassis, whereby a lower mechanical complexity and possibly a simpler installation of the wheel bearing is possible. The same applies, for example, in camps that are not always easily accessible, but can still be monitored comfortably over a certain distance. This is the case, for example, with rolling bearings of wind turbines, which can not be operated in the presence of a service force, but the radio link allows the necessary distance to the system and an analysis of the current system can be performed.

In the telemetry ring as a transmission means, a temporary transmission within the near field is ensured when the rolling element passes during the rolling position operation in the vicinity of the signal pickup. This is useful if a single signal transmission during one round is sufficient to be able to transmit all data or information.

In addition, it is possible in this way to accomplish a slip measurement system by reference to perform a slip measurement, which is executable in combination with conventional speed sensors. This is achieved by comparing the respective measured rotational speeds with one another and determining a discrepancy when the rolling elements do not roll on the raceways in accordance with the operation and thus do not follow the rotation about the bearing axis with the usual angular velocity. In the case of a wheel bearing, this would mean that the encoder of an ABS system would be moved faster than two times the rolling body angular velocity, which is not possible if the rolling elements roll off in accordance with their operation.

In an advantageous embodiment, the measuring element for the detection of airborne sound, structure-borne noise, temperature, lubricating film thickness, lubricating film quality, air pressure or water content within the rolling bearing is provided. In the detection of air and structure-borne noise, it is possible to detect damage to the bearing caused, for example, by a so-called pitting. If the raceways have been sustainably damaged, typically more than 3 microns indentation depth, noise can be generated, which are detectable by a sound sensor. Temperature measurements can be realized by means of a Peltier element or simply by a component with electrical resistance, which changes its ohmic resistance as a function of the temperature. Lubricating film thickness and lubricating film quality are detectable with an active optical measuring arrangement by measuring the transmission of light rays through the lubricant. If the transmission deteriorates, that is, if the absorption of the lubricant increases, a low lubricating film quality, for example due to wear, can be inferred. Alternatively, it can be concluded that the thickness of the lubricating film, whereby a malfunction within the bearing, for example, a Unterfettung or insufficient fat redistribution, can be detected.

In one embodiment of the invention, the measuring element is arranged on a recess in the rolling body and provided for the optical detection of light radiation. The recess may serve for metering the amount of lubricant to be examined or relieve the area of the rolling element in which the measuring element is mounted. It is an active sensor arrangement in which light radiation is generated for example by a diode and then the intensity of the light radiation transmitted through the lubricant is measured. Due to the shape of the recess different arrangement possibilities of the light source and the measuring element or a plurality of measuring elements are possible, whereby the radiation profile can be determined.

Advantageously, the light radiation is generated by at least one light source arranged on the recess and transmitted through a lubricant present in the recess before the light radiation is detected by the measuring element. Due to the transmission, the light radiation is changed in a way that allows statements about the condition of the lubricant. It may be a consideration of the intensity to a measurement of foreign particles within the lubricant, either penetrated by the seal assembly or caused by wear on the bearing. Alternatively, it is possible to perform a spectral analysis, which is ideally carried out with a white diode as the light source. If, for example, a substance within the lubricant is to be specifically detected, then the measuring element can be provided with a spectral filter, so that the intensity of a spectral region that is characteristic of the substance to be detected can be measured. This makes it possible to draw conclusions about the concentration of the substance to be detected.

In an advantageous embodiment, the light source is arranged such that the light radiation is reflected by a sensing element on a raceway surface of an outer or inner rolling bearing part prior to detection. This can ensure that, in particular with a small lubricant film thickness, sufficient loss of intensity is ensured by twice the transmission through the lubricant film.

The described rolling elements according to the invention are used in a rolling bearing arrangement, which has the signal of the transmission means wirelessly receiving signal sensor on a fixed component. Ideally, signal transducers and transmission means communicate with each other, so that, for example, a signal of the transmission means is sent only on request via the signal receiver, or alternatively is transmitted at regular intervals by the transmission means. An evaluation unit can be connected to the signal sensor and evaluate the signal for a corresponding use, wherein optionally the signal has already been processed in the sensed rolling element by another evaluation unit in some form or generated based on a measurement signal.

Further advantageous embodiments and preferred developments of the invention can be taken from the description of the figures and / or the dependent claims.

In the following the invention will be described and explained in more detail with reference to the exemplary embodiments illustrated in the figures.

• 1 ein erstes Kegelrollenlager mit einem lasttragenden, sensierten Wälzkörper,
• 2 ein zweites Kegelrollenlager mit einem sensierten Wälzkörper,
• 3 einen sensierten Wälzkörper mit modifizierter drahtloser Signalübertragung,
• 4 eine schematische Darstellung eines sensierten Wälzkörpers auf Funkbasis,
• 5 eine erste sensierte Kegelrolle auf einem Innenring,
• 6 eine zweite sensierte Kegelrolle auf einem Innenring,
• 7 einen sensierten Wälzkörper auf einem inneren Lagerteilen (z.B. Innenring) mit einer umlaufenden Nut,
• 8 einen sensierten Wälzkörper mit einer umlaufenden, spiralförmigen Nut, und
• 9 eine Ausnehmung in einem sensierten Wälzkörper mit aktivem Streudetektor.

Show it:

• 1 a first tapered roller bearing with a load-bearing, sensed rolling element,
• 2 a second tapered roller bearing with a sensed rolling element,
• 3 a sensed rolling element with modified wireless signal transmission,
• 4 a schematic representation of a sensed rolling element on a radio base,
• 5 a first sensed tapered roller on an inner ring,
• 6 a second sensed tapered roller on an inner ring,
• 7 a sensed rolling element on an inner bearing part (eg inner ring) with a circumferential groove,
• 8th a sensed rolling element with a circumferential, spiral groove, and
• 9 a recess in a sensed rolling element with active scatter detector.

embodiment

Description of the drawings

1 shows a first tapered roller bearing with a load-bearing, sensed rolling elements 2 , The rolling element 2 is designed as a tapered roller, wherein this has on its side surface, which is intended for guiding the sensed rolling elements, a recess which is both a measuring element 6 , as well as a delivery element 7 having. The recess is arranged such that on the one hand the load-bearing properties of the tapered roller 2 not obstructed and also the guide through the outboard of the inner ring 5 not impaired.

The measuring element 6 can be provided for a variety of measurements, such as structure-borne noise, temperature or expansions of the rolling element 2 (Strain gauges). It is advantageous that in any case the signal strength is very good in comparison to known sensor arrangements, since in the case of possible defects the sound source, the heat source or the effects in the form of a torsional force act primarily on the rolling elements.

The measuring element 6 is optionally via an evaluation unit with the transmission means 7 connected, which is for example formed as a coil, with the signal sensor 4 can come in wireless contact. It makes sense if the signal receiver 4 - Also via a coil - an operating power in the circuit de transmission means 7 transmits wirelessly, bringing the measuring element 6 and also the evaluation unit can be supplied with power. Thus, if necessary, for example, on request, a measurement can be performed, for which the measuring element 6 provides a measurement signal, which is optionally first processed in the evaluation and the transmission means 7 to the signal sensor 4 is sent.

Advantageously, the seal arrangement 3 only made of cold-formed sheet metal parts and elastomer-based sealing rings, whereby the radio signal of the transmission means 7 without further ado to the signal sensor 4 can be sent without being shielded by the seal assembly, especially through the outer ring 1 and the inner ring 5 a certain shielding is expected. For the same reason it is possible the required energy from the signal receiver 4 via the transmission medium 7 to transfer to the circuit.

The aforementioned evaluation unit may alternatively or optionally be used to detect vibrations caused by a so-called pitting. The measuring signal of the measuring element 6 is examined by the evaluation unit to a specific frequency range. If a sound wave can be detected, which is due to a pitting, a corresponding warning signal is generated, which by the transmission means 7 to the signal sensor 4 is sent.

2 shows a second tapered roller bearing with a sensed rolling element 22 , The rolling element 22 is a tapered roller, which is supposed to transmit no load as a sensor roller, but via the measuring elements 23 Measure different quantities directly in the rolling contact. The rolling element 22 This can ideally consist of an easy-to-handle plastic, with the corresponding recesses for the measuring elements 23 , a cable connection 8th for telemetry 26 and for telemetry 26 to do it yourself. It is conceivable that the rolling elements 22 is first brought into the form of a tapered roller and then said recesses, for example by drilling or other machining methods, are introduced. Alternatively, it is possible to overmold the said elements with a plastic and to bring this simultaneously in the desired tapered roller shape or another shape (sphere, cylinder).

A particular advantage of a sensor roller made of plastic is that when using strain gauges as a measuring element 23 For the detection of torsional forces large strains can be absorbed without damaging the sensor roller, whereby a better measurement signal can be generated than is the case with rolling elements made of metal.

Advantageously, the one or more measuring elements 23 Perform a measurement directly on the rolling contact, which, for example, a measurement of the lubricant film thickness, the surface of the track and other parameters are basically possible.

The telemetry ring 26 is through a signal pickup 24 supplied with energy and supplies this with a signal, the information on the measurement signal of the measuring elements 23 includes. The signal receiver 24 is in the inner ring 25 integrated and located in the mouth of a supply line 27 to the undercut 21 of the inner ring 25 , which is the side board of the outer race of the inner ring 25 separates. The supply line 27 passes through a plug 28 in the axle journal 29 , Due to the plug 28 Is it possible a movement of the inner ring 25 in the circumferential direction to prevent the non-illustrated axis of rotation of the tapered roller bearing. Thus, the supply line is suitable 27 optimally the signal receiver 24 be supplied with power, control data or the like without them having to be interrupted. This creates a tapered roller bearing that can be installed, such as a non-sensed tapered roller bearing, without the need for complicated installation steps. The only additional measure is the plug 28 when mounting the inner ring 25 on the axle journal 29 connect correctly.

In addition, such a sensor arrangement is extremely insensitive to environmental influences, since it is exposed only within the rolling space, which is sealed very well by sealing arrangements.

With the in the 2 The sensor arrangement shown, it is possible to perform a slip measurement when the sensor assemblies is combined with a conventional speed sensor. The sensor arrangement shown can by means of the signal sensor 24 detect when the telemetry ring 26 , or the rolling elements 22 During the rolling bearing operation on the signal sensor 24 passes. This can be compared with the rotational speed measured by means of an encoder associated with the unillustrated RPM sensor. If the tapered roller bearing is operated with a certain slip, the rolling element remains 22 behind the rotatable bearing parts with the encoder back, so there is a measurable discrepancy, which is now detectable and leads to a warning message for the user.

3 shows a sensed rolling element in the form of a roll 32 , eg a tapered roller or a cylindrical roller, with modified wireless signal transmission. The role 32 also consists of a plastic, in which the measuring elements 36 . 37 . 38 and 39 introduced and with the transfer agent 34 (Transmitter) are electrically connected.

A slip measurement is possible with the sensor arrangement shown, since this is combined with a speed sensor. It is in the shown tapered roller bearing to a wheel bearing of a truck. The inner ring 35 is firmly on the axle journal 29 arranged and the multipole encoder 53 is attached to the rotating bearing part. The signal receiver 51 is over the cable 27 supplies and realizes a dual sensor function by interacting with the multipole encoder 53 in a known manner determines the speed, but also by means of the transmission element 52 the signal from the transmission medium 34 to the signal sensor 51 is passed on. This is the signal of the transmission medium 34 first with the signal sensor 31 received and by means of a not shown cable to the transmission element 52 transfer. Because the delivery element 52 mounted on a rotating component, it is sufficient to pass on information on capacitive routes. Therefore, the near field transmission from the transmission means 34 to the signal receiver 31 capacitive (alternatively to radio transmission) to be accomplished. In the case of the capacitive near field transmission would be a power supply of the signal pickup 31 and the delivery element 52 unnecessary.

4 a schematic representation of a sensed rolling element 42 on a radio basis.

In the rolling element 42 It is a combination of the well-known Radio Frequency Identification (RFID) Technology and tapered roller bearing technology. The rolling element 42 includes an electrical resonant circuit consisting of the transmission element 41 , For example, a coil, and a measuring element 43 is formed. The measuring element 43 in turn, consists of a resistor 44 and a capacitor 45 ,

The rolling element can have all possible forms of rolling elements, such as cylindrical rollers, tapered rollers, balls, barrel rollers or similar types of rolling elements.

At the measuring element 43 it is a temperature sensor whose resistance 44 changes with the temperature and thus changes the natural frequency of the swim circle. This natural frequency can be communicated to the signal receiver by a corresponding signal, so that it can be detected which natural frequency the oscillating circuit currently has. On the basis of a previously determined calibration curve, which defines the natural frequency as a function of the temperature, it can be ascertained, after a natural frequency measurement by an analysis unit, which temperatures are present in the rolling element and therefore in the rolling element space of the tapered roller bearing.

5 shows a first sensed tapered roller 72 on an inner ring 75 , The tapered roller 72 has the recesses 73 on, which have a depth X and each at the bottom of the recess a light source 76 and an optical measuring element 74 are arranged. The light source 76 and the optical measuring element 74 form an active optical sensor that generates light radiation on the outer running surface of the inner ring 75 casts and measures the intensity of the reflected light. At each of the four recesses 73 Such an optical sensor can be provided so that monitoring of the lubricant film in a sufficient axial width can be ensured.

1. a) Stufe 1: sehr hohe Intensität (sehr starke Reflektion); kein oder zu wenig Schmiermittel
2. b) Stufe 2: hohe Intensität (starke Reflektion); optimaler Schmiermittelfilm
3. c) Stufe 3: geringe Intensität (wenig Reflektion); ausreichender Schmiermittelfilm
4. d) Stufe 4: kaum Intensität (zu wenig Reflektion); ungenügender Schmiermittelfilm (Schmiermittel ist zu alt oder mit zu vielen Fremdpartikeln durchsetzt)

Depending on the measured intensity of the reflected light radiation, it is possible to deduce the lubricant film quality. For example, 4 levels could be provided:

1. a) stage 1 : very high intensity (very strong reflection); no or too little lubricant
2. b) stage 2 : high intensity (strong reflection); optimal lubricant film
3. c) level 3 : low intensity (little reflection); sufficient lubricant film
4. d) level 4 : hardly any intensity (too little reflection); Insufficient lubricant film (lubricant too old or too much foreign particles)

At stage 2 and level 3 No actions are required. At the entrance of the stage 3 However, the user may receive information related to the life of the bearing and informs the user when to expect the failure of the bearing in the foreseeable future.

At the entrance of the stage 4 is ensured with appropriate message by the sensor unit that the rolling bearing is replaced before it comes to a complete failure of the bearing. This can be possible dangers out of the way.

Should be level 1 are present, so too thin a lubricant film is reported. Subsequently, an exchange of the rolling bearing or a relubrication of the same as adequate measures conceivable. Thus, the sensed rolling element allows 72 an early intervention before it comes to a bearing failure.

The depth X of the recesses 73 should be chosen so that neither the measuring element 74 , nor the light source 76 can be damaged by rolling or jounce. However, in principle, the depth X is better chosen as low as possible.

By a corresponding arrangement of the recesses and the optically active measuring elements, the lubricant can be monitored at different points of the raceways (inner race and outer race). This is particularly advantageous in tapered roller bearings, since a redistribution by the shape of the rolling element is not favored and often (for example, by cages provided for this purpose) must be improved by additional redistribution.

6 shows a second sensed tapered roller 62 on an inner ring 65 , This embodiment corresponds to that of 5 , where the arrangement of the light source 66 and the measuring elements 64 at the recesses 63 from the in 5 different. The light sources 66 borders from the narrower end of the tapered roller 62 to the recesses 63 , where at the same time the measuring elements 64 on the opposite side of the recesses 63 are arranged. Thus, the light radiation from the light source 66 generated and directly on the measuring element 63 directed. The measuring element 63 measures the intensity of the transmitted light, the intensity being due to the in the recess 63 existing lubricants (oil or grease) vary can. Again, different levels for the measured light intensity (similar to in 5 ) are provided, but with which not the quality of the lubricating film is measured, but the quality of the lubricant itself.

7 shows a sensed rolling element 82 on an inner bearing part 85 with a circumferential groove 83 , The measuring elements 84 are lined up along the groove bottom in the circumferential direction, whereby a detection of the intensity of the reflected light of the light source 86 is possible, in the circumferential direction of the measuring elements 84 followed. This unevenness in or on the tracks are also detectable in an optical manner. The light of the light source 86 is on the outer race of the inner bearing part 85 reflected and then in four measuring elements 84 detected. The intensity in the respective measuring element 84 is measured depends on the scattering angle, which in turn can vary greatly depending on the surface structure. On the basis of the measured intensity patterns different structures can be recognized on the raceways. Additionally or alternatively, an increasing contamination of the lubricant or the amount of lubricant can be detected by the measuring element 84.1 detects the entire reflected light in optimal operation, or at least the largest proportion thereof. With increasing contamination or an increase in the amount of lubricant, part of the light is also scattered more strongly. Thus the measuring elements become 84 - 2 . 84 - 3 and 84 - 4 detect more stray light in the mentioned cases. Both on the scattering angle, as well as the intensity in the individual measuring elements 84 - 1 . 84 - 2 . 84 - 3 and 84 - 4 can be deduced on the amount of lubricant (eg fat) and / or the lubricant contamination.

In the circumferential groove 83 can have multiple measuring elements 84 or light sources 86 to be ordered. The processing of the measurement signal, or a forwarding of the signal to a signal sensor can in the embodiment of the 7 , as well as in the embodiments of 5 . 6 . 8th and 9 optionally be solved as it is in the embodiments of the 1 to 3 is proposed.

8th shows a sensed rolling element 92 with a circumferential, spiral groove 93 , Similar to the embodiments of the 7 and 6 becomes a light intensity by means of the measuring elements 94 measured, which is reduced by the transmission through the lubricant. This will be the light source 96 and measuring elements 94 arranged in a groove opposite.

The groove extends over the outer surfaces of the rolling body 92 in a spiral, that is, it forms in the direction of the self-rotation axis of the rolling body 92 looks at a spiral.

It is, as well as in the embodiment of 6 monitors the lubricant quality, while ensuring a redistribution of the lubricant. By continually in the groove 93 transported lubricants, the mixing of the lubricant is improved, so that the determined light absorption is subjected to less local boundary conditions, but exactly the light absorption is measurable, which is assigned to a uniformly mixed lubricant. This makes the measuring result more reliable. Furthermore, it is possible to have multiple light sources 96 with associated measuring element 94 provide so that about the readings of these measuring elements 94 in addition can be averaged. This further increases the reliability of the sensor arrangement.

9 shows a recess in a sensed rolling element 102 with active scatter detector. Similar to the embodiment of 7 Also, a scatter detection can be accomplished by the measuring elements 104 across the width of the recess 103 are distributed, ie perpendicular to the circumferential direction of the rolling body 102 , Ideally, a single measuring element is used, which is a series of measuring elements 104 includes (array). Due to the large number of measured values of the measuring elements 104 Intensity distributions can be measured based on a specific structure (indentation depth, pitting) of the raceway surface of the bearing part 105 Close (eg inner ring or outer ring).

In addition, the absorption by a lubricant film 110 taking into account both the thickness of the lubricant film 110 measured, as well as the quality of the lubricant can be determined. Thus, the measuring element arrangement shown combines the measurement of three different parameters that are crucial for the rolling bearing operation and allow statements about the behavior of the rolling bearing and its life expectancy.

In summary, the invention relates to a rolling element having an outer surface for forming a first rolling contact with an outer race of an inner rolling bearing part and for simultaneously forming a second rolling contact with an inner race of an outer rolling bearing part, wherein the rolling bearing parts are rotatable relative to each other. Furthermore, the invention relates to a rolling bearing assembly, in particular wheel bearing assembly having such rolling elements. The aim is to expand the possibilities of measuring rolling bearing parameters, but at least to improve the signal strength of known measured variables m measuring element. For this purpose, it is proposed to equip a rolling body with a measuring element and a transmission means, wherein the transmission means can send a signal to a signal sensor and provides information on a measured variable directly on or in the rolling body. Thus, parameters of the rolling bearing during the rolling bearing operation can be measured and allow early detection of a lack of operation, such as a small lubricant film thickness or too small amount of lubricant.

LIST OF REFERENCE NUMBERS

R

axis of rotation

1

outer ring

2

rolling elements

3

sealing arrangement

4

signal sensor

5

inner ring

6

Kitchen sink

7

measuring element

8th

management

21

undercut

22

rolling elements

23

sensor array

24

signal sensor

25

inner ring

26

telemetry ring

27

electric wire

28

connector

29

journal

31

signal sensor

32

Tapered roller

33

sealing arrangement

34

transmission element

35

inner ring

36

Strain gauges

37

Lubricant measuring element

38

Temperature sensing element

39

Air pressure measuring element

41

Kitchen sink

42

rolling elements

43

measuring element

44

resistance

45

capacitor

51

signal sensor

52

About averaging element

53

Multipole encoder

62

rolling elements

63

recess

64

Optical measuring element

65

inner ring

66

light source

72

rolling elements

73

recess

74

Optical measuring element

75

inner ring

76

light source

82

rolling elements

83

groove

84

Optical measuring element

85

Inner warehouse part

86

light source

87

Reflected light radiation

92

rolling elements

93

Spiral-shaped groove

94

Optical measuring element

95

inner ring

96

light source

102

rolling elements

103

recess

104

Optical measuring element

105

bearing part

106

light source

107

light radiation

110

lubricant film

Claims (9)

Rolling elements (2, 22, 32, 42, 62, 72, 82, 92, 102) having an outer surface for forming a first rolling contact with an outer race of an inner rolling bearing part (5, 25, 35, 65, 75, 85, 95, 105 ) and for simultaneously forming a second rolling contact with an inner raceway of an outer rolling bearing part (1), wherein the rolling bearing parts (5, 25, 35, 65, 75, 85, 95, 105; 1) are rotatable relative to each other, wherein the rolling elements (2 , 22, 32, 42, 62, 72, 82, 92, 102) at least one measuring element (6, 23, 36, 37, 38, 39, 43, 64, 74, 84, 94, 104) and at least one transmission means (7, 26, 34, 41) for the wireless transmission of a signal, characterized in that the measuring element (64, 74, 84, 94, 104) at a recess (63, 73 , 83, 93, 103) in the rolling body (62, 72, 82, 92, 102) and for the optical detection of light radiation (87, 107) is provided. Rolling elements (2, 42, 62, 72, 102) according to Claim 1 wherein the rolling element (2, 42, 62, 72, 102) is a load-bearing rolling element (2, 42, 62, 72, 102). Rolling elements (2) after Claim 2 , wherein the measuring element (7) is arranged on a side surface of the rolling body (2). Rolling elements (2, 22, 32, 42, 62, 72, 82, 92, 102) according to one of the preceding claims, wherein the transmission means (7, 26, 34, 41) comprises a first coil (41), an antenna or a telemetry ring (26). Rolling elements (2, 22, 32, 42, 62, 72, 82, 92, 102) according to Claim 4 , wherein the first coil (41) for wireless energization of the measuring element (43) is provided. Rolling elements (2, 22, 32, 42, 62, 72, 82, 92, 102) according to one of the preceding claims, wherein the measuring element (6, 23, 36, 37, 38, 39, 43, 64, 74, 84, 94, 104) for the detection of airborne sound, structure-borne noise, temperature, lubricating film thickness, lubricating film quality, air pressure or water content is provided. Rolling elements (62, 72, 82, 92, 102) according to one of the preceding claims, wherein the light radiation (87, 107) before detection by the measuring element (64, 74, 84, 94, 104) of at least one at the recess (87 63, 73, 83, 93, 103) arranged light source (66, 76, 86, 96, 106) generated and transmitted through in the recess (63, 73, 83, 93, 103) existing lubricant. Rolling elements (72, 82, 102) according to Claim 7 wherein the light source (76, 86, 106) is arranged such that the light radiation (87, 107) on a raceway surface of an outer or inner rolling bearing part (75, 85, 105) before being detected by the measuring element (74, 84, 104) ) is reflected. Rolling bearing arrangement, in particular wheel bearing arrangement, having at least one rolling body (2, 22, 32, 42, 62, 72, 82, 92, 102) according to one of the preceding claims, wherein a communicating with the transmission means (7, 26, 34, 41) wirelessly Signal receiver (4, 24, 51) is fixed to a fixed component (25, 35) of the rolling bearing assembly.

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