DE102004054201A1 - Ball bearing has peripheral grooves in outer faces of outer ring, in which sensors, e.g. temperature or rpm sensors, are mounted - Google Patents

Abstract

The ball bearing has peripheral grooves (5, 6) in the outer faces of the outer ring (2). Sensors (8, 9), e.g. temperature or rpm sensors, are mounted in these.

Description

Territory of invention

The The invention relates to a rolling bearing with integrated sensors, in which between a fixed Bearing ring and a rotatable bearing ring arranged in a cage rolling elements and at least in at least one surface of the bearing rings a recess for receiving sensors is formed.

background the invention

Out Literature are measuring or sensor bearings in the most diverse embodiments known. Usually These measuring or sensor bearings are constructed as rolling bearings, which have a fixed and have a rotatable bearing ring, between which arranged rolling elements are. The measuring means of these bearings consist entirely of strain gauges with resistance complete bridge circuits, Temperature sensors, so-called SAW and BAW senors (SAW = surface-acoustic-waves or BAW = bulk acoustic waves) and speed sensors in the form of simple encoders. For example, with these sensors forces Speeds, rotational speeds and temperatures measurable. Provided these sensors are arranged on the rotatable bearing ring are their measuring signals directly, or processed by one on the bearing ring arranged microcomputer, via a transmitting device from the rotating system to a stationary System, for example to an evaluation and control device, Posted.

The mentioned sensors are usually in recesses or grooves in the cylinder surface of a the two bearing rings arranged such that their mounting locations from the rolling elements in the Storage operation can be rolled over are. In this Vorbeirollen the force-loaded rolling elements acts that of the respective rolling elements transferred the other bearing ring Force such on the sensors that characteristic and periodic repetitive measuring signal curves arise, by their evaluation, the above-mentioned physical Sizes can be determined are.

Such a sensor bearing is for example from the DE 100 17 572 A1 in which in the bearing outer ring or in the bearing inner ring in the cylinder jacket surfaces annular grooves are formed, which serve for the described recording of SAW or BAW sensors. In addition, grooves are formed on the end faces of the respective bearing ring, which are provided for receiving a transmitting antenna for the or the SAW or BAW sensors.

The usual arrangement the said sensors in the region of the curved cylinder jacket surfaces of the Bearing rings is relatively easy to install and expensive. Especially the application of strain-sensitive resistance bridges in Form of strain gauges in the particular small bearings narrow depressions is not without problems. The use of so-called thin-film technology, when the sensors directly by the application of thin layers are generated on the groove bottom of the bearing ring recess, in particular technologically in curved surfaces consuming and therefore also associated with relatively high costs. After all is to be cited as a further disadvantage of known sensor bearings with wireless measurement signal transmission, that in these the sensors as described above in a groove in one Cylinder surface are arranged and the transmitting antenna are guided to a bearing end face which has to be increased with Manufacturing costs associated with the affected bearing ring.

Task of invention

In front In this background, the invention is based on the object generic sensor bearing further develop such that this cheaper than known sensor bearings can be produced. In addition, the structure of this sensor bearing is a lighter accessibility to its sensors, to signal processing devices there as well as short signal paths to an optionally present transmitting antenna enable.

Summary the invention

The Asked task is according to the characteristics of claim 1 by a rolling bearing solved with integrated sensors, in which between a fixed bearing ring and a rotatable Bearing ring in a cage guided Arranged rolling elements and at least in at least one surface of the bearing rings a recess for receiving sensors is formed. there it is provided that the at least one recess in at least an end face of a bearing ring is formed.

By this deviating from the usual design construction of the sensor bearing, the sensors can be easily accessible, easy and thus cost-saving in a recess on at least one of the two plan end sides of a bearing ring attach. This plan front side surfaces and the plane and not cylindrical surface curved bottom of the wells are very suitable advantageous for receiving sensors, which are constructed there or applied in the so-called thin-film process. Also, the attachment of known thin and fragile strain gauges is significantly facilitated by said mounting location. In addition, can advantageously be dispensed with separate or relatively long connecting lines to a transmitting antenna and related grooves in the bearing ring.

The under claims describe preferred developments or refinements of Invention.

Therefore it is provided that the at least one recess on an end face is formed of the fixed bearing ring. Through this structure become costly wireless signal transmission means for transmission the signals of the sensors to stationary evaluation and display devices avoided.

One roller bearing according to the invention is also characterized in that in the at least one recess Force sensors designed as strain-sensitive resistance measuring bridges are arranged. With their help can be in per se known Way to the rolling bearing acting forces, Determine the speeds and directions of rotation of the rotatable bearing ring.

There for the detection of sudden occurring bearing damage a continuous measurement of the bearing forces is usually insufficient, is according to one another variant of the invention provides that in addition to the resistance bridges at least one temperature sensor and / or at least one structure-borne sound sensor is arranged in the at least one recess. The measuring signals complement these sensors and thus provide a comprehensive picture of the current bearing loads and the storage condition. In addition, with the help of the measured values of the temperature sensor an optionally recorded temperature drift of the other Sensor types are recorded and corrected.

Regarding the exact measurement of the forces acting on the rolling bearing forces or the effective force component of all these forces is preferably provided that the resistance bridges in such an angular pitch on the at least one end face of the preferably fixed bearing ring are arranged, which the angle division the revolving rolling element in corresponds to the Wälzkörperkäfig. In this way, an exact assignment between the overrun Resistance bridges and the respective rolling elements possible.

Around to be able to measure the ultimate effective force component on the rolling bearing as accurately as possible sees the invention that in the at least one frontal depression arranged with the same circumferential distance at least three resistance bridges are.

In further embodiment of the invention can also be provided that the resistance bridges on the two end faces of the stationary bearing ring in the front side comparison are arranged symmetrically to each other. By doubling in particular the force sensors (resistance bridges) at the two end faces a rolling bearing ring let yourself by adding the signals of the radially and axially immediately adjacent Sensors double the usable signal amplitudes and / or by Comparison of the measurement signals check their relevance or accuracy and / or improve the accuracy of the measurement result.

Prefers is also provided that the at least one structure-borne sound sensor and / or the temperature sensor is arranged circumferentially between two resistance bridges.

A Another variant of the invention provides that in the at least a depression in the face a bearing ring electronic circuits in the form of discrete Microcomponents or arranged in the form of a microcomputer and with the mentioned Sensors are technically connected. This microelectronics serves the measuring signal amplification, the calculation of the temperature compensation, the linearization of the Measuring signals or signal waveforms and / or the analog-to-digital conversion.

Preferably are the electronic circuits and / or the microcomputer arranged circumferentially between two resistance bridges.

The repeatedly mentioned recesses for receiving the sensors and / or the electronic circuits or the microcomputer can be used as a circulating Annular groove or as a series of discrete recesses in the bearing faces be educated.

Short description the drawings

The The invention will be described below with reference to the accompanying drawings in preferred embodiments explained in more detail. In this shows

1 a cross section through a schematically illustrated sensor bearing according to the invention,

2 a greatly simplified end view of the sensor bearing according to 1 in which the circumferential distribution of the rolling elements of the bearing and of the sensors can be seen,

3 a cross section through a bearing outer ring with a frontal groove and arranged therein sensors, and

4 an end view of the sensor bearing, in which the arrangement of the rolling elements and the measuring resistors of resistance bridges is visible.

Full Description of the drawings

The sensor bearing shown by way of example therefore comprises one on a component 1 fixed outer ring 2 and a rotatable inner ring 4 between which in a cage 17 held rolling elements 3 are arranged circumferentially distributed. The inner ring 4 carries a wave 7 at least by its own weight exerts a force F on said rolling bearing components.

The fixed outer ring 2 indicates at its two front sides 16 wells 5 and 6 on, which are designed here as circumferential grooves. In these recesses, sensors and optionally an electronics for processing the signals generated by the sensors and a transmitting antenna are arranged. The sensors are in 1 in general with the reference numbers 8th and 9 designated. This illustration illustrates particularly well that by the arrangement of the wells 5 . 6 on the bearing ring end faces 16 the sensors 8th . 9 can be easily mounted and built on the flat surfaces of these wells and cost-saving.

With the help of these sensors 8th . 9 For example, forces, torques, temperatures, rotational speeds, rotational speeds and directions of rotation can be measured, which are used, inter alia, to evaluate the service life of the bearing and to control and regulate a machine, not shown here, whose component is the shaft 7 is.

As the 2 and 3 clarify, for example, in the depression 5 arranged sensors 8th and 9 for example as resistance bridges 10 to 15 formed, the measuring resistors R1, R2, R3 and R4 are arranged in pairs radially one behind the other. Between these resistance pairs R1 and R3 or R2 and R4, the measuring voltage can be tapped in a known manner. During operation of the bearing, this measuring voltage has a sinusoidal, triangular or superposed signal waveform.

3 shows this radial arrangement of the resistor pairs R1 and R3 or R2 and R4, wherein a microelectronic evaluation circuit IC is arranged radially between these two pairs of resistors and / or in a circumferential distance between these two pairs of resistors. This evaluation circuit can also be designed as a microcomputer, wherein because of their larger dimensions as shown, an arrangement is circumferentially preferred between the respective resistance bridges.

3 also shows that in the wells 5 . 6 also temperature sensors 18 and the structure-borne noise sensors mentioned above 19 can be arranged. In the 3 illustrated geometric arrangement of these sensors 18 . 19 is only an example and can be adapted to the available space and the measuring requirements.

With regard to the temperature sensor 18 It should be noted here that through the formation of resistance bridges 10 to 15 Although a temperature-compensated signal of each such sensor is present as resistance full bridges. However, since installation conditions for the rolling bearing are not excluded, in which the bearing receiving component 1 even exerts a temperature-dependent force on the bearing, a temperature drift of the force acting on the bearing can be expected. For this reason, in order to achieve a higher measuring accuracy integrated in the rolling bearing separate temperature sensor 18 meaningful.

The at least one additional in the recess 5 . 6 The structure-borne sound sensor arranged in the sensor bearing 19 provides a measurement signal that informs nen about the surface condition of the rolling bearing raceways and the rolling elements 3 to derive. With their help, a statement about a possibly expected soon bearing failure can be derived.

Said sensor is preferably on the front sides of the fixed rolling bearing ring 2 arranged, although also the rotatable bearing inner ring 4 in the manner described can be equipped with these sensors and with the advantages mentioned. In the latter case, however, a device known per se for wireless signal transmission or optionally preprocessed sensor signals, for example in digital form, which also in the recess is useful 5 and or 6 is housed.

As 2 and 4 clarify are, in particular, the resistance bridges 10 to 15 in a frontal depression 5 . 6 the sensor bearing arranged such that the angular pitch "a" of those of the rolling elements 3 in the warehouse corresponds. This means that when the rolling bearing is stationary Rolling such to the resistance bridges 10 to 15 alignable that radially under each resistance measuring bridge 10 to 15 a rolling element 3 stands.

Of course it is Such an arrangement both in partial and full complement Rolling bearings possible. Further can such a sensor bearing as shown as roller or needle roller bearings, or as grooved or angular ball bearings be educated.

Distributed on the circumference with the same angle division are at least three resistance bridges 10 . 13 and 14 , by means of which the force F 'acting on the rolling bearing can be reliably determined. In the example chosen here, the angular distance between the three resistance bridges is 10 . 13 and 14 exactly 120º. These are from the mentioned resistive bridges 10 . 13 and 14 measured forces F1, F2 and F3, for example, in the electronic circuit IC as shown here only schematically in their force components F1 ', F2' and F3 'decomposed and added vectorially to the resulting force F'.

By the in 1 shown symmetrical arrangement of the described in particular force sensors (resistance bridges or structure-borne sound sensors) at the two end faces of the bearing ring 2 The number of identical measuring signals can be doubled, which can advantageously lead to a doubling of the signal amplitude for plausibility checking of the individual measuring signals and / or by adding the signals associated with each other in relation to the circumference.

In addition, by pairwise attaching resistance bridges 10 and 11 or 12 and 13 or 14 and 15 in each case a further, but + 90 ° or -90 ° phase-shifted measurement signal are obtained from the phase shift to the associated measurement signal of the immediately adjacent resistance measuring bridge, the direction of rotation of the bearing can be derived.

1

component

2

outer ring

3

rolling elements

4

inner ring

5

deepening

6

deepening

7

wave

8th

sensor

9

sensor

10

Resistance bridge

11

Resistance bridge

12

Resistance bridge

13

Resistance bridge

14

Resistance bridge

15

Resistance bridge

16

front

17

Cage

18

temperature sensor

19

Noise sensor

a

angular distribution

F

force

IC

electronic Circuit, microcomputer

R1

electrical resistance

R2

electrical resistance

R3

electrical resistance

R4

electrical resistance

Claims (11)

Rolling bearings with integrated sensors, in which between a fixed bearing ring ( 2 ) and a rotatable bearing ring ( 4 ) in a cage ( 17 ) guided rolling bodies ( 3 ) are arranged, and in which in at least one surface of the bearing rings ( 2 . 4 ) at least one depression ( 5 . 6 ) is designed for receiving sensors, characterized in that the at least one recess ( 5 . 6 ) in at least one end face ( 16 ) is formed of a bearing ring. Rolling bearing according to claim 1, characterized in that the at least one recess ( 5 . 6 ) on one end face of the stationary bearing ring ( 2 ) is trained. Rolling bearing according to claim 1 or 2, characterized in that in the at least one recess ( 5 . 6 ) as strain-sensitive resistance bridges ( 10 to 15 ) trained force sensors ( 8th . 9 ) are arranged. Rolling bearing according to claim 3, characterized in that in addition to the resistance bridges ( 10 to 15 ) at least one temperature sensor ( 18 ) and / or at least one structure-borne sound sensor ( 19 ) in the at least one recess ( 5 . 6 ) is arranged. Rolling bearing according to claim 3, characterized in that the resistance measuring bridges ( 10 to 15 ) in such an angular pitch at the at least one end face ( 16 ) of a bearing ring ( 2 ) are arranged, the angle of the pitch (a) of the rotating rolling elements ( 3 ) corresponds. Rolling bearing according to claim 5, characterized in that in the at least one front-side recess ( 5 . 6 ) with the same circumferential distance at least three resistance bridges ( 10 . 13 . 14 ) are arranged. Rolling bearing according to claim 6, characterized gekenn records that the resistance bridges ( 10 to 15 ) on the two end faces ( 16 ) of the stationary bearing ring ( 2 ) are arranged symmetrically to each other in the end comparison. Rolling bearing according to one of claims 1 to 7, characterized in that the structure-borne sound sensor ( 19 ) and / or temperature sensor ( 18 ) circumferentially between two resistance bridges ( 10 . 13 . 14 ) is arranged. Rolling bearing according to one of claims 1 to 7, characterized in that in the at least one recess ( 5 . 6 ) Electronic circuits and / or a microcomputer (IC) for signal amplification, temperature compensation, linearization of the waveforms and / or analog-to-digital conversion are arranged. Rolling bearing according to claim 9, characterized in that the electronic circuits and / or the microcomputer (IC) circumference conditions between each two resistance bridges ( 10 to 15 ) are arranged. Rolling bearing according to claim 8, characterized in that the at least one recess ( 5 . 6 ) is designed to receive the sensors and / or the electronic circuits or the microcomputer (IC) as a circumferential groove.