Roller bearing arrangement with an angle sensor

Translation of description of equivalent WO 2011134955 A2

p0001Title of invention

p0002Rolling arrangement with an angle sensor

p0003description

p0004Field of the Invention

p0005The invention relates to a rolling bearing assembly with an angle sensor according to the preamble of claim 1 and a method for mounting such a rolling bearing assembly with an angle sensor.

p0006Background of the Invention

p0007A generic arrangement which designated a roller bearing and a as a resolver as absolute encoder comprises formed angle sensor is known for example from US 2006/0087315 A1. The angle sensor has an output connected to the outer ring of the rolling bearing stator, as well as an inlet connected to the stator sammenwirkenden rotor which is formed as an eccentric ring and formed by the inner ring of the rolling bearing.

p0008A further equipped with a provided for detecting a rotation parameter sensor roller bearing is known from EP 1518126 B1. In this case, micro Mikrosende- and receiving coils of the sensor on a support, namely a substrate of a printed circuit are arranged. Next is a on the carrier arranged processing circuit which includes an oscillator and phase demodulators.

p0009From US 7,135,860 B2 operating according to the principle of variable reluctance resolver is known, comprising a rotor having a plurality of detection areas, which is intended in particular a reliable zero recognition.

p0010Object of the invention

p0011The invention is based, a specify particular for smaller types of rolling bearings, Example as deep groove ball bearings with less than 40 mm outside diameter, suitable arrangement of storage and angle sensor, which is characterized by both a small footprint as well as by an especially simple mounting option the task. It is another object of the invention to provide a manufacturing technology advantageous angle sensor which is usable even without assembling a rolling bearing.

p0012Summary of the Invention

p0013This object is achieved by a one working according to the principle of variable reluctance angle sensor and a roller bearing assembly comprising the features of claim 1, by a sensor arrangement with the features of claim 21, and by a method for assembling an AN for absolute measurement angle sensor having rolling bearing assembly having the features of claim 22. in the following, in conjunction with the previous directions mentioned embodiments and advantages of the invention apply mutatis mutandis to the assembly process, and vice versa.

p0014The includes the angle sensor comprising rolling bearing assembly

p0015• a roller bearing with two concentric to its axis of rotation, each one or more parts bearing rings, namely an inner ring and an outer ring, wherein between the bearing rings at least one row rolling elements, such as balls, needles, cylindrical rollers, tapered rollers, Ku gelrollen or spherical rollers, arranged .

p0016• one with the rolling bearing coupled relative to the second bearing ring is provided for detecting the angular position of the first bearing ring, an absolute angle measurement that is suitable angle sensor, which

p0017· A rotation with a bearing ring or surrounding components, esp. Having casing connected sensor ring and a rotatably connected to the second bearing ring material measure, which

p0018• on the sensor toroidal coils, namely at least one - are arranged transmitting coil and at least one receiving coil, a signal above a magnetic circuit between the - preferably exactly one

p0019Transmitting coil and the receiving coil by the material measure a variable reluctance is given in the magnetic circuit and transferable,

p0020• the transmitter coil metrieachse an identical with the rotational axis of the rolling bearing symbols, namely, the central axis having, and forming in a part of the magnetic circuit, a U-shaped cross section having annular, concentric to the rotation axis, associated with one of the bearing rings shell core is arranged,

p0021• the measuring scale as between or in front of the legs of the U-shaped

p0022Core shell arranged, that is the base of the U-shaped pot-type core of opposing ring is formed,

p0023• a receiving coil is disposed at least partially inside and partially outside the shell core. The measuring scale, which serves to close the magnetic circuit is preferably arranged on the rotating ring in the case of a bearing assembly with a rotating shaft so the inner ring. In the case of a stationary inner ring and rotating outer ring, the scale is accordingly connected to the outer ring.

p0024In particular manufacturing friendly way at least one coil, each coil preferably, the sensor ring is constructed as a printed circuit. In a preferred embodiment in this context are several receiver coils, namely sine each formed by a plurality of coils and cosine coils are provided, the windings of the sine or cosine coils are arranged alternately on adjacent layers of a formed as Mulitlayer PCB printed circuit. Two turns of a sine coil or two coils of a cosine coil are preferably arranged on each layer. This is a good error compensation, with the particular geometric inaccuracies and related inhomogeneities in the magnetic field are compensated, accessible. The signals supplied by the various sine-cosine coil or coils are further processed by a series circuit subtracted from each other and outside the sensor. According of an alternative, particularly space-saving Ausführungsorm sine and cosine coils are arranged on the same layer.

p0025The supply of a signal, for example, 4 kHz signal in the coils, which are constructed as a multilayer board, is preferably carried out from the inside to the outside. This capacitive coupling between the primary and secondary coil are minimized, thereby shielding layer can be saved on the board.

p0026According to a preferred embodiment, the rolling bearing as a radial bearing, eg deep groove ball bearings, formed, the sensor ring with the outer ring as the first bearing ring and the material measure in the form of an eccentric to the bearing axis ring, preferably double eccentric ring, the inner ring as a two- tem bearing ring is connected. Notwithstanding an eccentric or double eccentric design of functioning as a measuring graduation ring embodiments are also feasible in which the ring is arranged concentrically to the rotation axis and - viewed in the axial direction - has only circular contours, but one ne along the periphery of varying thickness. In both embodiments, an angle-dependent air gap between the scale and the pot core is given.

p0027In order to connect the metallic shell core in a simple and stable manner with a relatively rigid support structure to the outer ring of the angle sensor as well as with the coil, the core shell is pierced several times at its radially outer U-legs. The support structure preferably comprises a formed as a plastic injection molded part holding element, which is attached directly to the outer ring and radially surrounded by a support ring of metal, which contacts a front face of the outer ring. Firstly, metal and other parts formed from plastic, such as the shell core and the retaining member, are rational in the two-component injection molding method.

p0028The support ring surmounted in an advantageous embodiment the shell core in the axial direction, wherein the support ring comprises according to a first variant in its the pot core sur- restricting portion a radially jutting-out of its periphery inward attachment tab for supporting a device connected to the sensor ring cable. According to an alternative variant, the supporting ring only one recess on its circumference, which is provided for passage of a cable. This cable is preferably designed as a flexible printed circuit board in this area and attached to a strip-shaped holder which is integrally formed with the shell core and merges into the plane orthogonal to the axis of rotation of the angle sensor and the entire rolling bearing assembly U-base of the shell core.

p0029In pot core, an iron powder core is provided optionally. This combines good magnetic properties in an advantageous manner with low electrical conductivity resistance and low eddy currents. In an analogous manner, can be formed by an iron powder component having the material measure.

p0030A particularly good use of space is be saved in a preferred embodiment in which the radially outer U-legs of the shell core disposed radially outside of the inner ring and the radially inner U-legs of the shell core radially inside the layer formed by the inner ring raceway of the rolling bodies. Here, the radius of the described by the outer U-leg, symmetrical to the axis of rotation circle is preferably less than the inner radius of the outer ring.

p0031Briefly, the rolling bearing assembly according to the invention the following features:

p0032• a Rolling arbeiten- with an on the principle of variable reluctance of, trained as an absolute encoder angle sensor is connected, which

p0033• a rotationally fixed to one of the bearing rings of the rolling bearing connected sensor ring and a rotatably connected to the second bearing ring, designed as an annular measuring scale, said

p0034· On the sensor ring coils, namely at least one transmitting coil and at least one receiver coil are arranged, and

p0035• the coil having a view identical with the axis of rotation symmetry axis and having a U-shaped cross-section, annular, concentric to the rotation axis of the rolling bearing metallic shell core is disposed, and

p0036• is a receiving coil arranged partially inside and partially outside the shell core.

p0037The advantage of the invention is in particular that core with the U-shaped shell, in which a single transmitter coil - without an iron core - is a very space-saving, among other things, for commutation of electric motors verwendba- rer resolver is provided which is suitable for small roller bearing types, eg deep groove ball bearings with 15 mm inner diameter and 35 mm outer diameter, temperatures up to 150 ° C, and strong shock and vibration.

p0038The mounting a body having the angle sensor rolling bearing assembly according to the invention is carried out in the following steps:

p0039as a radial bearing, eg deep groove ball bearings or angular contact or - suitable circumferential groove is formed roller bearings, designed bearing with two bearing rings, namely an inner ring and an outer ring, in each bearing ring at least one of a rolling member adjacent, principally for receiving a sealing ring, is provided .

p0040an axis of rotation of the roller bearing eccentric, acting as a material measure metallic ring is snapped into the circumferential groove of the inner ring,

p0041designed as a plastic injection molded part holding member is inserted into a support ring made from metal, whose external diameter corresponds at most to the outer diameter of the outer ring of the roller bearing, wherein between the internal diameter of the support ring and a portion of the retaining element remains an annular gap, the retaining element in the circumferential groove of the outer ring snapped, wherein the supporting ring abuts against an end face of the outer ring, designed as a printed circuit, for performing an angle measurement according to the principle of variable-reluctance sensor provided ring on which are coils, namely at least one transmitting coil and at least one receiver coil arranged to be on the holding member so placed that it is located partially in the annular gap between the retaining element and the support ring and partially radially inn- within the holding element, wherein remain between the inner circumference of the holding element and the radially arranged inside the holder parts of the sensor ring slots, which portions of an annular space describe, • a ring-shaped, in cross section U-shaped, the end face of the roller bearing toward the open pot-type core made ​​of metal, as well as the eccentric ring is a component of a magnetic circuit b ildet is pushed up in the axial direction of the arrangement of the holding element, the support ring and the sensor ring and snapped thereto, wherein a radially outwardly disposed U-legs of the shell core, adjacent to the inner periphery of the retaining element, engages in the zones adjacent to this annular space, while an inner U-leg of the pot core is disposed completely radially within the sensor ring.

p0042The inner U-leg of the pot core has an inside diameter which is slightly larger than the inner diameter of the inner ring. An optional in-nere support sleeve is in abutment on the surrounded by the inner ring of the bearing shaft in the region of the radially inwardly arranged U- leg of the pot core, to the end face of the inner ring, postponed.

p0043A sensor assembly is achieved with the task underlying the invention, has a rotation axis enclosing sensor ring and a relatively rotatable about this material measure, which

p0044- Are arranged on the sensor ring coils, namely at least one transmitting coil and at least one receiver coil, a signal above a magnetic circuit between the transmitting coil and the receiving coil transferable and by the material measure a variable reluctance is given in the magnetic circuit,

p0045- The transmitting coil forming a part of the magnetic circuit, a U-shaped cross section having annular, concentric to the rotation axis shell core is arranged,

p0046- The measuring scale is provided as a ring which closes the magnetic circuit between the legs of the U-shaped pot-type core is formed,

p0047- A receiving coil is partially inside and partially outside the shell core. Embodiments of the invention are explained in detail using a drawing. Herein show:

p0048Brief Description of Drawing

p0049FIG. 1 A first embodiment of a rolling bearing assembly with angle sensor in a perspective view,

p0050Fig. 2 shows the arrangement according to Fig. 1 in top view,

p0051Fig. 3 shows the arrangement according to Fig. 1 in a sectional view, Fig. 4 coils of a sensor ring of the angle sensor of the arrangement according

p0052Fig. 1

p0053Fig. 5 shows a second embodiment of a rolling bearing assembly with angle sensor in a perspective, sectional view

p0054Fig. 6, the partial arrangement of FIG. 5 in plan view,

p0055FIGS. 7, 8, different variants of the coils of a sensor ring of the angle sensor of the arrangement in FIG. 5.

p0056Detailed description of the drawing

p0057The following statements, in particular the design of the angle sensor, refer, unless otherwise indicated, always to all embodiments. For similar or identical parts the same reference numerals are used.

p0058An illustrated in Figures 1 to 3, denoted as a whole by the numeral 1 roller bearing assembly is made up of a rolling bearing 2, namely, a deep groove ball bearings, and an angle sensor 3. As a component of the rolling bearing 2 3 are shown in Fig., An inner ring 4, an outer ring 5 , 6 rolling elements, namely balls, a leading this cage 7, and a sealing plate 8 can be seen on a first end side of the roller bearing second _{Λ Λ}

p0059- 10 -

p0060Coupled with the Rolling 2 angle sensor 3 has a sensor ring 9 which is rotatably connected to the outer ring 5, and a scale 10, which is formed 2 eccentric metal ring as relative to the axis of rotation R of the roller bearing and rotatably connected to the inner ring. 4

p0061As for the structure of the sensor ring 9 is made to the figures 3 and 4. FIG. As a metallic component, the sensor 9 comprises an annular ring, the axis of rotation R of the roller bearing 2 concentric, cross-sectionally U-shaped pot-type core 1 to 1. The U-shaped profile of the shell core 1 1 is for the sealing disc 8 facing away from end face of the roller bearing 2 open towards an outer U-leg 12 lies on the surface of an imaginary cylinder whose axis of symmetry is identical to the axis of rotation R, and the radius is greater than the outer radius of the inner ring 4, but smaller than the inner radius of the outer ring. 5 At the outer U- leg 2 is followed by a radially - relative to the rotational axis R - on extending U-base 13; to which in turn is an inner U-leg 14 connects to, the one on the virtual surface, the axis of rotation R concentric cylinder lies, the radius of which is greater than the inner radius of the inner ring 4, but smaller than the outer radius of the inner ring 4. The minimum radius of the raceway 15 of the rolling elements 6 on the Innening 4, that is the minimum distance of the track 15 from the axis of rotation R, is greater than the radius of the cylinder described by the inner U-leg fourteenth Between the end face of the roller bearing 2 facing end of the inner U-leg 14 and the inner ring 4, a sealing gap 16 is formed.

p0062For holding the shell core 11 and the other, described in more detail below components of the sensor ring 9 on the outer ring 5, a holding member 17 is provided made of plastic, which is secured in a circumferential groove 18 in the outer ring. 5 Radially outside the holding element 17, having an outer diameter which is only slightly smaller than the outer diameter of the outer ring 5, there is a support ring 19 made of metal which abuts to the end face of the outer ring 5 and serves as a mounting aid, as well as a mechanical protection of the angle sensor 3 represents. Between the inner circumferential surface of the support ring 19 and the holding member 17 ""

p0063- 11 - is a ring space 20, that is, an annular gap is formed, which in the completely assembled rolling bearing assembly 1 is filled with components described in more detail below the sensor ring 9 (FIGS. 1-3).

p0064The sensor ring 9 has a transmission coil 21, which is concentric to the axis of rotation R, that is lying in a substantially to the end face of the roller bearing 2 parallel plane arranged completely inside the U-profile of the shell core eleventh The average diameter of the transmitter coil 21 is about as large as the diameter of the raceway 15 on the inner ring 4. In the embodiment, the coil 21 is designed as a 12-layer multilayer PCB. With the transmitting coil 21 which is supplied with a signal having a frequency of, for example 4000 Hz, cooperate different receiving coils 22,23 with a coupling in the manner of a transformer. Each of the receiving coils 22,23 is partially disposed within the U-section of the shell core 11 and partially outside of this U-shaped profile. The corresponding circuit board 24 on which the receiving coil analogous to the transmitting coil 21 is designed as a printed circuit are arranged 22,23, has a plurality of segment-like individual sections of an annular space descriptive openings 25th For one project into these openings 25 sections of the holding member 17; secondly remain with plugged on the retaining element 17 PCB 24 nor slots 26 radially inside the holder 17, through which 11 are plugged directly in fully assembled sections of the outer U-leg 12 of the shell core. These sections of the outer U-leg 12 project in the axial direction - with respect to the rotation axis R - continue on the rolling elements 6 to, even on the angle sensor 3 facing end side of the roller bearing 2 addition, as the inner re U-leg 14th

p0065Radially inside of the rolling bearing 2 facing end of the outer U-leg 12 is the scale 10, wherein between said components of 12,10 used for measuring angles magnetic circuit a variable, angle-dependent gap is formed. To measure the dependent of the gap width reluctance 22.23 different sine coil 22 and in Figure 4 is only indicated cosine coils 23 are provided as a receiving coil. There- when located on a single layer 27, that is on a single layer, the circuit board 24 either two coils 28 of the sine coil 22 or two turns 29 of the cosine coil 23, the coils 28 of the sine coil 22 against the windings 29 of the cosine coil 23 are twisted by 90 °. The angular fertilize 28 of the sine coil 22 and the turns 29 of the cosine coil 23 are alternately arranged on different layers 27, that is, to a layer 27 with turns 28 of the sine coil 22 is a further layer 27, with windings 29 of the cosine coil set 23, then again the sine coil 22. listening layer 27 and so on. Overall, the board sets 24 from 1 each layers together 27 of the sine coil 22 and the cosine coil 23rd

p0066The supplied from angle sensor 3 electrical signal is transmitted through a device connected to the coil 21, 22,23 cable 30 to a spatially separated from the angle sensor 3 control and evaluation 31st between The spatial separation see the angle sensor 3 and any electronic components is the rolling bearing assembly 1 including angle sensor 3 particularly for high operating temperatures, for example up to 155 ° C. The cable 30 is held on a fastening tab 31, the bends 19 of one of the shell core 11 projecting in the axial direction over the area of ​​the support ring inwardly.

p0067The embodiment of FIG. 5 is true with regard to the basic function of the rolling bearing assembly 1 including angle sensor 3 with the embodiment according to Figures 1 to 4 match. Differences between the two embodiments are given in particular in terms of mechanical connection of the angle sensor 3 to the roller bearing 2, the connection of the cable 30, and the shape of the material measure 10:

p0068The made of plastic, fixed to the outer ring 5 of the rolling bearing 2, the mounting of the sensor ring 9 serving retaining element 17 is in the embodiment of Fig. 5, extended lower compared to the embodiment according to Figures 1 to 4 in the axial direction relative to the rotation axis R and is adjacent to a front side of the circuit board 24. Similarly, the support ring 19 in the embodiment of FIG. 5 has a smaller axial extension of, whereby the rolling bearing assembly 1 _

p0069- Has a total space-saving built -. 13 This is made possible by an extremely narrow profile structure electrical and mechanical connection components:

p0070The U-base 13 of the shell core 11 tion with a project through a recess 33 of the support ring 19, radially outward, striped Kabelhalte- 34 integrally connected. At this cable holder 34 made of sheet metal, the cable 30, which is embodied in this case as a flexible circuit board attached. Within the U-shaped pot-type core 11, the printed circuit board, which merges integrally into the flat cable 30 reinforced by an additional, firmer layer. The metallic cable holder 34 has three functions, namely a strain relief, the angular adjustment of the sensor ring 9, and a potential equalization to ambient components. With regard to the angular position of the sensor ring 9, as for the function of the angle sensor 3, the angular relationship between the shell core 11 and a surrounding component, in particular motor housing of an electric motor, prevail.

p0071In addition to the outer support ring 19 on the outer ring 5 5 an inner, held on the inner ring 4 supporting ring is in the embodiment of Fig. 35, wherein both support rings 19,35 have the same axial extension and protrude slightly beyond the U-base 13 of the shell core 11 also , The inner support ring 35 allows, as well as the outer support ring 19, the transmission of axial forces by the rolling bearing assembly 1 and constitutes a mechanical protection of the angle sensor 3 and ensures the supply for improved sealing of the rolling bearing assembly first

p0072For optimized sealing also the geometry of the ring 10 serving as a measuring scale contributes which is visible in Fig. 5 in cross section. In Fig. 6 this ring, that is, the scale 10 of the angle sensor 3, shown in plan view. This is good, the double eccentric shape of the material measure 10 is visible: Both an inner contour 36 and an outer contour 37 of the scale 10 is formed eccentrically.

p0073The assembly of the rolling bearing assembly 1 of FIG. 5 for example, starts with the pressing of the shell core 11 in the annular circuit board 24. Subsequently, a non-magnetic spacer 38 is inserted into the pot core 11, which has the task of an exactly constant distance between the U- legs to provide 12.14. For the same purpose, in the completely assembled rolling bearing assembly 1, as shown in Fig. 5, radially outwardly of the shell core 11, between the Holding member 17 and the outer support ring 19, a spring element 39 is provided, which presses the outer U-leg 12 against the U-base 13 parallel spacer 38th

p0074In Figures 7 and 8 different variants respectively have a layer 27 of the sensor shown sorrings 9, which are suitable for both the embodiment of Figures 1 to 4 and for the embodiment of FIGS 5 and 6. FIG. While in the example of Figure 7, just as in the Example according to Fig. 4, only either two sine coils 22 or two cosine coils 23 are disposed on the layer 27, 8, the layer 27 of FIG. Four coils, namely two sine -Coils 22 and two cosine coils 23, with each of these receiving coils extends over approximately 90 ° 22.23. All Layer 27 of the circuit board 24 of Figure 8 are congruent, that is another without twisting, arranged. Through the arrangement, both of the sine coil and minus sine coil 22 and of coil cosine and minus-cosine-coils 23 on a single layer 27 is the number of layers 27 with identical number of turns 28,29 half as large as in the variant according to FIG. 7. in contrast to the variant according to FIG. 7 encloses according to FIG. 8 each turn 28,29 not two, but only one of the four slot-shaped openings 25 of the printed circuit board 24. with all embodiments are angular resolution of the order reachable from 1 °.

LIST OF REFERENCE NUMBERS

p00761 roller bearing assembly

p00772 Rolling

p00783 angle sensor

p00794 inner ring

p00805 outer ring

p00816 rolling elements

p00827 cage

p00838 sealing disc

p00849 sensor ring

p008510 Measuring standard

p00861 1 Schalenkem

p008712 outer U-legs

p008813 U-base

p008914 inner U-leg

p009015 career

p009116 sealing gap

p009217 retainer

p009318 circumferential groove

p009419 support ring

p009520 annulus

p009621 transmitter coil

p009722 receiving coil

p009823 receiving coil

24 PCB

p010025 opening

p010126 slot

p010227 layer

p010328 Swirl

p010429 Swirl

p010530 cable Control and evaluation unit

p0106fastening tab

p0107recess

p0108cable bracket

p0109support ring

p0110inner contour

p0111outer contour

p0112spacer

p0113Spring element ationsachse