Rolling element bearing

Abstract

A rolling element bearing, comprising an outer ring (3), an inner ring (4), rolling elements (7) accommodated between the outer ring (3) and the inner ring (4), an insulation layer (9) forming the inner circumference of the rolling element bearing (1), and a current supply device (12) which is provided on an axial side of the rolling element bearing (1) and which does not rotate when mounted, said current supply device (12) comprising an input connection (14) for a current supply; wherein the current supply device (12) is in contact with a current relay device (13) which does rotate in the assembly position, an outlet connection (15) being provided on said current relay device (13); wherein the current supply device (12) has a conductive ring (26) accommodated in a housing, said conductive ring having a inlet connection (14), and the current relay device (13) comprises a conductor (32) embedded in the insulation layer (9); wherein the conductive ring (26) is in contact with the conductor (32).

Description

[0001] rolling bearings

[0002] The invention relates to a rolling bearing.

[0003] Rolling bearings are used wherever two components need to be mounted so they can rotate relative to each other. One example is the mounting of the rotor of an electric machine, such as those found in electric axles in the automotive sector. These rolling bearings, which are usually ball bearings, can be designed to be electrically insulating or current-dissipating in such applications, as they are used in current-carrying or current-generating areas. In addition to mounting the rotor, if the electric machine is designed as a separately excited machine, a controlled current supply to the electrical windings on the rotor is required. For this purpose, a special, separate rotary feedthrough is typically provided, connecting stationary terminals on the housing to the rotating rotor shaft. This necessitates separate slip ring elements on the rotor shaft.

[0004] The invention is based on the problem of providing an improved rolling bearing.

[0005] To solve the problem, a rolling bearing is provided according to the invention, comprising an outer ring, an inner ring, rolling elements received between the outer ring and the inner ring, an insulating layer forming the inner circumference of the rolling bearing, and a current supply device provided on an axial side of the rolling bearing, which does not rotate in the mounting position and comprises an input connection for a current supply, wherein the current supply device is contacted with a current transmission device which rotates in the mounting position and on which an output connection is provided, wherein the current supply device has a guide ring received in a housing which has an input connection and the current transmission device comprises a conductor embedded in the insulating layer, wherein the guide ring is in contact with the conductor.The rolling bearing according to the invention is characterized, firstly, by the typical bearing components in the form of an outer ring, an inner ring, and rolling elements mounted between them, which roll on corresponding raceways. While the outer ring is fixedly mounted in a corresponding bearing seat on a housing, the inner ring sits on the rotor shaft and thus rotates with it. Additionally, the rolling bearing includes a device that allows current to be directed to the rotor via the rolling bearing itself in order to energize the windings there. For this purpose, the rolling bearing according to the invention includes a current supply device that does not rotate in the mounted position and has an input terminal to which a power source can be connected. Furthermore, a current distribution device is provided that is connected to the current supply device.While the current supply device is stationary, i.e., it does not rotate, the current distribution device is connected to the rotating part of the rolling bearing and therefore rotates with the rotor. This current distribution device has an output terminal that can be connected to a downstream winding on the rotor side. Consequently, a corresponding operating current can be supplied from an external source to the winding to be energized via the current supply device and the current distribution device, with this current supply occurring solely through the rolling bearing.

[0006] According to the invention, the current supply device has a guide ring, e.g., a simple sheet metal ring, which has an input terminal. Likewise, the current transmission device has an output terminal. This means that the rolling bearing enables integrated single-pole current transmission. To achieve this, the current supply device is designed with a guide ring that is in contact with the current transmission device. The current transmission device, in turn, comprises a conductor embedded in the insulating layer by which the rolling bearing is electrically insulated from the rotor shaft, and which has the output terminal or is in contact with one. Consequently, a conduction path is realized that is formed via the input terminal, the guide ring, the embedded conductor, and the output terminal.

[0007] The rolling bearing according to the invention is thus a multifunctional bearing designed as a compact unit. On the one hand, it provides the bearing function by which the rotor shaft can be rotatably supported in the housing, and on the other hand, it offers a current-carrying function, as it is equipped with a single-pole, i.e., simple, current-carrying function. With the installation of the rolling bearing according to the invention, both functionalities are available, so that no rotary feedthrough or any sliding contacts on the rotor shaft are required. To implement the second pole for winding current supply, a further bearing according to the invention is used in the installation position to support the rotor shaft.

[0008] The guide ring is advantageously contacted with the conductor via a sliding contact. In the rolling bearing according to the invention, the contact plane is implemented as a sliding contact plane, which is, however, integrated into the rolling bearing. Preferably, a sliding contact disc is provided as part of the current supply device to implement the sliding contact, with the guide ring bearing axially against the sliding contact disc. Thus, a package consisting of the guide ring and the sliding contact disc is provided, which is part of the current supply device. The sliding contact disc preferably has a radial sliding contact section via which it is contacted with a radial contact section of the conductor. This radial sliding contact enables simple assembly of the current supply device, since the radial sliding contact to the inner ring is automatically formed when the corresponding sliding contact disc is arranged axially.

[0009] The sliding contact disc is preferably made of carbon, sometimes also called a carbon disc, which is a disc consisting of carbon fibers or a carbon fiber mesh, possibly impregnated with plastic. This sliding contact disc allows for a correspondingly high current-carrying sliding contact that is extremely wear-resistant. However, the sliding contact disc can also be made of other conductive materials, such as copper.

[0010] To contact the sliding contact disc with the conductor, the conductor is advantageously connected to a contact ring embedded in the insulating layer, with the sliding contact disc being in contact with the contact ring. The contact ring thus forms a continuous contact section to which the conductor is locally connected, resulting in a permanent sliding contact. Preferably, the sliding contact disc is contacted to the contact ring via a radial sliding contact section.

[0011] As described, the conductor embedded in the insulating layer provided on the inner circumference of the inner ring is a central element. The insulating layer provides electrical insulation of the rolling bearing from the rotor shaft. It is made of a suitable insulating material, usually a plastic. According to the invention, the conductor is embedded in this insulating layer in such a way that it is also electrically insulated relative to the inner ring, meaning there is no contact between the conductor and the inner ring. The conductor itself can be a simple metal conductor, particularly made of steel or copper, but it can also be made of a conductive composite or fiber-reinforced composite material.

[0012] To accommodate the corresponding components of the current supply device that serve the current conductor, the current supply device preferably has an annular housing with an annular receiving chamber in which the guide ring and, if applicable, the sliding contact disc are received. This annular housing encapsulates and protects the ring or disc assembly. The housing can also simultaneously provide the possibility of axial contacting the ring or disc assembly, i.e., that the corresponding components are axially clamped within the housing.

[0013] The housing itself can advantageously include an axially end connecting disc, via which the current supply device is connected to the outer ring, and another axially end angled disc, which is connected to the connecting disc via a cylindrical connecting section, so that the receiving space is formed between the connecting disc and the angled disc. The housing is thus designed in only two parts, comprising the connecting disc and the angled disc. The connecting disc links the housing to the outer ring, so that the housing is firmly connected to this positionally fixed part of the bearing section of the rolling bearing. The angled disc completes the housing.It is connected to the connecting disc via a cylindrical connecting section on the angled disc. This section, for example, has several openings in the connecting disc with corresponding fingers that are crimped behind the connecting disc. The annular receiving space is defined between the connecting disc and the angled disc, in which the guide ring and, if applicable, the sliding contact disc are located. The housing design is therefore very simple, as is its assembly and connection to the outer ring.

[0014] The receiving space preferably contains insulating discs that insulate the conductor and the sliding contact disc from the connecting disc and the angled disc. These insulating discs thus provide axial insulation to the connecting disc and the angled disc if they are made of metal. This results in a multi-part ring or disc assembly, for example, consisting of two end insulating discs between which the conductor and the sliding contact disc are mounted. The insulating discs themselves are, of course, made of a suitable electrically insulating material, in particular a plastic.

[0015] To attach the housing to the bearing section, the housing's connecting washer can be provided with an annular fastening section that engages in an annular groove on the outer ring. This achieves a simple, positive-locking connection, requiring only the fastening section to snap into the annular groove.

[0016] The invention is explained below with reference to exemplary embodiments and the drawing. The drawing is a schematic representation.

[0017] The figure shows a schematic representation of a rolling bearing according to the invention in a sectional view.

[0018] The figure shows a schematic representation of a rolling bearing according to the invention 1.

[0019] The rolling bearing 1 according to the invention has, firstly, the actual bearing section.

[0020] 2, which is formed by an outer ring 3, an inner ring 4, and, between them, rolling elements 7 in the form of balls that roll on raceways 5, 6. The rolling bearing 1 is arranged in a bearing seat of a housing via its outer circumference 8, in which the rolling bearing 1, or rather the outer ring 3, is received. The inner ring 4 is equipped with an insulating layer 9, by which it is electrically insulated from a rotor shaft 10 (shown here only symbolically), on which it sits.

[0021] The rolling bearing 1 further comprises a current conducting device 11, comprising a current supply device 12 and a current distribution device 13. The current supply device 12 is equipped with an input terminal 14. The current distribution device 13 is provided with an output terminal 15. While the input terminal 14 is fixed in position because the current supply device 12 as a whole is fixed in position, the output terminal 15 is rotatable because it is located on the rotating part of the rolling bearing 1 and is to be connected to windings of the rotor (not shown).

[0022] The power supply device 12 comprises a housing 16, including an axially terminal connecting disc 17, which is connected to the outer ring 3 via a mounting section 18. The outer ring 3 has an annular groove 19 into which the mounting section 18 engages. Furthermore, the housing 16 has an angled disc 20, which displays a cylindrical connecting section 21. This connecting section has corresponding retaining fingers 22 that extend through axial openings in the connecting disc 17, the retaining fingers 22 being bent behind the connecting disc 17. A radial recess 23 is provided in the cylindrical connecting section 21, through which a contact, on which the input terminal 14 is arranged, is guided. This will be discussed in more detail below.

[0023] Inside the housing, a receiving chamber 25 is formed in which a ring or disc assembly is arranged. This assembly comprises a guide ring 26, which is designed as a simple metal sheet ring. The guide ring 26 extends through the recesses 23 with a contact section 27, and the input terminal 14 is arranged on the contact section 27. A sliding contact disc 28 is axially adjacent to the guide ring 26. This disc is preferably a carbon fiber disc or carbon round, which has a radial sliding contact 29 formed on its inner circumference. The sliding contact disc 28 is in electrical contact with the guide ring 26, and the current supplied via the input terminal 14 is transmitted through it to the rotating part of the current conduction device 11 or the current distribution device 13.

[0024] Furthermore, two insulating washers 30, 31 are provided, by which the guide ring 26 and the sliding contact disc 28 are insulated from the connecting disc 17 and the angle disc 20, respectively. This results in a corresponding ring or disc assembly, which is axially clamped inside the receiving space 25, the axial clamping being provided by the corresponding connection of the angle disc 20 to the connecting disc 17.

[0025] The current transmission device 13 comprises a conductor 32 embedded in the insulation layer 9, which is connected to a contact ring 33 also embedded in the insulation layer 9. The sliding contact section 29 rests against the contact ring 33. At the other end, the conductor 32 extends from the insulation layer 9 and is connected to the output terminal 15. The conductor 32 is electrically insulated from both the rotor shaft 10 and the inner ring 4 via the insulation layer 9.

[0026] The rolling bearing according to the invention is therefore equipped with both a bearing section 2 serving as a rotary bearing and a single-pole current-conducting device 11 serving as a current-conducting device. This current-conducting device 11 has an insulated conductor path formed via the input terminal 14, the guide ring 26, the sliding contact disc 28, the contact ring 33, the embedded conductor 32, and the output terminal 15. Since the current-input device 12 is positionally fixed, as it is connected to the positionally fixed outer ring 3 via its housing 16, and since the current-conducting device 13 is coupled to the rotating part of the rolling bearing 1, i.e., the inner ring 4, but an electrical sliding contact is provided between the two, the current can be supplied directly to the rotor shaft or the windings provided therein via the rolling bearing 1 itself. List of reference symbols

[0027] Rolling bearing Bearing section Outer ring Bearing section Raceway

[0028] career

[0029] rolling elements

[0030] External circumference

[0031] Insulation layer

[0032] Rotor shaft

[0033] Current conduction device

[0034] Power supply device, power distribution device, input connection

[0035] Output connector housing

[0036] Connecting disc

[0037] Fastening section

[0038] Ring groove

[0039] Angle disc

[0040] Connection section

[0041] Holding finger

[0042] Exclusion

[0043] Recording room

[0044] Line

[0045] Contact section

[0046] Grinding contact disc

[0047] Sliding contact section

[0048] Insulating glass

[0049] Insulating glass

[0050] Director

[0051] Contact ring

Claims

Patent claims 1. Rolling bearing comprising an outer ring (3), an inner ring (4), rolling elements (7) received between the outer ring (3) and the inner ring (4), an insulating layer (9) forming the inner circumference of the rolling bearing (1), and a current supply device (12) provided on an axial side of the rolling bearing (1), which does not rotate in the mounting position and comprises an input terminal (14) for a current supply, wherein the current supply device (12) is contacted with a current transfer device (13) which rotates in the mounting position and on which an output terminal (15) is provided, wherein the current supply device (12) comprises a guide ring (26) received in a housing (16) which has an input terminal (14), and the current transfer device (13) comprises a conductor (32) embedded in the insulating layer (9), wherein the guide ring (26) is in contact with the conductor (32).

2. Rolling bearing according to claim 1, characterized in that the guide ring (26) is contacted with the conductor (32) via a sliding contact.

3. Rolling bearing according to claim 2, characterized in that the current supply device (12) has a sliding contact disc (28), wherein the guide ring (26) rests axially against the sliding contact disc (28).

4. Rolling bearing according to claim 3, characterized in that the grinding contact disc (28) is a carbon disc.

5. Rolling bearing according to claim 3 or 4, characterized in that the sliding contact disc (28) is contacted with the conductor (4) via a radial sliding contact section (29).

6. Rolling bearing according to claim 5, characterized in that a contact ring contacted with the conductor (32) is embedded in the insulation layer (9), against which the sliding contact section rests.

7. Rolling bearing according to one of the preceding claims, characterized in that the housing (16) is annular and has an annular receiving space (25) in which the line (26) and optionally the sliding contact disc (28) are received.

8. Rolling bearing according to claim 7, characterized in that the housing (16) is formed via an axially terminal connecting disk (17) via which the current supply device (12) is connected to the outer ring (3), and a further axially terminal angle disk (20) which is connected to the connecting disk (17) via a cylindrical connecting section (21) so that the receiving space (25) is formed between the connecting disk (17) and the angle disk (20).

9. Rolling bearing according to claim 8, characterized in that insulating discs (30, 31) are received in the receiving space (25), by means of which the guide ring (26) and the sliding contact disc are insulated from the connecting disc (17) and the angle disc (20).

10. Rolling bearing according to claim 8 or 9, characterized in that the connecting disc (18) has an annular fastening section (19) which engages in an annular groove (20) provided on the outer ring (3).

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