Anti-friction bearing

Abstract

The invention relates to an anti-friction bearing, comprising an outer ring (3), an inner ring (4), rolling bodies (7) accommodated between the outer ring (3) and the inner ring (4), an insulation layer (9) forming the inner circumference of the anti-friction bearing (1), and a current supply device (12) which does not rotate in the mounted position, is provided on an axial side of the anti-friction bearing (1) and comprises at least one input connection (14, 15) for a current supply, the current supply device (12) making contact with a current transporting device (13) which rotates in the mounted position and on which at least one output connection (16, 17) is provided, the current supply device (12) having two conducting rings (28, 29) which are insulated with respect to one another and each have an input connection (14, 15), and the current transporting device (13) comprising two conductors (39, 40) which are embedded into the insulation layer (9) and each have an output connection (16, 17), each conducting ring (28, 29) making contact with a conductor (39, 40).

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 at least one 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 at least one output connection is provided, wherein the current supply device has two mutually insulated guide rings, each with an input connection, and the current transmission device comprises two conductors embedded in the insulating layer, each with an output connection, wherein each guide ring is contacted with a 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 at least one input terminal to which a current source can be connected. Furthermore, a current distribution device is provided that is contacted with the current supply device.While the current supply device is stationary and 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 at least one 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 two mutually insulated conductor rings, e.g., two simple sheet metal rings, each with an input terminal. Similarly, the current transmission device has two output terminals. This means that the rolling bearing enables integrated two-pole current transmission. To achieve this, the current supply device is designed with two mutually insulated conductor rings, each of which is separately contacted with the current transmission device. The current transmission device, in turn, comprises two separate conductors embedded in the insulating layer that electrically insulates the rolling bearing from the rotor shaft, each of which has one of the output terminals or is contacted with one of them. One conductor ring is contacted with one conductor, and the other conductor ring is contacted with the other conductor.Accordingly, two separate guide paths are implemented: one via the first input terminal, the first guide disk, the first embedded conductor and the first output terminal, and the other guide via the second input terminal, the second guide disk, the second embedded conductor and the second 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 2-pole current-carrying function. With the installation of the rolling bearing according to the invention, both functionalities are therefore available, so that no rotary feedthrough or any sliding contacts on the rotor shaft are required.

[0008] The guide rings are advantageously each contacted with a 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, two sliding contact discs are provided as part of the current supply device for the sliding contacts, with one conductor bearing axially against one sliding contact disc and the other conductor bearing axially against the other sliding contact disc. Thus, a package consisting of the two conductors and the corresponding sliding contact discs is provided, which is part of the current supply device. The sliding contact discs preferably have radial sliding contact sections via which they are contacted with radial contact sections of the conductors.These radial sliding contacts enable easy assembly of the power supply device, since the radial sliding contact to the conductors is automatically achieved when the corresponding sliding contact discs are arranged axially.

[0009] The sliding contact discs are preferably made of carbon discs, sometimes also called carbon discs, which are discs consisting of carbon fibers or a carbon fiber mesh, possibly impregnated with plastic. These sliding contact discs allow for a correspondingly high current-carrying sliding contact that is extremely wear-resistant. In principle, however, the sliding contact discs can also be made of other conductive materials, such as copper. To connect the two sliding contact discs to the two conductors, each conductor is advantageously connected to a contact ring embedded in the insulating layer, with each sliding contact disc being contacted by a contact ring. The contact rings thus form continuous contact sections to which the individual conductors are locally connected, ensuring a permanent sliding contact.Preferably, each sliding contact disc is contacted via a radial sliding contact section to a contact ring.

[0010] Preferably, the current supply device includes at least one insulating washer by which the conductor rings are insulated from each other. Since a pole is defined via each conductor ring, the two conductor rings are advantageously insulated from each other, for which purpose an insulating washer is provided, which is arranged axially between them. This insulating washer provides electrical insulation, while at the same time allowing the ring or washer assembly to be arranged and designed in a very compact axial manner.

[0011] To accommodate the corresponding components of the current supply device that serve the current transmission, the current supply device preferably has an annular housing with an annular receiving chamber in which the guide discs and, optionally, the sliding contact discs and the insulating 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.

[0012] 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 by means of a cylindrical connecting section on the angled disc. This section, for example, extends through several openings in the connecting disc with corresponding fingers that are crimped behind the connecting disc. Between the connecting disc and the angled disc, an annular receiving space is defined, in which the two guide rings and, if provided, the sliding contact discs as well as at least one insulating disc are located. The housing design is therefore very simple, as is its assembly and connection to the outer ring.

[0013] The receiving space preferably contains additional insulating discs that insulate the guide rings from the connecting disc and the angled disc. These additional insulating discs 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, followed by two sliding contact discs, followed by the two guide rings, and finally an insulating disc positioned between them. Of course, a package of several separate or, for example, bonded insulating discs can also be provided, depending on the available axial installation space and / or the thickness of the insulating disc. The insulating discs themselves are, of course, made of a suitable electrically insulating material, in particular a plastic.

[0014] As described, the two conductors embedded in the insulating layer provided on the inner circumference of the inner ring are 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 two conductors are embedded in this insulating layer in such a way that they are also electrically insulated relative to the inner ring, meaning there is no contact between the conductors and the inner ring. The conductors themselves are advantageously simple metal conductors, particularly made of steel or copper, but also of a conductive composite or fiber-reinforced composite material. As described, each conductor is connected to a corresponding output terminal. To simplify this, a protruding terminal section can be provided at each conductor end, where the electrical contact of the windings takes place.Both the input and output connections are designed, for example, as protruding flags or similar.

[0015] As described, two input terminals and two output terminals are provided. These two terminals can be arranged at different angular positions relative to each other. The terminals can be aligned axially, or they can be offset by a rotational angle. For example, a rotational angle of 180° is advantageous, meaning that one input terminal and one output terminal are at 0°, and the other input terminal and one output terminal are at 180°. This is merely an example; of course, any other rotational angle is conceivable. A corresponding angular offset inevitably leads to a shifted embedding of the conductors within the insulation layer.

[0016] The invention is explained below with reference to exemplary embodiments and the drawings. The drawings are schematic representations and show:

[0017] Figure 1 shows a schematic representation of a rolling bearing according to the invention in a sectional view, and

[0018] Figure 2 shows an enlarged partial view of the rolling bearing from Figure 1.

[0019] Figures 1 and 2 each show a schematic representation of a rolling bearing 1 according to the invention, with Figure 2 showing an enlarged partial view of the upper rolling bearing part shown in Figure 1, from which the structure can be seen in more detail. The rolling bearing 1 according to the invention comprises, firstly, the actual bearing section 2, which is formed by an outer ring 3, an inner ring 4, and rolling elements 7 in the form of balls rolling on raceways 5, 6 between them. The rolling bearing 1 is arranged in a bearing seat of a housing via the outer circumference 8 of the outer ring 3, in which the rolling bearing 1, or rather the outer ring 3, is received. The inner ring 4 is equipped on its inner circumference with an insulating layer 9, by means of which it is electrically insulated from a rotor shaft 10, shown here only symbolically, on which it sits.

[0020] The rolling bearing 1 further comprises a current conducting device 11, which includes a current supply device 12 and a current distribution device 13. The current supply device 12 is equipped with two input terminals 14, 15, which in the example shown are arranged offset from each other by 180°. Likewise, the current distribution device 13 is provided with two output terminals 16, 17, which are also arranged offset from each other by 180°. While the input terminals 14, 15 are fixed in position because the current supply device 12 as a whole is fixed in position, the two output terminals 16, 17 are rotatable because they are located on the rotating part of the rolling bearing 1 and are to be connected to windings of the rotor (not shown in detail).

[0021] The current supply device 12 and the current distribution device 13 are shown in detail in Figure 2. The current supply device 12 comprises a housing 18, including an axially terminal connecting disk 19, which is connected to the outer ring 3 via a mounting section 20. The outer ring 3 has an annular groove 21 into which the mounting section 20 engages. Furthermore, the housing 18 has an angled disk 22, which displays a cylindrical connecting section 23. This connecting section has corresponding retaining fingers 24 that extend through axial openings in the connecting disk 19, with the retaining fingers 24 being bent behind the connecting disk, as shown in Figure 2. Two radial recesses 25, 26 (see Figure 1) are provided in the cylindrical connecting section 23, through which respective contacts, on which the input terminals 14, 15 are arranged, are guided. These will be discussed in more detail below.Inside the housing, a receiving chamber 27 is formed in which a ring or disk assembly is arranged. This assembly comprises two guide rings 28, 29, each designed as a simple sheet metal ring. Guide ring 28 extends through the recesses 25 with a contact section 30, and the input terminal 14 is located on the contact section 30. The second guide ring 29 extends through the recess 26 with a contact section 31, and the input terminal 15 is located on it.

[0022] Furthermore, a first insulating washer 32 is provided, which is arranged axially between the two conducting rings 28, 29. Instead of just one sufficiently thick insulating washer 32, several thin insulating washers can also be provided, as long as the electrical insulation of the two conducting rings 28, 29 is ensured.

[0023] Each guide ring 28, 29 is axially adjacent to a sliding contact disc 33, 34, which are preferably carbon fiber discs or carbon discs, respectively, each having a radial sliding contact 35, 36 formed on its inner circumference. The sliding contact discs 33, 34 are in electrical contact with the two guide rings 28, 29, and the current supplied via the input terminals 14, 15 is transmitted via them to the rotating part of the current conduction device 11 or the current distribution device 13.

[0024] Furthermore, two additional insulating washers 37, 38 are provided, which insulate the two sliding contact washers 33, 34 from the connecting washer 19 and the angle washer 22, respectively. This results in a corresponding ring or washer assembly, which is axially clamped inside the receiving space 27, the axial clamping being provided by the corresponding connection of the angle washer 22 to the connecting washer 19.

[0025] The current conduction device 13 comprises two conductors 39, 40 embedded in the insulation layer 9, each having an output terminal 16, 17. The first conductor 39 is connected to output terminal 16 and the second conductor 40 to the second output terminal 17, see Fig. 1. In the example shown, the two conductors are embedded offset from each other by 180°, so that the output terminals 16, 17 are also offset accordingly. They are electrically insulated from each other, from the inner ring 4, and from the rotor shaft 10 via the insulation layer 9.

[0026] At the other two ends of conductors 39, 40, also embedded in the insulation layer 9, a contact ring 41, 42 is provided, with contact ring 41 being connected to the first conductor 39 and contact ring 42 to the second conductor 42. Both contact rings 41, 42 are exposed so that the sliding contacts 35, 36 can rest against them. Sliding contact 35 rests against contact ring 414 and sliding contact 36 rests against contact ring 42.

[0027] The rolling bearing according to the invention is therefore equipped with both a bearing section 2 serving as a rotary bearing and a two-pole current-conducting device 11 serving as a current-conducting device. This current-conducting device 11 has two mutually insulated conductor paths, the first conductor path being formed via the input terminal 14, the guide ring 28, the sliding contact disc 33, the contact ring 41, the first conductor 39, and the output terminal 16. The second conductor path is formed via the input terminal 15, the guide ring 29, the sliding contact disc 34, the contact ring 42, the second conductor 40, and the output contact 17. Both conductor paths are completely insulated from each other.Since the current supply device 12 is fixed in position, as it is connected to the fixed outer ring 3 via its housing 18, and since the current transmission device 13 is coupled to the rotating part of the rolling bearing 1, i.e., the inner ring 4, but an electrical sliding contact exists between the two, the current supply to the rotor shaft or the windings provided therein can therefore take place directly via the rolling bearing 1 itself. By mounting only one such rolling bearing 1, two winding blocks can therefore be energized separately, since the rolling bearing is designed for 2-pole current conduction. (See list of reference symbols.)

[0028] Rolling bearing Bearing section Outer ring Inner ring

[0029] career

[0030] career

[0031] rolling elements

[0032] Outer circumference, insulation layer, rotor shaft, current conductor

[0033] Power supply device, power distribution device, input connection, input connection

[0034] Output connection

[0035] Output connector housing

[0036] Connecting washer, fastening section, ring groove

[0037] Angle disc

[0038] Connection section

[0039] Holding finger

[0040] Exclusion

[0041] Exclusion

[0042] Recording room

[0043] Line

[0044] Line

[0045] Contact section

[0046] Contact section insulating washer

[0047] Grinding contact disc

[0048] Grinding contact disc

[0049] Sliding contact

[0050] Sliding contact

[0051] Insulating glass

[0052] Insulating glass

[0053] Director

[0054] Director

[0055] Contact ring

[0056] 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 at least one input connection (14, 15) for a current supply, wherein the current supply device (12) is contacted with a current transmission device (13) which rotates in the mounting position and on which at least one output connection (16, 17) is provided, wherein the current supply device (12) has two mutually insulated guide rings (28, 29) each with an input connection (14, 15) and the current transmission device (13) has two conductors (39, 40) embedded in the insulating layer (9) each with an output connection (16, 17). 17) comprises, wherein a guide ring (28, 29) is contacted with a conductor (39, 40).

2. Rolling bearing according to claim 1, characterized in that each guide ring (28, 29) is contacted via a sliding contact with a conductor (39, 40).

3. Rolling bearing according to claim 2, characterized in that the current supply device (12) has two sliding contact discs (33, 34), wherein one guide ring (28, 29) rests axially against one sliding contact disc (33, 34) and the other guide ring (28, 29) rests against the other sliding contact disc (33, 34).

4. Rolling bearing according to claim 3, characterized in that the grinding contact discs (33, 34) are carbon discs.

5. Rolling bearing according to claim 3 or 4, characterized in that each conductor (39, 40) is connected to a contact ring (41, 42) embedded in the insulating layer (9), wherein a sliding contact disc (33, 34) is contacted with a contact ring (41, 42).

6. Rolling bearing according to claim 5, characterized in that each grinding contact disc (33, 34) is contacted via a radial grinding contact section (35, 36) on a contact ring (41, 42).

7. Rolling bearing according to one of the preceding claims, characterized in that the current supply device (12) has at least one insulating disk (32) by which the guide rings (28, 29) are insulated from each other.

8. Rolling bearing according to one of the preceding claims, characterized in that the current supply device (12) has an annular housing (18) with an annular receiving space (27) in which the guide rings (28, 29) and optionally the sliding contact discs (33, 34) and the insulating disc (32) are received.

9. Rolling bearing according to claim 8, characterized in that the housing (18) is formed via an axially terminal connecting disk (19), via which the current supply device (12) is connected to the outer ring (3), and a further axially terminal angle disk (22), which is connected to the connecting disk (19) via a cylindrical connecting section (23), so that the receiving space (27) is formed between the connecting disk (19) and the angle disk (22).

10. Rolling bearing according to claim 9, characterized in that further insulating discs (37, 38) are received in the receiving space (27), via which the guide rings (28, 29) are insulated from the connecting disc (19) and the angle disc (22).

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