DE102019133881B4 - Bearing unit with integrated clamping sleeve for an electric drive assembly and drive assembly with the bearing unit - Google Patents

Abstract

Bearing unit (300) for an electric drive arrangement (1) with a bearing device (110) for supporting a shaft (4), the bearing device (110) having a first bearing ring (111) and a second bearing ring (112), with between the two bearing rings (111, 112) at least one row of rolling bodies (113) is arranged in a rolling manner, with a discharge device (200) for dissipating an electrical charge and/or voltage from a rotor (6) of an electric motor (3) via the shaft (4) and one of the bearing rings (111, 112) as a first diverting partner (P1) to the other bearing ring (111, 112) as a second diverting partner (P2), the diverting device (200) having a supporting body device (210) for electrical and mechanical connection with one of the diverting partners (P1, P2) and a contact device (220) for the electrical connection to the other of the diverting partners (P1, P2),the supporting body device (210) is designed as a clamping sleeve which is radially outward on d em a bearing ring (111, 112) is arranged in order to electrically and mechanically connect the contact device (220) to the bearing ring (111, 112) via a clamp assembly, characterized in that a connection section (221) of the contact device (220) in the axial is held positively and/or non-positively between a collar-shaped support section (211) of the support body device (210) and the bearing ring (111, 112), the support section (211) for the electrical and mechanical connection of the contact device (220) to the one bearing ring ( 111, 112) is provided and the connection section (221) of the contact device (220) is pressed via the support section (211) to form the clamping connection on the front side against a fastening section (114, 115) of the bearing ring (111, 112), the fastening section (114, 115) is formed on an axial end face of the bearing ring (111, 112) and that the supporting body device (210) has a connecting section (212) for electrically and mechanically fixing the support body device (210) on an axial end face of the bearing ring (111, 112), which directly adjoins the support section (211).

Description

The invention relates to a bearing unit for supporting a shaft of an electric drive arrangement with the features of claim 1. The invention also relates to an electric drive arrangement with the bearing unit.

In electric vehicles or hybrid vehicles, an electric machine is used as a traction motor. While the electrical machine seems to work with little or no wear and, in particular, very few problems when viewed superficially, problems arise on closer inspection that can be attributed to the way the electrical machines work. It is known that a voltage and/or charge is induced in the rotor of the electrical machine, so that a potential difference of several 100 V can build up between the rotor and a housing.

The rotor is usually designed in one piece with a rotor shaft or is mechanically connected, and there is also electrical contact between the rotor and the rotor shaft, so that the potential difference is present between the rotor shaft and the housing at the same time. The rotor shaft is usually mounted relative to the housing via a rotor bearing or rotor shaft bearing. Due to the potential difference, discharges occur between the rolling elements and the rolling element tracks in the rotor shaft bearings, damaging the rolling element tracks.

the U.S. 10,190,640 B2 shows an electric drive arrangement. The bearing device for supporting the rotor shaft of an electrical machine is formed from two roller bearings. A mechanical diverting device is arranged between the bearing rings of one of the rolling bearings, via which the potential differences around the rolling contact of the rolling elements are diverted. The diverting device consists of a supporting body which is fixed to the outer ring and of several elastic rods attached to the supporting body. The bars are elastically prestressed against the inner ring so that there is an electrically conductive bridge with low electrical resistance.

Are known for example from the GB 990 354 A also arrangements in which conductive fabric materials are carried by the supporting body in the manner of rubbing seals and rest rubbing against one of the bearing rings.

The document WO 2018/177 461 A1 discloses a roller bearing for supporting a drive shaft in an electric motor, wherein a carbon fiber composite component is attached to one of the bearing rings and is electrically connected to the other bearing ring. The carbon fiber composite component creates an electrically conductive connection between the drive shaft and a stationary surrounding structure via the bearing rings, so that the potential difference can be reduced.

From the DE 10 2014 204 719 A1 a ball bearing with an electrically conductive seal emerges. The seal has a supporting body on which both the sealing elements and the conductive material are carried. The supporting body is snapped into a groove in the outer ring. An outer seal is a gap seal that delimits a sealing gap to the inner ring. The inner seal is a rubbing seal and, like conductive fibers, rubs against the inner ring.

JP 2008 - 286 229 A shows a bearing device designed as a ball bearing of the type for bearing a shaft. Between the inner ring and the outer ring of the ball bearing, a discharge device is arranged in the manner of a sealing plate, which is formed from two clamping plates. The interconnected clamping plates are fixed to the outer ring and bridge the gap between the inner and outer ring. Conductive fibers are clamped between the clamping plates, which are in sliding contact with the inner ring and thus create an electrically conductive connection between the inner ring and the outer ring.

Another storage unit is with the JP 2018 - 168 967 A disclosed. Between the inner ring and the outer ring of the ball bearing, there is a discharge device whose support body can be arranged either on one of the bearing rings, ie either on the inner ring or on the outer ring. Electrically conductive fibers protrude from the electrically conductive support body and then rub against the other of the bearing rings.

The invention is based on the object of creating a storage unit with the discharge device, which is characterized by simple assembly and a compact structure. This object is achieved by a bearing unit having the features of claim 1 and a drive assembly having the features of claim 10. Preferred or advantageous embodiments of the invention result from the dependent claims, the following description and the attached figures.

The invention relates to a bearing unit which is designed and/or suitable for an electric drive arrangement. The drive arrangement is preferably designed and/or suitable for a vehicle. The vehicle is preferred designed as a passenger car, bus or truck. In alternative configurations, the vehicle can also be designed as a bicycle, motorcycle, e-scooter and/or one-track or two-track and/or one-axle or two-axle. The vehicle is designed as an electric vehicle, in particular as a purely electric vehicle or as a hybrid vehicle.

The electric drive arrangement serves in particular to create and/or provide a traction torque, in particular a main traction torque, for the vehicle. The electric drive arrangement can be coupled or is coupled to an energy device, in particular to an energy storage device, in particular to a battery or accumulator, in order to obtain energy for generating the traction torque.

The electric drive assembly includes an electric motor section. An electric motor, also referred to as an electric machine, is arranged in the electric motor section. The electric motor is preferably designed as an asynchronous electric motor. Preferably, the electric motor defines a main axis. The electric motor has a stator and a rotor, which are arranged concentrically and/or coaxially with one another. Furthermore, the electric motor section has a shaft, the shaft being geared to the rotor. In particular, the shaft is driven via and/or by the rotor. The shaft is particularly preferably designed as a rotor shaft. In particular in the configuration as a rotor shaft, this can be connected to the rotor in a rotationally fixed, rigid and/or integral manner. Furthermore, it is provided that the shaft is electrically connected to the rotor. This means that if there is a potential difference between the rotor and a surrounding structure, the same potential difference will exist between the shaft and the surrounding structure.

The electric drive arrangement has a transmission section, with a transmission device being arranged in the transmission section. The transmission device can be designed as a clutch device and/or as a shifting device and/or as a transmission device. The shaft is connected to the transmission device in terms of transmission technology, in particular the shaft forms an input shaft into the transmission device.

The bearing unit has a bearing device, which is used for, in particular rotatable, bearing of the shaft. The bearing device has a first and a second bearing ring, with at least or precisely one row of rolling elements being arranged in a rolling manner between the two bearing rings. In particular, one bearing ring is designed as a bearing groove ring, via which the bearing device is supported on the shaft. In particular, the other bearing ring is designed as an outer bearing ring, via which the bearing device is supported on the surrounding structure. The two bearing rings each have a raceway for the rolling elements. The bearing unit is thus designed as a roller bearing, for example as a ball or roller bearing.

Furthermore, the storage unit has a diverting device. The diverting device has the function of diverting an electrical charge and/or electrical voltage from the rotor via the shaft and one of the bearing rings, in particular the bearing inner ring, with the bearing ring forming a first diverting partner. The derivation takes place to a second derivation partner, which is formed by the other bearing ring, in particular the bearing outer ring. The second diverting partner is arranged in particular in a stationary manner on the surrounding structure or a housing section or a component which is electrically conductively connected to the housing section or the surrounding structure. In particular, the surrounding structure or the housing section is connected to ground and/or grounded. In particular, the diverting device forms an electrical connection between the first diverting partner and the second diverting partner. In particular, there is a permanent electrical connection between the discharge partners, which is present both stationary and dynamic, ie during operation of the electrical drive arrangement.

The diverting device has a supporting body device, which is used for the mechanical connection to one of the diverting partners, in particular so that the diverting device is fixed directly or indirectly to this diverting partner. Furthermore, the supporting body device is used for the electrical connection to this diverting partner. The mechanical and electrical connection can coincide, but these can also be implemented side by side or in parallel with one another. Furthermore, the diverting device has a contact device for the electrical connection to the other of the diverting partners. The contact device can, for example, be electrically connected directly to the other diverting partner and preferably indirectly connected to the first-mentioned diverting partner via the supporting body device. Alternatively, however, the contact device can also be electrically connected to the other conductor partner indirectly, e.g. via an electrically conductive intermediate component arranged on one of the bearing rings.

It is envisaged that the discharge device for bridging an annular gap between one and the other derivative partner is formed. The discharge device preferably has the shape of a circular ring, with the inside diameter and the outside diameter being adapted to or corresponding to the inside diameter and outside diameter of the respective discharge partner. The discharge device is preferably designed to be continuous in the direction of rotation around the main axis.

According to the invention, it is provided that a connection section of the contact device is held in the axial direction in a positive and/or non-positive manner between a collar-shaped support section of the support body device and the bearing ring. The support section is provided for the electrical and mechanical connection of the contact device to one bearing ring. In this case, the connection section of the contact device is pressed onto a fastening section of the bearing ring on the face side via the support section to form the clamping connection. The fastening section is formed on an axial end face of the bearing ring. The support body device has a connecting section for electrically and mechanically fixing the support body device on an axial end face of the bearing ring, which connects directly to the support section. The support body device is designed as a clamping sleeve. In particular, the clamping sleeve is designed as a rotationally symmetrical hollow body. The clamping sleeve is preferably designed as a separate component which is and/or can be connected in a rotationally fixed manner to one of the conductor partners. For this purpose, the clamping sleeve is clamped radially on the outside to one of the bearing rings in order to electrically and mechanically connect the contact device to the bearing ring via a clamping assembly. Thus, the discharge device and the storage device form a common assembly as the storage unit. In particular, the contact device is captively held on one of the bearing rings via the clamping assembly. In principle, the clamping sleeve can be connected to the bearing inner ring and can thus be carried along by the shaft in the direction of rotation when the electric motor is in operation. However, the clamping sleeve is preferably connected to the bearing outer ring and thus remains stationary when the electric motor is in operation. The clamping sleeve is preferably connected to the corresponding bearing ring in a form-fitting and/or force-fitting manner in the radial and/or axial direction. For example, the clamping sleeve is pressed onto the bearing outer ring radially on the outside.

The advantage of the invention is, in particular, that the clamping sleeve makes it possible to mount the contact device on one of the bearing rings in a particularly simple manner. Due to the clamping sleeve, the discharge device can thus be mounted on or removed from the storage device particularly quickly. For example, the diverting device can be pre-installed on the bearing device via the clamping sleeve, so that the bearing unit can be installed in the drive arrangement as a pre-assembled assembly. In addition, a diverting device is proposed which is characterized by a small number of components, so that the diverting device can be manufactured simply and inexpensively.

In a preferred embodiment of the invention, it is provided that the supporting body device has a sleeve-shaped connecting section which is designed and/or suitable for the electrical and mechanical connection of the supporting body device to the one bearing ring. In particular, the sleeve-like connecting section is designed in the form of a cylinder sleeve. In addition, the support body device designed as a clamping sleeve has a collar-shaped support section which is designed and/or suitable for the electrical and mechanical connection of the contact device to the bearing ring. In particular, the collar-shaped support section is in the form of a flange and preferably extends in a radial plane of the main axis. When the clamping sleeve is arranged on the outer ring, the flange section is directed radially inwards and extends in the direction of the bearing inner ring. Alternatively, when the clamping sleeve is arranged on the bearing inner ring, the flange section is directed radially outwards and extends in the direction of the bearing outer ring. To form the clamping connection, the contact device is arranged or held in the axial direction in a form-fitting and/or force-fitting manner between the collar-shaped support section and the corresponding bearing ring.

In a further embodiment it is provided that one bearing ring has a cylindrical fastening section which is designed and/or suitable for receiving the clamping sleeve. For this purpose, the fastening section is arranged on an axial end face of the bearing ring in relation to the main axis. In particular, the fastening section is designed as a cylindrical projection, which is directly connected to the corresponding bearing ring in the axial direction. The fastening section is preferably arranged offset in the radial direction relative to the bearing ring. The radial offset thus formed is greater than or equal to a radial width of the connecting section, so that the clamping sleeve terminates at least flush with the bearing ring.

In a further development it is provided that the supporting body device has a support section which is designed and/or suitable for supporting the contact device. Included the support section connects at an angle to the support section, with a support angle being formed between the support section and the support section. The support section preferably extends in a radial plane with respect to the main axis, with the support section adjoining the support section at a support angle of more than 10 degrees, preferably more than 30, preferably more than 50 degrees, with respect to the radial plane. Alternatively or optionally in addition, the support section adjoins the carrying section at a support angle of less than 60 degrees, preferably less than 40 degrees, in particular less than 20 degrees, in relation to the radial plane. In this case, the contact device is supported on the support section, in particular in an installation situation, with the formation of the support bracket. Thus, in particular the contact device makes contact with the discharge partner or possibly with the intermediate component, forming an angle deviating from a right angle, in particular the support angle. By supporting the contact device, greater rigidity of the contact device can be achieved, so that the risk of lifting off and an associated interruption in the electrical connection is minimized. In addition, the risk of the contact device slipping out of its clamp between the bearing ring and the clamping sleeve is reduced.

In a further constructive embodiment it is provided that the discharge device has at least or exactly one abrasion protection device. The abrasion protection device has the function of protecting the electric motor against abrasion from the contact device. In particular, the abrasion is generated during operation of the electric motor due to friction during a relative movement between the two diverting partners. The abrasion protection device is arranged on the side of the electric motor of the contact device in order to prevent or at least reduce the transfer of abrasion from the contact device to the electric motor. In particular, the abrasion protection device is designed and/or suitable for covering and/or sealing a transition region between the support body device and the discharge partner that is directly or indirectly connected to the contact device. The abrasion protection device particularly preferably forms an abrasion-tight separation in the direction of rotation around the main axis.

According to this embodiment, it is provided that the abrasion protection device is mechanically connected to the bearing ring via the clamping assembly. The contact device and the abrasion protection device are jointly connected to one of the bearing rings via the support section on the one hand and rest directly or indirectly on the other bearing ring on the other hand. In particular, the abrasion protection device extends circumferentially, in particular in the direction of rotation around the main axis, between the two discharge partners without interruption and/or overlapping the contact device. In particular, “uninterrupted” should be understood to mean that the abrasion protection device has no interruptions, openings or the like. In particular, “overlapping” should be understood to mean that the abrasion protection device and the contact device overlap at least partially or completely, at least in an axial view with respect to the main axis. In particular, the abrasion protection device and the contact device are arranged and/or designed congruently with one another. The contact device and optionally the abrasion protection device are particularly preferably designed in the shape of a ring or a circular ring. In particular, the abrasion protection device is designed as an annular sealing disk. The sealing disk is preferably arranged coaxially with respect to the axis of rotation, and this delimits and/or closes off the annular space in the direction of the electric motor. As a result, a discharge device is proposed which is characterized by a particularly compact design.

The diverting device can optionally have a further abrasion protection device in order to prevent the abrasion from being transferred in the direction of the gear section. The abrasion protection device is arranged on the side of the gear device of the contact device in order to avoid or at least reduce a transfer of abrasion from the contact device to the gear device and/or to prevent or at least reduce the entry of oil, in particular at the contact point between the contact device and the contacting diverting partner. The further abrasion protection device can be connected together with the abrasion protection device and the contact device to the bearing ring via the clamping sleeve and/or be held in a clamped manner

In a further specification, it can be provided that the abrasion protection device has a circumferential sealing lip. In particular, a touching, preferably a dynamic, seal is implemented by the sealing lip. At least the sealing lip is preferably made of an elastic material, for example rubber, so that the sealing lip bears against the sealing partner in a sealing manner in the circumferential direction, in particular in a fluid-tight manner. In particular, the entire abrasion protection device is made of the elastic material, so that it is flexible. The sealing partner can be formed by the other bearing ring or an intermediate component connected to the bearing ring. The abrasion protection device is preferably in the form of a wave lip seal puts. An abrasion protection device is thus proposed which is characterized by a particularly high degree of tightness, so that the entry of abrasion into the electric motor is significantly reduced or prevented.

In a further specification it is provided that the discharge device has a sleeve. The sleeve is designed in particular as a separate component which is and/or can be connected in a rotationally fixed manner to one of the bearing rings. For this purpose, the sleeve has a cylinder section which is designed and/or suitable for electrical and mechanical connection to the bearing ring. The sleeve is preferably designed as a cylinder sleeve. In particular, the sleeve is non-rotatably connected to the rotating discharge partner, in particular the bearing inner ring. Alternatively, however, the sleeve can also be connected to the stationary discharge partner, in particular the bearing outer ring. For this purpose, the sleeve is pressed onto the bearing inner ring, for example via the cylinder section, or alternatively pressed into the bearing outer ring.

According to this embodiment, the sleeve has a flange section which is designed and/or suitable for bridging a radial distance between the contact device and the cylinder section in order to indirectly electrically connect the contact device to the discharge partner to be contacted. The sleeve thus serves as a bridge between the support body device and the derivation partner to be contacted. In particular, the flange section extends in a radial plane of the main axis. When the sleeve is arranged on the bearing inner ring, the flange section is directed radially outwards and extends radially in the direction of the stationary discharge partner. When the sleeve is arranged on the bearing outer ring, the flange section is directed radially inwards and extends radially in the direction of the rotating discharge partner. Most preferably, the sleeve is made of an electrically conductive material, such as silver or copper. As a result, a radial structural dimension of the contact device can be significantly reduced, so that a more stable system for the contact device can be implemented.

In a further specification, it is provided that the flange section bridges more than half the radial width of an annular gap, the annular gap being formed between the first and the second bearing ring. In particular, the flange section extends in the radial direction over more than 50%, preferably more than 65%, in particular more than 80% of the radial width of the annular gap. The annular gap is particularly preferably formed as an air gap surrounding the main axis, via which the two discharge partners are radially spaced from one another. By bridging a major portion of the annular gap with the flange section, it can be ensured that particularly large radial distances can be bridged and at the same time the stability of the discharge device can be ensured.

In a further embodiment of the invention it is provided that the discharge device has at least one opening which forms or forms an air passage in the annular gap in an axial direction. The opening cross section of the opening and/or the air passage is preferably larger than 2 square millimeters, in particular larger than 4 square millimeters. In particular, the opening forms at least or precisely one continuous channel in the axial direction as an air passage or part of an air passage. The at least one opening can be designed as a through-opening, which is arranged in a radial area between the outer diameter and the inner diameter of the discharge device. In particular, the through-opening is designed to be closed all the way around. Alternatively or additionally, the opening is designed as an opening at the edge, which is delimited on a radial side by one of the diverting partners. This configuration has the advantage that the annular ring of the discharge device is not weakened by the opening and is therefore more stable in continuous operation. Provision can be made for the discharge device to have at least one through opening and at least one opening at the edge. The at least one opening can be arranged in the supporting body device and/or in the contact device and optionally in the at least one abrasion protection device. Alternatively, the at least one opening or optionally at least one further opening can be arranged in the sleeve, in particular the flange section. For example, the opening can be designed with a constant, free diameter in the axial course. The opening serves to reduce a pressure difference in a functionally reliable manner and in particular in a manner that is safe from contamination. By reducing the pressure difference, it is avoided that the discharge device is loaded in the axial direction and can shift or tilt in continuous operation.

In a further embodiment of the invention, it is provided that the contact device has a contact section, which is used for the electrical connection to the discharge partner. In addition, the contact device has a connecting section, via which the contact device is connected to the supporting body device, in particular the supporting section of the supporting body device. The connection section is preferably connected indirectly to the other diverting partner via the supporting body device, in particular the supporting section. The contact section can basically be configured arbitrarily in its basic form.

In principle, the contact section can be formed by one or more, preferably elastically deformable, filaments, strips or circular ring segments. Preferably, however, the contact section and/or the contact device is designed as a ring-shaped or annular component, with the contact section preferably being designed concentrically to the shaft and/or to the housing section. In its basic form, the contact section is particularly preferably designed as an open or closed ring disk and/or blank, with the contact section having an opening, in particular a central hole, for receiving the shaft. The contact section is preferably deformed and/or deformable in the axial direction in the form of a plate or a wave.

In principle, the contact device and/or the support body device can be made of an electrically conductive metal or a metal alloy, e.g. steel, copper or aluminum. In particular, the contact device and the support body device can be made of different electrically conductive materials.

Alternatively, the contact device and/or the support body device is made from a composite material and/or a composite material which has electrically conductive properties. For example, the composite material is made from a graphite-copper-resin composite mixture.

Alternatively, the contact device and/or the support body device is provided with an electrically conductive coating. For example, the coating can be applied to the contact section as a particle, layer or fiber composite material.

Alternatively, the contact device, in particular the contact section, can be formed from electrically conductive fibers. In particular, these fibers can be present as loose fibers, as a yarn or as a woven fabric. As a fabric, the electrically conductive fibers can be processed, for example, into a felt or into a woven, embroidered or tufted fabric layer. The fabric can be formed entirely or partially from electrically conductive fibers and partially from other fibers, e.g. plastic fibers. The electrically conductive fibers are preferably designed as metallic fibers or as filled or coated polymer fibers, but particularly preferably as carbon fibers.

According to this embodiment, the contact device has electrically conductive fibers and an adhesive layer for embedding the electrically conductive fibers, the electrically conductive fibers being arranged on the contact section for contacting one of the discharge partners. The conductive fibers are preferably arranged on the contact section at least in a region of the contact point. The adhesive layer is used to materially connect the electrically conductive fibers to the contact section. The adhesive layer preferably forms an adhesive bed for the electrically conductive fibers. The adhesive layer is preferably formed from an electrically conductive adhesive, the adhesive being designed, for example, as a dispersion adhesive or as a solvent-based adhesive. The adhesive layer is applied to the contact section, with the adhesive layer preferably being able to be applied to the contact section and/or used up by spraying, rolling, brushing or dipping the contact section or by a pad printing or screen printing process. In particular, the adhesive layer can be cured, so that the electrically conductive fibers can be introduced into the adhesive layer in a wet and/or liquid and/or viscous state and are firmly connected to the contact section after the adhesive layer has cured and/or solidified. The electrically conductive fibers are preferably embedded with one of their ends in the adhesive layer, with the other ends being designed as free ends of the electrically conductive fibers. In particular, the free ends of the electrically conductive fibers can be placed on the discharge partner to be contacted and/or are in contact with it. The electrically conductive fibers are preferably held elastically in the adhesive layer, so that when the electrically conductive fibers are in contact with one of the conductor partners, flexible deformation of the electrically conductive fibers results in a dimensional overlap of the electrically conductive fibers with one of the conductor partners. The electrically conductive fibers preferably have a fiber length of at least 0.3 mm, in particular at least 0.2 mm, in particular at least 0.1 mm, the electrically conductive fibers preferably having a maximum fiber length of 5 mm, in particular a maximum of 10 mm , in particular of a maximum of 20 mm.

In a further possible embodiment, the conductive fibers are designed as flock fibers for flocking the contact section. The flock fibers preferably have a uniform fiber length and/or the same fiber thickness. The flock fibers are designed to be electrically conductive, with electrical conductivity of the flock fibers being provided by their material itself and/or by an electrically conductive coating on the flock fibers ben is. The flock fibers are preferably applied to the contact section in a flocking process. In principle, the flock fibers can be applied to the contact section using any desired flocking method, for example in a form flocking method, a surface flocking method, an electrostatic flocking method or an electrostatic-pneumatic flocking method. The contact section is preferably electrostatically flocked with the flock fibers, the contact section preferably being designed as a carrier substrate for the flock fibers and having the adhesive layer.

In electrostatic flocking, the flock fibers are applied into the wet adhesive in an electrostatic field between an anode and a cathode, specifically between an applicator with an anode and the contact section as a cathode. The flock fibers attach themselves to the adhesive layer, with the flock fibers forming a flock pile on the adhesive-wetted area of the contact section. The flock fibers align themselves in the electrostatic field, so that the flock fibers are preferably aligned due to the process, e.g. perpendicular to a surface of the contact section. Alternatively or optionally in addition, with this or another flocking method, the flock fibers are specifically aligned, e.g. can be applied and/or applied with an angular offset to the surface of the contact section or anchored in a random alignment of the individual flock fibers with the adhesive layer. It is advantageous that through a targeted orientation of the flock fibers, the electrical contact with one of the discharge partners can be improved and undesirable frictional resistances, for example due to flock fibers aligned counter to a direction of rotation of the shaft, can be reduced.

In a further possible configuration, the electrically conductive fibers are in the form of carbon fibers. The carbon fibers, also referred to as carbon fibers or as carbon or carbon fibers, are preferably made from a carbon-containing starting material which can be carbonized to carbon in a pyrolysis process. The carbon fibers are designed to be electrically conductive and are preferably applied to the contact section by the flocking process. The carbon fibers are embedded in the adhesive layer, with the adhesive layer bonding the carbon fibers to the contact section. The contact section is electrically connected to one of the discharge partners via the carbon fibers; in particular, the carbon fibers form the sliding contact between the contact section and one of the discharge partners. Alternatively, the electrically conductive fibers are formed as derivatives of carbon fibers, as metallic fibers or as filled polymer fibers.

A further object of the invention relates to the electric drive arrangement with the bearing unit as has already been described above. The electric drive arrangement has a separating section, with the separating section being arranged between the electric motor section and the transmission section, in particular in the axial direction of the main axis. The partition section includes a partition wall between the electric motor section and the transmission section. In particular, the electric motor section has a motor compartment and the transmission section has at least one transmission compartment, with the separating section separating the motor compartment from the adjacent transmission compartment, in particular separating it in a dirt-tight or oil-tight manner. For example, the electric motor section has a motor part housing and the transmission section has a transmission part housing, with the separating section being arranged in a separating manner between the motor part housing and the transmission part housing. Preferably, the motor part housing and the transmission part housing together form a housing for the electric drive arrangement. The electric motor section is preferably designed as a dry area. The transmission section, in particular the adjoining transmission space, is implemented either as an oil area or as a dry area. In the event that this is implemented as a dry area, the separating section forms a dirt-tight separation. If this is implemented as an oil area, the separating section forms an oil-tight partition.

The shaft, in particular the rotor shaft, is guided through the separating section and sealed off from the separating section with a sealing device. The sealing device can be designed as a contact sealing device or as a non-contact sealing device, in particular as a gap seal. For example, the sealing device is designed as a shaft bushing.

It is further proposed that the bearing unit, in particular the discharge device, is arranged on a motor side of the sealing device and/or in the electric motor section. Thus, the drain device is arranged on the electric motor side with respect to the sealing device. This has the advantage that the electrical/electronic components are all arranged on the side of the electric motor section, so that the responsibility for the electrical/electronic conversion is assigned to the electric motor section and the responsibility for the mechanical conversion to the transmission section. In addition, the discharge device is installed where the electrical charge and/or electrical voltage in the rotor arises so that it can be dissipated spatially close. In particular, the bearing unit is arranged in the axial direction in relation to the main axis between the rotor and the sealing device. The diverting device is thus shifted to the side of the electric motor which faces the sealing device. The remaining space which is available between the bearing device arranged on the transmission side and the sealing device can thus be used for the diverting device.

For example, the diverting device can be arranged between the bearing device and the sealing device. With this configuration, the diverting device is moved further from the free end of the rotor shaft in the electric motor section to the center of the rotor shaft, so that the voltage and/or the electrical charge can be diverted centrally from the rotor shaft as diverting partner to the other diverting partner. In addition, the position particularly protects the transmission section with the transmission device, so that any bearings in the transmission device cannot suffer any damage from the passage of current. As an alternative to this, the discharge device can be arranged on the side of the bearing device which is remote from the sealing device. In particular, the diversion device is arranged between two bearing devices, with the two bearing devices forming or concomitantly forming the rotor bearing.

• 1 eine schematische Darstellung einer Antriebsanordnung mit einer Ableitvorrichtung als ein Ausführungsbeispiel der Erfindung;
• 2 die Antriebsanordnung in gleicher Darstellung wie 1 als ein weiteres Ausführungsbeispiel der Erfindung;
• 3 eine stark schematisierte Darstellung der Ableitvorrichtung der 1 und 2;
• 4a, b jeweils eine Schnittdarstellung einer Lagereinheit für die Antriebsanordnung der 1 und 2.

Further features, advantages and effects of the invention result from the following description of preferred exemplary embodiments of the invention. It shows:

• 1 a schematic representation of a drive assembly with a discharge device as an embodiment of the invention;
• 2 the drive arrangement in the same representation as 1 as another embodiment of the invention;
• 3 a highly schematic representation of the discharge device 1 and 2 ;
• 4a, b each a sectional view of a bearing unit for the drive assembly of 1 and 2 .

1 shows a schematic representation of an electric drive arrangement 1 for a vehicle, not shown, as an embodiment of the invention. For example, the vehicle can be designed as a single or multi-track vehicle and/or as a single or multi-axle vehicle. For example, the vehicle is a purely electric vehicle or a hybrid vehicle. The vehicle can, for example, be in the form of a passenger car, bus or truck. Alternatively, however, the vehicle can also be in the form of a bicycle (pedelec), motorcycle (electric motorcycle) or e-scooter, for example.

The drive arrangement 1 serves to generate and/or provide a traction torque, in particular a main traction torque, for the vehicle. For this purpose, the drive arrangement 1 has an electric motor section 2, which has an electric motor 3 for generating the traction torque and a shaft 4 for transmitting the traction torque. The electric motor 3 can be electrically connected to an energy device, e.g. The electric motor 3 can be designed, for example, as a direct current, synchronous or asynchronous motor.

The electric motor 3 has a stator 5 and a rotor 6 . The rotor 6 is drivingly connected to the shaft 4 so that the shaft 4 is driven via and/or by the rotor 6 . The shaft 4 is thus designed as a rotor shaft and is mechanically, e.g. non-rotatably, and electrically connected to the rotor 6 for this purpose. The shaft 4 defines a main axis H with its axis of rotation, the stator 5 and the rotor 6 being arranged coaxially and/or concentrically with respect to the main axis H with respect to one another.

For the rotatable mounting of the shaft 4, the electric motor section 2 has a first and a second bearing device 110, 120, the shaft 4 being supported in the radial direction on the stator 5 via the bearing devices 110, 120. In the exemplary embodiment shown, the bearing devices 110, 120 are each designed as a ball bearing, in particular a grooved ball bearing.

Furthermore, the electric drive arrangement 1 has a transmission section 7 which serves to transmit and/or increase and/or distribute the traction torque of the electric motor 3 . For this purpose, a transmission device 8, indicated only schematically, is arranged in the transmission section 7, with the transmission device 8 being a clutch device, e.g. a positive or pure-locking clutch, and/or a shifting device, e.g a transmission device, e.g. a planetary and/or step wheel transmission. The electric motor section 2 and the transmission section 7 are connected to one another in terms of transmission via the shaft 4 , the shaft 4 forming an input shaft into the transmission device 8 . The traction torque can be passed on to one or more wheels of the vehicle, for example, via an output shaft 9 .

Furthermore, the electric drive arrangement 1 has a separating section 10 which separates a motor compartment of the electric motor section 2 from an adjacent gear compartment of the gear section 7 . For this purpose, the separating section 10 is arranged in the axial direction in relation to the main axis H between the electric motor section 2 and the transmission section 7 . For example, the engine compartment can be a dry area and the adjoining gear compartment can be another dry area or an oil area, with the separating section 10 forming a dirt-tight and optionally an oil-tight separation between the electric motor section 2 and the gear section 7 . The shaft 4 is guided through the separating section 10 and sealed off from the separating section 10 by a sealing device 11 . The sealing device 11 can be designed, for example, as a contacting sealing device, for example a shaft sealing ring, or as a non-contacting sealing device, for example a gap seal.

When the electric motor 3 is operating as a motor, discharge currents can be caused which can discharge via the bearing devices 110, 120 and damage the bearing devices 110, 120. For this purpose, the electrical drive arrangement 1 has a discharge device 200, which is used to discharge an electrical charge and/or electrical voltage from the rotor 6 via the shaft 4 and a first discharge partner P1 to a second discharge partner P2.

The first diverting partner P1 is a rotating diverting partner P1, which is connected to the shaft 4 in a rotationally fixed manner. The second diverting partner P2 forms a stationary diverting partner compared to the first diverting partner P1. The second diverting partner P2 can do this, for example, with the stator 5 itself and/or with a housing section, e.g. motor housing, and/or a surrounding construction, e.g. chassis, and/or a component which is electrically connected to the stator 5, the housing section or the surrounding construction is conductively connected to be rotatably connected. The diverting device 200 forms an electrical connection between the first diverting partner P1 and the second diverting partner P2. In this case, the second diverting partner P2 is connected to ground and/or grounded, so that the shaft 4 is grounded via the diverting device 200 . For this purpose, the discharge device 200 forms a current path with a lower resistance compared to the storage devices 110, 120, so that the discharge currents are discharged parallel to the storage devices 110, 120. The two diverting partners P1, P2 are constantly electrically connected to one another via the diverting device 200, with electrical diverting taking place both stationary and dynamic, ie during engine operation.

In the exemplary embodiment shown, the diverting device 200 is arranged in the axial direction with respect to the main axis H between the first bearing device 110 and the separating section 10 in the electric motor section 2 . The diverting device 200 is thus arranged on the side close to the transmission in relation to the first bearing device 110 in the engine compartment. This position close to the transmission allows the transmission section 7 to be protected from discharge currents, so that any bearings in the transmission device 8 are not damaged.

2 shows the drive assembly 1 in the same representation as 1 as another embodiment of the invention. In the exemplary embodiment shown, the diverting device 200 is arranged in the axial direction with respect to the main axis H between the rotor 6 and the first bearing device 110 in the electric motor section 2 . The diverting device 200 is thus arranged on the side close to the engine in relation to the first bearing device 110 in the engine compartment. Due to this position close to the motor, the discharge device 200 can be installed where the electrical charge and/or electrical voltage is generated in the rotor 6, so that it can be discharged spatially close.

3 shows the discharge device 200 in a highly schematized block diagram, the individual blocks being defined as function blocks and optional configurations being indicated by dotted lines.

The discharge device 200 has a support body device 210 and a contact device 220, the contact device 220 being electrically and mechanically connected to the support body device 210. For this purpose, the support body device 210 has a support section 211 and the contact device 220 has a connection section 221, the contact device 220 being connected to the support section 211 via the connection section 221, for example in a form-fitting and/or non-positive manner.

Furthermore, the supporting body device 210 has a connecting section 212 which directly adjoins the supporting section 211 . The connecting section 212 is used to mechanically and electrically fix the supporting body device 210 to the second diverting partner P2. The mechanical and electrical connection can coincide, but these can also be implemented side by side or in parallel with one another. The connecting section 212 can be connected directly to the second diverting partner P2 and/or can be in contact with it. Alternatively or optionally in addition, the connecting section 212 be indirectly connected to the second diverting partner P2 via an intermediate component, not shown.

The contact device 220 has a contact section 222 which directly adjoins the connection section 221 . The contact section 222 212 serves to make electrically conductive contact between the contact device 220 and the first diverting partner P1. In motor operation, the shaft 4 rotates about the main axis H, with the diverting device 200 remaining stationary on the second diverting partner P2 and the two diverting partners P1, P2 being in permanent electrically conductive contact with one another via the contact section 222. In this case, the contact section 222 can be directly electrically connected to the first diverting partner P1 and/or can be in contact with it. Alternatively, however, the contact section 222 can also be indirectly electrically connected to the first diverting partner P1 via a sleeve 230 as an optional intermediate component.

During motor operation, abrasion can occur at the contact point of the contact section 222 with the shaft 4 or the sleeve 230 due to the relative rotation between the two conductor partners P1, P2. This abrasion can have electrically conductive particles which must be kept away from the electric motor 3 . For this purpose, the diverting device 200 optionally has an abrasion protection device 240 which protects the electric motor 3 against abrasion. For this purpose, the abrasion protection device 240 is arranged on the side of the electric motor 3 of the contact device 220 in order to prevent the abrasion from being transferred to the electric motor 3 . The abrasion protection device 240 is connected together with the contact device 220 to the supporting section 211 of the supporting body device 210 . Abrasion protection device 240 is designed, for example, in such a way that it shields the entire contact device 220 or at least the contact point between the contact section 220 and the shaft 4 or the sleeve 230 from the electric motor 3 in relation to the main axis H, both in the axial direction and in the circumferential direction and/or sealed. The abrasion protection device 240 forms an abrasion-tight separation between the first bearing device 110 and the sealing device 10, as in FIG 1 is shown. Alternatively, the abrasion protection device 240 forms an abrasion-tight separation between the rotor 6 and the first bearing device 110, as in FIG 2 is shown.

Optionally, the diverting device 200 can have a further abrasion protection device 250 in order to prevent the abrasion from being transferred in the other direction, in particular to the transmission section 7 . The additional abrasion protection device 250 is connected to the supporting section 211 of the supporting body device 210 together with the abrasion protection device 240 and the contact device 220 . Abrasion protection device 240 is designed, for example, in such a way that it shields the entire contact device 220 or at least the contact point between the contact section 220 and the shaft 4 or the sleeve 230 from the transmission section 7 in relation to the main axis H, both in the axial direction and in the circumferential direction and/or sealed. The additional abrasion protection device 250 can thus enclose or encapsulate the abrasion between the two abrasion protection devices 240, 250, so that a transfer to the electric motor 3, e.g. through openings arranged in the discharge device 200, can be ruled out. In addition, the entry of foreign particles from the transmission section 7, e.g. oil, to the contact point of the contact device 220 can be prevented by the further abrasion protection device 250.

The diverting device 200 serves to bridge an annular gap between the two diverting partners P1, P2, the diverting device 200 optionally having at least one opening 260 in the annular gap in order to form an air passage in the axial direction. For example, the opening 260 can be formed by at least or precisely one through-opening, e.g. one or more bores or one or more openings, or as at least or precisely one edge-side opening, e.g. one or more cutouts. It is conceivable that a large number of passage openings form a grid-like structure, for example, in order to prevent or at least reduce the transfer of solids, in particular abrasion, to the electric motor 3 .

The opening 260, indicated schematically here by a dashed line, can optionally be introduced into the support body device 210 and/or the contact device 220. For example, the opening 260 can be made in the support section 211 and/or the connection section 221 and optionally in the abrasion protection device 240 and/or the further abrasion protection device 250 . Alternatively, the opening 260 or optionally a further opening can be made in the contact section 222 and optionally in the abrasion protection device 240 and/or the further abrasion protection device 250 . Alternatively, the opening 260 or optionally a further opening can be made in the sleeve 230 .

the 4a, b each show a sectional view of a bearing unit 300, the bearing unit 300 being the first bearing device 110 of FIG 1 and 2 and the discharge device 200, as in 3 described, includes. The diverting device 200 and the storage device 110 together form a structural unit, with the diverting device Direction 200 and the storage device 110 are connected to each other for this purpose.

The first bearing device 110 is designed as a deep groove ball bearing and is therefore used for the radial and axial bearing of the shaft 4 in the electric motor section 2. The first bearing device 110 has a first bearing ring 111 as the first diverting partner P1 and a second bearing ring 112 as the second diverting partner P2. wherein between the two bearing rings 111, 112 a row of rolling elements 113, in particular balls, are arranged in a rolling manner. The first bearing ring 111 is designed as an inner bearing ring and the second bearing ring 112 is designed as an outer bearing ring.

The first bearing ring 111 has a first fastening section 114 and the second bearing ring 112 has a second fastening section 115, which are each formed on an axial end face of the associated bearing ring 111, 112. The two fastening sections 114, 115 are each designed as a cylindrical extension and are offset in the radial direction in relation to the associated bearing ring 111, 112.

The supporting body device 210 is designed as a clamping sleeve, the contact device 221 being clamped to the second fastening section 115 of the second bearing ring 112 via the supporting body device 210 . The connection section 221 of the contact device 220 is clamped or held in a force-fitting manner in the axial direction between the second fastening section 115 and the supporting section 211 . Optionally, it can be provided that the abrasion protection device 240 and/or the further abrasion protection device 250, as in 3 described, are held captive via the clamping connection between the second fastening section 115 and the supporting section 211 .

The supporting body device 210 is designed, for example, as a rotationally symmetrical, in particular annular, shaped sheet metal component. The connecting section 212 is designed as a hollow cylinder running around the main axis H and the supporting section 211 as a radially inwardly directed flange. The supporting body device 210 is mounted circumferentially on the second fastening section 115 via the connecting section 212, with the connection section 221 of the contact device 220 being pressed onto the end face of the second fastening section 114 via the supporting section 211 to form the clamping connection. For example, the supporting body device 210 can be fixed to the second fastening section 115 by means of a press fit.

In addition, the support body device 210 has a support section 213 which adjoins the support section 211 at an angle to form a support angle. In this case, the contact device 220, in particular the contact section 222, is supported on the support section 213, so that the contact section 222 bears against the sleeve 230 at an angle. For example, the support section 213 is angled at a support angle of approximately 45 degrees relative to the support section 211 . On the one hand, the support section 213 can improve the clamping connection, so that the contact device 220 is secured against slipping out. On the other hand, a more stable abutment of the contact section 222 on the sleeve 230 can be ensured.

The sleeve 230 has a cylinder section 231, a flange section 232 and a stop section 233, with the flange section 232 directly adjoining the cylinder section 232 in the radial direction and the stop section 233 in turn adjoining the flange section 232 at an angle. The sleeve 230 is designed, for example, as a further rotationally symmetrical, in particular annular, shaped sheet metal component. The sleeve 230 is mounted on the circumference of the first fastening section 114 via the cylinder section 231 and can be fixed thereto, for example by means of a press fit, so that the sleeve 230 is entrained in the direction of rotation about the main axis H by the first bearing ring 111 mounted on the shaft 4 during motor operation will. In this case, the contact section 233 forms a contact surface on which the contact section 222 makes contact in motor operation. The flange section 232 has the function of bridging a radial distance A between the contact section 222 and the first bearing ring 111 . For this purpose, the flange section 232 extends in the radial direction over more than half the radial width of the annular gap which is formed between the two bearing rings 111 , 112 . Thus, the contact device 220 can be formed with a small radial width, so that the contact with the approach section 233 can be improved.

Like in the 4a shown, the contact section 233 is designed as a cylindrical projection, which preferably adjoins the flange section 232 at right angles. In this case, the cylinder section 231 and the contact section 233 are aligned coaxially and/or in the same direction with respect to one another. The contact section 233 thus defines a contact surface for the contact section 222, which is formed by a straight cylinder surface of the contact section 233. A sleeve 230 is thus proposed which is characterized by a particularly simple and cost-effective design.

Like in the 4b shown, the approach section 233 is designed as a truncated cone-shaped extension, which preferably follows the flange section 232 at an angle, for example at an angle of more than 30 degrees. In this case, the cylinder section 231 and the contact section 233 are aligned coaxially and/or in opposite directions to one another. The contact section 233 thus defines a contact surface for the contact section 222, which is formed by an inclined cylinder surface of the contact section 233. Thus, a sleeve 230 is proposed, which is distinguished by a particularly simple assembly of the support body device 210 and the contact device 220 .

Reference List

1

drive assembly

2

electric motor section

3

electric motor

4

Wave

5

stator

6

rotor

7

gear section

8th

gear mechanism

9

output shaft

10

separation section

11

sealing device

110

first storage facility

111

first bearing ring

112

second bearing ring

113

rolling elements

114

first attachment section

115

second attachment section

120

second storage facility

200

discharge device

210

supporting body device

211

carrying section

212

connection section

213

support section

220

contact facility

221

connection section

222

contact section

230

sleeve

231

cylinder section

232

flange section

233

approach section

240

abrasion protection device

250

further abrasion protection device

260

opening

300

storage unit

H

main axis

P1

first derivative partner

p2

second derivative partner

Claims (10)

Bearing unit (300) for an electric drive arrangement (1) with a bearing device (110) for supporting a shaft (4), the bearing device (110) having a first bearing ring (111) and a second bearing ring (112), with between the two bearing rings (111, 112) at least one row of rolling bodies (113) is arranged in a rolling manner, with a discharge device (200) for dissipating an electrical charge and/or voltage from a rotor (6) of an electric motor (3) via the shaft (4) and one of the bearing rings (111, 112) as a first diverting partner (P1) to the other bearing ring (111, 112) as a second diverting partner (P2), the diverting device (200) having a support body device (210) for electrical and mechanical connection with one of the diverting partners (P1, P2) and a contact device (220) for electrical connection to the other of the diverting partners (P1, P2), the supporting body device (210) is designed as a clamping sleeve which is radially outward is arranged on one bearing ring (111, 112) in order to electrically and mechanically connect the contact device (220) to the bearing ring (111, 112) via a clamping assembly, characterized in that a connection section (221) of the contact device (220) in is held positively and/or non-positively in the axial direction between a collar-shaped support section (211) of the support body device (210) and the bearing ring (111, 112), the support section (211) for the electrical and mechanical connection of the contact device (220) to one bearing ring (111, 112) is provided and the connection section (221) of the contact device (220) is pressed via the support section (211) to form the clamping connection on the front side against a fastening section (114, 115) of the bearing ring (111, 112), the Fastening section (114, 115) is formed on an axial end face of the bearing ring (111, 112) and that the supporting body device (210) has a connecting piece Section (212) for electrically and mechanically fixing the support body device (210) on an axial end face of the bearing ring (111, 112) which directly adjoins the support section (211). Bearing unit (300) after claim 1 , characterized in that the connecting portion (212) is sleeve-shaped and that the support portion (211) is collar-shaped. Bearing unit (300) after claim 1 or 2 , characterized in that one bearing ring (111, 112) has a cylindrical fastening section (114, 115) for fastening the supporting body device (210) designed as a clamping sleeve, which is arranged in the axial direction on an axial end face of the bearing ring (111, 112). . Storage unit (300) according to one of the preceding claims, characterized in that the support body device (210) has a support section (213) for supporting the contact device (220), the support section (213) being at an angle to the support section (211 ) connects and wherein the contact device (220) is supported to form the support angle on the support section (213). Bearing unit (300) according to one of the preceding claims, characterized in that the deflection device (200) has at least one abrasion protection device (240) for protecting the electric motor (3) against abrasion of the contact device (220), the abrasion protection device (240) being connected via the Clamping assembly is mechanically connected to the bearing ring (111, 112). Bearing unit (300) according to one of the preceding claims, characterized in that the diverting device (200) has a sleeve (230), the sleeve (230) having a cylinder section (231) for the electrical and mechanical connection to one of the diverting partners (P1, P2 ) and a flange section (232) for bridging a radial distance (A) between the contact device (220) and the cylinder section (231), so that the contact device (220) is connected indirectly via the sleeve (230) to the discharge partner (P1, P2) is electrically connected. Bearing unit (300) after claim 6 , characterized in that the flange section (232) bridges more than half the radial width of an annular gap which is formed between the two bearing rings (111, 112). Bearing unit (300) according to one of the preceding claims, characterized in that the deflection device (200) has at least one opening (260) which forms or also forms an air passage in the annular gap in an axial direction. Storage unit (300) according to one of the preceding claims, characterized in that the contact device (220) has a contact section (222) for electrical connection to the discharge partner (P1, P2) and in that the contact device (220) has a connection section (221) for electrical and mechanical connection to the support body means (210), the contact means (220) having electrically conductive fibers and an adhesive layer, the electrically conductive fibers being embedded in the adhesive layer, and the electrically conductive fibers on the contact portion (222) for electrical Connection with one of the derivative partners (P1, P2) are arranged. Electric drive arrangement (1) with an electric motor section (2), the electric motor section (2) having an electric motor (3) with a rotor (6) and a shaft (4), the shaft (4) with the rotor (6) being electrically and is transmission-wise connected to a transmission section (7), a transmission device (8) being arranged in the transmission section (7), the shaft (4) being transmission-connected to the transmission device (8) and to the bearing unit (300). one of the preceding claims, characterized by a separating section (10), the separating section (10) being arranged between the electric motor section (2) and the gear section (7) and by a sealing device (11) for sealing the shaft (4) when passing through the separating section (10), wherein the bearing unit (300) is arranged on an engine side of the sealing device (11) and/or in the electric motor section (2).

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