DE102022207817A1 - Electric axle with a wheel hub lubrication system and vehicle with the electric axle - Google Patents

Abstract

There is an electric axle 1 for driving a vehicle, with a first wheel hub arrangement 2a arranged on a first side of the vehicle and a second wheel hub arrangement 2b arranged on a second side of the vehicle, with an electric drive unit 3 arranged between the first and second wheel hub arrangements 2a, 2b for driving the first and second wheel hub arrangement 2a, 2b, which is connected in terms of drive technology via a first drive shaft 4a to the first wheel hub arrangement 2a and via a second drive shaft 4b to the second wheel hub arrangement 2b, with a first axle housing section 6a and arranged between the first wheel hub arrangement 2a and the drive unit 3 with a second axle housing section 6b arranged between the second wheel hub arrangement 2b and the drive unit 3, the first drive shaft 4a being guided through the first axle housing section 6a and the second drive shaft 4b being guided through the second axle housing section 6b, with a lubricant system 10 for lubricating and/or cooling the electric drive unit 3, proposed, wherein the electric axle 1 has a wheel hub lubrication system 11 for actively supplying lubricant to the first and second wheel hub arrangements 2a, 2b, which is integrated into a lubricant circuit of the lubricant system 10, so that the first and second wheel hub arrangements 2a, 2b with lubricant can be supplied from the lubricant system 10.

Description

The invention relates to an electric axle for driving a vehicle with the features of the preamble of claim 1. The invention further relates to a vehicle with the electric axle.

Electric drive trains, in particular electric axle systems, with one or more drives, in particular electric machines, are known. Such axle systems usually have an axle housing in which the drive shafts of the electric drive are rotatably mounted. The drive shafts each drive a wheel hub of the axle system, which is lubricated or cooled by means of a lubricant, preferably oil, located within the axle housing.

The publication DE 199 39 357 A1 discloses an interconnected venting device for a motor vehicle axle assembly, with a plurality of venting devices being connected at different locations to a further venting device which is located at the highest point of lubricant movement. This makes it possible for the lubricant to emerge from one venting device and be returned to the other venting device without the lubricant escaping to the substrate. Such an interconnected vent arrangement minimizes the extent of leakage of lubricant to the outside due to factors such as foaming of the lubricant, entrainment of air in the lubricant, volumetric expansion of the lubricant due to elevated operating temperatures, pumping action or splashing of the lubricant through internal fluids rotating or moving parts, by a flow of lubricant as a result of a tilting movement of the vehicle and thus the motor vehicle axle arrangement and / or an acceleration or deceleration of the motor vehicle.

The invention has set itself the task of creating an electric axle of the type mentioned, which is characterized by improved operating behavior.

This object is achieved according to the invention by an electric axle with the features of claim 1 and a vehicle with the features of claim 13. Advantageous refinements result from the subclaims, the drawings and/or the description.

The subject of the invention is an electric axle which is designed and/or suitable for driving a vehicle. The axle can be designed as a front or rear axle of the vehicle.

The electric axle has a first and a second wheel hub arrangement, the first wheel hub arrangement being arranged on a first side of the vehicle and the second wheel hub arrangement being arranged on a second side of the vehicle. In particular, the first and second wheel hub arrangements each serve to rotatably support at least one vehicle wheel. Preferably, the two wheel hub assemblies are arranged coaxially with respect to a common main axis of rotation.

The electric axle has an electric drive unit which is designed and/or suitable for driving the first and second wheel hub arrangements. The electric drive unit is arranged, in particular in the axial direction with respect to the main axis of rotation, between the first and the second wheel hub arrangement, the electric drive unit being connected in terms of drive technology to the first wheel hub arrangement via a first drive shaft and to the second wheel hub arrangement via a second drive shaft. In principle, the electric drive unit can have a central electric machine, which is connected in terms of drive technology to the two drive shafts via a gear, for example a differential gear. Alternatively, the electric drive unit has two electric machines that can be operated independently of one another, with a first electric machine being connected in terms of drive technology to the first drive shaft and a second electric machine to the second drive shaft directly or via a respective gear, for example a transmission gear. Preferably, the wheel hub arrangements or the vehicle wheels of the electric axle can be driven independently of one another, also known as “torque vectoring”.

The electric axle has a first and a second axle housing section, the first axle housing section being arranged between the first wheel hub arrangement and the drive unit and the second axle housing section being arranged between the second wheel hub arrangement and the drive unit. The first drive shaft is guided through the first axle housing section and the second drive shaft is guided through the second axle housing section. In particular, the electric axle has an axle housing, with the first and second axle housing sections forming an integral part of the axle housing. The axle housing preferably has a further axle housing section for receiving the drive unit, in particular the electric machine and/or of the gearbox. In principle, the first and second axle housing sections as well as the further axle housing section can be made in one piece, in particular from a common material section. Alternatively, the first and second axle housing sections as well as the further axle housing section can be designed as separate components which are connected to one another in a form-fitting and/or material-locking and/or force-fitting manner.

Furthermore, the electric axle has a lubricant system which is designed and/or suitable for lubricating and/or cooling the electric drive unit. In particular, the lubricant system has a lubricant circuit, wherein lubricant is circulated along a main flow path in order to preferably supply the drive components, such as the stator and/or rotor and/or rotor bearings, etc., with lubricant. The lubricant system is preferably used to implement dry sump lubrication.

Within the scope of the invention it is proposed that the electric axle has a wheel hub lubrication system which is designed and/or suitable for actively supplying lubricant to the first and second wheel hub arrangements. For this purpose, the wheel hub lubrication system is integrated into the lubricant circuit of the lubricant system, so that the first and second wheel hub arrangements can be or are supplied with lubricant from the lubricant system. In particular, for this purpose, a subset of lubricant is discharged from the lubricant system along a partial flow path via the wheel hub lubrication system to the wheel hub arrangements. Preferably, the partial quantity removed via the wheel hub lubrication system serves to lubricate and/or cool the respective wheel hub arrangement. The partial flow path can be branched off from the main flow path of the lubricant circuit, for example by means of a 3-way valve and/or by means of a fitting.

The invention is based on the knowledge that known axle systems are usually filled with lubricant in order to supply the wheel bearings with sufficient lubricant. However, this can lead to churning losses and irregularities in the supply of lubricant, especially when cornering or due to the lubricant building up. The active supply of lubricant to the wheel hub assemblies ensures that a sufficient amount of lubricant is made available to the wheel hub assemblies in all driving situations and at the same time parasitic losses caused by the lubricant can be significantly reduced. An electric axis is therefore proposed which is characterized by improved operating behavior.

In a specific embodiment, it is provided that the wheel hub lubrication system has a first supply connection for supplying the first wheel hub arrangement with lubricant from the lubricant system and a second supply connection for supplying the second wheel hub arrangement with lubricant from the lubricant system. For this purpose, the first feed connection is arranged on a top side of the first axle housing section near the first wheel hub arrangement and the second feed connection is arranged on a top side of the second axle housing section near the second wheel hub arrangement. In particular, the two feed connections are arranged in a transition region of the respective axle housing section to the respective wheel hub arrangement. The transition area is to be understood as the part of the axle housing section which has a reduction in diameter for supporting and/or supporting the wheel hub arrangement. Particularly preferably, the two supply connections are arranged on the respective axle housing section in such a way that the lubricant can be supplied directly to the two wheel hub arrangements. A wheel hub lubrication system is therefore proposed which can be easily connected to the axle housing and at the same time enables a targeted supply of lubricant to the wheel hub arrangements.

In a further embodiment it is provided that the first and the second wheel hub arrangement each have one or more wheel bearings, with an outlet opening of the supply connections being aligned in the direction of the respective associated wheel bearing in order to specifically supply a subset of lubricant of the lubricant system to the respective associated wheel bearing. In particular, the first and second axle housing sections are connected in a rotationally fixed manner to the drive unit or the further axle housing section, with one wheel hub of the first and second wheel hub arrangement being rotatably mounted on the respective associated axle housing section via the respective associated wheel bearing and being connected in a rotationally fixed manner to the respective drive shaft. Preferably, the first and second axle housing sections have a connection opening in the area of the wheel bearing or near the wheel bearing, in which the respective associated feed connection is mounted. Optionally, the two drive shafts are each rotatably supported on the associated axle housing section via one or more shaft bearings, which can also be supplied with lubricant from the lubricant system via the supply connections. Particularly preferably, it is provided that the outlet openings are dimensioned such that not more than 20%, preferably not more than 15%, in particular no more than 10% of a quantity of lubricant in the lubricant circuit of the lubricant system is discharged per side in the direction of the respective wheel hub arrangement. The direct supply of lubricant to the wheel bearings/shaft bearings from the lubricant system enables a particularly efficient lubricant supply.

In a further specification, it is provided that the lubricant system has a distribution pipe, also referred to as a “common rail”, which is designed and/or suitable for the uniform distribution of lubricant to the two supply connections. For this purpose, the distributor pipe has a main connection for connecting to the lubricant system and a first and a second distributor connection for connecting the two supply connections. In particular, the partial amount of lubricant removed from the lubricant system is distributed evenly or in equal parts to the two supply connections via the distributor pipe. The distributor pipe thus ensures that the two wheel hub assemblies are supplied with the same amount of lubricant. In addition, the distribution pipe enables a particularly simple connection to the lubricant circuit of the lubricant system.

In a further specification, it is provided that the lubricant system has a first and a second distribution line, wherein the first supply connection is fluidly connected to the first distribution connection via the first distribution line and wherein the second supply connection is fluidly connected to the second distribution connection via the second distribution line. Furthermore, the wheel hub lubrication system can have a main line via which the main connection is integrated into the lubricant system. A lubricant system is proposed which is characterized by a simple connection of the two supply connections.

In a specific implementation, it is provided that the lubricant system has a suction pump, which is designed and/or suitable for sucking lubricant from a lubricant sump of the drive unit into a lubricant reservoir. In addition, the lubricant system has a pressure pump, which is designed and/or suitable for supplying lubricant from the lubricant reservoir to one or more lubrication points of the drive unit. The lubricant circuit is thus formed, with lubricant from the lubricant reservoir being supplied to the lubrication points via the pressure pump and, after passing through the drive unit, being collected in the lubricant sump and conveyed back into the lubricant reservoir via the suction pump. The wheel hub lubrication system is fluidically integrated on a pressure side of the suction pump. In other words, the suction pump is designed to convey lubricant from the lubricant sump into the lubricant reservoir and at the same time to convey a subset of lubricant to the two supply connections. Alternatively, the wheel hub lubrication system is fluidically integrated on a pressure side of the pressure pump. In other words, the pressure pump is designed to deliver lubricant from the lubricant reservoir to the lubrication points of the drive unit and at the same time to deliver a subset of lubricant to the two supply connections. Preferably, the main connection is connected via the main line to a pressure line of the suction pump or a pressure line of the pressure pump. The invention is based on the knowledge that electric drives must be cooled and lubricated using a lubricant, whereby dry sump lubrication with a lubricant reservoir is usually implemented due to parasitic losses. By connecting the wheel hub lubrication system to the pressure side of the suction or pressure pump, a particularly simple supply of lubricant to the wheel hub arrangement can be achieved using an already existing lubricant system.

In a further development it is provided that the lubricant reservoir is formed within the first and the second axle housing section, the lubricant reservoir within the first and the second axle housing section being delimited on both sides in the axial direction by a partition wall. The first and second axle housing sections are preferably designed for the fluid connection of the suction pump and/or the pressure pump in the area of the lubricant reservoir. In particular, the lubricant reservoir is formed by an annular space formed between the drive shaft and the respective associated axle housing section. In principle, the partitions can be supported in a fluid-tight manner on the respective axle housing section and/or the respective drive shaft in the radial direction with respect to the main axis of rotation. Preferably, the partitions each extend in a separate radial plane of the main axis of rotation and/or parallel to one another. The partition walls preferably each have a central through opening for the passage of the respective drive shaft. By integrating the lubricant reservoir into the two axle housing sections, there is no need for an additional lubricant tank. Another advantage is that the large axle housing enables particularly easy heat dissipation and thus efficient cooling of the lubricant. which means no additional cooling element is required.

In a further specific implementation, it is provided that the wheel hub lubrication system has a first return connection for returning lubricant from the first axle housing section into the lubricant system and a second return connection for returning lubricant from the second axle housing section into the lubricant system. For this purpose, the first feedback connection is arranged on an underside of the first axle housing section near the first wheel hub arrangement and the second feedback connection is arranged on an underside of the second axle housing section near the second wheel hub arrangement. In particular, in an installation situation of the electric axle, the two supply connections are in an upper part, preferably in one 12:00 o'clock position, and the two feedback connections are arranged in a lower part, preferably in a 6 o'clock position, of the respective axle housing section. Preferably, the two return connections are dimensioned such that the lubricant arranged in the two axle housing sections can flow independently via the two return connections due to its gravity pressure. Optionally, however, it can also be provided that the two return connections are fluidly connected to a suction side of a further suction pump in order to actively suck out the lubricant collected in a bottom region of the axle housing sections. A wheel hub lubrication system is therefore proposed which is characterized by a controlled supply and removal of lubricant.

In a further specification, it is provided that the two return connections are each fluidly connected to the lubricant sump via a return line. Preferably, the lubricant sump is formed within the further axle housing section, preferably the at least one electric machine and/or the at least one transmission. In particular, the amount of lubricant collected in the axle housing sections can flow into the lubricant sump via the return connections. In particular, the return connections are dimensioned and/or arranged in the respective axle housing section in such a way that from a specified excess amount of lubricant within the axle housing section or in the floor area, lubricant can flow out into the lubricant sump via the return opening. An electric axle is therefore proposed which is characterized by improved operation when there is an excess of lubricant within the axle housing sections. Furthermore, minimal quantity lubrication or cooling of the two wheel hub arrangements can be achieved through the targeted supply and removal of lubricant.

In a constructive implementation it is provided that at least the supply connections and/or the return connections each have a hose connection. It is optionally provided that the main connection also has a hose connection. For this purpose, the two distribution lines and/or the two return lines and/or possibly the main line are each designed as a flexible hose line. For example, the lines can thus be fixed to the axle housing sections in a simple manner, for example using hose clamps or cable ties, to save installation space. In principle, the two supply connections and/or the two return connections can each be formed by a separate connection piece, which is mounted in a corresponding connection opening of the respective axle housing section. Alternatively, the two supply connections and/or the two return connections can also be connected in one piece, preferably from a common material section, to the respective axle housing section. An electric axis is therefore proposed, which is characterized by simple and space-saving cable routing.

In a further specification it is provided that the hose connection is designed to be pivotable. In particular, the hose connection can be pivoted relative to a connection screw having the outlet opening, with a permanent fluidic connection existing between the hose connection and the outlet opening. Preferably, the hose connection can be pivoted about a central axis of the connection screw. In particular, the connection screw is mounted or screwed into the associated connection opening via a screw connection. For example, the two supply connections and/or the two return connections are each formed by a pivoting nozzle. An electric axis is therefore proposed, which is characterized by flexible and simple assembly of the distribution lines.

In a further implementation it is provided that the first and second axle housing sections are each formed by an axle tube. In particular, the axle tubes serve to absorb the bending moments that occur when supporting the vehicle. The drive shafts of the drive unit can therefore be designed with a smaller diameter, since they are only subjected to torsion. The axle tubes and the partition walls located therein preferably remain When the drive unit is in operation, it is rotationally fixed to the two drive shafts. The two supply connections and optionally the two return connections are preferably arranged on the outer circumference of the axle tubes. In principle, the feed connections and/or the return connections can be aligned or mounted in the radial direction on the respective axle tube. Alternatively, the feed connections and/or the return connections are aligned or mounted at an angle, in particular with respect to the main axis of rotation.

A further subject of the invention relates to a vehicle with the electric axle, as has already been described previously or according to one of claims 1 to 12. In particular, the vehicle is designed as an electric vehicle, with the electric axle forming a drive axle of the electric vehicle. The electric axle can either form a front-wheel drive or a rear-wheel drive of the vehicle. Optionally, however, the vehicle can also have a further identical electric axle to form an all-wheel drive, with one electric axle forming a front-wheel drive and the other electric axle forming a rear-wheel drive of the vehicle.

• 1 eine schematische Darstellung einer elektrischen Achse für ein Fahrzeug als ein Ausführungsbeispiel der Erfindung;
• 2 eine schematische Darstellung einer ersten Seite der elektrischen Achse mit einer ersten Anbindungsmöglichkeit eines Radnabenschmiersystems an ein Schmiermittelsystem;
• 3 eine alternative Anbindungsmöglichkeit des Radnabenschmiersystems an das Schmiermittelsystem in gleicher Darstellung wie 2;
• 4 eine weitere alternative Anbindungsmöglichkeit des Radnabenschmiersystems an das Schmiermittelsystem in gleicher Darstellung wie 2;
• 5 eine Seitenansicht eines Zuführungsanschlusses des Radnabenschmiersystems.

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

• 1 a schematic representation of an electric axle for a vehicle as an embodiment of the invention;
• 2 a schematic representation of a first side of the electric axle with a first connection option for a wheel hub lubrication system to a lubricant system;
• 3 an alternative connection option for the wheel hub lubrication system to the lubricant system in the same illustration as 2 ;
• 4 Another alternative connection option for the wheel hub lubrication system to the lubricant system in the same illustration as 2 ;
• 5 a side view of a feed connection of the wheel hub lubrication system.

The 1 shows an electric axle 1, which is designed and/or suitable as a drive axle for a vehicle. The electric axle 1 has on a first vehicle side a first wheel hub arrangement 2a for receiving a first vehicle wheel and on a second vehicle side a second wheel hub arrangement 2b for receiving a second vehicle wheel.

The electric axle 1 has an electric drive unit 3, which is used to electrically drive the first and second wheel hub arrangements 2a, 2b. For this purpose, the electric drive unit 3 has at least one electric machine, not shown, which is connected to the first and second wheel hub arrangements 2a, 2b in terms of transmission technology. In the case of torque distribution, also known as “torque vectoring”, the drive unit 3 can have a further electric machine, with one electric machine driving one of the wheel hub arrangements 2a, 2b.

The electric drive unit 3 is connected to the first wheel hub arrangement 2a via a first drive shaft 4a and to the second wheel hub arrangement 2b via a second drive shaft 4b. The two drive shafts 4a, 4b extend coaxially to the respective side of the vehicle with respect to a common main axis of rotation 100. The first and second drive shafts 4a, 4b can be connected in terms of transmission technology, for example via a transmission, not shown, to the electrical machine or to the respective associated electrical machine.

Furthermore, the electric axle 1 has an axle housing 5, the axle housing 5 having a first and second axle housing section 6a, 6b, which are each connected to a further axle housing section 6c. The first axle housing section 6a is designed as a first axle tube, through which the first drive shaft 4a is guided to the first wheel hub arrangement 2a. The second axle housing section 6b is designed as a second axle tube, through which the second drive shaft 4a is guided to the second wheel hub arrangement 2b. The further axle housing section 6c is designed as a motor and/or transmission housing, which serves to accommodate the electric machine and/or the transmission. For example, the axle housing sections 6a, 6b, 6c are designed as separate housing parts, which can be connected to one another in a force-fitting and/or material-locking manner.

The first and second wheel hub arrangements 2a, 2b each have a wheel hub 7a, 7b, which is connected in a rotationally fixed manner to the respective drive shaft 4a, 4b. The wheel hubs 7a, 7b are each supported radially via two wheel bearings 8a, 8b on the respective axle housing section 6a, 6b and are rotatably mounted relative thereto, with the axle housing sections 6a, 6b remaining non-rotatable when the drive unit 3 is in operation. The wheel bearings 8a, 8b are each formed, for example, by two tapered roller bearings in an O arrangement.

In addition, the drive shafts 4a, 4b are rotatably mounted in the area of the respective wheel hub arrangement 2a, 2b relative to the associated axle housing section 6a, 6b. For this purpose, the drive shafts 4a, 4b are supported radially within the respective axle housing section 6a, 6b via a shaft bearing 9a, 9b, which can be designed, for example, as a plain bearing.

The electric axle 1 has a lubricant system 10, shown here only in a highly schematic form, which serves to cool and/or lubricate the electric drive unit 4. Furthermore, the electric axle 1 has a wheel hub lubrication system 11, which is used for active lubrication and/or cooling of the first and second wheel hub arrangements 2a, 2b, the wheel hub lubrication system 11 being integrated into the lubricant system 10 in such a way that it is supplied with lubricant from the lubricant system 10 can be supplied.

The wheel hub lubrication system 11 has a first and a second supply connection 12a, 12b, the first supply connection 12a being arranged in a transition region of the first axle housing section 6a to the first wheel hub arrangement 2a and the second supply connection 12b being arranged in a transition region of the second axle housing section 6b to the second wheel hub arrangement 2b is arranged. For example, the transition areas are to be understood as the part of the first and second axle housing sections 6a, 6b, at which the diameter is reduced to support the wheel hub 7a, 7b or to support the drive shaft 4a, 4b.

The two supply connections 12a, 12b each serve to supply lubricant directly to the associated wheel hub arrangement 2a, 2b. For this purpose, the two supply connections 12a, 12b each have an outlet opening 13a, 13b, which is aligned in the direction of the respective wheel bearing 8a, 8b in order to supply the wheel bearings 8a, 8b directly with lubricant.

The wheel hub lubrication system 11 also has a distribution pipe 14, also referred to as a “common rail”, which serves to evenly distribute a partial amount of lubricant from the lubricant system 10 to the two supply connections 12a, 12b. For this purpose, the distributor pipe 14 has a main connection 15 for connecting to the lubricant system 10 and a first distribution connection 16a for connecting the first supply connection 12a via a first distribution line 17a and a second distribution connection 16b for connecting the second supply connection 12b via a second distribution line 17b. During operation, a partial amount of lubricant is removed from the lubricant system 10, distributed via the distributor pipe 14 to the two supply connections 12a, 12b and fed via the outlet openings 13a, 13b to the wheel bearings 8a, 8b and the shaft bearings 9a, 9b. For example, the outlet openings 13a, 13b of the two supply connections 12a, 12b are dimensioned such that no more than 30% of a main volume flow of the lubricant system 10 is used for wheel hub lubrication or is supplied to the two wheel hub arrangements 2a, 2b.

Furthermore, the wheel hub lubrication system 11 has a first and a second feedback connection 18a, 18b, wherein the first feedback connection 18a is arranged in a bottom region of the first axle housing section 6a and the second feedback connection 18b is arranged in a bottom region of the second axle housing section 6b. The two return connections 18a, 18b each serve to return lubricant from the axle housing sections 6a, 6b into the lubricant system 10. The supply connections 12a, 12b are on an upper side, for example essentially in a 12 o'clock position, and the return connections 18a, 18b is arranged on an underside, for example essentially in a 6 o'clock position, on the respective axle housing section 4a, 4b.

The lubricant system 10 is used to implement dry sump lubrication, with the drive unit 3 having a lubricant sump 19 for this purpose. To return the lubricant from the two axle housing sections 4a, 4b, the two return connections 18a, 18b are fluidly connected to the lubricant sump 19 via a return line 20a, 20b.

The 2 until 4 each show a highly schematic representation of the electrical axle 1 with different connection variants of the wheel hub lubrication system 11 to the lubricant system 10. In general, the lubricant system 10 comprises a suction pump 21, which conveys lubricant from a lubricant sump 19 formed within the drive unit 4 into a lubricant reservoir 22, as well as a Pressure pump 23, which conveys lubricant from the lubricant reservoir 22 to several lubrication points 24 arranged within the drive unit 4.

For this purpose, the suction pump 21 is connected to the lubricant sump 19 on its suction side via a suction line 25 and to the lubricant reservoir 22 on its pressure side via a pressure line 26. The pressure pump 23 is connected on its suction side via a further suction line 27 Lubricant reservoir 22 and connected on its pressure side via a further pressure line 28 to a lubricant distributor 29 for distributing lubricant to the several lubrication points 24. For example, the suction pump 21 is designed as a gear pump, which conveys the lubricant conveyed from the lubricant sump 19 via the suction line 25 into the lubricant reservoir 22 via the pressure line 26. The pressure pump 23, which can also be designed as a gear pump, for example, conveys the lubricant conveyed from the lubricant reservoir 22 via the further suction line 27 via the further pressure line 28 to the lubricant distributor 29, where the lubricant is distributed to the lubrication points 24. After passing through the drive unit 3, i.e. lubricating the lubrication points 24, the lubricant is collected in the lubricant sump 19 and made available to the suction pump 21 again.

In a first version, as in 2 shown, the wheel hub lubrication system 11 is integrated on the pressure side of the pressure pump 23, so that a subset of lubricant for supplying lubricant to the wheel hub units 2a, 2b can be discharged via the further pressure line 28 to the supply connections 12a, 12b. For this purpose, the wheel hub lubrication system 14 has a main line 30, which is connected to the main connection 15 of the distributor pipe 13, the main line 30 being fluidly integrated into the further pressure line 28.

In an alternative version, as in 3 shown, the wheel hub lubrication system 14 is integrated on the pressure side of the suction pump 21, so that a partial amount of lubricant for supplying lubricant to the wheel hub units 2a, 2b can be discharged via the pressure line 26 to the supply connections 12a, 12b. For this purpose, the wheel hub lubrication system 14 is fluidly integrated into the pressure line 26 via the main line 30.

In another alternative embodiment, as in 4 shown, the lubricant reservoir 22 is formed within the first and second axle housing sections 6a, 6b in the free space formed radially between the inner circumference of the axle housing section 6a, 6b and the respective drive shaft 4a, 4b. For this purpose, the lubricant reservoir 22 is delimited on both sides in the axial direction in relation to the main axis of rotation 100 by a first and a second partition wall 31, 32, which are fixed axially in the respective axle housing section 6a, 6b. For example, the partitions 31, 32 are each designed as a sheet metal cover, which are welded on the circumference to the respective axle housing sections 6a, 6b.

The first and second axle housing sections 6a, 6b each have in the area of the lubricant reservoir 22 a pressure connection 33 for the pressure-side connection of the suction pump 21 and a suction connection 34 for the suction-side connection of the pressure pump 23. For this purpose, the suction pump 21 is connected on its pressure side via the pressure line 26 to the pressure connection 33 and the pressure pump 23 on its suction side is connected to the suction connection 34 via the further suction line 27. The pressure connection 33 can, for example, be arranged on a top side, for example essentially in a 12 o'clock position, and the suction port 34 on a bottom side, for example essentially in a 6 o'clock position, on the respective axle housing section 6a, 6b. open into the respective lubricant reservoir 22.

For example, the supply ports 12a, 12b, the return ports 18a, 18b, the distributor ports 16a, 16b, the main port 15, the pressure ports 33 and / or the suction ports 34 can have a hose port 35, as in 5 shown as an example using the supply connections 12a, 12b, with the associated lines 17a, 17b, 20a, 20b, 25, 26, 27, 28, 30 each being designed as flexible hose lines. The lines 17a, 17b, 20a, 20b, 25, 26, 27, 28, 30 can therefore be laid particularly easily and secured to the axle housing 5 inexpensively, for example using cable ties.

As in 5 shown, at least the feed connections 12a, 12b can be designed as a swivel nozzle 36. For this purpose, the supply connections 12a, 12b have a fixed connection screw 37, which has the outlet opening 13a, 13b. The hose connection 35 can be pivoted relative to the connection screw 37, with a permanent fluidic connection being established between the hose connection 35 and the outlet opening 13a, 13b. In an installation situation, the connecting screw 37 is screwed in via a connection opening, not shown, arranged in the respective axle housing section 6a, 6b. Accordingly, the connections 15, 16a, 16b, 18a, 18b, 33, 34 can also be designed as a swivel nozzle 36 if necessary. This makes a particularly flexible line connection possible.

Reference symbols

1

Electric axis

2a, b

Wheel hub assemblies

3

Drive unit

4a, b

drive shafts

5

Axle housing

6a, b, c

Axle housing sections

7a, b

wheel hubs

8a, b

Wheel bearing

9a, b

shaft bearing

10

Lubricant system

11

Wheel hub lubrication system

12a, b

Feed connections

13a, b

Exhaust openings

14

distribution pipe

15

Main connection

16a, b

Distributor connections

17a, b

distribution lines

18a, b

Return connections

19

Lubricant sump

20a, b

Return lines

21

Suction pump

22

Lubricant reservoir

23

pressure pump

24

Lubrication points

25

suction line

26

pressure line

27

another suction line

28

another pressure line

29

Lubricant distributor

30

main line

31

first partition

32

second partition

33

Pressure connection

34

Suction connection

35

Hose connection

36

swivel nozzle

37

Connection screw

100

Main axis of rotation

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19939357 A1 [0003]

Claims (13)

Electric axle (1) for driving a vehicle, with a first wheel hub arrangement (2a) arranged on a first side of the vehicle and with a second wheel hub arrangement (2b) arranged on a second side of the vehicle, with a wheel hub arrangement (2a, 2b) between the first and the second side. arranged electric drive unit (3) for driving the first and second wheel hub arrangements (2a, 2b), the electric drive unit (3) being connected to the first wheel hub arrangement (2a) via a first drive shaft (4a) and via a second drive shaft (4b). the second wheel hub arrangement (2b) is connected in terms of drive technology, with a first axle housing section (6a) arranged between the first wheel hub arrangement (2a) and the drive unit (3) and with a second axle housing section arranged between the second wheel hub arrangement (2b) and the drive unit (3). (6b), wherein the first drive shaft (4a) is guided through the first axle housing section (6a) and the second drive shaft (4b) is guided through the second axle housing section (6b), with a lubricant system (10) for lubricating and/or cooling the electric drive unit (3), characterized by a wheel hub lubrication system (11) for actively supplying lubricant to the first and second wheel hub arrangements (2a, 2b), the wheel hub lubrication system (11) being integrated into a lubricant circuit of the lubricant system (10), so that the first and second Wheel hub arrangement (2a, 2b) can be supplied with lubricant from the lubricant system (10). Electric axis (1). Claim 1 , characterized in that the wheel hub lubrication system (11) has a first supply connection (12a) for supplying the first wheel hub arrangement (2a) with lubricant and a second supply connection (12b) for supplying the second wheel hub arrangement (2b) with lubricant, the first supply connection ( 12a) is arranged on a top side near the first wheel hub assembly (2a) in the first axle housing section (6a) and wherein the second feed connection (12b) is arranged on a top side near the second wheel hub assembly (2b) in the second axle housing section (6b). Electric axis (1). Claim 2 , characterized in that the first and second wheel hub arrangements (2a, 2b) each have at least one wheel bearing (8a, 8b), with an outlet opening (13a, 13b) of the feed connections (12a, 12b) pointing in the direction of the respective associated wheel bearing (8a , 8b) is aligned in order to specifically supply the associated wheel bearing (8a, 8b) with lubricant. Electric axis (1). Claim 2 or 3 , characterized in that the wheel hub lubrication system (11) has a distribution pipe (14) for the uniform distribution of lubricant to the two supply connections (12a, 12b), the distribution pipe (14) having a main connection (15) for connection to the lubricant system (10). and a first and a second distribution connection (16a, 16b) for connection to the two supply connections (12a, 12b). Electric axis (1). Claim 4 , characterized in that the wheel hub lubrication system (11) has a first and a second distribution line (17a, 17b), the first supply connection (12a) being fluidly connected to the first distribution connection (16a) via the first distribution line (17a) and the second Supply connection (12b) is fluidly connected to the second distribution connection (16b) via the second distribution line (17b). Electric axle (1) according to one of the preceding claims, characterized in that the lubricant system (10) has a suction pump (21) for sucking lubricant from a lubricant sump (19) of the drive unit (3) into a lubricant reservoir (22) and a pressure pump ( 23) for supplying lubricant from the lubricant reservoir (22) to at least one lubrication point (24) of the drive unit (3), the wheel hub lubrication system (11) being either on a pressure side of the suction pump (21) or on a pressure side of the pressure pump (23). are integrated fluidically. Electric axis (1). Claim 6 , characterized in that the lubricant reservoir (22) is formed within the first and second axle housing sections (6a, 6b), the lubricant reservoir (22) being delimited on both sides in the axial direction by a partition (31, 32). Electric axle (1) according to one of the preceding claims, characterized in that the wheel hub lubrication system (11) has a first feedback connection (18a) for returning lubricant from the first axle housing section (6a) into the lubricant system (10) and a second feedback connection (18b). for returning lubricant from the second axle housing section (6b) into the lubricant system (10), the first return connection (18a) being on an underside near the first wheel hub assembly (2a) in the first Axle housing section (6a) is arranged and wherein the second feedback connection (18b) is arranged on an underside near the second wheel hub assembly (2b) in the second axle housing section (6b). Electric axis (1). Claim 8 , characterized in that the two return connections (18a, 18b) are each fluidly connected to the lubricant sump (19) via a return line (20a, 20b). Electric axis (1) according to one of the Claims 2 until 9 , characterized in that at least the two supply connections (12a, 12b) and / or the two return connections (18a, 18b) each have a hose connection (35). Electric axis (1). Claim 10 , characterized in that the hose connection (35) is designed to be pivotable. Electric axle (1) according to one of the preceding claims, characterized in that the first and second axle housing sections (6a, 6b) are each formed by an axle tube. Vehicle with the electric axle (1) according to one of the preceding claims.

Images