Multifunctional housing and electric axle drive train

Abstract

The invention relates to a multifunctional housing (10) for accommodating components of an electric axle drive train for a motor vehicle. To simplify the provision of different fluids in the electric axle drive train for the motor vehicle, the multifunctional housing (10) comprises a central housing body (1) in which fluid channels (65, 66) for different fluids are integrated.

Description

The invention relates to a multifunction housing for receiving components of an electric axle drive train for a motor vehicle. The invention further relates to an electric axle drive train for a motor vehicle having such a multifunction housing.A detailed illustration of an electric drive is given in an article of the journal ATZ 113. Vol. 05 / 2011, pages 360-365 of Erik Schneider, Frank Fickl, Bernd Cebulski and Jens Liebold, with the title: High-Integration and Flexible Electric Drive Unit for E-vehicles. In this article, a drive unit for an axle of a vehicle is described, which drive unit comprises an electric motor which is arranged concentrically and coaxially with a bevel gear differential, wherein a shiftable 2-gear planetary gear set is arranged in the power train between electric motor and bevel gear differential, which is also positioned coaxially with the electric motor or the bevel gear differential or spur gear differential. The drive unit is of very compact construction and, owing to the shiftable 2-gear planetary gear set, allows a good compromise between climbing capability, acceleration and energy consumption. Drive units of this type are also referred to as E-axles or electrically operable axle drive train. German laid-open specification DE 10 2018 124 220 A1 discloses an electric pump actuator, in particular for actuating a clutch, in particular in the drive train of a motor vehicle, comprising a pump and an electric motor, wherein the pump and the electric motor are formed in a one-piece housing which has a closable mounting opening on at least one end side. German Offenlegungsschrift DE 10 2021 129 917 A1 discloses an exhaust manifold for an engine, comprising: a plurality of exhaust manifold pipes coupling a plurality of cylinder exhaust outlet openings to an exhaust outlet opening, wherein the plurality of exhaust manifold pipes forms at least a first exhaust passage and a second exhaust passage at the exhaust outlet opening; an upper cooling jacket positioned vertically above the first exhaust passage; a lower cooling jacket positioned vertically below the one central cooling jacket positioned vertically below the first exhaust passage and vertically above the second exhaust passage.DE 10 2020 211 234 A1 discloses a transmission, in particular for an electric drive arrangement, having a housing, wherein the housing has a housing wall having an inner surface and an outer surface, wherein at least one guide element is arranged on the inner surface of the housing, wherein the guide element is designed and arranged in such a way that it defines, together with the housing wall, a lubricant channel along which a lubricant located in the housing can be guided.DE 10 2018 220 496 A1 discloses a common housing for an electric machine and a transmission. The common housing includes a water jacket cooling system for an electric machine having cooling channels running in the common housing.DE 10 2020 209 606 A1 relates to an electric drive which comprises an electric machine, power electronics and a one-piece system housing, wherein the one-piece system housing has three first, second and third main spaces delimited from one another, wherein the electric machine in the first main space and the power electronics in the second main space are connected to one another and pre-assembled.WO 2021 / 048095 A1 discloses a compact module for tempering a motor vehicle, having a refrigerant circuit for guiding a refrigerant, having an electric refrigerant compressor and having two heat exchangers and having an expansion valve, and a duct plate in which refrigerant ducts of the refrigerant circuit and coolant ducts for guiding a coolant are integrated, and a modular valve unit as connection region for coolant lines of the motor vehicle.DE 10 2017 002 972 A1 shows a mounting arrangement of an electric drive train on a motor vehicle body shell, having a frame structure which is held on the motor vehicle body shell and by means of which the drive train having at least one electric drive is supported, wherein the drive train is mounted on the frame structure in a vibration-decoupled manner via a drive train mounting, and wherein the frame structure is mounted on the motor vehicle body shell in a vibration-decoupled manner via a frame structure mounting, is designed as a cast component, and has integrated holding brackets for connection to the motor vehicle body shell.A device for supplying oil to an electric machine is known from DE 10 2020 212 685 A1. In this case, a device for supplying oil to an electric machine, comprising an assembly having an assembly housing, wherein an oil pump, an oil filter and an oil cooler are arranged in the assembly housing, wherein the assembly comprises at least one first inner channel for conducting oil to an inlet and an outlet, and wherein the inlet and the outlet are designed for fluidic connection of the at least one first inner channel to oil line connections of an electric machine.It is an object of the invention to simplify the provision of different fluids in an electric axle drive train for a motor vehicle.The object is achieved in a multifunction housing for accommodating components of an electric axle drive train for a motor vehicle, in that the multifunction housing comprises a central housing body in which fluid channels for different fluids are integrated. The electric axle drive train comprises at least one traction machine, power electronics and a transmission. The central housing body with the fluid channels significantly simplifies the realization of different fluid circuits for supplying the components of the electric axle drive train with different fluids. Bores and labyrinths for the purpose of representing the fluid circuits are preferably designed as casting geometries. Depending on a required accuracy, for example in the region of valve seats, a mechanical, in particular machining, post-processing may be necessary. According to a further aspect, filters required in the fluid circuits are integrated into the fluid channels. The filters are advantageously arranged in the fluid channels in such a way that they can be easily replaced after dismantling peripheral components. The multifunctional housing as claimed enables an electric axle drive train to be realized which, in addition to the traction machine, the transmission and the power electronics, also comprises cooling and air conditioning components. The different fluids comprise at least one cooling and / or lubricating medium and a further medium which is compressible, at least in certain states.According to the invention, the multifunction housing is distinguished in that the central housing body comprises bearing receptacles for at least two transmission shafts. The central housing body preferably serves to represent a transmission housing body. This transmission housing body has a transmission side, by means of which the central housing body can be mounted on a transmission housing with a transmission. In addition, the central housing body advantageously has a traction machine side facing away from the transmission side, on which the traction machine is mounted on the central housing body. The bearing receptacles for the at least two transmission shafts are advantageously supplied with a suitable cooling and / or lubrication medium via the fluid channels.According to the invention, the central housing body of the multifunction housing comprises fluid channels for a cooling and / or lubricating medium. The cooling and / or lubricating medium is, for example, an oil which is suitable both for lubricating and for cooling, in particular transmission components such as bearing components. However, the fluid can also be water, which is mainly used for cooling. The cooling and / or lubricating medium is preferably an incompressible medium.In addition, the central housing body of the multifunction housing comprises fluid channels for a refrigerant. The refrigerant is preferably a medium which is compressible, that is to say in particular gaseous, at least in certain states. The fluid channels for the refrigerant preferably serve to represent a refrigerant circuit, for example for an air conditioning system, in the central housing body.According to the invention, the multifunction housing is distinguished in that the central housing body has mounting surfaces for at least two valve plates which, in combination with the fluid channels in the central housing body, represent fluid circuits for different fluids which are fluidically separated from one another. One of the valve plates, in combination with corresponding fluid channels in the central housing body, preferably serves to form a lubrication and / or cooling circuit in the multifunction housing. The other valve plate, in combination with corresponding fluid channels in the central housing body, preferably serves to represent a refrigerant circuit in the multifunction housing. The valve plates are fixed, preferably with the interposition of suitable sealing means, at least in a fluid-pressure-tight manner to the central housing body. Different joining techniques, for example, screwing, adhesive bonding, welding or soldering, can be used for fastening the valve plates. The fluid channels preferably extend in a main direction, which is referred to as a longitudinal direction, for example. Transverse bores for the purpose of providing functional circuits are preferably of short design. All bore openings are preferably part of the respective fluid circuit. The fluid circuit is closed or covered by the sealing devices or valve plates mentioned. This provides the advantage that separate closure elements and correspondingly precise connection geometries can be dispensed with.A preferred exemplary embodiment of the multifunction housing is characterized in that the central housing body has an add-on interface for an accumulator and / or a filter device. The accumulator is preferably assigned to the refrigerant circuit of the air conditioning system. The mounting interface for the accumulator is preferably provided on the traction machine side of the central housing body. This simplifies the connection of the accumulator.The mounting interface for the optional filter device is preferably a recess which is provided for this purpose, for example, in a fluid channel or at the end of a fluid channel. The filter device is preferably an in-line filter. In a line to be equipped with the filter, a seat for this line-integrated filter is advantageously provided for this purpose.A further preferred exemplary embodiment of the multifunction housing is characterized in that the valve plates have mounting surfaces for a leadframe. With the aid of the leadframe, which is also referred to as the English term leadframe, connections to the multifunction housing can advantageously be carried out in only a single assembly step. The connections advantageously comprise a large part of the electrical and / or fluidic connections required. The ports include supply interfaces, sensor interfaces, and line interfaces. All connections are advantageously designed as plug connections. The plug connections are particularly advantageously oriented in one direction. Thus, with and / or on the claimed leadframe, all required electrical contacts and all required fluid connections can be produced in a single assembly step.A further preferred exemplary embodiment of the multifunction housing is characterized in that the valve plates and the central housing body have mounting interfaces for valve devices. The valve devices comprise different components. The components are, for example, so-called cartridge valves, holding magnets or other valves or valve elements, in particular check valves. Furthermore, the valve plates and the central housing body advantageously comprise connection interfaces or attachment interfaces for pumps or compressors. The valve devices are preferably integrated into the valve plates. However, it is also possible to connect individual valve devices to the central housing body via a separate interface.A further preferred exemplary embodiment of the multifunction housing is characterized in that the valve plates and the central housing body have connection interfaces for fluid lines. These connection interfaces are preferably standardized. In addition, the connection interfaces on the valve plates and the central housing body are advantageously arranged and aligned such that connection is made possible particularly advantageously in only a single assembly step.The object indicated above is also achieved by an electric axle drive train for a motor vehicle having a multifunction housing described above. The electric axle drive train preferably comprises at least one electric traction machine which is drive-connectable or connected to at least one wheel of the motor vehicle via a transmission. The transmission and the electric traction machine are incorporated at least for cooling and / or lubrication purposes into a fluid system which is realized with the aid of the multifunction housing described above. The claimed electric axle drive train advantageously also comprises, in addition to the electric traction machine, the transmission and the power electronics, cooling and air conditioning components with fluid circuits which are integrated into the multifunction housing.The invention optionally also relates to at least one separately tradeable individual part for a multifunction housing described above.Further advantages, features and details of the invention will become apparent from the following description, in which various exemplary embodiments are described in detail with reference to the drawing. The following are shown: FIG. 1 shows a perspective illustration of a central housing body of a multifunction housing with a view to a traction machine side; FIG. 2 shows the central housing body from FIG. 1 with a view to a transmission side; FIG. 3 is the same view as in FIG. 1, wherein two valve plates and one lead frame are mounted on the central housing body; FIG. 4 is the same view as in FIG. 2, wherein here too the two valve plates and the lead frame are mounted on the central housing body; FIG. 5 shows an enlarged detail from FIG. 3 without the lead frame; FIG. 6 is a sectional view of one of the valve plates in FIG. 4; and FIG. 7 shows an enlarged illustration of a mounting surface for one of the valve plates on the central housing body in a plan view.FIGS. 1 to 6 show a multifunction housing 10 with a central housing body 1 in various perspectives and views. The multifunction housing 10 serves to accommodate components of an electric axle drive train 40.The multifunction housing 10 with the central housing body 1 comprises a traction machine side 29 facing a traction machine, which can be seen in FIGS. 1 and 3, and a transmission side 30 facing a transmission, which can be seen in FIGS. 2 and 4.The multifunction housing 10 is embodied in multiple parts and comprises, in addition to the central housing body 1, two valve plates 2, 3, a lead frame 4 and an accumulator 5. the valve plate 2 together with the central housing body 1 and the lead frame 4 serves to produce a labyrinth-like fluid circuit for a hydraulic medium, which is also referred to as oil for short. Therefore, the corresponding fluid circuit is also referred to as an oil circuit.The valve plate 3 serves together with the central housing body 1 and the lead frame 4 to represent a fluid circuit for a refrigerant which is independent of the oil circuit. Therefore, this fluid circuit is also referred to as a refrigerant circuit. The oil circuit is fluidically separated from the refrigerant circuit in the central housing body 1.As can be seen inter alia in FIG. 1, the central housing body 1 has on its traction machine side 29 a mounting interface 20 for the accumulator 5, which is again illustrated in FIG. 3. In addition, the central housing body 1 has on its traction machine side 29 four attachment elements 6, 7, 8, 9 for the traction machine, which attachment elements are arranged on a pitch circle. The add-on elements 6 to 9 serve in particular to center the traction machine in the installed state and to support it during the transmission of torques.The central housing body 1 has at the top a mounting surface 11 for the valve plate 2. The mounting surface 11 for the valve plate 2 comprises a labyrinth of fluid channels 66, which together with corresponding fluid channels in the central housing body 1 serve to represent the oil circuit.The oil circuit comprises line connections 12 and 13 on the traction machine side 29 of the central housing body 1. The line connection 13 is, for example, a cooling oil inlet. The cooling oil is provided, for example, by a suitable pump. The cooling oil is then supplied via the line connection 12 to a heat exchanger, for example.Furthermore, the central housing body 1 has an attachment surface 15 for the valve plate 3. The mounting surface 15 comprises a labyrinth of fluid channels 65, which together with corresponding fluid channels in the central housing body 1 serve to represent the refrigerant circuit.The central housing body 1 has a power connection 16 at the top in FIG. 1. In addition, the refrigerant circuit has connection interfaces 21, 22 and 23 on the transmission side 30, as can be seen in FIG. 2. Between the connection interfaces 21 and 23, a sensor connection 25 is furthermore provided on the transmission side 30 of the central housing body 1.Moreover, the central housing body 1 is provided with valve seats 17, 18, 19 of valve devices for the refrigerant circuit. Two transmission interfaces 27, 28 serve in the central housing body 1 for passing through transmission shafts, of which a transmission shaft 31 is shown in FIG. 3. The transmission shaft 31 is preferably a transmission input shaft. The transmission input shaft serves to provide a drive connection to a rotor of the traction machine.The lead frame or lead frame 4 comprises a central terminal 32. The valve plates 2 and 3 are fastened to the central housing body 1 with the aid of screw connections 34. For sealing purposes, sealing devices are provided between the valve plates 2, 3 and the central housing body 1, of which sealing devices a sealing device 60 is shown in section in FIG. 6. The sealing device 60 preferably comprises a sealing plate which is combined with a suitable seal.The refrigerant circuit comprises valve devices 35 with retaining magnets 36 which are mounted on the valve plate 3 and, in the region of the valve seats 18, 19, on the central housing body 1, as can be seen in FIG. 3. In Figs. 3 and 4, it can be seen that bearings 37, 38, 39 are built into the central housing body 1. The bearings 37 and 38 serve for supporting two transmission shafts. The bearing 39 serves for supporting an intermediate shaft.It can be seen in FIG. 5 that the valve devices 35 and the holding magnets 36 are all contacted in an assembly direction, from above in FIG. 5. As can be seen in FIG. 5, connection elements 51 to 54 are mounted in the same mounting direction, that is to say from above in FIG. 5. A solenoid 45 having a contact 47 is contacted in the same mounting direction, from above in FIG. 5. This equal alignment simplifies the assembly, in particular the connection, considerably.It can be seen in FIG. 6 that fluid channels in the valve plate 3 and in the central housing body 1 are illustrated with the aid of bores 61 to 63. The bores 62 and 63 are also referred to as longitudinal bores. Analogously, the bore 61 is referred to as a transverse bore. In general, transverse bores in the multifunction housing 10 are embodied to be significantly shorter than longitudinal bores.FIG. 6 shows how the valve device 35 designed as a switching valve is combined with a nonreturn valve 68 in the multifunction housing 10. The valve device 35 is arranged in the valve plate 3. The check valve 68 is disposed in the central case body 1.In FIG. 7, the mounting surface 11 for the valve plate 2 on the central housing body 1 is shown solely in plan view. In the enlarged illustration, it can be seen that the mounting surface 11 comprises altogether nine holes 72 on the outside for a screw connection. The screw holes 72 are disposed outside a seal groove 73. A plurality of bores 69, an optional blind line 70 and a leakage return 71 are provided in a transmission chamber within the sealing groove 73. Moreover, an optional seat 74 for a filter device is provided within the sealing groove 73. The filter device is an on-line filter.List of reference characters1 Central housing body 2 Valve plate 3 Valve plate 4 Leadframe 5 Accumulator 6 Attachment element 7 Attachment element 8 Attachment element 9 Attachment element 10 Multifunction housing 11 Attachment surface 12 Line connection 13 Line connection 15 Attachment surface 16 Line connection 17 Valve seat 18 Valve seat 19 Valve seat 20 Attachment interface 21 Connection interface 22 Connection interface 23 Connection interface 25 Sensor connection 27 Transmission interface 28 Transmission interface 29 Traction machine side 30 Transmission side 31 Transmission shaft 32 Central connection 34 Screw connection 35 Valve device 36 Retaining magnet 37 Bearing 38 Bearing 39 Bearing 40 Electrical axle drive train 41 Line connection 42 Line connection 45 Switching magnet 47 Contact 51 Connection element 52 Connection element 53 Connection element 54 Connection element 60 Sealing device 61 Bore 62 Bore 63 Bore 65 Fluid channels 66 Fluid channels 68 Check valve 69 Bores 70 Optional blind line 71 Leakage return 72 Holes for a screw connection 73 Sealing groove 74 Optional seat of a filter device

Claims

Multifunction housing (10) for accommodating components of an electric axle drive train (40) for a motor vehicle, wherein the multifunction housing (10) comprises a central housing body (1) in which fluid ducts (65, 66) for different fluids are integrated, wherein the central housing body (1) comprises bearing mounts for at least two transmission shafts (31) and fluid ducts (66) for a cooling and / or lubricating medium, characterized in that the central housing body (1) comprises fluid ducts (65) for a refrigerant and has mounting surfaces (11, 15) for at least two valve plates (2, 3) which, in combination with the fluid ducts (66, 65) in the central housing body (1), represent fluid circuits for different fluids which are fluidically separated from one another.Multifunction housing according to Claim 1, characterized in that the central housing body (1) has an attachment interface (20) for an accumulator (5) and / or a filter device.Multifunction housing according to Claim 1 or 2, characterized in that the valve plates (2, 3) have mounting surfaces for a leadframe (4).Multifunction housing according to one of the preceding claims, characterized in that the valve plates (2, 3) and the central housing body (1) have mounting interfaces for valve devices (35).Multifunction housing according to one of the preceding claims, characterized in that the valve plates (2, 3) and the central housing body (1) have connection interfaces (21 to 23) for fluid lines.An electric axle drive train (40) for a motor vehicle having a multifunction housing (10) according to one of the preceding claims.

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