Electric auxiliary power take-off assembly for a utility vehicle
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-28
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026052179_13082026_PF_FP_ABST
Abstract
Description
[0001] ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0002] Electric power take-off system for a commercial vehicle
[0003] The invention relates to an electric power take-off arrangement for a commercial vehicle with the features of the preamble of claim 1.
[0004] It is common practice to operate superstructures on commercial vehicles, such as cranes, tippers, etc., via the combustion engine using PTOs (power take-offs). The energy is usually supplied by a hydraulic pump, which acts as a power transmission and can handle high loads. The electrification of vehicle technology also requires a corresponding solution for the independent operation of these superstructures. For this purpose, the combustion engine or transmission is replaced by an electric motor, which generates the necessary torque to drive the hydraulic pump.
[0005] For example, German patent application DE 102021 205866 A1 discloses a heat transfer arrangement for a power train of a machine, comprising a first electric drive, a second electric drive, a gearbox connected to the first and second electric drives for torque transmission, and a heat transfer system with a cooling circuit, wherein the heat transfer system is configured to dissipate heat generated during operation of the power train by the electric drives by means of a coolant flow from the cooling circuit and to supply at least a portion of the dissipated heat to the gearbox for heating purposes. For example, the second electric drive can provide work power for adjusting a tool of the machine.
[0006] The invention aims to create a secondary drive arrangement of the type mentioned above, which is characterized by a robust design and simple assembly.
[0007] This problem is solved according to the invention by a secondary drive arrangement with the features of claim 1. Advantageous embodiments will become apparent from the dependent claims, the drawings and / or the description. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0008] The invention relates to an electric power take-off (PTO) arrangement designed and / or suitable for use in a commercial vehicle. In particular, the PTO arrangement serves to transmit energy to at least one implement that can be coupled and / or is coupled to the commercial vehicle. The commercial vehicle can be an agricultural machine, for example a tractor, a construction machine, for example an excavator, or a special-purpose vehicle.
[0009] The power take-off (PTO) assembly includes a power take-off, also known as a "PTO". The PTO primarily serves to provide auxiliary power to the implement. For this purpose, the implement can be mechanically and / or hydraulically connected to the PTO.
[0010] The power take-off arrangement includes an electric machine designed and / or suitable for providing electric drive torque or power for the power take-off. The electric machine can be directly or via a gearbox coupled to the power take-off. In other words, the power take-off can be formed or driven either by a drive shaft of the electric machine or by an output shaft of a gearbox. Preferably, the electric machine is designed as an internal rotor. The electric machine essentially comprises a stator and a rotor, which is arranged radially within the stator. The electric machine defines an axis of rotation, particularly with the rotor axis.
[0011] The power take-off assembly has a heat transfer system with a cooling circuit and an oil circuit, wherein the heat transfer system is designed and / or suitable for transferring heat generated during the operation of the electric machine between the cooling circuit and the oil circuit. In particular, the cooling circuit serves essentially to cool one or more electrical components of the power take-off assembly, such as the electric machine and / or power electronics for the electric machine. The oil circuit serves essentially to lubricate one or more mechanical components of the power take-off assembly, such as the ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0012] The oil circuit is used for the electric motor and / or the gearbox. Optionally, it can be used to cool one or more components of the electric motor and / or the gearbox.
[0013] The heat transfer system comprises several fluid-carrying components. Subfluid-carrying components are, in particular, components of the heat transfer system that serve to guide and / or control a fluid from the cooling circuit and / or the oil circuit. Preferably, the components are designed as independent units that are mounted or attached separately.
[0014] The power take-off assembly comprises a housing designed and / or suitable for accommodating the electric machine. The housing consists of a base and a cover, which are connected to each other axially with respect to the axis of rotation. In particular, the base and cover define a housing space, in which the electric machine is arranged. Specifically, the stator is arranged within the base and / or rotationally fixed to it. Preferably, the base has an axially open mounting opening for mounting the electric machine, especially the stator, which is closed by the cover in the final assembly state. For example, the base and cover are designed as cast components, such as those made of die-cast aluminum.
[0015] The housing cover has a power take-off (PTO) connection interface arranged coaxially to the axis of rotation, which is designed and / or suitable for connecting a drive unit to the PTO. In particular, the drive unit is mechanically connected to the housing cover via the PTO connection interface, and is also technically connected to the PTO. The drive unit can be designed as a mechanical or hydraulic drive unit. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0016] For example, the mechanical drive device can be a power take-off (PTO) shaft or a driveshaft. For example, the hydraulic drive device can be a hydraulic pump. Preferably, the at least one attachment component is arranged radially offset from the PTO connection interface. Particularly preferably, all attachment components are arranged distributed around the PTO connection interface.
[0017] Within the scope of the invention, it is proposed that at least or exactly one, preferably several, and in particular all, of the attachment components of the heat transfer system are recessed in the housing cover in an axial direction with respect to the axis of rotation, such that a mounting space for the at least one attachment component is arranged at least partially in the housing body in the axial direction. In other words, the housing cover is designed such that the at least one attachment component is received at least partially within the housing cover and simultaneously extends partially into the housing body or the housing space. In particular, the attachment components arranged on the housing cover are located outside a mounting space of the drive unit. In other words, a mounting space of the drive unit is arranged axially offset and / or spaced apart from the mounting space of the attachment components.
[0018] The invention is based on the understanding that integrating an electric motor for a power take-off (PTO) in commercial vehicles is usually associated with limited installation space. Furthermore, the power requirements can vary depending on the application, which means the size and weight of the electric motor can vary accordingly. The output speeds required for hydraulic pumps are usually around 2000 rpm, which is below the capacity of the electric motor, so higher speeds can only be achieved with the aid of a gearbox. The variety of possible drive devices, such as hydraulic pumps, that can be connected, especially in conjunction with an integrated gearbox, presents the challenge of providing a sufficient support base across the housing division. In the previous design, the mounting components were attached to the housing.
[0019] The housing cover is positioned, which also serves as the interface for connecting the power take-off unit. To prevent the mounting components from protruding into the installation space of the power take-off unit, the housing cover is slightly cup-shaped. This positions the mounting points to the vehicle relatively far from the power take-off connection interface, resulting in a long lever arm. The weight and vibrations or shocks from the power take-off unit can thus lead to considerable bending loads on the housing. Depending on the length of the lever arm, this can result in very high stresses on the housing.
[0020] The advantage of the invention lies in the fact that the housing cover can be made significantly flatter due to the recessed arrangement of the mounting component(s), without the mounting components creating an interfering contour during the assembly of the drive unit or protruding into the installation space of the drive unit. The flat design of the housing cover reduces the lever arm and thus the bending loads on the housing. This results in a power take-off arrangement that is characterized by a significantly more robust construction. Furthermore, the recessed arrangement of the mounting components simplifies the assembly of the housing cover, as they do not create an interfering contour during assembly.
[0021] In a specific embodiment, the at least one mounting component is recessed into the housing cover in such a way that the axial projection of the mounting component(s) to the housing cover is less than or equal to the axial projection of the power take-off connection interface. In particular, at least one, preferably all, mounting component(s) is largely recessed into the housing cover. "Largely" here means that the mounting components are recessed into the housing cover by more than 50%, preferably more than 70%, and specifically more than 90% of their axial length. This ensures that none of the mounting components protrudes into the installation space of the drive unit and allows the housing cover to be designed with a particularly flat profile.
[0022] In a further specific embodiment, it is provided that the housing base and the housing cover are aligned in the axial direction in a housing sealing plane. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0023] are connected to each other, wherein at least one, preferably all, attachment components^) lie in the housing sealing plane and / or penetrate the housing sealing plane. In particular, the housing sealing plane is defined by a radial plane of the axis of rotation. Preferably, the housing base body and the housing cover abut each other fluid-tight in the housing sealing plane, preferably via at least one sealing means. For this purpose, the housing base body and the housing cover each have a sealing flange, via which the housing base body and the housing cover abut each other in a sealing manner in the axial direction and / or are connected to each other, preferably screwed together. In simplified terms, the housing sealing plane forms a separating plane between the housing base body and the housing cover.It is particularly preferred that the at least one mounting component is arranged largely, preferably more than 50%, and preferably more than 80%, behind the housing sealing plane within the housing body or in the housing space. In other words, the axial installation space for the mounting components is largely shifted into the housing or the housing space. This allows the housing cover to be designed particularly flat, thereby reducing the bending load acting on the housing cover.
[0024] In a further development, the power take-off arrangement is provided with a gearbox located in the housing, which is designed and / or suitable for translating the electric drive torque. For this purpose, the electric machine is coupled to a gearbox input, preferably an input shaft, and the power take-off is coupled to a gearbox output, preferably an output shaft, of the gearbox. The gearbox can be designed as a multi-stage or planetary gearbox, or the like. Preferably, the gearbox is designed for speed reduction, whereby a higher speed of the electric machine is translated into a higher speed at the power take-off.
[0025] According to this further development, it is provided that the at least one mounting component is arranged axially, at least partially, within a gearbox section of the housing, in particular the housing space. Specifically, the housing space is divided into a motor section for accommodating the electric motor. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0026] and a transmission section to accommodate the transmission. In principle, the transmission section and the motor section can be spatially and / or fluidically separated from each other. Alternatively, the motor section and the transmission section can also jointly form the housing space. Particularly preferably, the transmission input and the transmission output, or the input shaft and the output shaft, are arranged coaxially and / or concentrically to the axis of rotation or the power take-off connection interface. In particular, the transmission section is designed such that both the transmission itself and the at least one attachment component fit within it. Preferably, the transmission is arranged radially offset from the at least one attachment component, and in particular radially within all attachment components. Particularly preferably, the transmission section is limited in the radial direction by the housing body and in the axial direction by the housing cover.A power take-off arrangement is therefore proposed in which the gearbox and the attachment components are overlapping each other within the gearbox section, resulting in a particularly compact and space-saving housing.
[0027] In a specific implementation, the housing cover is provided with at least one or exactly one recess, preferably for each mounting component, in which the respective mounting component is recessed. In particular, the recess is produced using a forming process, preferably a die casting process. The recess is especially preferably formed by a trough that is open outwards at least in one axial direction with respect to the axis of rotation. In other words, the mounting components are inserted or can be inserted into the respective recess in the axial direction. The recesses allow the drive components to be easily recessed into the housing cover, while simultaneously increasing the rigidity of the housing cover.
[0028] In a more detailed specification, it is stipulated that at least one mounting component is positively engaged and / or precisely fitted within the recess. In particular, the recesses each form a negative contour for the respective mounting component. Optionally, it may be provided that one, several, or ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0029] All mounting components can be inserted or installed in their respective recesses in only one orientation. Specifically, the mounting components are held fluid-tight within their respective recesses, ensuring a seal against the housing cover. Furthermore, the mounting components within the recesses can be separated from the housing space, particularly the gearbox section. This enables a particularly secure installation of the mounting components.
[0030] In a further specification, it is provided that the at least one recess is bounded in the axial direction by a base surface extending in a radial plane of the axis of rotation, with a corresponding fluid connection for the respective mounting component integrated into the base surface. In particular, the at least one mounting component can rest against and / or be mounted on the base surface in the axial direction. In principle, the mounting component and the respective associated fluid connection can be in direct contact with each other. Alternatively or optionally, a fluid chamber is formed between the base surface and the mounting component, whereby the fluid connection and the mounting component are fluidically connected to each other. The fluid connection can be connected to at least one fluid line formed and / or routed in the housing, preferably of the oil or cooling circuit.Specifically, the fluid connection is formed by a through-opening, preferably a bore, axially aligned with the axis of rotation. A fluid connection between the fluid connection and the associated mounting component is particularly preferred when the mounting component is installed in the recess, preferably via a plug connection. A housing cover is thus proposed, which enables a particularly simple connection of the mounting components to the respective fluid connection.
[0031] In a further development, it is stipulated that the housing base body has at least one or exactly one vehicle connection interface, which is designed and / or suitable for connecting the housing to a chassis of the commercial vehicle. The vehicle connection interface is located in a connection plane extending radially to the axis of rotation, whereby the at least one mounting component is located in ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0032] the connection plane and / or penetrates the connection plane. In particular, the housing base body is mechanically connected or connectable to the chassis via the vehicle connection interface. Preferably, the housing base body has more than two, preferably more than four, and in particular more than six, vehicle connection interfaces, with at least two of the vehicle connection interfaces being located opposite each other in the connection plane. Particularly preferably, the vehicle connection interfaces are each designed as a screw boss. In particular, the axial distance between the housing sealing plane and the connection plane, or between the power take-off connection interface and the vehicle connection interface, is as small as possible. For example, it can be provided that the axial distance between the housing sealing plane and the connection plane, or between the power take-off connection interface and the vehicle connection interface, is as small as possible.The distance between the power take-off (PTO) connection interface and the vehicle connection interface should be less than 50 mm, preferably less than 20 mm, and specifically less than 10 mm. By placing at least one vehicle connection interface close to the PTO connection interface, the lever arm between the drive unit and the vehicle connection interface can be reduced, or the center of gravity of the drive unit can be moved closer to the vehicle connection interface, thereby increasing the housing stiffness.
[0033] In a further specification, it is provided that the power take-off (PTO) connection interface lies in a further connection plane extending radially to the axis of rotation, wherein the connection plane of the vehicle connection interface lies axially between the radial plane of the at least one base surface and the further connection plane of the PTO connection interface. Specifically, the housing sealing plane is arranged axially between the two connection planes. In particular, the base surfaces of the various mounting components extend in different axially spaced radial planes, with the connection plane arranged between the housing sealing plane and all radial planes of the base surfaces. In simplified terms, the recesses are offset axially inwards into the housing relative to the at least one vehicle connection interface.Thus, the housing base body can be pulled forward axially as far as necessary, ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03.
[0034] that the vehicle connection interface can be arranged very close to the power take-off connection interface or the further connection level.
[0035] In a specific embodiment, the housing cover comprises a cylindrical section arranged coaxially to the axis of rotation and a flanged section extending radially to the axis of rotation. The power take-off connection interface is located on the end face of the cylindrical section and / or formed by it. Furthermore, the at least one mounting component is recessed into the flanged section. In particular, the power take-off is routed out of the housing via the cylindrical section and / or can be connected to the drive unit. In simplified terms, the cylindrical section forms a mounting flange to which the drive unit can be attached, in particular bolted, to the housing cover. Preferably, the cylindrical section and the flanged section are manufactured from a single piece of material, preferably from a single casting.In particular, the flange section extends in a further radial plane of the axis of rotation or parallel to the housing sealing plane. Most preferably, the flange section forms the sealing flange of the housing cover, via which the housing cover is connected to the housing body. Specifically, in its simplest embodiment, the flange section is designed as a flat plate into which the recesses for receiving the respective mounting components are formed. This results in a particularly flat design of the housing cover, thereby minimizing the axial projection of the cylinder section and / or the axial distance between the at least one vehicle connection interface and the power take-off connection interface.
[0036] In a further development, it is provided that several reinforcing ribs, spaced apart from each other in the circumferential direction, are formed between the cylinder section and the flange section. In particular, the reinforcing ribs extend in a radial direction with respect to the axis of rotation. Preferably, the reinforcing ribs are arranged at uniform intervals from each other in the circumferential direction. Specifically, the housing cover has more than ten, preferably more than twenty, of the reinforcing ribs. Specifically, the reinforcing ribs extend in axia-ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0037] The direction extends largely or completely beyond the axial projection of the cylinder section. Therefore, a housing cover is proposed which is characterized by particularly high rigidity.
[0038] In a further specific implementation, it is provided that the cooling circuit and the oil circuit run at least partially through the housing, with the fluid-carrying attachments within the housing being fluidically connected to the cooling circuit and / or the oil circuit. Preferably, at least one attachment is designed as an oil-carrying attachment, which is fluidically connected to the oil circuit in order to guide and / or control an oil flow. Alternatively or optionally, at least one attachment is designed as a coolant-carrying attachment, which is fluidically connected to the cooling circuit in order to guide and / or control a coolant flow. In particular, the fluid-carrying attachments are fluidically connected to the cooling circuit or the oil circuit within the housing via the respective fluid connection.Preferably, the oil circuit includes an oil sump, with the oil circuit running from the oil sump to at least one drive component of the electric machine and / or at least one transmission component of the gearbox via the at least one oil-carrying component within the housing. Preferably, the power take-off assembly, preferably the housing, has a coolant inlet and a coolant outlet, with the cooling circuit running from the coolant inlet to the coolant outlet via the at least one coolant-carrying component within the housing. The fluid-flow connection of the fluid-carrying components within the housing allows for a particularly compact and simple fluid routing.Because all fluid connections of the add-on components are integrated into the housing cover, they can be easily connected to the respective circuit and the add-on components can be easily replaced in case of repair or service.
[0039] In a specific implementation, it is planned that the fluid-carrying attachment components will be connected to the cooling circuit and the oil circuit by a flow-related ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0040] The system consists of a connected heat exchanger, an oil pump fluidically connected to the oil circuit, and an oil filter fluidly connected to the oil circuit, wherein the oil circuit and the cooling circuit are thermally coupled via the heat exchanger. Preferably, the heat exchanger, the oil filter, and the oil pump are each recessed, preferably mostly or completely recessed, in a corresponding recess in the housing. Preferably, all fluid connections necessary for the respective component open within the recess, so that they are fluidically connected to the respective circuit within the recess. In particular, the heat exchanger is fluidically arranged downstream of the heat source, preferably the power electronics. Specifically, the heat exchanger serves for heat transfer between the cooling circuit and the oil circuit.In simplified terms, the heat exchanger serves as a heat sink for the cooling circuit or the oil circuit. Specifically, the oil pump is designed as a suction pump, which draws the oil from the oil sump and delivers it to at least one oil supply point of the electric motor and / or the transmission. The oil filter, in particular, serves to filter the oil, and is preferably located on the pressure side of the oil pump. A housing cover is therefore proposed, to which all components, preferably those subject to wear and / or requiring connections, are mounted and thus easily accessible.
[0041] In a further specification, it is provided that the heat exchanger is fluidically integrated into the oil circuit between the oil filter and the oil pump. Specifically, the heat exchanger is arranged circumferentially with respect to the axis of rotation on the front of the housing cover between the oil filter and the oil pump. Preferably, the heat exchanger and the oil pump are arranged in a lower housing half and / or the oil filter in an upper housing half. Thus, an arrangement of the components is proposed which is characterized by a particularly simple connection and fluid-related integration of the components. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0042] In a further specification, the heat exchanger is provided with an oil inlet and an oil outlet, which are arranged diagonally opposite each other. The heat exchanger is mounted at an angle in the housing cover, so that the oil pump is connected directly to the oil inlet via exactly one oil inlet channel, and the oil filter is connected directly to the oil outlet via exactly one oil outlet channel. Preferably, the oil inlet channel and / or the oil outlet channel are formed directly in the housing cover, for example, by means of a bore. In particular, the oil inlet channel and / or the oil outlet channel each form a fluid connection that opens within the recess of the respective attachment component. Preferably, the oil inlet channel and / or the oil outlet channel open within the respective fluid chamber. The oil inlet channel and / or the oil outlet channel can form the fluid connection that is integrated into the base surface.Alternatively, the oil inlet channel and / or the oil outlet channel can also form an additional fluid connection, which is optionally integrated into the base surface or opens radially into the fluid chamber with respect to the axis of rotation. Particularly preferably, the heat exchanger is arranged in an inclined position such that the diagonally opposite oil inlet and oil outlet are perpendicular or substantially perpendicular to each other with respect to a vertical axis of the housing. This allows for a particularly simple design of the oil inlet and oil outlet channels. Furthermore, the inclined position of the heat exchanger prevents any intersection between fluid channels, thus enabling particularly simple fluid flow.Furthermore, the inclined position of the heat exchanger frees up additional installation space for at least one further vehicle connection interface, which is located or can be located laterally, particularly in the area of the heat exchanger.
[0043] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These will show:
[0044] Fig. 1 shows a sectional view of a power take-off arrangement as an embodiment of the invention; ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0045] Fig. 2 shows the auxiliary drive arrangement in three-dimensional representation with a mounted drive unit;
[0046] Fig. 3 shows a housing of the auxiliary drive assembly in a perspective front view;
[0047] Fig. 4 shows the housing of the auxiliary drive assembly in a perspective view from below;
[0048] Fig. 5 shows the housing in a perspective sectional view;
[0049] Fig. 6 shows a sectional view through a heat exchanger arranged in the housing;
[0050] Fig. 7 shows a sectional view through an oil filter arranged in the housing;
[0051] Fig. 8 shows a sectional view through an oil pump arranged in the housing;
[0052] Fig. 9 shows a sectional view in a radial plane of a rotational axis through the heat exchanger, oil filter and oil pump arranged in the housing.
[0053] Figure 1 shows a power take-off arrangement 1, which is designed to drive an attachment (not shown) that can be coupled to and / or is coupled to a commercial vehicle. For this purpose, the power take-off arrangement 1 has a power take-off 2, via which the attachment can be driven directly or via a drive unit 3, as shown in Figure 2.
[0054] The power take-off arrangement 1 comprises an electric machine 4, which generates an electric drive torque for the power take-off 2. The electric machine 4 includes a stator 5 and a rotor 6, the rotor 6 being arranged radially inside the stator 5. Furthermore, the electric machine 4 has a rotor shaft 7, which is non-rotatably connected to the rotor 6 and is rotatably mounted with respect to a rotational axis 100. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0055] The power take-off assembly 1 includes a gearbox 8, through which the electrical drive torque is transmitted to the power take-off 2. The gearbox 8 has an input shaft 9 and an output shaft 10, which are arranged coaxially to the axis of rotation 100. For this purpose, the gearbox 8 is, for example, designed as a planetary gearbox, wherein the input shaft 9 is non-rotatably connected to a sun gear 11 and the output shaft 10 to a planet carrier 12. The rotor shaft 7 is in turn non-rotatably connected to the input shaft 9, and the power take-off 2 is non-rotatably connected to or formed by the output shaft 10. Several planet gears 13 are rotatably mounted on the planet carrier 12, which mesh with the sun gear 11 on one side and with a ring gear 14 on the other.
[0056] The auxiliary power unit 1 has a housing 15 comprising a housing base 16 and a housing cover 17. The housing base 16 and the housing cover 17 are connected to each other in an axial direction with respect to the axis of rotation 100 in a housing sealing plane 101 and / or are abutting each other in an axial direction with respect to the axis of rotation 100 in the housing sealing plane 101, preferably sealingly.
[0057] The housing 15 essentially comprises a motor section 18 for accommodating the electric machine 4 and a transmission section 19 for accommodating the gearbox 8, wherein the motor section 18 and the transmission section 19 are spatially and / or fluidically separated from one another. Furthermore, the housing 15 has an oil chamber 20, which is located in a base region of the housing 15 or radially below the motor section 18 and the transmission section 19. An oil sump may be arranged in the oil chamber 20, into which oil from the motor section 18 and / or the transmission section 19 can flow or drip and is collected.
[0058] Furthermore, the auxiliary drive arrangement 1 has power electronics 21, which are located on a radial outer side, in particular radially opposite the oil-ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0059] The space 20 is located on the upper side of the housing base 16. The power electronics 21 are electrically connected to the electric machine 4 and serve to control and supply power to the electric machine 4.
[0060] Figure 2 shows the power take-off assembly 1 in a perspective view, with the housing 15 graphically suppressed to better illustrate a heat transfer system 22 of the power take-off assembly 1. The heat transfer system 22 has a cooling circuit 23 and an oil circuit 24, which are thermally coupled. The heat transfer system 22 also has several attachment components 25, which are designed to control and / or guide a fluid of the cooling circuit 23 and / or the oil circuit 24.
[0061] The cooling circuit 23 serves to cool the power electronics 21, with the cooling circuit running section by section through the housing 15. For this purpose, the secondary drive arrangement 1 has a coolant inlet 26 and a coolant outlet 27, via which the cooling circuit 23 can be connected to a cooling system of the commercial vehicle. The power electronics 21 are arranged fluidically between the coolant inlet 26 and the coolant outlet 27, so that the cooling circuit 23 runs section by section through the power electronics 21.
[0062] The oil circuit 24 serves to cool and / or lubricate the electric machine 4 and / or the gearbox 8, the oil circuit 24 being a closed circuit within the housing 15. For this purpose, oil is supplied along the oil circuit 24 from the oil chamber 20 to the electric machine 4, preferably the rotor 6 and / or the stator 5, and / or the gearbox 8, and then collected again in the oil chamber 20.
[0063] The mounting components 25 are designed as an oil pump 28, an oil filter 29, and a heat exchanger 30, all of which are mounted axially with respect to the axis of rotation 100 on the housing cover 17, as shown in Figure 3. The heat exchanger 30 is fluidically integrated into the oil circuit 24 on one side and into the cooling circuit 23 on the other. (ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03)
[0064] The cooling circuit 23 and the oil circuit 24 are thermally coupled to each other via the heat exchanger 30 for heat transfer. The heat exchanger 30 has an oil inlet 31 and an oil outlet 32 for connecting the oil circuit 24, as well as a coolant inlet 33 and a coolant outlet 34 for connecting the cooling circuit 23. At least the coolant outlet 27 is formed by the coolant outlet 34 or is located directly on the heat exchanger 30.
[0065] The oil pump 28 is designed to pump oil from the oil chamber 20 along the oil circuit 24 to several oil supply points 35a, 35b, wherein the oil pump 28 is connected on a suction side to the oil chamber 20 and on a pressure side to the oil inlet 31 of the heat exchanger 30. The oil filter 29 serves to filter the oil circulating along the oil circuit 24, which for this purpose passes through the oil filter 29. The oil filter 29 is fluidically integrated into the oil circuit 24 between the oil outlet 32 and the oil supply points 35a, 35b. In simplified terms, the heat exchanger 30 is fluidically arranged between the oil pump 28 and the oil filter 29, with the attachment components 25 being fluidly connected to each other within the housing 15.
[0066] In the illustrated embodiment, the drive unit 3 is designed as a hydraulic pump, which is configured to transmit a power take-off to the attachment. For this purpose, the drive unit 3 is attached to the housing cover 17 via a power take-off connection interface 36 arranged on the housing cover 17, as shown, for example, in Figure 1 or 3, and connected to the power take-off 2.
[0067] Figure 3 shows the housing 15 with the attachment components 25 in a perspective view from the front, showing that all attachment components 25 are recessed axially in the housing cover 17 with respect to the axis of rotation 100, so that the attachment components 25 are arranged at least partially in the housing base body 15, preferably in the transmission section 19. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0068] The housing cover 17 has a cylindrical section 37 arranged coaxially to the axis of rotation 100 and a flanged section 38, which extends radially with respect to the axis of rotation 100 and parallel to the housing sealing plane 101. The power take-off connection interface 36 is located on the end face of the cylindrical section 37 or is formed by it, with the power take-off 2 being guided coaxially and / or concentrically to the axis of rotation 100 through the cylindrical section 37. In an assembled state, the drive unit 3 is connected to the power take-off 2 via a drive connection, for example, a plug connection, and to the cylindrical section 37 via a mechanical connection, for example, a screw connection.The mounting components 25 are mostly, preferably more than 90%, recessed in the flange section 38, so that an axial projection of the mounting components 25 with respect to the axis of rotation 100 is less than or equal to an axial projection 102 of the cylinder section 37 or the auxiliary power connection interface 36.
[0069] Furthermore, it can be seen from Figure 3 that several stiffening ribs 39 are formed between the cylinder section 37 and the flange section 38, which are evenly spaced from each other in the circumferential direction with respect to the axis of rotation 100 and extend in the axial direction over the axial projection 102.
[0070] Figure 4 shows the housing 15 with the mounting components 25 in a perspective view from below, revealing that the housing base 16 has four vehicle connection interfaces 40a, 40b, 40c, 40d. The vehicle connection interfaces 40a, 40b, 40c, 40d are each designed as a screw boss, via which the housing base 16 can be screwed to a chassis of the commercial vehicle (not shown). Two of the vehicle connection interfaces 40a, 40b, located in the area of the housing cover 17, lie in a common connection plane 103, which preferably extends parallel to the housing sealing plane 101. It is provided that all mounting components 25 lie in or penetrate the housing sealing plane 101 and / or the connection plane 103.Thus, the installation space for the attachment components 25 is largely relocated to the housing base body 16, whereby the flange-ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03.
[0071] Section 38 can be designed to be flat and / or level. This allows the cover-side vehicle connection interfaces 40a, 40b to be arranged as close as possible to the PTO connection interface 36, or the axial projection 102 to be reduced to a minimum. This significantly increases the stiffness and robustness of the housing 15.
[0072] Figure 5 shows the housing 15 in a sectional view along the axis of rotation 100, revealing that the housing cover 17 has a corresponding recess 41a, 41b, 41c for each mounting component 25 (only recess 41b for the oil pump 29 is shown here), in which the respective mounting component 25 is recessed. The recesses 41a, 41b, 41c are designed to be complementary in shape to the respective mounting component 25, so that they are positively and / or precisely fitted within their respective recesses 41a, 41b, 41c. The recesses 41a, 41b, 41c are integrally formed in the flange section 38, thereby providing additional stiffening to the housing cover 17. The recesses 41 a, 41 b, 41 c extend in an axial direction with respect to the axis of rotation 100 within the housing base body 16 in the gear section 19.
[0073] Figure 5 further shows that the auxiliary drive connection interface 36 lies in a further connection plane 104, which is arranged axially spaced from the connection plane 103 and the housing sealing plane 101. The housing sealing plane 101 is arranged axially between the two connection planes 103 and 104.
[0074] Figures 6 to 8 each show a sectional view along the axis of rotation 100 through the respective attachment component 25, showing that the respective recess 41a, 41b, 41c is bounded axially with respect to the axis of rotation 100 by a base surface 42a, 42b, 42c. The base surfaces 42a, 42b, 42c extend in a radial plane 105a, 105b, 105c of the axis of rotation 100, with the connection plane 103 being arranged axially between the further connection plane 104 and all radial planes 105a, 105b, 105c of the base surfaces 42a, 42b, 42c. Furthermore, it can be seen that at least one ZF Friedrichshafen AG file 304400 Friedrichshafen 2025-02-03
[0075] Fluid connection 43 for the respective attachment component 25 is integrated into the corresponding base surface 42a, 42b, 42c. The attachment components 25 are connected to the cooling circuit 23 or the oil circuit 24 via the fluid connection 43.
[0076] As shown in Figure 6, the heat exchanger 30 is directly connected to several fluid connections 43 arranged in the base surface 42c – only one of the fluid connections 43 is shown here – in order to connect the heat exchanger 30 to the cooling circuit 23 and the oil circuit 24. Specifically, this means that three fluid connections 43 are arranged in the base surface 42c, through which the oil inlet 31, the oil outlet 32, and the coolant inlet 33 are connected. In the sectional view shown, a coolant channel 46 is formed in the housing body 16, which fluidically connects the coolant inlet 26 with the coolant outlet 27, with the coolant channel 46 being directly connected to the coolant inlet 33 via one of the fluid connections 43.
[0077] As shown in Figure 7, the oil filter 29 is directly connected to a fluid connection 43 located in the base surface 42c to connect the oil filter 29 to the oil circuit 24. Specifically, this means that a fluid connection 43 is arranged in the base surface 42b, through which the oil filter 29 is directly connected on one outlet side. In the sectional view shown, an oil distribution channel 47 is formed in the housing body 16, which fluidically connects the outlet side of the oil filter 29 to the oil supply points 35a, 35b, with the oil distribution channel 47 being directly connected to the oil filter 29 via the fluid connection 43.
[0078] According to Figure 8, the oil pump 28 is connected to a fluid connection 43 arranged in the base surface 42a via a fluid chamber 48 to connect the oil pump 28 to the oil circuit 24. Specifically, this means that a fluid chamber 48 is formed axially between the base surface 42a and the oil pump 28, with a fluid connection 43 arranged in the base surface 42a. The oil pump 28 is connected to the oil circuit 24 on a suction side via the fluid chamber 48. In the sectional view shown, the fluid connection 43 opens into the ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03
[0079] oil chamber 20, so that oil can be drawn from the oil sump of the oil chamber 20 directly via the fluid connection 43 or via an oil suction line 49 connected to the fluid connection 43, as shown in Figure 1.
[0080] Figure 9 shows a sectional view of the housing 5 in a radial plane of the axis of rotation 100, in particular the connection plane 103, through the mounting components 25. It can be seen that the heat exchanger 30 is arranged at an angle, so that the oil inlet 31 and the oil outlet 32 are arranged essentially perpendicular to one another with respect to a vertical axis 106 of the housing 15. An oil inlet channel 44 and an oil outlet channel 45 are formed in the housing cover 17 to connect the heat exchanger 30 to the oil circuit 24. The oil inlet channel 44 fluidically connects a pressure side of the oil pump 28 to the heat exchanger 30, with the oil inlet channel 44 being directly connected to the oil inlet 31 via the fluid connection 43. The oil outlet channel 45 connects an inlet side of the oil filter 28 fluidically with heat exchanger 30, where the oil outlet channel 45 is directly connected to the oil outlet 32 via the fluid connection 43.
[0081] The inclined arrangement of the heat exchanger 30 ensures simple fluid flow without crossing the coolant and oil channels 44, 45, 46, 47. Furthermore, additional vehicle connection interfaces (not shown) can be implemented in the area of the heat exchanger 30, or vehicle connection interfaces can be positioned laterally. For example, either four or six of the vehicle connection interfaces 40a, 40b, 40c, 40d can be accommodated on the housing 15. ZF Friedrichshafen AG File 304400
[0082] Friedrichshafen 2025-02-03
[0083] Reference mark
[0084] 1. Power take-off arrangement
[0085] 2 Power take-off
[0086] 3 Drive unit
[0087] 4 electric machine
[0088] 5 Stator
[0089] 6 Rotor
[0090] 7 Rotor shaft
[0091] 8 gearboxes
[0092] 9 Input shaft
[0093] 10 Output shaft
[0094] 11 Sun wheel
[0095] 12 planetary carriers
[0096] 13 planetary gears
[0097] 14 Ring gear
[0098] 15 cases
[0099] 16 Housing base bodies
[0100] 17 Housing covers
[0101] 18 Engine section
[0102] 19 Gearbox section
[0103] 20 Oil room
[0104] 21 Power Electronics
[0105] 22 Heat transfer system 23 Cooling circuit
[0106] 24 Oil circuit
[0107] 25 attachment components
[0108] 26 Coolant inlet
[0109] 27 Coolant drain
[0110] 28 Oil pump
[0111] 29 oil filters
[0112] 30 heat exchangers
[0113] 31 Oil inlet ZF Friedrichshafen AG File 304400
[0114] Friedrichshafen 2025-02-03
[0115] 32 Oil outlet
[0116] 33 Coolant inlet
[0117] 34 Coolant outlet
[0118] 35a, b Oil supply points
[0119] 36 Power take-off connection interface 37 Cylinder section
[0120] 38 Flange section
[0121] 39 stiffening ribs
[0122] 40a, b, c, d Vehicle connection interfaces 41a, b, c In-depth
[0123] 42a, b, c Floor area
[0124] 43 Fluid connection
[0125] 44 Oil intake channel
[0126] 45 Oil outlet channel
[0127] 46 Coolant channel
[0128] 47 Oil distribution channel
[0129] 48 Fluid space
[0130] 49 Oil suction line
[0131] 100 rotary axis
[0132] 101 Housing sealing plane
[0133] 102 axial overhang
[0134] 103 Connection level
[0135] 104 additional connection levels
[0136] 105a, b, c Radial plane
[0137] 106 High ax se
Claims
ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03 Patent claims 1. Electric power take-off arrangement (1 ) for a commercial vehicle, - with a power take-off (2); - with an electric machine (4) to provide an electric drive torque for the auxiliary drive (2), wherein the electric machine (4) defines a rotation axis (100); - with a heat transfer system (22) for transferring heat generated during the operation of the electric machine (4) between a cooling circuit (23) and an oil circuit (24), wherein the heat transfer system (22) has several fluid-carrying attachment components (25); - with a housing (15) for receiving the electric machine (4), wherein the housing (15) has a housing base body (16) and a housing cover (17), wherein the housing base body (16) and the housing cover (17) are connected to each other in an axial direction with respect to the axis of rotation (100) and wherein the housing cover (17) has a power take-off connection interface (36) arranged coaxially to the axis of rotation (100) for connecting a drive device (3) to the power take-off (2); characterized by the fact that at least one of the attachment components (25) of the heat transfer system (22) is recessed in an axial direction with respect to the axis of rotation (100) in the housing cover (17), so that a space for the at least one attachment component (25) is arranged at least sectionally in the housing body (16) in an axial direction.
2. Electric power take-off arrangement (1) according to claim 1, characterized in that the at least one mounting component (25) is recessed in the housing cover (17) such that the axial projection of the mounting components (25) to the housing cover (17) is less than or equal to the axial projection (102) of the power take-off connection interface (36). ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03 3. Electric power take-off arrangement (1) according to claim 1 or 2, characterized in that the housing base body (16) and the housing cover (17) are connected to each other in the axial direction in a housing sealing plane (101), wherein the at least one mounting component (25) lies in the housing sealing plane (101) and / or penetrates the housing sealing plane (101).
4. Electric power take-off arrangement (1) according to one of the preceding claims, characterized by a gearbox (8) arranged in the housing (15) for translating the electric drive torque, wherein the electric machine (4) is coupled to a gearbox input and the power take-off (2) to a gearbox output of the gearbox (8), wherein the at least one attachment component (25) is arranged in the axial direction at least sectionally in a gearbox section (19) of the housing (15).
5. Electric auxiliary power take-off arrangement (1) according to one of the preceding claims, characterized in that the housing cover (17) has at least one recess (41a, b, c) in which the at least one mounting component (25) is recessed.
6. Electric auxiliary drive arrangement (1) according to claim 5, characterized in that the at least one mounting component (25) is positively engaged and / or precisely fitted within the recess (41a, b, c).
7. Electric auxiliary power take-off arrangement (1) according to claim 5 or 6, characterized in that the at least one recess (41a, b, c) is limited in the axial direction by a bottom surface (42a, b, c) lying in a radial plane (105a, b, c) of the axis of rotation (100), wherein a corresponding fluid connection (43) for the respective attachment component (25) is integrated into the bottom surface (42a, b, c).
8. Electric power take-off arrangement (1) according to one of the preceding claims, characterized in that the housing base body (16) has at least one vehicle connection interface (40a, b, c, d) for connecting the housing. ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03 (15) to a chassis of the commercial vehicle, wherein the vehicle connection interface (40a, b, c, d) is located in a connection plane (103), wherein at least one attachment component (25) is located in the connection plane (103) and / or penetrates the connection plane (103).
9. Electric power take-off arrangement (1) according to claim 8, characterized in that the power take-off connection interface (36) lies in a further connection plane (104), wherein the connection plane (103) of the vehicle connection interface (40a, b, c, d) lies in the axial direction between the radial plane (105a, b, c) of at least one bottom surface (42a, b, c) and the further connection plane (104) of the power take-off connection interface (36).
10. Electric power take-off arrangement (1) according to one of the preceding claims, characterized in that the housing cover (17) has a cylinder section (37) arranged coaxially to the axis of rotation (100) and a flange section (38) extending radially to the axis of rotation (100), wherein the power take-off connection interface (36) is arranged on the end face of the cylinder section (37) and the mounting components (25) are arranged recessed in the flange section (38).
11. Electric auxiliary power take-off arrangement (1 ) according to claim 10, characterized in that several stiffening ribs (39) spaced apart from each other in the circumferential direction are formed between the cylinder section (37) and the flange section (38).
12. Electric power take-off arrangement (1) according to one of the preceding claims, characterized in that the cooling circuit (23) and the oil circuit (24) run at least sectionally through the housing (15), wherein the fluid-carrying attachment components (25) are fluidically connected within the housing (15) to the cooling circuit (23) and / or the oil circuit (24).
13. Electric power take-off arrangement (1) according to one of the preceding claims, characterized in that the fluid-carrying attachment components (25)ZF Friedrichshafen AG File 304400 Friedrichshafen 2025-02-03 a heat exchanger (30) fluidically connected to the oil circuit (24) and the cooling circuit (23), an oil pump (28) fluidly connected to the oil circuit (24) and an oil filter (29) fluidly connected to the oil circuit (24), wherein the cooling circuit (23) and the oil circuit (24) are thermally coupled to each other via the heat exchanger (30).
14. Electric auxiliary drive arrangement (1) according to claim 13, characterized in that the heat exchanger (30) is fluidically integrated into the oil circuit (24) between the oil filter (29) and the oil pump (28).
15. Electric auxiliary drive arrangement (1) according to claim 13 or 14, characterized in that the heat exchanger (30) has an oil inlet (31) and an oil outlet (32) which are arranged diagonally opposite each other, wherein the heat exchanger (30) is arranged in an inclined position in the housing cover (17) so that the oil pump (28) is connected directly to the oil inlet (31) via exactly one oil inlet channel (44) and the oil filter (29) is connected directly to the oil outlet (32) via exactly one oil outlet channel (45).