Wheel head for an attachment and modular wheel head kit

Abstract

The present invention relates to an electrified wheel head for an attachment of a working machine. The invention additionally relates to a modular wheel head kit. The wheel head has a traction motor (10), which is designed as an electric motor and has a motor shaft (14), and a transmission (16). In order to transfer torque, the transmission has a drive assembly (20) with a first planetary gear set (22) and an output assembly (30) with a second planetary gear set (32). The drive assembly (20) and the output assembly (30) are provided in different variants which can be combined with each other in the wheel head.

Description

[0001] Wheel head for an attachment and modular wheel head kit

[0002] Technical area

[0003] The present invention relates to an electrified wheel head for an attachment of a work machine. Furthermore, the invention relates to a modular wheel head assembly kit.

[0004] State of the art

[0005] Work machines are used, for example, in agriculture and construction work. Depending on the desired work, mobile attachments are coupled to the work machine, for example, as a trailer. Typically, the drive power is provided solely by the work machine. However, such work machines must be very powerful in order to be able to operate even at full load with the respective attachments. This can make such work machines expensive and heavy.

[0006] For this reason, there are already attachments that have driven axles. For example, a drive axle of an attachment can be driven via the working hydraulics of the work machine or an electric traction motor in the attachment. A disadvantage, however, can be a limited gear ratio, which means that the attachment can only be operated inefficiently and, alternatively or additionally, a large and expensive drive motor must be installed in the attachment. In addition, attachments are usually produced in small quantities and there are many variants and designs of attachments, which makes providing an efficient transmission optimized for the respective attachment very complex. In addition, drives in attachments can hinder fast overland travel, for example because they can reach excessively high speeds due to fast travel movements with a low load, causing additional drag losses.Overall, the effort required to equip attachments of work machines with a drive is high and can lead to disadvantages in situations where this drive is not required. Description of the invention.

[0007] A first aspect relates to a wheel head for an attachment. It can be an attachment wheel head. The attachment can be coupled to a work machine. The work machine can be designed, for example, as an agricultural machine or construction machine. The work machine can be a motor vehicle. The work machine can, for example, provide hydraulic work power. The work machine can, for example, function as a tractor for the attachment. The work machine can be designed to supply the attachment, for example with electrical, mechanical and, alternatively or additionally, hydraulic power. The attachment can be a vehicle. The attachment can, for example, only be operable together with the work machine. The attachment can enable additional work functions. The attachment can, for example, be designed as a trailer. The attachment can, for example, be designed as a plow.The attachment can, for example, have at least one driven axle. The wheel head can have a wheel or serve to support and drive a wheel of the attachment. The wheel head can also hold and optionally drive a track chain. A wheel can then be understood as a pinion that engages with the track chain. The wheel head can be designed as an electrified wheel head, by means of which the attachment and thus a tractor combination consisting of the work machine and attachment can be driven. The wheel head can also have the wheel, the pinion and, alternatively or additionally, the track chain. The wheel head can be part of an axle of the attachment, for example a steered axle. The wheel head can be attached to the attachment so that it can pivot about a vertical direction.

[0008] The wheel head has a traction motor designed as an electric motor with a motor shaft. The electric motor can be designed to convert electrical energy into mechanical energy. The electric motor can optionally also be designed for recuperation. The electric motor is supplied with electrical energy, for example, by the work machine during operation. The attachment can also have a generator for this purpose, for example, which is driven by the work machine, for example with a power take-off shaft. The electric motor can be designed, for example, as a synchronous machine or an asynchronous machine. The electric motor can be controllable by an inverter. The inverter can be part of the work machine or the attachment. The inverter can be part of the traction motor. For example, the inverter can be integrated into the traction motor.For example, output power can be provided on the motor shaft of the traction motor.

[0009] The traction motor can be designed to be actively cooled. For example, the traction motor can be designed for cooling with a cooling liquid, such as water. The wheel head can have a cooling device designed to cool the traction motor. The cooling device can have a heat exchanger outside a motor housing. The cooling device can have a pump. The cooling device can have cooling channels within the motor housing. This allows the traction motor to provide high drive power even with a compact design and, alternatively or additionally, with a high level of integration into the attachment.

[0010] The wheel head has a gearbox. The gearbox can be designed to transmit torque from the motor shaft to a wheel of the attachment. The gearbox can be designed to transmit torque from the motor shaft to an output. The output can be designed as a wheel or pinion. The output can also be an output of the gearbox, such as an output shaft. The gearbox can provide a gear ratio. For example, the gearbox can have a constant gear ratio. However, the gearbox can also have a stepped or continuously variable gear ratio. The gearbox can, for example, have one or more gears. The gearbox can have an input shaft which is rotatably connected to the motor shaft or is permanently connected in a rotationally fixed manner. The gearbox can have an output shaft which is rotatably connected to the wheel or the track chain or is permanently connected in a rotationally fixed manner.

[0011] The transmission has a drive assembly and an output assembly. This can facilitate a modular design of the transmission and thus adaptation to the traction motor, the work machine, the attachment, and the respective planned applications. The drive assembly can be arranged on the traction motor side to the output assembly in the torque flow. In the axial direction, the drive assembly can be arranged on a side of the output assembly facing the traction motor. Both assemblies can be pre-assembled and then each fastened as a unit to one another and alternatively or additionally to the traction motor. This can simplify assembly. The drive assembly can have a housing. The output assembly can have a housing. The housing of an assembly can also be formed by a rotating element of the assembly.

[0012] The drive assembly includes a first planetary gear set. The first planetary gear set includes a first sun gear, a first planet carrier, and a first ring gear. The first planetary gear set can be configured as a negative planetary gear set or a positive planetary gear set. The first planetary gear set can include a set of first planet gears, which are rotatably mounted on the first planet carrier, for example. The first planetary gear set can include three or four planet gears, for example. The first planet gears can mesh with the first sun gear and the first ring gear, for example.

[0013] The output assembly includes a second planetary gear set. The second planetary gear set includes a second sun gear, a second planet carrier, and a second ring gear. The second planetary gear set can be configured as a negative planetary gear set or a positive planetary gear set. The second planetary gear set can include a set of second planet gears, which are rotatably mounted on the second planet carrier, for example. The second planetary gear set can include three or four planet gears, for example. The second planet gears can mesh with the second sun gear and the second ring gear, for example.

[0014] A planetary gear set is designed, for example, as a minus planetary gear set or a plus planetary gear set. The sun gears, planet carrier, and ring gears of a planetary gear set, for example, form its rotating elements. Each planetary gear set can have one or more planetary gears that are rotatably attached to the planet carrier. For example, the planet gears of a planetary gear set each mesh with a sun gear and a ring gear of a planetary gear set. Each planetary gear set can be free of any elements other than those mentioned here. Each planetary gear set can be free of any rotating elements other than those mentioned here. An axis of rotation of a planetary gear set can correspond to an axis of rotation of the rotating elements. The rotating elements of each planetary gear set can be designed as one or more parts. For example, the first sun gear can have a gear element and a shaft element that are permanently connected to one another in a rotationally fixed manner.The transmission may be free of switching elements other than those mentioned here.

[0015] By using planetary gear sets, a high gear ratio can be achieved with little installation space. For example, the diameter of the first planetary gear set and, alternatively or additionally, the second planetary gear set can be the same as or smaller than the diameter of the traction motor. In addition, a planetary gear set can withstand high torques well. The numbering is merely for assignment purposes. For example, the input assembly and, alternatively or additionally, the output assembly can be free of any other planetary gear sets. For example, the second planetary gear set has only a single ring gear, a single sun gear, and a single planet carrier. The designation as a second sun gear can, for example, serve to clearly assign this sun gear to the second planetary gear set. In general, the numbering and, alternatively or additionally, the designation of components according to their assembly can serve for assignment.The transmission can be free of additional planetary gear sets. The transmission can be free of spur gear stages.

[0016] The motor shaft and the first sun gear are permanently connected to each other in a rotationally fixed manner. The first sun gear can, for example, form the input shaft of the drive assembly. The drive power from the traction motor, for example, is transmitted to the transmission via the first sun gear.

[0017] The first planet carrier is permanently connected to the second sun gear in a rotationally fixed manner. This allows torque to be transmitted between the first planetary gear set and the second planetary gear set, and thus between the input assembly and the output assembly. For example, the second sun gear can have external teeth and the first planet carrier can have internal teeth, providing the rotationally fixed connection. During assembly of the gear head, the external toothed section of the second sun gear, which, for example, does not mesh with the respective second planet gears, can be inserted into the first planet carrier.

[0018] The second planet carrier forms an output of the transmission. The second planet carrier can also form the output of the wheel head. The second planet carrier can correspond to the output shaft of the transmission. For example, the second planet carrier is permanently connected to the wheel, in particular to a wheel rim, in a rotationally fixed manner. The wheel can, for example, be attached to the second planet carrier radially on the outside or on the front side. For example, a pinion, which drives a drive chain, can also be permanently connected to the second planet carrier in a rotationally fixed manner.

[0019] The second ring gear is permanently fixed to a stationary component. For this purpose, the second ring gear can, for example, be permanently connected to the stationary component in a rotationally fixed manner. This allows a torque transmitted in the second planetary gear set to be supported. For example, the second ring gear can be permanently connected indirectly or directly to a frame or body of the attachment in a rotationally fixed manner. The stationary component can be designed as a housing of the drive assembly. The stationary component can also be designed as the first ring gear or a housing of the traction motor. The stationary component can, for example, be an immovable part of the frame or body of the attachment. The stationary component can be designed in one piece or in multiple pieces, although these parts do not necessarily have to be connected to one another.

[0020] The first ring gear can, for example, also be permanently fixed to the stationary component or can be fixed by a switching element. For this purpose, the first ring gear can, for example, be permanently connected to the stationary component in a rotationally fixed manner or can be connected to the stationary component in a rotationally fixed manner by actuating the switching element. This allows the torque transmitted in the first planetary gear set to be supported.

[0021] Overall, this results in a compact transmission with a high gear ratio. The traction motor can assist the work machine during travel. For example, the traction motor can also drive the tractor unit in rough terrain, such as in a wet field or in an assembly line. The work machine can thus have a lower-power drivetrain.

[0022] A non-rotatable connection between two elements is defined as a connection in which the two elements are essentially rigidly coupled to each other under all intended conditions. This also includes a frictional connection, which may result in intentional or unintentional slippage. Permanently non-rotatable elements can, for example, be formed as individual components permanently connected to each other in a non-rotatable manner, or even as a single piece.

[0023] A connection between two elements via a further element can mean that this further element can be involved in an indirect operative connection between the two elements. For example, this element can be arranged in the power flow between these two elements. A connection between two elements via two or more elements can mean that these further elements are all involved in an indirect operative connection between the two elements. A switchable connection can enable torque transmission between two elements in one state, for example through a rigid coupling, and essentially interrupt this torque transmission in another state. For this purpose, a corresponding switching element can be provided between the two elements. If two elements can be connected in a rotationally fixed manner, these two elements can be connected to one another in a rotationally fixed manner, for example via a switching element.If two elements are mechanically operatively connected, they can be connected, for example, via a switching element for torque transmission. An operative connection can be provided, for example, by intermeshing gears and, alternatively or additionally, a spur gear stage between two elements. In an operative connection, a rotation of one of the two elements can cause a corresponding reaction in the other of the two operatively connected elements. The direction of rotation and the speed can differ.

[0024] The traction motor, the transmission, and alternatively or additionally the wheel can be arranged coaxially. For example, the input shaft of the transmission can be coaxial with the output shaft of the transmission. For example, the input shaft of the transmission can be coaxial with the motor shaft. For example, the drive assembly and the output assembly can be arranged coaxially. For example, a rotational axis of the first planetary gear set and a rotational axis of the second planetary gear set can be coaxial. This can result in a compact and simple design. For example, the wheel head can be easily integrated as an axle drive or drive for a wheel of the attachment.

[0025] The traction motor and the drive assembly can be mounted to each other, for example, by screwing a housing of the traction motor to a housing of the drive assembly. The output assembly can be mounted to the traction motor and, alternatively or additionally, to the drive assembly, for example, by screwing the second ring gear to the housing of the drive assembly or the traction motor.

[0026] In a further embodiment of the wheel head, it can be provided that the drive assembly has a separating element by means of which a torque transmission from the motor shaft to the second sun gear in the first planetary gear set can be interrupted. For example, the separating element can be designed as a switching element. For example, the separating element can be designed as a frictional switching element, such as a multi-plate clutch, or as a positive switching element, such as a dog clutch. The separating element can be actuated electrically or hydraulically, for example. The separating element can be adjustable, for example, between an open position in which the torque transmission is interrupted, and a closed position in which the torque transmission is possible. The first ring gear can be fixable to the stationary component by means of the separating element for torque transmission.For example, when actuated, the separating element establishes a rotationally fixed connection between the first ring gear and the stationary component, such as the housing of the drive assembly or the traction motor.

[0027] The separating element allows the traction motor to be decoupled from the transmission output. This can, for example, reduce drag losses when no drive power is provided by the traction motor during a journey. For example, when driving quickly along a country road, a tractor combination often only requires a fraction of the drive power of the work machine, and it can then be more efficient to deactivate and decouple the attachment's traction motor. In addition, the transmission can then be optimally designed for driving ranges where high torque but low speed are required, such as when plowing a field or exiting an excavation pit on a steep ramp. Decoupling can also prevent the traction motor from reaching excessively high speeds.

[0028] For example, the wheel head has an electric pump mounted on the housing of the traction motor or the drive assembly. The electric pump keeps the separating element closed during operation to enable torque transmission. The separating element can be designed, for example, as a multi-disk clutch or a dog clutch. The separating element can be arranged in an interior space of the housing of the drive assembly. The separating element can, for example, have a diameter substantially identical to that of the ring gear and, for example, have a smaller diameter than the traction motor.

[0029] In a further embodiment of the wheel head, it can be provided that the drive assembly has a speed sensor which is designed to detect a speed of the first ring gear. For example, the first ring gear can rotate when it is decoupled from the stationary component by the separating element and the attachment is pulled or pushed by the work machine. The wheel head can have a control device. The control device can be designed to control the traction motor depending on the detected speed of the ring gear in order to synchronize a speed of the motor shaft with the speed of the first ring gear for switching the separating element to restore the torque transmission when torque transmission is interrupted by the separating element. The control device can be designed, for example, as the inverter.If the control device is not directly integrated into the wheel head, for example because the control device is part of the work machine, the wheel head can also be understood as a wheel head system that includes the control device. The speed sensor can also not be part of the wheel head, but rather of the attachment. In this case, too, the wheel head can be understood as a wheel head system that includes the speed sensor. The first ring gear can have external teeth, to which at least part of the speed sensor can be attached and which, alternatively or additionally, induces a speed signal. The speed sensor can, for example, be designed as a Hall sensor.

[0030] The control device allows the separating element to be closed even during ferry operation to couple the traction motor, even if the separating element is designed as a claw clutch, for example. The speed of the motor shaft and the first ring gear can be considered synchronous even with small deviations, for example, a deviation of approximately 50 revolutions per minute. The deviation in the speeds can prevent heads from colliding when the separating element is closed. The separating element can also protect the traction motor from excessively high speeds at high travel speeds by decoupling.

[0031] In a further embodiment of the gear head, the first ring gear can be permanently fixed to the stationary component. Alternatively, the first ring gear can also be permanently connected to the stationary component in a rotationally fixed manner, and alternatively or additionally, the drive assembly can have no separating element. Generally, the transmission can be free of any possibility of interrupting the torque transmission, and the traction motor can thus not be decoupled. The gear head can then be particularly compact and cost-effective.

[0032] In a further embodiment of the wheel head, the drive assembly can be provided with a brake by means of which the second planetary carrier can be locked. The brake can thus function as a service brake and thus brake the output of the transmission. The brake can, for example, be designed as a frictional switching element by means of which the second planetary carrier can be connected to the stationary component. The brake can provide additional braking power in a space-saving manner. This means, for example, that a service brake of the work machine can be designed for lower power outputs and does not have to be designed for the additional drive power of attachments with an electrified wheel head in ferry operation. The brake can, for example, be designed as a drum brake or multi-disk clutch.The brake can, for example, be arranged radially outwardly of the first planetary gear set and, alternatively or additionally, the first ring gear. This allows the brake to have a large diameter and thus be very powerful. The brake can be designed as a dry brake. This makes the brake particularly cost-effective. The brake can be designed to switchably and non-rotatably connect the second planetary carrier to the housing of the drive assembly, the first ring gear, and, alternatively or additionally, the housing of the traction motor.

[0033] Alternatively, the wheel head has a brake that acts directly on the wheel, such as a wheel rim. This brake can be part of the output assembly. Alternatively, the drive assembly, the output assembly, and alternatively or additionally the wheel head as a whole are free of a brake. If a brake is provided in the output assembly, the drive assembly can be free of a brake, and vice versa.

[0034] In a further embodiment of the gear head, it can be provided that the output assembly has a brake by means of which the second planetary carrier can be locked. For example, the brake can connect the second planetary carrier to the stationary component. The brake can also be designed to block the second planetary gear set, for example by two rotating elements of the second planetary gear set becoming rotationally fixed with one another in order to thus lock the second planetary carrier. For example, the brake in the output assembly can be designed to rotationally connect the second planetary carrier to the second ring gear or the second sun gear. For example, the brake in the output assembly can be designed to connect the second ring gear to the second sun gear. The brake in the output assembly can, for example, be designed as a wet brake, for example as a multi-plate clutch.For example, the brake in the working assembly can be integrated into the second planetary gear set. For example, the brake in the output assembly can be arranged radially inside the second ring gear and alternatively or additionally have a diameter that is the same size as or smaller than the diameter of the traction motor. The wheel head can thus be particularly compact radially. Discs of the brake of the output assembly can be rotationally connected to a toothing of the second ring gear, which also serves to mesh with the second planet gears. There can thus be an axial section of this toothing for meshing with the second planet gears and another axial section of this toothing for fastening the discs. The two toothing areas can be manufactured together cost-effectively.Discs of the output assembly's brake can be rotationally connected to a toothing of the second sun gear, which also serves to mesh with the second planet gears. Thus, there can be an axial section of this toothing for meshing with the second planet gears and another axial section of this toothing for securing the discs. The two toothing areas can be manufactured together cost-effectively.

[0035] If the output assembly brake connects the second sun gear to the second ring gear for braking, only a low torque can act on the brake due to the gear ratio in the second planetary gear set. This allows the brake in the output assembly to be compact and have low wear.

[0036] The second planet carrier can radially enclose the planetary gear set and the output assembly as a whole. The second planet carrier can be cup-shaped, for example. The second planet carrier can extend axially radially outward to the brake of the input assembly, for example, along the output assembly. The second planet carrier can form a type of housing for the second planetary gear set and, alternatively or additionally, the output assembly.

[0037] In a further embodiment of the wheel head, the second ring gear can be constructed in two parts. For example, a connection to the brake in the drive assembly can simply be provided. Furthermore, procurement and alternatively or additionally production of the respective parts can be easier. For example, the second ring gear can have a ring and a carrier. The two-part design makes tolerance compensation easy and the transmission quiet. Alternatively, the second ring gear can be constructed in one piece. Such a design can be very cost-effective. Furthermore, the second ring gear can withstand high loads and, for example, facilitate installation of the brake in the output assembly.

[0038] The gearing of the first planetary gear set and, alternatively or additionally, the second planetary gear set can be designed as helical gears. For example, the gearing of the first planetary gear set and the second planetary gear set can be designed so that the first planet carrier is pressed axially toward the second planetary gear set and the second sun gear is pressed axially toward the first planetary gear set. As a result, torque transmission places little stress on the mounting of the output assembly and, alternatively or additionally, the drive assembly.

[0039] A second aspect relates to a modular wheel head kit. The wheel head kit can be designed for an attachment, wherein the attachment can be coupled to a work machine. The wheel head kit can be designed to enable a wheel head according to the first aspect to be assembled from various selectable modules. The wheel head kit can be designed to produce a wheel head according to the first aspect therefrom. Depending on the selected modules, the wheel head can have a different configuration. The configurations can correspond to one or more different embodiments of the wheel head according to the first aspect. Respective further features, embodiments, and advantages can be found in the descriptions of the first aspect. Conversely, features, embodiments, and advantages of the second aspect also represent features, embodiments, and advantages of the first aspect.

[0040] For example, with the wheel head kit, you can choose between different drive assemblies as selectable modules. The wheel head kit can feature these differently designed drive assemblies. For example, with the wheel head kit, you can choose between different output assemblies as selectable modules. The wheel head kit can feature these differently designed output assemblies. For example, with the wheel head kit, you can choose between different traction motors as selectable modules. The wheel head kit can feature these differently designed traction motors. This allows the transmission and the traction motor to be easily matched to each other and to the performance requirements of the attachment and the work machine.In addition, additional functions can be easily selected when assembling and assembling a wheel head, such as a separating element for decoupling the traction motor and, alternatively or additionally, a brake. Cost requirements and installation space requirements can also be taken into account. The various modules can have many identical parts. Some parts can even use the same semi-finished products, which are then reworked depending on the selected module. For example, a housing for the drive assembly can use the same raw part and, depending on whether the drive assembly includes the brake, can be additionally milled for its integration. The wheel head produced from the wheel head kit can thus be very cost-effective despite its adaptation. All selectable modules or just certain modules of the wheel head kit can be compatible with each other.

[0041] The wheel head kit comprises at least one traction motor embodied as an electric motor with a motor shaft and a gearbox for transmitting torque from the motor shaft to an output. The traction motor can be modularly selected. The gearbox has a drive assembly and an output assembly. The drive assembly can be modularly selected. The output assembly can be modularly selected. The gearbox can thus be composed of two modules. For at least one of the modules, for example, the drive assembly or the output assembly, the wheel head kit can have two different variants to choose from. For modularly selectable parts, the wheel head kit can, for example, have at least two different options.

[0042] Each variant of the input assembly has a first planetary gear set with a first sun gear, a first planet carrier, and a first ring gear. Each variant of the output assembly has a second planetary gear set with a second sun gear, a second planet carrier, and a second ring gear. The motor shaft and the first sun gear are permanently connected to one another in a rotationally fixed manner in the gear head, which can be manufactured from the gear head kit. The first planet carrier is permanently connected to the second sun gear once the gear head is assembled. In every variant, the second planet carrier forms an output of the transmission. The second ring gear can be permanently fixed to a stationary component in every variant. Depending on the variant, the first ring gear is, for example, permanently fixed to the stationary component or can be fixed by means of a separating element.

[0043] The wheel head assembly can have at least two different drive assemblies. The wheel head assembly can alternatively or additionally have at least two different output assemblies. The various selectable drive assemblies can differ, for example, in their functions or the presence or absence of switching elements and, alternatively or additionally, in the width of the teeth of the first planetary gear set. The various selectable output assemblies can differ, for example, in their functions or the presence or absence of switching elements and, alternatively or additionally, in the width of the teeth of the second planetary gear set. The respective mounting interfaces can be the same for all modules.

[0044] The wheel head assembly can have at least two different traction motors. For the traction motor, for example, traction motors of different power and, alternatively or additionally, different radial lengths can be selected. The diameter of the various traction motors and, alternatively or additionally, their mounting interfaces can be the same. Depending on the power of the selected traction motor, the drive assembly and, alternatively or additionally, the output assembly, for example, their planetary gear sets, can have gears of different widths. For example, only the gears of the second planetary gear set can be selected wider if a more powerful traction motor is used.

[0045] In at least one of the modularly selectable drive assemblies, the first ring gear is permanently fixed to the stationary component. For example, in each of the modularly selectable drive assemblies, the first ring gear can be permanently fixed to the stationary component. In a further embodiment of the modular wheel head kit, it can be provided that at least one of the modularly selectable drive assemblies has a separating element by means of which a torque transmission from the motor shaft to the second sun gear in the first planetary gear set can be interrupted. In at least one further of the modularly selectable drive assemblies, the first ring gear can be permanently fixed to the stationary component. The at least one further of the modularly selectable drive assemblies can be free of such a separating element. As a result, when assembling the wheel head from the kit, it can be selected whether the traction motor can be decoupled.

[0046] In a further embodiment of the modular wheel head kit, it can be provided that at least one of the modularly selectable drive assemblies has a brake by means of which the second planetary carrier can be locked. At least one further of the modularly selectable drive assemblies can be free of such a brake. This makes it possible to select whether a service brake for the attachment is provided by the drive assembly. The brake in the drive assembly is not normally used in combination with a brake in the output assembly, for example. All selectable drive assemblies can also have the brake by means of which the second planetary carrier can be locked.

[0047] In a further embodiment of the modular wheel head kit, it can be provided that at least one of the modularly selectable output assemblies has a brake by means of which the second planetary carrier can be locked. At least one further of the modularly selectable output assemblies can be free of such a brake. This makes it possible to select whether a service brake for the attachment is provided by the output assembly. The brake in the output assembly is not normally used in combination with the brake in the drive assembly, for example. All selectable output assemblies can also have the brake by means of which the second planetary carrier can be locked.

[0048] In a further embodiment of the modular wheel head kit, it can be provided that at least one toothing of the modularly selectable output assemblies is wider than a toothing of at least one other of the modularly selectable output assemblies. This allows the toothing in spur gear sets to be adapted to an expected maximum torque. For example, the width of all rotating elements of an assembly can be varied depending on the power class of the selected traction motor.

[0049] The various module properties may overlap. For example, there may be a drive assembly with a brake and a separator, a drive assembly without a brake and with a separator, a drive assembly with a brake and without a separator, and a drive assembly without a brake and without a separator. However, there may also be fewer different modules to choose from.

[0050] In the wheel head kit, one of the modules, two of the modules, or all of the modules can have two or more variants. For example, the wheel head kit can have only two variants or more for the traction motor, and the design of the drive assembly and the output assembly is fixed. For example, the wheel head kit can have only two variants or more for the output assembly, and the design of the drive assembly and the traction motor is fixed. For example, the wheel head kit can have only two variants or more for the drive assembly, and the design of the output assembly and the traction motor is fixed. For example, the wheel head kit can have only two variants or more for the output assembly and the drive assembly, and the design of the traction motor is fixed.For example, the wheel head kit may have only two or more variants for the traction motor and the output assembly or the drive assembly, and the design of the drive assembly or the output assembly is then fixed accordingly. For example, the wheel head kit may also have two or more variants for the drive assembly, the output assembly, and the traction motor.

[0051] Brief description of the figures Fig. 1 shows a schematic sectional view of a first variant of a drive assembly for a modular wheel head kit for a wheel head of an attachment, wherein the wheel head has a gearbox with a drive assembly and an output assembly.

[0052] Fig. 2 shows a schematic sectional view of a second variant of a drive assembly for the modular wheel head kit.

[0053] Fig. 3 shows a schematic sectional view of a third variant of a drive assembly for the modular wheel head kit.

[0054] Fig. 4 shows a schematic sectional view of a fourth variant of a drive assembly for the modular wheel head kit.

[0055] Fig. 5 shows a schematic sectional view of a first variant of an output assembly for the modular wheel head kit.

[0056] Fig. 6 shows a schematic sectional view of a second variant of an output assembly for the modular wheel head kit.

[0057] Fig. 7 shows a schematic sectional view of a third variant of an output assembly for the modular wheel head kit.

[0058] Fig. 8 shows a schematic sectional view of a fourth variant of an output assembly for the modular wheel head kit.

[0059] Fig. 9 shows a schematic sectional view of a first variant of a wheel head for a work machine, wherein the wheel head was formed from the first variant of the drive assembly and the first variant of the output assembly.

[0060] Fig. 10 shows a schematic sectional view of a second variant of a wheel head for a work machine, wherein the wheel head was formed from the first variant of the drive assembly and the second variant of the output assembly. Fig. 11 shows a schematic sectional view of a third variant of a wheel head for a work machine, wherein the wheel head was formed from the first variant of the drive assembly and the third variant of the output assembly.

[0061] Fig. 12 shows a schematic sectional view of a fourth variant of a wheel head for a work machine, wherein the wheel head was formed from the first variant of the drive assembly and the fourth variant of the output assembly.

[0062] Fig. 13 shows a schematic sectional view of a fifth variant of a wheel head for a work machine, wherein the wheel head was formed from the second variant of the drive assembly and the first variant of the output assembly.

[0063] Fig. 14 shows a schematic sectional view of a sixth variant of a wheel head for a work machine, wherein the wheel head was formed from the second variant of the drive assembly and the second variant of the output assembly.

[0064] Fig. 15 shows a schematic sectional view of a seventh variant of a wheel head for a work machine, wherein the wheel head was formed from the second variant of the drive assembly and the third variant of the output assembly.

[0065] Fig. 16 shows a schematic sectional view of an eighth variant of a wheel head for a work machine, wherein the wheel head was formed from the second variant of the drive assembly and the fourth variant of the output assembly.

[0066] Fig. 17 shows a schematic sectional view of a ninth variant of a wheel head for a work machine, wherein the wheel head was formed from the third variant of the drive assembly and the first variant of the output assembly.

[0067] Fig. 18 shows a schematic sectional view of a tenth variant of a wheel head for a work machine, wherein the wheel head was formed from the third variant of the drive assembly and the second variant of the output assembly. Fig. 19 shows a schematic sectional view of an eleventh variant of a wheel head for a work machine, wherein the wheel head was formed from the fourth variant of the drive assembly and the first variant of the output assembly.

[0068] Fig. 20 shows a schematic sectional view of a twelfth variant of a wheel head for a work machine, wherein the wheel head was formed from the fourth variant of the drive assembly and the second variant of the output assembly.

[0069] Detailed description of embodiments

[0070] Fig. 9 to Fig. 20 each show a schematic sectional view of a variant of a wheel head for an attachment, which was assembled from a wheel head kit. The attachment can be coupled to a work machine, whereby the wheel head can then assist driving via an electric drive. For this purpose, the wheel head has a traction motor 10, which is designed as an electric motor. In the figures, the traction motor 10 is shown without its windings or stator. However, a housing 12 of the traction motor 10 and a motor shaft 14 are shown, to which drive power can be provided by the traction motor 10. The motor shaft 14 rotates with a rotor of the traction motor 10.

[0071] The wheel head also has a gearbox 16. The gearbox 16 is designed to enable torque transmission from the motor shaft 14 to a wheel of the attachment and to provide a gear ratio. The gearbox 16 has a drive assembly 20 and an output assembly 30. Various variants of the drive assembly 20 are each shown in a sectional view in Fig. 1 to Fig. 4. Various variants of the output assembly 30 are each shown in a sectional view in Fig. 5 to Fig. 8. The drive assemblies 20 and the output assemblies 30 can be combined in pairs to form different variants of the wheel head. This results in a modular wheel head kit with which gearboxes 16 can be provided for different attachments and work machines as needed. Each variant of the drive assembly 20 has the same basic structure, which is described below.The drive assembly 20 has a first planetary gear set 22 with a first sun gear 24, a first planet carrier 26, and a first ring gear 28. A set of first planet gears is rotatably mounted on the first planet carrier 26, each of which meshes with the first sun gear 24 and the first planet carrier 26. The first sun gear 24 forms an input shaft of the transmission 16 and is permanently connected in the gear head in a rotationally fixed manner to the motor shaft 14. For this purpose, the motor shaft 14 has internal teeth that engage with external teeth of the first sun gear 24. The first planet carrier 26 forms an output shaft of the drive assembly 20 and is permanently connected in a rotationally fixed manner to an input shaft of the output assembly 30 in order to transmit the torque there.Depending on the variant, the first ring gear 28 is permanently connected in a rotationally fixed manner to a stationary component of the transmission 16, here a housing 40 of the drive assembly 20, or can be connected to this stationary component.

[0072] The housing 40 of the drive assembly 20 is permanently connected to the housing 12 of the traction motor 10 by a screw connection, thereby mounting the drive assembly 20 in the wheel head on the traction motor 10. The traction motor 10 and the drive assembly 20 are arranged coaxially with each other in the wheel head. The housing 40 of the drive assembly 20 also provides a lubricating oil supply for at least the first planetary gear set 22.

[0073] Each variant of the output assembly 30 has the same basic structure, which is described below. The input assembly 30 has a second planetary gear set 32 ​​with a second sun gear 34, a second planet carrier 36, and a second ring gear 38. A set of second planet gears, which each mesh with the second sun gear 34 and the second planet carrier 36, is rotatably mounted on the second planet carrier 36. The second sun gear 34 forms an input shaft of the output assembly 30 and is permanently connected in the gear head to the first planet carrier 26 in a rotationally fixed manner. For this purpose, the second planet carrier 36 has internal teeth which engage with external teeth of the second sun gear 34. The second planet carrier 36 forms an output shaft of the output assembly 30 and thus an output of the transmission 16. The second planet carrier 36 is permanently connected in the wheel head to the wheel of the attachment in a rotationally fixed manner.The second ring gear 38 is connected in the gear head in a rotationally fixed manner to a stationary component of the transmission 16, here the housing 40 of the drive assembly 20, and is thus permanently fixed. This also mounts the output assembly 30 to the drive assembly 20. The second ring gear 38 is screwed to the housing 40 of the drive assembly 20 and also engages with an external toothing into an internal toothing of the housing 40. This allows the output assembly 20 to be plugged into the drive assembly 30, and the assembly can withstand high loads.

[0074] The second planet carrier 36 forms a type of housing for the output assembly 30. For this purpose, the second planet carrier 36 is cup-shaped and surrounds the second ring gear 38 radially on the outside, connecting to a bearing plate 42. The second planet carrier 36 is permanently connected to the bearing plate 42 by a screw connection in a rotationally fixed manner. The output assembly 30 and the drive assembly 20 are arranged coaxially to one another in the gear head. In the examples shown, two angular contact bearings are arranged on the bearing plate 42, by means of which the second planet carrier 36 is rotatably mounted on the housing 40 of the drive assembly 20.

[0075] Fig. 1 shows a first variant of the drive assembly 20. This variant has a separating element 50, which is designed as a positive switching element and is not present in some other variants. By means of the separating element 50, the first ring gear 38 can be switchably connected to the housing 40 of the drive assembly 20 in a rotationally fixed manner. When the separating element 50 is closed, the first ring gear 38 is thus fixed, and torque can be transmitted from the motor shaft 14 via the first planetary gear set 22 to the output assembly 30.

[0076] When the separating element 50 is open, the first ring gear 38 can rotate. This interrupts the transmission of torque from the motor shaft 14 to the second sun gear 34 in the first planetary gear set 22. The traction motor 10 is thus decoupled from the output of the transmission 16 and thus from the wheel. This protects the traction motor 10 from high speeds and also prevents drag losses when no drive from the wheel head is required during a trip. In one embodiment, this variant of the drive assembly 20 has a speed sensor designed to detect a speed of the first ring gear 28.This allows a control device to control the traction motor 10 depending on the detected rotational speed of the first ring gear 28 in order to synchronize a rotational speed of the motor shaft 14 with the rotational speed of the first ring gear 28 when the torque transmission is interrupted by the separating element 50, thereby closing the separating element 50 and restoring the torque transmission. This allows the traction motor 10 to be engaged even while driving despite the positive-locking separating element 50, which in the illustrated embodiments is designed as a claw clutch.

[0077] Fig. 2 shows a second variant of the drive assembly 20. This variant does not have a separating element. Instead, the first ring gear 28 is permanently and non-rotatably attached to the housing 40. In another embodiment, the first ring gear 28 and the housing 40 of the drive assembly 20 are formed as a single piece.

[0078] Furthermore, in the second variant of the drive assembly 20, the housing 40 is designed differently compared to the first variant. The respective oil channels are routed differently here. Furthermore, the housing 40 or the drive assembly 20 is shorter, since no installation space is required for a separating element. However, the housing 40 can be manufactured from the same blank. For the second variant, the radially protruding flange axially facing the traction motor 10 was removed.

[0079] Fig. 3 shows a third variant of the drive assembly 20, which is based on the first variant. The third variant of the drive assembly 20 additionally has a brake 60, which is arranged radially outwardly of the first planetary gear set 22. The brake 60 is designed as a dry brake, here as a drum brake. In addition, the housing 40 of the output assembly 30 has an additional flange component 44, which is rotatable relative to the housing 40 already shown in the first variant - modified in the third variant for fastening and integration of the brake 60. The flange component 44 is connected in the wheel head to the second planet carrier 36 in a rotationally fixed manner, here by a screw connection. The brake 60 functions as the service brake of the attachment. The brake 60 can be used to lock the second planet carrier 36 and thus also decelerate the wheel of the wheel head.

[0080] Fig. 4 shows a fourth variant of the drive assembly 20, which is based on the second variant. The fourth variant of the drive assembly 20 also has the brake 60, like the third variant. However, the fourth variant does not have a separating element 50, unlike the third variant. The housing 40 and its flange component 44 can be manufactured from the same blank in the third and fourth variants. For the third variant, for example, the housing of the fourth variant is then used as the blank and milled further radially inward in an end region facing the traction motor 10 in order to be able to insert the separating element 50.

[0081] Fig. 5 shows a first variant of the output assembly 30. The second ring gear 38 is formed in one piece.

[0082] Fig. 6 shows a second variant of the output assembly 30. Unlike the first variant, the second ring gear 38 is constructed in two parts. Furthermore, the toothing of the rotating elements of the second planetary gear set 32 ​​is wider than in the first variant. The second variant of the output assembly 30 is used when a more powerful electric motor is selected for the traction motor 10.

[0083] Fig. 7 shows a third variant of the output assembly 30, which is based on the first variant. The second ring gear 38 is still formed in one piece, but extends axially further in the direction of the bearing plate 42 and also the drive assembly 20. This creates additional installation space in the output assembly 30 and within the second ring gear 38. There, a brake 70 is arranged axially next to the toothing of the rotating elements of the second planetary gear set 32 ​​in the direction of the bearing plate 42 and also the drive assembly 20. The brake 70 of the output assembly 30 also serves to fix the second planet carrier 36. The brake 70 therefore also forms a service brake for the attachment. In the example shown, the brake 70 can connect the second ring gear 38 to the second sun gear 34 in a rotationally fixed manner. This blocks the second planetary gear set 32 ​​and thus also fixes the second planet carrier 36.Due to this design, a low torque acts on the brake 70. In the wheel head, variants of the output assembly 30 with brake 70 are not typically combined with variants of the drive assembly 20, since two brakes are normally not required in the wheel head.

[0084] The brake 70 of the output assembly 30 is designed as a wet brake, here as a multi-disk brake. The brake 70 does not require any additional radial installation space, making this variant of the output assembly 30 particularly suitable for attachments with limited radial installation space that require a service brake. Radially outer plates of the brake 70 are held in a rotationally fixed manner on the second ring gear 38 via a toothing of the second ring gear 38. In one embodiment, this is a toothing region of a radially inner toothing of the second ring gear 38, which also meshes with the second planet gears. The toothing regions can be manufactured jointly and cost-effectively. Radially inner plates of the brake 70 are held in a rotationally fixed manner on the second sun gear 34 via a toothing of the second sun gear 34.In one embodiment, this is a toothed area of ​​a radially outer toothing of the second sun gear 34, which also meshes with the second planet gears. The toothed areas can be manufactured together cost-effectively. Alternatively, in one example, this toothed area is formed by a separate, pressed-on gear.

[0085] Fig. 8 shows a fourth variant of the output assembly 30, which is based on the third variant. As with the first and second variants, the toothing of the rotating elements of the second planetary gear set 32 ​​is wider in the fourth variant than in the third variant. The fourth variant of the output assembly 30 is used when a more powerful electric motor is selected for the traction motor 10.

[0086] The four variants of the drive assembly 20 and the four variants of the output assembly 30 can be selected modularly and combined to provide the wheel head. In the examples shown, a combination with two traction motors 10 of different power outputs is also possible.

[0087] Fig. 9 shows a first variant of the wheel head, in which the first variant of the drive assembly 20 according to Fig. 1 and the first variant of the output assembly 30 according to Fig. 5 were combined.

[0088] Fig. 10 shows a second variant of the wheel head, in which the first variant of the drive assembly 20 according to Fig. 1 and the second variant of the output assembly 30 according to Fig. 6 were combined.

[0089] Fig. 11 shows a third variant of the wheel head, in which the first variant of the drive assembly 20 according to Fig. 1 and the third variant of the output assembly 30 according to Fig. 7 were combined.

[0090] Fig. 12 shows a fourth variant of the wheel head, in which the first variant of the drive assembly 20 according to Fig. 1 and the fourth variant of the output assembly 30 according to Fig. 8 were combined.

[0091] Fig. 13 shows a fifth variant of the wheel head, in which the second variant of the drive assembly 20 according to Fig. 2 and the first variant of the output assembly 30 according to Fig. 5 were combined.

[0092] Fig. 14 shows a sixth variant of the wheel head, in which the second variant of the drive assembly 20 according to Fig. 2 and the second variant of the output assembly 30 according to Fig. 6 were combined.

[0093] Fig. 15 shows a seventh variant of the wheel head, in which the second variant of the drive assembly 20 according to Fig. 2 and the third variant of the output assembly 30 according to Fig. 7 were combined. Fig. 16 shows an eighth variant of the wheel head, in which the second variant of the drive assembly 20 according to Fig. 2 and the fourth variant of the output assembly 30 according to Fig. 8 were combined.

[0094] Fig. 17 shows a ninth variant of the wheel head, in which the third variant of the drive assembly 20 according to Fig. 3 and the first variant of the output assembly 30 according to Fig. 5 were combined.

[0095] Fig. 18 shows a tenth variant of the wheel head, in which the third variant of the drive assembly 20 according to Fig. 3 and the second variant of the output assembly 30 according to Fig. 6 were combined.

[0096] Fig. 19 shows an eleventh variant of the wheel head, in which the fourth variant of the drive assembly 20 according to Fig. 4 and the first variant of the output assembly 30 according to Fig. 5 were combined.

[0097] Fig. 20 shows a tenth variant of the wheel head, in which the fourth variant of the drive assembly 20 according to Fig. 4 and the second variant of the output assembly 30 according to Fig. 6 were combined.

[0098] Reference symbol

[0099] Traction motor

[0100] Traction motor housing

[0101] Motor shaft

[0102] Gearbox

[0103] Drive assembly

[0104] First planetary gear set

[0105] First sun wheel

[0106] First planet carrier

[0107] First ring gear

[0108] Output assembly

[0109] Second planetary gear set

[0110] Second sun gear

[0111] Second planet carrier

[0112] Second ring gear

[0113] Drive assembly housing

[0114] bearing plate

[0115] Flange component

[0116] Separating element

[0117] brake

[0118] brake

Claims

Patent claims 1 . A wheel head for an attachment, wherein the attachment can be coupled to a work machine, wherein the wheel head has a traction motor (10) designed as an electric motor with a motor shaft (14) and a transmission (16) for transmitting torque from the motor shaft (14) to an output, wherein the transmission (16) has a drive assembly (20) and an output assembly (30), wherein the drive assembly (20) has a first planetary gear set (22) with a first sun gear (24), a first planet carrier (26), and a first ring gear (28), wherein the output assembly (30) has a second planetary gear set (32) with a second sun gear (34), a second planet carrier (36), and a second ring gear (38), wherein the motor shaft (14) and the first sun gear (24) are permanently connected to one another in a rotationally fixed manner, wherein the first planet carrier (26) is permanently connected to the second sun gear (32) in a rotationally fixed manner,wherein the second planet carrier (36) forms an output of the transmission (16), and wherein the second ring gear (38) is permanently fixed to a stationary component (40).

2. Wheel head according to claim 1, characterized in that the drive assembly (20) has a brake (60) by means of which the second planet carrier (36) can be fixed.

3. Wheel head according to at least one of the preceding claims, characterized in that the output assembly (30) has a brake (70) by means of which the second planet carrier (36) can be fixed.

4. Wheel head according to at least one of the preceding claims, characterized in that the drive assembly (20) has a separating element (50) by means of which a torque transmission from the motor shaft (14) to the second sun gear (32) in the first planetary gear set (22) can be interrupted.

5. Wheel head according to at least one of the preceding claims, characterized in that the first ring gear (28) is permanently fixed to the stationary component (40).

6. Wheel head according to at least one of the preceding claims, characterized in that the second ring gear (38) is permanently fixed to a stationary component (40) and wherein the first ring gear (28) is permanently fixed to the stationary component (40).

7. Wheel head according to at least one of the preceding claims, characterized in that the drive assembly (20) has a speed sensor which is designed to detect a speed of the first ring gear (28), and the wheel head has a control device which is designed to control the traction motor (10) as a function of the detected speed of the first ring gear (28) in order to synchronize a speed of the motor shaft (14) with the speed of the first ring gear (28) for switching the separating element (50) to restore the torque transmission when the torque transmission is interrupted by the separating element (50).

8. Wheel head according to at least one of the preceding claims, characterized in that the drive assembly (20) has a brake (60) by means of which the second planet carrier (36) can be fixed.

9. Wheel head according to at least one of the preceding claims, characterized in that the second ring gear (38) is formed in two parts.

10. Modular wheel head assembly kit for an attachment, wherein the attachment can be coupled to a work machine, wherein the wheel head assembly has at least one traction motor (10) designed as an electric motor with a motor shaft (14) and a transmission (16) for transmitting torque from the motor shaft (14) to an output, wherein the transmission (16) has a modularly selectable drive assembly (20) and a modularly selectable output assembly (30), wherein each of the modularly selectable drive assemblies (20) has a first planetary gear set (22) with a first sun gear (24), a first planet carrier (26) and a first ring gear (28), wherein each of the modularly selectable output assemblies (30) has a second planetary gear set (32) with a second sun gear (34), a second planet- planet carrier (36) and a second ring gear (38), wherein the motor shaft (14) and the first sun gear (24) are permanently connected to one another in a rotationally fixed manner in the wheel head, wherein the first planet carrier (26) in the wheel head is permanently connected to the second sun gear (34) in a rotationally fixed manner, wherein the second planet carrier (36) in the wheel head forms an output of the transmission (16), wherein the second ring gear (38) in each of the modularly selectable output assemblies (30) is permanently fixed to a stationary component, wherein the wheel head kit has at least two different drive assemblies (20) and wherein the wheel head kit has at least two different output assemblies (30).

11. Modular wheel head kit according to at least one of the preceding claims, characterized in that at least one of the output assemblies (30) has a brake (70) by means of which the second planet carrier (36) can be fixed.

12. Modular wheel head kit according to at least one of the preceding claims, characterized in that at least one of the drive assemblies (20) has a brake (60) by means of which the second planet carrier (36) can be fixed.

13. Modular wheel head kit Modular wheel head kit according to at least one of the preceding claims, characterized in that at least one of the modularly selectable drive assemblies (30) has a separating element (50) by means of which a torque transmission from the motor shaft (14) to the second sun gear (32) in the first planetary gear set can be interrupted and in at least one of the modularly selectable drive assemblies (20) the first ring gear (28) is permanently fixed to the stationary component (40).

14. Modular wheel head kit Modular wheel head kit according to at least one of the preceding claims, characterized in that at least one of the modularly selectable drive assemblies (20) has a brake (60) by means of which the second planet carrier (36) can be fixed and at least one further one of the modularly selectable drive assemblies (20) is free of such a brake (60).

15. Modular wheel head kit Modular wheel head kit according to at least one of the preceding claims, characterized in that at least one of the modularly selectable output assemblies (30) has a brake (70) by means of which the second planet carrier (36) can be fixed and at least one further of the modularly selectable output assemblies (30) is free of such a brake (70).

16. Modular wheel head kit Modular wheel head kit according to at least one of the preceding claims, characterized in that at least one toothing of the modularly selectable output assemblies (30) is wider than a toothing of at least one further one of the modularly selectable output assemblies (30).

Images