Gearbox device with electromagnetic engagement function for one vehicle axle

Abstract

Transmission device (1) for a motor vehicle, comprising a differential (2) and a coupling device (9) configured to selectively couple an outer differential basket (7) connected to a drive side (3) of the differential with an inner differential basket (8) connected to an output side (4) of the differential (2), wherein the coupling device (9) is arranged outside the outer differential basket (7) and is configured to couple the inner differential basket (8) with the outer differential basket (7) in a coupling state of a movable coupling element (10) and to decouple the inner differential basket (8) from the outer differential basket (7) in a decoupling state of the movable coupling element (10), wherein the coupling element (10) is movably mounted in the axial direction with respect to a rotational axis (11) of the transmission device (1) and wherein the inner differential basket (8) has a first coupling section (12),in particular a first coupling body, and the outer differential basket (7) has a second coupling section (13), in particular a second coupling body, characterized in that the coupling sections (12, 13) extend axially away from the differential (2) and an electromagnetic actuator (14) of the coupling device (9) encompasses the coupling sections (12, 13), wherein the coupling device (9) has at least one electromagnetic actuator (14) configured to move the coupling element (10) between the decoupling state and the coupling state.

Description

[0001] The invention relates to a transmission device for a motor vehicle, comprising a differential and a coupling device, which is configured to selectively couple an outer differential basket connected to a drive side of the differential with an inner differential basket connected to an output side of the differential.

[0002] Transmission devices for motor vehicles that incorporate a differential are generally known from the prior art. A distinction is made between an outer differential carrier, which may be part of the differential housing, and an inner differential carrier, which carries or is coupled to the other components of the differential, such as differential gears and bevel gears. In other words, the output side of the differential, i.e., the side of the differential that leads to the wheels of the motor vehicle, particularly via drive shafts, is connected to the inner differential carrier, while the input side, i.e., ultimately the drive mechanism, is connected to the outer differential carrier.

[0003] By coupling the inner differential carrier to the outer differential carrier, torque can be transmitted in both directions. Primarily, torque is transmitted from the drive side to the driven side of the vehicle. However, driving conditions are possible, such as coasting, in which the components of the transmission system are dragged along by the moving vehicle. This dragging of the transmission components is undesirable in many driving conditions, which is why coupling devices are known that can selectively engage or disengage the drive and driven sides. In particular, the coupling between the outer and inner differential carriers can be engaged or disengaged depending on the desired driving condition.

[0004] Known coupling devices are typically arranged within the differential, specifically within the outer differential housing, to ensure space-saving design. This allows for coupling and disconnection between the inner and outer differential housings at a suitable point. A further challenge lies in performing the coupling process as efficiently as possible. Particularly with positive-locking coupling devices, such as those that establish the coupling state by inserting a claw element, it is known that engaging the coupling is complex. This requires, for example, synchronization or matching of the rotational speeds, whereby the positive lock can usually only be achieved within a limited speed range.If the coupling element, for example a claw, is moved at the wrong time, a tooth-on-tooth position can occur, preventing the positive fit from being established initially. Only after the tooth-on-tooth position is resolved, particularly by a low relative rotational speed of the coupling partners, can engagement take place.

[0005] The invention is based on the objective of providing an improved transmission device for a motor vehicle.

[0006] The problem is solved by a transmission device with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0007] As described, the invention relates to a transmission device for a motor vehicle, comprising a differential and a coupling device. The coupling device is designed to couple or disconnect the drive side of the differential from the driven side. For this purpose, the coupling device selectively establishes a connection between the outer differential housing and the inner differential housing. The outer differential housing is understood to be the part of the differential that is connected to the drive side, for example via a spur gear or a ring gear. The inner differential housing is understood to be that part of the differential that is connected to the drive wheels of the motor vehicle, for example by means of a coupling with drive shafts. The outer differential housing surrounds the inner differential housing, at least partially, for example in the manner of a housing or housing section.The transmission device may also include a transmission housing that can surround the differential.

[0008] The invention is based on the finding that the coupling device is arranged outside the outer differential cage and is designed to couple the inner differential cage to the outer differential cage in a coupling state of a movable coupling element and to decouple the inner differential cage from the outer differential cage in a decoupling state of the movable coupling element. In other words, the coupling device has a movable coupling element, which can, for example, be designed as a claw element. The coupling element can be moved into different positions, in particular axial positions with respect to the axis of rotation of the coupling element or of the two coupling partners.Here, at least one first position is provided in which the coupling state between the inner differential basket and the outer differential basket is established, and at least one second position in which the coupling state is separated or the decoupling state is reached.

[0009] Thus, to establish the coupling, the coupling element can be moved from the decoupling state to the coupling state, and to decouple, it can be moved from the coupling state to the decoupling state. For example, the coupling element can be constantly engaged with a toothed section on one of the two coupling partners, such as the outer differential carrier, and in the coupling state, it can couple the toothed section of the outer differential carrier with a toothed section of the inner differential carrier. The toothed sections can be located on any coupling segment, such as coupling bodies. For example, the coupling element may have an internal toothed section that corresponds to external toothed sections of the outer and inner differential carriers.

[0010] The coupling device can include at least one electromagnetic actuator configured to move the coupling element between the decoupling state and the coupling state. The at least one electromagnetic actuator can thus generate an actuating force, for example by creating a magnetic field, to move the coupling element between the decoupling state and the coupling state. In particular, it can be provided that the actuator performs the movement from the decoupling state to the coupling state, or exclusively performs the movement from the decoupling state to the coupling state. It can also be provided that the actuator exclusively performs the movement from the coupling state to the decoupling state.The other movement can be accomplished, for example, by a spring element, so that when the actuating force is removed, the spring force exerted on the coupling element by the spring element moves the coupling element into the respective state. The spring element can thus be designed to return the coupling element to either the coupled or uncoupled state.

[0011] It is also possible for the at least one electromagnetic actuator to generate movement of the coupling element in both directions, for example by generating a first magnetic field that exerts a first actuating force on the coupling element in a first direction and by generating a second magnetic field that exerts a second actuating force on the coupling element in a second direction, the first and second directions being opposite. Alternatively, at least two electromagnetic actuators can be provided, one of which effects the movement into the coupled state and the other the reverse movement into the decoupling state.

[0012] As described, the coupling device can ultimately establish an arbitrary coupling between the inner and outer differential baskets, each of which has a coupling section that can be coupled to the coupling section of the other element of the differential by the coupling element. According to one embodiment, the inner differential basket can have a first coupling section, in particular a first coupling body, and the outer differential basket has a second coupling section, in particular a second coupling body, wherein the coupling sections extend axially away from the differential and the coupling device, in particular the electromagnetic actuator of the coupling device, encompasses the coupling sections.

[0013] According to this design, the coupling sections, where the coupling between the inner and outer differential cages can ultimately be established or disconnected, are located outside the interior of the differential. The coupling sections are, in effect, "led outwards." They form a projection extending axially from the center of the differential. This projection is encompassed by the coupling device, in particular the electromagnetic actuator of the coupling device. At least the electromagnetic actuator is thus designed in the form of a ring or ring segment, for example, as a closed ring, ring coil, or ring coil segment, and circumferentially surrounds the area of ​​the coupling sections where the coupling element is movably arranged in the axial direction.

[0014] In other words, the coupling device defines a space that is at least partially enclosed in the circumferential direction and whose axial length can be defined by the axial length of the coupling sections or the axial extent of the electromagnetic actuator. By appropriately generating a magnetic field, the coupling element can be moved axially to assume the coupled or uncoupled state, as described above. In other words, a coaxial arrangement of the coupling sections at a first radial position or different first radial positions, the coupling element at a second radial position, and the electromagnetic actuator at a third radial position is provided.To simplify the coupling process, the two coupling sections are preferably arranged in the same radial position, so that the teeth can be engaged by axially displacing the coupling element. Alternatively, the coupling element can have two different toothed sections that can be engaged with the respective teeth of the coupling sections. In such a configuration, it is not necessary for the teeth of the two coupling sections to be arranged in the same radial position.

[0015] The transmission device can be further developed such that it is equipped with an electromagnetic actuator for detecting the state of the coupling device, in particular for detecting the position or relative position of the gear teeth of the coupling sections relative to each other and / or to the gear teeth of the coupling element. In other words, the transmission device is capable of detecting the state of the coupling device. Advantageously, the electromagnetic actuator described above, which is also used to move the coupling element, can be used for this purpose. The electromagnetic actuator thus fulfills at least two tasks: firstly, actuating the coupling device, and secondly, detecting the state of the coupling device.

[0016] For this purpose, the actuator can not only be used to generate a magnetic field to move the coupling element, but the effects of the positioning or movement of the individual elements, in particular the first and second coupling sections and / or the coupling element itself, on the magnetic field within the coaxially arranged electromagnetic actuator around the same axis of rotation can be used to detect the state. Detecting the state of the coupling device allows for particularly advantageous control of the movement of the coupling element. In this way, the coupling element can be moved in such a way that tooth-to-tooth alignment can be effectively prevented.The movement of the coupling element can, for example, be precisely controlled so that when the coupling element reaches the corresponding axial position, a tooth-to-tooth alignment is reliably achieved and engagement with the toothing of the corresponding coupling section is possible.

[0017] Here, the parameters of the coupling element's movement can be selected according to the coupling state. For example, an actuation speed and / or an actuation point can be chosen so that a desired transition to the coupling state can be reliably achieved without having to wait for a tooth-to-tooth alignment. If the change from the decoupling state to the coupling state is initiated, for example by a control device or user input, the current state of the coupling device can be used to determine the actuation speed at which the coupling element must be moved to achieve direct engagement of the gear teeth without having to wait for a tooth-to-tooth alignment and to execute the transition to the coupling state as quickly as possible.Furthermore, it is possible to reliably identify the current state of the coupling device without additional sensors, in particular to identify and verify whether the coupling state or the decoupling state has been engaged.

[0018] The coupling device can be configured, in particular, to detect its state based on an electromagnetic parameter, specifically a magnetic flux and / or a magnetic field and / or a current flow and / or a voltage and / or a change in an electromagnetic parameter. As described, the response of the coupling device's state to the magnetic field within the electromagnetic actuator can ultimately form the basis for the electromagnetic actuator's detection of the coupling device's state. At least one of the aforementioned electromagnetic parameters, or a change thereof, can be used to detect the state or a transition of the coupling device's state. In this context, the relative positioning of the coupling sections' gears to each other, or...one of the coupling sections relative to the toothing of the coupling element exhibits a detectable property of the magnetic field that can be described by the electromagnetic parameter.

[0019] In particular, the coupling state differs from the decoupling state by a first electromagnetic parameter or a first set of electromagnetic parameters, which can be assigned to the coupling state, for example, and a second electromagnetic parameter or a second set of electromagnetic parameters, which can be assigned to the decoupling state, for example. Similarly, a tooth-to-tooth alignment or a tooth-to-gap alignment can be determined by electromagnetic parameters or sets of electromagnetic parameters. Here, too, a first electromagnetic parameter (or a third electromagnetic parameter) or a first set of electromagnetic parameters (or a third set of electromagnetic parameters) can be assigned to the tooth-to-tooth alignment, and a second electromagnetic parameter (or a fourth electromagnetic parameter) or a second set of electromagnetic parameters can be assigned to the tooth-to-tooth alignment.A second set of electromagnetic parameters (or a fourth set of electromagnetic parameters) can be assigned to the tooth-on-gap position. By acquiring at least one electromagnetic parameter, in particular a set of electromagnetic parameters, the current state of the coupling device can be described and used for controlling the coupling device. For this purpose, the electromagnetic actuator can be connected to a control device that can evaluate and further process the corresponding electromagnetic parameters.

[0020] As described, the coupling device can move the coupling element based on the detection of at least one electromagnetic parameter. In other words, the coupling device can be configured to move the coupling element depending on the at least one detected electromagnetic parameter. The coupling device can define or control at least one actuation parameter or movement parameter, in particular an actuation time at which the movement of the coupling element is triggered, and an actuation speed at which the coupling element is moved between the decoupling state and the coupling state, in particular from the decoupling state to the coupling state, depending on the detected electromagnetic parameter.

[0021] In a further embodiment, the coupling device can be configured to move the coupling element based on at least one detected electromagnetic parameter in such a way as to prevent a jamming position, in particular a tooth-on-tooth position. For example, the coupling device can adjust the actuation point and the actuation speed, or the movement speed of the coupling element, such that upon reaching the corresponding axial position, the jamming position is reliably released and the gear teeth can engage. This ensures that the coupling element does not stop in the jamming position. Unnecessarily high actuation speeds, which would inevitably lead to a jamming position, can thus be avoided.

[0022] The transmission device can comprise at least one housing section that at least partially surrounds the at least one actuator and a bearing arrangement, which bearing arrangement is located between the outer differential carrier and the housing section. The bearing arrangement can, for example, be designed as a roller bearing. The bearing arrangement can support forces acting in the axial and / or radial direction between the housing section and the outer differential carrier. The housing section can surround the electromagnet or the electromagnetic actuator, so that the electromagnetic actuator can be arranged on or accommodated in the housing section.

[0023] In addition to the transmission device, the invention relates to a motor vehicle comprising a previously described transmission device. Furthermore, the invention relates to a method for controlling a transmission device, in particular a previously described transmission device. In the method, the coupling device is arranged outside the outer differential housing, wherein, in a coupled state, a movable coupling element couples the inner differential housing to the outer differential housing, and in a disengaged state, the movable coupling element disengages the inner differential housing from the outer differential housing.

[0024] All advantages, details, and features described in relation to the transmission device are fully transferable to the motor vehicle and the method. In particular, it may be provided that the method for controlling the transmission device generates movement of the coupling element. This movement of the coupling element is generated, in particular, by an electromagnetic actuator. The electromagnetic actuator can also be used, in particular, to detect the coupling state of the coupling device.

[0025] In particular, an electromagnetic parameter can be recorded that allows conclusions to be drawn about the coupling state.

[0026] The invention is explained below with reference to an exemplary embodiment and the figures. The figures are schematic representations and show: Fig. 1 a transmission device for a motor vehicle in a coupled state, and Fig. 2 the gearbox of Fig. 1 in a decoupling state.

[0027] Fig. 1, Fig. Figure 2 shows a transmission device 1 for a motor vehicle not shown in detail, or a section of a motor vehicle having a transmission device 1. Fig. 1 and Fig. The two differ in the state in which the transmission device 1 is located. Here, it shows... Fig. 1 a coupling state of the transmission device 1 and Fig. Figure 2 shows a decoupling state of the transmission device 1. The basic structure of the transmission device 1 can thus be understood with reference to both figures, with the details relating to the coupling state and the decoupling state being shown in Figure 2. Fig. 1 or from Fig. 2 are evident.

[0028] The transmission device 1 has a differential 2 with a drive side 3 and an output side 4. For illustrative purposes only, the depicted embodiments show a spur gear 5 and side shafts 6, which connect the differential 2 to the drive side 3 and the output side 4, respectively. Any other connection, such as a ring gear, is also possible instead of the spur gear 5 and is not essential for the described object. In this embodiment, the drive side 3 is connected to an outer differential carrier 7, which is, for example, formed integrally with the spur gear 5, for instance, by a welded connection.The differential 2 further comprises an inner differential basket 8 which is coupled to the output side 4, for example via the usual components of a differential 2 shown in this embodiment, for example differential gears and bevel gears which establish the connection to the side shafts 6.

[0029] To selectively establish and disconnect the coupling between the drive side 3 and the output side 4, the transmission device 1 has a coupling device 9. The coupling device 9 in turn has a coupling element 10, which is movably mounted in the axial direction with respect to a rotary axis 11 of the transmission device 1. By moving the coupling element 10, or by bringing the coupling element 10 into the corresponding axial positions, the coupling state, which is defined in Fig. 1 is shown and the decoupling state that is in Fig. 2 is shown, to be taken.

[0030] The coupling element 10 is designed, for example, for the positive-locking coupling of the inner differential cage 8 with the outer differential cage 7. The coupling element 10 can, for example, be designed as a claw element and have a toothing that corresponds to a toothing of a first coupling section 12 of the inner differential cage 8 and to a toothing of a second coupling section 13 of the outer differential cage 7. In other words, in the coupled state, a rotationally fixed connection is established between the two coupling sections 12, 13, and thus between the outer differential cage 7 and the inner differential cage 8. In the uncoupled state, the described rotationally fixed connection is broken, so that the inner differential cage 8 can rotate freely relative to the outer differential cage 7.In the illustrated embodiment, each coupling section 12, 13 has a coupling body which in turn establishes the connection to the inner differential basket 8 or the outer differential basket 7 via a corresponding toothing.

[0031] In this embodiment, the coupling device 9 has an electromagnetic actuator 14. In principle, the use of any other actuator is also possible, for example a pneumatic, hydraulic or electromechanical actuator, whereby the detection of the state of the coupling device 9 by the electromagnetic actuator 14, as described below, is particularly advantageous.

[0032] The electromagnetic actuator 14 is arranged coaxially with respect to the axis of rotation 11 to the coupling sections 12, 13 and thus also coaxially with the coupling element 10. The electromagnetic actuator 14 is, for example, ring-shaped or designed as a ring segment and arranged concentrically on the axis of rotation 11. The axis of rotation 11 here forms, for example, the axis of rotation of the side shafts 6, the inner differential cage 8, or the outer differential cage 7. The electromagnetic actuator 14 is designed to generate a magnetic field in order to move the coupling element 10 in the axial direction, i.e., along the axis of rotation 11. This allows the coupling element 10 to move into the Fig. 1, Fig. The two states shown can be moved. The electromagnetic actuator 14 can, for example, be configured to generate both the movement into the coupling state and the movement into the decoupling state, for example by means of two different electromagnets, each of which generates a corresponding magnetic field.

[0033] It is also possible to generate only one of the two directions of movement using the electromagnetic actuator 14 and to generate the reverse movement using a spring element that exerts a spring force on the coupling element 10. For example, the electromagnetic actuator 14 can thus generate a movement from the coupled state to the uncoupled state, with the spring force causing a movement back into the coupled state. Conversely, it is also possible for the electromagnetic actuator 14 to initiate a movement from the uncoupled state to the coupled state, with the spring element being responsible for moving the coupling element 10 back into the uncoupled state.

[0034] By moving the coupling element 10 in such a way as to establish the decoupling state, the connection between the drive side 3 and the output side 4 can be separated, so that the corresponding parts of the transmission device 1 do not have to be dragged along. The decoupling state can also be referred to as the "disconnected" state and the coupling state can also be referred to as the "connected" state.

[0035] As described in Fig. Figure 1 shows the coupling state in which the coupling between coupling sections 12 and 13 is established by the coupling element 10. If the coupling element 10 is moved out of the toothing of the first coupling section 12, i.e., "to the right" in the drawing, the coupling state changes. Fig. 1 into the decoupling state, which is in Fig. 2 is shown, transitioned. Conversely, from the in Fig. 2 decoupling state shown by a movement of the coupling element 10 “to the left”, i.e., into the toothing of the first coupling section 12, into which in Fig. The coupling state shown in Figure 1 can be transitioned to. The direction of movement can be changed arbitrarily, for example by the coupling element 10 remaining continuously engaged with the first coupling section 12 and optionally establishing a connection to the second coupling section 13.

[0036] The electromagnetic actuator 14 of the coupling device 9 can further be configured to detect a state of the coupling device 9. The current configuration or arrangement of the coupling sections 12, 13, and the coupling element 10 influences the magnetic field within the annular space bounded by the electromagnetic actuator 14. In other words, the electromagnetic actuator 14 can be used to detect an electromagnetic parameter, for example, a magnetic field strength and / or a magnetic flux and / or a current and / or a voltage and / or a change in at least one of the described electromagnetic parameters. For this purpose, the electromagnetic actuator 14 can be connected to a control device (not shown) to provide the corresponding measurement signals, which can then be further processed by the control device.

[0037] In this way, it is particularly possible to determine how the first coupling section 12 is oriented relative to the second coupling section 13, i.e., how their gear teeth are positioned relative to each other in the circumferential direction. In the decoupling state, the first coupling section 12 and the second coupling section 13 can rotate freely relative to each other in the circumferential direction, that is, about the axis of rotation 11. If the coupling state is to be established from the decoupling state, the coupling element 10 must, as described, be inserted into the gear teeth of the respective other coupling section 12, 13 in order to connect the two coupling sections 12, 13 and thus the outer differential basket 7 with the inner differential basket 8.

[0038] The electromagnetic actuator 14 thus allows, firstly, the detection of whether the coupling or decoupling state is established. Secondly, in the decoupling state, it can detect the relative position of the teeth of the coupling sections 12, 13. Depending on the detected state, the movement of the coupling element 10 can then be controlled. For example, the actuation point and the actuation speed at which the coupling element 10 is moved can be selected such that a blocking position, in particular a tooth-on-tooth position, is avoided when establishing the coupling. The coupling element 10 can be moved precisely so that it reliably engages with the teeth of the coupling section 12, 13 to be coupled, in this embodiment the first coupling section 12.

[0039] The transmission device 1 further comprises a bearing arrangement 15 for a housing section 16 that partially surrounds the electromagnetic actuator 14. The housing section 16 thus surrounds the electromagnetic actuator 14, at least partially. The bearing arrangement 15 is provided for supporting the housing section 16 on the outer differential carrier 7, or the outer differential carrier 7 is supported on the housing section 16 by the bearing arrangement 15. Reference sign 1 Gearbox device 2 Differential 3 Drive side 4 Output side 5 Spur gear 6 Side shaft 7 outer differential basket 8 inner differential basket 9 Coupling device 10 coupling element 11 axis of rotation 12 first coupling section 13 second coupling section 14 electromagnetic actuator 15 Storage facility 16 Housing section

Claims

[1] Transmission device (1) for a motor vehicle, comprising a differential (2) and a coupling device (9) configured to selectively couple an outer differential basket (7) connected to a drive side (3) of the differential with an inner differential basket (8) connected to an output side (4) of the differential (2), characterized by , that the coupling device (9) is arranged outside the outer differential basket (7) and is designed to couple the inner differential basket (8) with the outer differential basket (7) in a coupling state of a movable coupling element (10) and to decouple the inner differential basket (8) from the outer differential basket (7) in a decoupling state of the movable coupling element (10). [2] Gear device (1) according to claim 1, characterized by, that the coupling device (9) has at least one electromagnetic actuator (14) configured to move the coupling element (10) between the decoupling state and the coupling state. [3] Gear unit (1) according to claim 1 or 2, characterized by , that the inner differential basket (8) has a first coupling section (12), in particular a first coupling body, and the outer differential basket (7) has a second coupling section (13), in particular a second coupling body, wherein the coupling sections (12, 13) extend in the axial direction away from the differential (2) and the coupling device (9), in particular the electromagnetic actuator (14) of the coupling device (9), encompasses the coupling sections (12, 13). [4] Gear unit (1) according to claim 2 or 3, characterized by, that the coupling device (9) is designed by means of the electromagnetic actuator (14) to detect a state of the coupling device (9), in particular to detect a position or a relative position of the teeth of the coupling sections (12, 13) relative to each other and / or to the teeth of the coupling element (10). [5] Gear unit (1) according to claim 4, characterized by , that the coupling device (9) is configured to detect the state based on an electromagnetic parameter, in particular based on a magnetic flux and / or a magnetic field and / or a current flow and / or a voltage and / or a change in an electromagnetic parameter. [6] Gear unit (1) according to claim 4 or 5, characterized by , that the coupling device (9) is designed to move the coupling element (10) depending on the at least one detected electromagnetic parameter. [7] Gear unit (1) according to any one of claims 4 to 6, characterized by , that the coupling device (9) is designed to move the coupling element (10) based on at least one detected electromagnetic parameter in such a way as to avoid a blocking position, in particular a tooth-to-tooth position. [8] Gear unit (1) according to any one of the preceding claims, characterized by , that the transmission device (1) has at least one housing section (16) surrounding at least one actuator (14) at least partially and a bearing device (15) which bearing device is arranged between the outer differential basket (7) and the housing section (16). [9] Motor vehicle comprising a transmission device (1) according to any of the preceding claims. [10] Method for controlling a transmission device (1) for a motor vehicle, comprising a differential (2) and a coupling device (9) configured to selectively couple an outer differential basket (7) connected to a drive side (3) of the differential with an inner differential basket (8) connected to an output side (4) of the differential, characterized by , that the coupling device (9) is arranged outside the outer differential basket (7), wherein in a coupling state a movable coupling element (10) couples the inner differential basket (8) with the outer differential basket (7) and in a decoupling state the movable coupling element (10) decouples the inner differential basket (8) from the outer differential basket (7).

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