Actuation device and vehicle driving assembly and vehicle

Abstract

The disclosure concerns an actuation device 2 for a differential locking mechanism 46 and a gearbox 44 of a vehicle. The actuation device comprises a barrel cam 4 with a rotational axis 8 and at least a first group of tracks 10 and a second group of tracks 16. A first track follower 32 is configured to follow the first group of tracks as the barrel cam is rotated about the rotational axis, and a second track follower 34 is configured to follow the second group of tracks as the barrel cam is rotated about the rotational axis. The first track follower is configured to connect to a first shifting shaft 38 arranged to operate the differential locking mechanism, and the second track follower is configured to connect to a second shifting shaft 40 arranged to shift at least a first gear of the gearbox.

Description

[0001] Actuation Device and Vehicle Driving Assembly and Vehicle

[0002] TECHNICAL FIELD

[0003] The invention relates to an actuation device for a differential locking mechanism and a gearbox of a vehicle. The invention further relates to a vehicle driving assembly, as well as to a vehicle.

[0004] BACKGROUND

[0005] Gearboxes, differentials, and differential locking mechanisms form part of powertrains of vehicles. Gearboxes are responsible for transferring torque from a vehicle propulsion power source to drive wheels of the vehicle. In the gearbox, different gears are shifted and engaged to provide different gear ratios. The differential enables the drive wheels to rotate at different speeds while distributing equal torque to them e.g. when the relevant vehicle drives along a curve. The differential locking mechanism locks the differential to prevent the drive wheels from rotating at different speeds, which helps distribute torque to the drive wheel with best traction of the drive wheels e.g., for improving traction under challenging driving conditions.

[0006] In conventional vehicle powertrains, gear shifting and differential locking are typically actuated separately, using different mechanisms. For example, gear shifting may be performed manually by the driver or through actuators, such as a pneumatic, hydraulic, or electromagnetic actuators. Differential locking is actuated using a separate actuation system.

[0007] Existing actuation systems for gear shifting and differential locking are not necessarily optimized for precise and synchronized control of the various mechanical movements involved. This can result in suboptimal performance, increased wear on the components, and potential reliability issues.

[0008] In recent years, there has been growing interest in the development of electric actuation systems for vehicle transmissions. Electric actuators offer several potential advantages over traditional pneumatic, hydraulic, and electromagnetic systems, including improved efficiency, reduced weight, and more precise control.

[0009] US 2011 / 0100144 discloses a barrel cam shift mechanism for a dual clutch transmission which employs a rotating barrel cam having at least three tracks which are engaged by and translate at least three associated cam followers. The cam followers extend from shift fork bodies which slide on rails and include shift forks which bi-directionally translate at least three synchronizer clutches which engage at least five forward gears or speeds and reverse. A single electric motor and gear train drive the barrel cam.

[0010] SUMMARY

[0011] Providing electric actuation systems for gear shifting and for differential locking functions remain technical challenges, particularly in terms of achieving compact and efficient designs that can fit within a limited space of a vehicle.

[0012] It would be advantageous to achieve a compact arrangement for gear shifting and operation of a differential locking mechanism. In particular, it would be desirable to provide a device for common gear shifting and operation of a differential locking mechanism. To better address one or more of these concerns, one or more of an actuation device, a vehicle driving assembly, and / or a vehicle having the features defined in one or more of the independent claims is provided.

[0013] According to a first aspect there is provided, an actuation device for a differential locking mechanism and a gearbox of a vehicle. The actuation device comprises a barrel cam having a rotational axis and being provided with at least a first group of tracks and a second group of tracks, an electric actuator operatively connected to the barrel cam for controlling a rotation of the barrel cam, a first track follower configured to follow the first group of tracks as the barrel cam is rotated about the rotational axis, and a second track follower configured to follow the second group of tracks as the barrel cam is rotated about the rotational axis. The first track follower is configured to connect to a first shifting shaft arranged to operate the differential locking mechanism, and the second track follower is configured to connect to a second shifting shaft arranged to shift at least a first gear of the gearbox.

[0014] In this way there is provided an electrically driven actuation device that integrates gear shifting functionality with differential locking functionality.

[0015] Thus, differential locking and gear shifting are provided by the actuation device using the barrel cam, which provides a compact and efficient solution for integrating these functions in a single actuation device. This represents an advancement in vehicle transmission and differential locking technology, offering a compact solution for actuating both differential locking and gear shifting, improved performance, reduced complexity, and potential cost savings for vehicle manufacturers and end-users alike. Further, since the first and second groups of tracks are provided on the barrel cam, the tracks of each group are fixed in relation to each other, this means that movements of the first and second track followers are perfectly aligned with each other as the barrel cam is rotated, which accordingly, enables precise control of the differential locking and gear shifting, improving the performance of differential locking and gear shifting in a vehicle provided with the actuation device.

[0016] According to a second aspect, there is provided a vehicle driving assembly for a vehicle. The vehicle driving assembly is configured to support at least two drive wheels of the vehicle. The vehicle driving assembly comprises an axle beam, two drive shafts arranged to drive the drive wheels, a gearbox, a differential, a differential locking mechanism, and an electric machine configured to drive the two drive shafts via the gearbox and the differential, and an actuation device according to any one of aspects and / or examples discussed herein.

[0017] As discussed above with reference to the actuation device, in the vehicle driving assembly, the actuation device provides an integrated differential locking and gear shifting functionality. The functionality is provided in a compact and efficient manner to reduce complexity and provide potential cost savings, while providing precise control of the differential locking and gear shifting via the aligned first and second groups of tracks.

[0018] According to a third aspect, there is provided a vehicle comprising a vehicle driving assembly according to any one of aspects and / or examples discussed herein.

[0019] As discussed above with reference to the actuation device and the vehicle driving assembly, the actuation device provides an integrated differential locking and gear shifting functionality. The functionality is provided in a compact and efficient manner to reduce complexity and provide potential cost savings, while providing precise control of the differential locking and gear shifting via the aligned first and second groups of tracks.

[0020] In the vehicle, the axle beam may be connected to a chassis of the vehicle. Alternatively, the axle beam of the vehicle driving assembly may from part of a chassis of the vehicle.

[0021] The at least two drive wheels may be supported at opposite lateral sides of the vehicle and at opposite ends of the axle beam. The two drive shafts arranged to drive the drive wheels may extend at least partially through the axle beam between the differential and the drive wheels. The two drive shafts form output shafts from the differential or are connected to output shafts from the differential.

[0022] The differential locking mechanism is arranged in connection with the differential and is operated to enable two different states of the differential, an unlocked state when the differential locking mechanism is disengaged, and a locked state when the differential locking mechanism is engaged. In the unlocked state, normal differential functionality is provided by the differential i.e. , distributing torque between the drive wheels and enable different rotational speeds of the drive wheels. In the locked state, the differential functionality is prevented and both drive shafts are driven rotationally locked to each other to provide the same rotational speed for both drive wheels.

[0023] The gearbox is arranged between the electric machine and the differential. The gearbox includes at least two gears that can be shifted to provide different gear ratios between the electric machine and the drive wheels. The gearbox may comprise an input shaft, an output shaft and a layshaft. Gearwheels arranged on these shafts are engaged in different combinations to provide the different gear ratios.

[0024] The gearbox may be included in a transmission of the vehicle. Such a transmission may include further sections of gears beside the gearbox, e.g. the transmission may comprise a planetary gearset connected to the gearbox.

[0025] The electric machine is operable as an electric motor to drive the drive wheels of the vehicle. Optionally, the electric machine is operable as an electric generator e.g., for charging batteries aboard the vehicle.

[0026] The electric machine may be the only source of torque configured for propelling the vehicle. Alternatively, the electric machine may be complemented with further sources of torque arranged to propel the vehicle, such as one or more further electric machines and / or an internal combustion engine.

[0027] The barrel cam of the actuation device may have a generally round shape, such as a cylindrical shape.

[0028] Each group of tracks may be provided in an outer surface of the barrel cam i.e., tracks of the group of tracks are formed by at least partially circumferentially extending recesses in a body of the barrel cam. Within each group of tracks, the depth of the tracks may differ between tracks and / or along one or more of the tracks.

[0029] Each group of tracks may include a track, such as a main track, that extends circumferentially around the entire barrel cam and at least one track, such as a side track, that branches off from the track that extends circumferentially around the entire barrel cam. The track that branches off from the track that extends circumferentially around the entire barrel cam may extend a partial distance around the circumference of the barrel cam.

[0030] During use of the actuation device, the barrel cam is rotated about the rotational axis by the electric actuator. The electric actuator is configured for precisely controlling the rotation of the barrel cam about the rotational axis. This means that partial and full rotations of the barrel cam, in both directions, can be achieved with angular precision to enable the first and second track followers to follow the tracks of the respective first and second groups of tracks.

[0031] The first shifting shaft forms part of a connection between the first track follower and the differential locking mechanism. The first shifting shaft is arranged to shift the differential locking mechanism between a disengaged state when the differential operates normally and an engaged state when the differential is locked.

[0032] The first shifting shaft is linearly moved as the first track follower follows along the first group of tracks. Accordingly, a position of the first shifting shaft is affected as the first track follower follows along the tracks of the first group of tracks. The position of the first shifting shaft affects whether the differential locking mechanism is in the disengaged state or the engaged state.

[0033] The second shifting shaft forms part of a connection between the second track follower and the gearbox. The second shifting shaft is linearly moved as the second track follower follows along the second group of tracks. Accordingly, a position of the second shifting shaft is affected as the second track follower follows along the tracks of the second group of tracks. The position of the second shifting shaft affects shifting of at least the first gear of the gearbox, between an engaged position and a disengaged position.

[0034] Optionally in some examples, the first group of tracks comprises a first main track and at least one first side track branching off from the first main track. The first main track extends circumferentially around the barrel cam. The at least one first side track is axially displaced from the first main track and has a limited circumferential extension. The second group of tracks comprises a second main track and at least one second side track branching off from the second main track. The second main track extends circumferentially around the barrel cam, and the at least one second side track is axially displaced from the second main track and has a limited circumferential extension. In this manner, precise control of the differential locking mechanism and gear shifting may be provided.

[0035] Thus, for instance, during use of the actuation device, by rotating the barrel cam for the second track follower to enter the at least one second side track, the first gear of the gearbox may be engaged and by rotating the barrel cam further, the first track follower enters the at least one first side track for the differential locking mechanism to engage and lock the differential.

[0036] Optionally in some examples, one or more portions of the first main track are shallower than the at least one first side track, and one or more portions of the second main track are shallower than the at least one second side track. In this manner, the first track follower can be brought to enter the at least one first side track and the second track follower can be brought to enter the at least one second side track by rotating the barrel cam.

[0037] By arranging the first and second track followers, e.g. by biasing thereof, to follow the bottom of the respective first and second group of tracks, the first track followers will naturally enter the at least one first side track from the shallower first main track and the second track follower will enter the at least one second side track from the shallower second main track.

[0038] Optionally in some examples, rotation of the barrel cam in a first direction about the rotational axis causes the first track follower to enter the at least one first side track and the second track follower to enter the at least one second side track. Rotation of the barrel cam in a second direction about the rotational axis causes the first track follower to exit the at least one first side track and / or to follow along the first main track and the second track follower to exit the at least one second side track and / or to follow along the second main track. In this manner, by controlling the rotational direction of the barrel cam, the first track follower can be brought to enter the at least one first side track and the second track follower can be brought to enter the at least one second side track.

[0039] For instance, the at least one first side track may branch off at an acute angle from the first main track seen as the barrel cam rotates in the first rotational direction. Accordingly, seen as the barrel cam rotates in the opposite second direction, the at least one first side track extends at an obtuse angle to the first main track. Thus, entering and exiting the at least one first side track by the first track follower may be enabled. Similarly, the at least one second side track may branch off at an acute angle from the second main track seen as the barrel cam rotates in the first rotational direction. Accordingly, seen as the barrel cam rotates in the second direction, the at least one second side track extends at an obtuse angle to the second main track. Thus, entering and exiting the at least one second side track by the second track follower may be enabled.

[0040] Further, the above discussed shallower first main track than the at least one first side track may be implemented in connection with the arrangement of the at least one first side track at the acute angle to the first main track and the shallower second main track than the at least one first second track may be implemented in connection with the arrangement of the at least one second side track at the acute angle to the second main track.

[0041] Optionally in some examples, a first side track of the at least one second side track extends along a first circumferential portion of the barrel cam, and a first side track of the at least one first side track extends along only part of the first circumferential portion of the barrel cam.

[0042] In this manner, by rotating the barrel cam for the second track follower to follow the first side track of the at least one second side track only a partial distance along the first circumferential portion of the barrel cam, the first gear is engaged in the gearbox while the first track follower does not enter the first side track of the at least one first side track and the differential locking mechanism remains disengaged. By rotating the barrel cam further, the second track follower will follow the first side track of the at least one second side track further along the first circumferential portion of the barrel cam. This enables the first track follower to enter the first side track of the at least one first side track which causes the differential locking mechanism to engage and lock the differential.

[0043] Thus, a two-step functionality is provided where, in a first step a gear, such as the first gear, is engaged in the gearbox while normal operation of the differential is maintained, and in a second step with the relevant gear remaining engaged, the differential is locked.

[0044] Optionally in some examples, a second side track of the at least one second side track extends along a second circumferential portion of the barrel cam, and a second side track of the at least one first side track extends along only part of the second circumferential portion of the barrel cam. In this manner, similarly, as discussed above in relation to the respective first side track of the at least one first and second side tracks, a two-step functionality is provided also for a second gear of the gearbox. Accordingly, in a first step the second gear is engaged in the gearbox while normal operation of the differential is maintained, and in a second step with the second gear remaining engaged, the differential is locked.

[0045] Optionally in some examples, the barrel cam is provided with a third group of tracks, and the actuation device comprises a third track follower configured to follow the third group of tracks as the barrel cam is rotated about the rotational axis. The third track follower is configured to connect to a third shifting shaft arranged to shift at least one further gear of the gearbox. In this manner, the actuation device can be utilised for shifting further gears of the gearbox.

[0046] Optionally in some examples, the third group of tracks comprises a third main track and at least one third side track branching off from the third main track. The third main track extends circumferentially around the barrel cam. The at least one third side track is axially displaced from the third main track and has a limited circumferential extension. In this manner, the actuation device may be configured to be utilising for shifting further gears of the gearbox.

[0047] Optionally in some examples, one or more portions of the third main track are shallower than the at least one third side track. In this manner, similarly, as discussed above with reference to the first and second main tracks, the third track follower can be brought to enter the at least one third side track by rotating the barrel cam.

[0048] Optionally in some examples, rotation of the barrel cam in a first direction about the rotational axis causes the third track follower to enter the at least one third side track. Rotation of the barrel cam in a second direction about the rotational axis causes the third track follower to exit the at least one third side track and / or to follow along the third main track. In this manner, similarly, as discussed above in connection with the first and second groups of tracks, by controlling the rotational direction of the barrel cam, the third track follower can be brought to enter the at least one third side track.

[0049] Optionally in some examples, a first side track of the at least one third side track extends along a third circumferential portion of the barrel cam, and a third side track of the at least one first side track extends along only part of the third circumferential portion of the barrel car??. In this manner, similarly, as discussed above in relation to the respective first side tracks of the at least one first side track and the at least one second side track, a two-step functionality is provided also for a third gear of the gearbox. Accordingly, in a first step the third gear is engaged in the gearbox while normal operation of the differential is maintained, and in a second step with the third gear remaining engaged, the differential is locked. Optionally in some examples, the electric actuator comprises an electric motor and a transmission system. The electric motor is connected to the transmission system for transmitting rotation of the electric motor to the barrel cam. This configuration allows for a precise control of the rotation of the barrel cam to enable precise control of the differential locking mechanism and gear shifting.

[0050] For instance, the transmission system may reduce a rotational speed of the electric motor such that the barrel cam can be precisely controlled.

[0051] Optionally in some examples, the actuation device comprises the first shifting shaft and the second shifting shaft. In this manner, the first and second shift shafts may be provided together with the actuation device.

[0052] Alternatively, the first and second shifting shafts may be provided as part of the vehicle driving assembly, or as separate parts.

[0053] Optionally in some examples, the electric machine is configured to synchronize a rotational speed of one half of a dog clutch of a gear of the gearbox to be engaged while the barrel cam is rotationally positioned by the electric actuator to engage the gear of the gearbox to be engaged. In this manner, smooth engagement of the dog clutch during gear shift is enabled.

[0054] Herein, a synchronised rotational speed is a rotational speed that matches a target rotational speed within a limited rotational speed difference.

[0055] Further features of, and advantages with, the invention will become apparent when studying the appended claims and the following detailed description.

[0056] BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various aspects and / or embodiments / examples of the invention, including its particular features and advantages, will be readily understood from the examples discussed in the following detailed description and the accompanying drawings, in which:

[0058] Fig. 1 illustrates an example of a vehicle,

[0059] Figs. 2a and 2b schematically illustrate portions of a vehicle driving assembly, and

[0060] Figs. 3a - 3d schematically illustrate an actuation device and parts thereof. DETAILED DESCRIPTION

[0061] Aspects and / or embodiments / examples of the invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and / or clarity.

[0062] Fig. 1 illustrates an example of a vehicle 80.

[0063] The vehicle 80 may be any kind of vehicle configured for land-based propulsion, such as e.g., a bus, a truck, a heavy truck, a car, or a train. In Fig. 1 , the vehicle 80 is illustrated as a heavy load vehicle in the form of a truck.

[0064] The vehicle 80 includes at least two drive wheels 78. The drive wheels 78 are designed to engage with the ground to propel the vehicle 80.

[0065] The vehicle 80 includes a schematically indicated vehicle driving assembly 72, which is designed to support at the least two drive wheels 78 of the vehicle 80.

[0066] The drive wheels 78 are connected to drive shafts of the vehicle driving assembly 72. The drive shafts and the drive wheels 78 receive torque from an electric machine via a gearbox and a differential, thereby driving the vehicle 80.

[0067] The electric machine, the gearbox, the differential, and a differential locking mechanism may form part of the vehicle driving assembly 72. The vehicle driving assembly 72 is discussed further below with reference to Figs. 2a and 2b.

[0068] The vehicle 80 and the vehicle driving assembly 72 also include an actuation device 2, which controls the operation of the differential locking mechanism and shifting of gears in the gearbox. The actuation device 2 is further discussed below with reference to Figs. 3a - 3d.

[0069] Figs. 2a and 2b schematically illustrate portions of a vehicle driving assembly 72. The vehicle driving assembly 72 is a vehicle driving assembly 72 for a vehicle, such as one of the vehicles discussed above with reference to Fig. 1, e.g. a vehicle 80 in the form of heavy load vehicle as shown. Accordingly, in the following reference is also made to Fig. 1.

[0070] As mentioned above, the vehicle driving assembly 72 is configured to support at least two drive wheels 78 of the vehicle 80. The vehicle driving assembly 72 comprises: an axle beam 68, two drive shafts 70 arranged to drive the drive wheels 78, a gearbox 44, a differential 74, a differential locking mechanism 46, an electric machine 76 configured to drive the two drive shafts 70 via the gearbox 44 and the differential 74, and an actuation device 2.

[0071] Fig. 2a shows the axle beam 68 including a housing 71 inside which further components of the vehicle driving assembly 72 may be arranged. According to some examples, some components of the vehicle driving assembly 72 may be arranged outside the housing 71, such as connected to the housing 71.

[0072] Fig. 2b schematically illustrates components of the vehicle driving assembly 72 to be arranged in connection with the axle beam 68, such as within, and / or attached to, the housing 71.

[0073] The axle beam 68 is designed to support the two drive wheels 78 of the vehicle 80. Thus, the axle beam 68 is a structural component of the vehicle driving assembly 72 and provides the necessary support and rigidity to the vehicle driving assembly 72.

[0074] The two drive shafts 70 are arranged to drive the drive wheels 78 of the vehicle 80. The drive shafts 70 are connected to the drive wheels 78 and are arranged to transfer a torque from the electric machine 76 via the gearbox 44 and the differential 74 to the drive wheels 78. The drive shafts 70 are arranged between the differential 74 and the drive wheels 78. The drive shafts 70 may be directly or indirectly connected to the differential 74 and to the drive wheels 78.

[0075] Each of the drive shafts 70 may extend through a sidewardly extending portion 69 of the axle beam 68, from the differential 74 to towards the drive wheels 78. In Fig. 2b, portions of the drive shafts 70 are shown with broken lines.

[0076] The differential 74 is arranged between the gearbox 44 and the drive shafts 70. The differential 74 is a component of the vehicle driving assembly 72 and is designed to distribute the torque from the electric machine 76 to the drive shafts 70.

[0077] The differential 74 of the vehicle driving assembly 72 includes the differential locking mechanism 46. In a known manner, the differential locking mechanism 46 is designed to lock the differential 74 when engaged. Accordingly, the differential locking mechanism 46 is arranged to be shifted between a disengaged state when the differential 74 operates normally and an engaged state when the differential 74 is locked.

[0078] The differential locking mechanism 46 includes an engagement mechanism 48, which is configured to enable shifting of the differential locking mechanism 46.

[0079] Mentioned purely as an example, the differential locking mechanism 46 may comprise a splined sleeve which is axially moveable between a disengaged position and an engaged position. The axial movement of the splined sleeve is in parallel with an axis of the splined sleeve. In a known manner, the splined sleeve rotationally locks two parts of the differential 74 to each other in the engaged position, and thus, locks the differential 74. In the disengaged position, the splined sleeve is positioned such that the two parts of the differential 74 can rotate in relation to each other and the differential 74 is unlocked to provide its normal functionality.

[0080] The engagement mechanism 48 is connected to a first shifting shaft 38 for being moved thereby. In the example of the differential locking mechanism 46 comprising a splined sleeve, the splined sleeve is moved by the first shifting shaft 38 and the engagement member 48 between the disengaged and engaged positions along the axial direction.

[0081] The first shifting shaft 38 is arranged to provide a linear movement, which may be arranged to move in parallel with the axis of the splined sleeve, in the example above. The movement of the first shifting shaft 38 is controlled by the actuation device 2, see further below, inter alia with reference to Figs. 3a - 3d.

[0082] The engagement member 48 may comprises a resilient member. Thus, the differential locking mechanism 46 does not have to immediately follow a movement of the first shifting shaft 38. For instance, splines of the splined sleeve and of a shaft or axle of the differential 74 may not line up properly for the differential locking mechanism 46 to engage. In such a situation, the resilient member biases the differential locking mechanism 46 towards the engaged position for it to engage, once properly aligned, which may be caused by a rotational speed difference between parts within the differential 74.

[0083] Thus, locking of the differential 74 may be delayed for a period of time after moving of the first shifting shaft 38. The resilience provided by the resilient member of the engagement member 48 also unloads an electric actuator 6 of the actuation device 2 in such situations.

[0084] The resilient member of the engagement member 48 may provide a similar functionality when the differential locking mechanism 46 is disengaged. In this case, disengagement is delayed until the differential locking mechanism 46 is unloaded and, in the example with the splined sleeve, the sleeve can be moved to the disengaged position.

[0085] The gearbox 44 is arranged between the differential 74 and the electric machine 76. In the gearbox 44, gears are shifted for controlling the torque provided to the drive wheels 78 of the vehicle 80. The actuation device 2 is configured to control the shifting of gears in the gearbox 44.

[0086] The gearbox 44 includes at least a first gear 50 that can be shifted under the control of the actuation device 2. The gearbox 44 may include two gears, three gears, or four gears as shown in Fig. 2b, or more than four gears. The gearbox 44 may have any suitable configuration that provides a desired number of gears for propelling the vehicle 80. Shifting of gears may be performed by linear movements in parallel with one or more rotational axes of the gearbox 44.

[0087] A second shifting shaft 40 is arranged to shift at least the first gear 50 of the gearbox 44. The second shifting shaft 40 is arranged to provide a linear movement.

[0088] If the number of gears of the gearbox 44 so requires, a third shifting shaft 42 is arranged to shift the relevant gear or gears. The third shifting shaft 42 is arranged to provide a linear movement.

[0089] The movement of the second shifting shaft 40, and if present, the movement of the third shifting shaft 42 is controlled by the actuation device 2, see further below, inter alia with reference to Figs. 3a - 3d.

[0090] Gearboxes including meshing gearwheels 52, 53, 56, 55, 60, 57, utilising shifting sleeves 62 and dog clutches 64 are known in the art, as is operation and shifting between gears within such gearboxes. For demonstrative purposes, in the context of the shifting of gears utilising the present actuation device 2, an example gearbox 44 is briefly presented in the following with reference to Fig. 2b. A number of the gearwheels 53, 55, 57 are connected to a layshaft 63 and rotationally fixed in relation thereto. When the electric machine 76 is operated as an electric motor, the layshaft 63 and the gearwheels 53, 55, 57 are driven by the electric machine 76 via a gearwheel 65 connected to a shaft 69 of the electric machine 76. The shaft 69 of the electric machine 76 may be considered to be an input shaft of the gearbox 44.

[0091] An output shaft 61 of the gearbox 44 is connected via a gearwheel 67 to the differential 74. A number of gearwheels 52, 56, 60 are arranged on the output shaft 61. These gearwheels 52, 56, 60 are rotatable in relation to the output shaft 61. However, each of these gearwheels 52, 56, 60 can be rotationally locked to the output shaft 61 by a dog clutch 64.

[0092] The gearbox 44 includes a first gear 50, a second gear 54, and according to some examples a third gear 58, and optionally a fourth gear 59, and even further gears. Each gear in the gearbox 44 is designed to provide a specific gear ratio, thereby allowing the vehicle 80 to operate at various ranges of speeds and torques.

[0093] For the first gear 50 a corresponding first gearwheel 52 on the output shaft 61 meshes with a further first gearwheel 53 on the layshaft 63. When the first gearwheel 52 is rotationally locked to the output shaft 61 rotational movement from the electric machine 76 is transferred via the first gear 50 to the drive shafts 70.

[0094] For the second gear 54 a corresponding second gearwheel 56 on the output shaft 61 meshes with a further second gearwheel 55 on the layshaft 63. When the second gearwheel 56 is rotationally locked to the output shaft 61 rotational movement from the electric machine 76 is transferred via the second gear 54 to the drive shafts 70. The second gear 54 is designed to provide a gear ratio different from the gear ratio of the first gear 50, thereby allowing the vehicle 80 to operate at different speed and torque ranges.

[0095] For the third gear 58 a corresponding third gearwheel 60 on the output shaft 61 meshes with a further third gearwheel 57 on the layshaft 63. When the third gearwheel 58 is rotationally locked to the output shaft 61 rotational movement from the electric machine 76 is transferred via the third gear 56 to the drive shafts 70. The third gear 58 is designed to provide a different gear ratio than the first gear 50 and the second gear 54, thereby allowing the vehicle 80 to operate at different speed and torque ranges.

[0096] The gearbox 44 includes shift sleeves 62. The shift sleeves 62 are arranged in connection with the first, second, and third gearwheels 52, 56, 60 and further gearwheels, if present, and are designed to enable the selection and engagement of the specific gears in the gearbox

[0097] 44.

[0098] The gearbox 44 includes dog clutches 64. The dog clutches 64 are designed to engage and disengage the first gearwheel 52, the second gearwheel 56, and the third gearwheel 60 and further gearwheels, if present, with the output shaft 61 of the gearbox 44. The dog clutches 64 allow for the selection and engagement of the specific gears in the gearbox 44. Each dog clutch 64 comprises two halves, one half connected, and rotationally locked, to the relevant shifting sleeve 62 and one half connected, and rotationally locked, to the relevant gearwheel 52, 56, 60. The two halves of each dog clutch 64 utilise teeth and openings between the teeth to securely engage the relevant gearwheel 52, 56, 60 with the output shaft 61.

[0099] The shift sleeve 62 is arranged to move the half of a relevant dog clutch 64 connected to the shaft 61 into and out of engagement with the other half of the dog clutch 64 connected to the relevant gearwheel 52, 56, 60. Thus, the shift sleeves 62 support the precise movement and synchronization of the gear engagement process.

[0100] In the example of Fig. 2b, the first gear 50 is engaged i.e., the two halves of the dog clutch 64 of the first gear 50 are engaged to transfer torque from the electric machine 76 via the layshaft 63, the further first gearwheel 53, the first gearwheel 52 to the output shaft 61. The dog clutches 64 of the other gears 54, 58, 59 remain disengaged.

[0101] The gearbox 44 includes shift forks 66. The shift forks 66 are designed to control the precise movement of the shift sleeves 62 to provide the engagement and disengagement of the dog clutch 64 halves. The shift forks 66 are directly or indirectly connected to the second and third shifting shafts 40, 42, such that the actuation device 2 is enabled to shift gears in the gearbox 44.

[0102] In the present disclosure, the first gear 50 is shifted by the second shifting shaft 40, the second gear 54 is shifted by the second shifting shaft 40, and the third gear 58 is shifted by the third shifting shaft 42.

[0103] The vehicle driving assembly 72 includes the electric machine 76. The electric machine 76 is designed to drive the two drive shafts 70 when it is operated as an electric motor. Batteries (not shown) may be provided aboard the vehicle 80 to power the electric machine 76 when operated as an electric motor. The electric machine 76 may also be operable as an electric generator in order to charge the onboard batteries e.g., when the vehicle 80 is coasting downhill and the drive wheels 78 transfer torque to the electric machine 76 via the drive shafts 70, the differential 74, and the gearbox 44 in which a gear is engaged.

[0104] The rotational speed of the electric machine 76 may be controlled. A control arrangement 75 may be provided inter alia for this purpose. For instance, with a gear engaged in the gearbox 44, the torque of the electric machine 76 may be controlled to provide a desired traveling speed of the vehicle 80.

[0105] A further example is during gear shifting in the gearbox 44, when the rotational speed of the electric machine 76 may be controlled by the control arrangement 75 to synchronise the rotational speed of the first, second, or third gearwheels 52, 56, 60 in the gearbox 44 with that of the output shaft 61 of the gearbox 44, depending on which of the first, second, or third gear 50, 54, 58 is to be engaged.

[0106] A synchronised rotational speed is a rotational speed that matches a target rotational speed within a limited rotational speed difference range, such as within a range of 0 - 20 rpm rotational speed difference. A slight difference in rotational speed, such as within this range, may even be advantageous since this will facilitate engagement of the two halves of the relevant dog clutch 64 since respective teeth of the two dog clutch halves will be prevented from being constantly positioned opposite to each other.

[0107] The synchronization of the two halves of a dog clutch 64 for engagement of a relevant gear 50, 54, 58, 59 involves the rotation of the relevant first, second, or third gearwheel 52, 56, 60 at a speed substantially that of the output shaft 61. The first, second, and third gearwheels 52, 56, 60 are rotated via the meshing gearwheel 53, 55, 57 on the layshaft 63 by the electric machine 76. The output shaft 61 , in turn, has a rotational speed that depends on the rotational speed of the drive wheels 78 and a gear ratio between the drive wheels 78 and the output shaft 61 as dependent inter alia on the gear ratio within the differential 74 and between the differential 74 and the gearwheel 67 connecting the output shaft 61 to the differential 74.

[0108] The rotational speed of the electric machine 76 is controlled by the control arrangement 75.

[0109] For this purpose, the control arrangement 75 includes relevant gear ratio data, rotational speed data, and calculation capability to synchronise rotational speeds such that the electric machine 76 rotates the relevant first, second, or third gearwheel 52, 56, 60 with substantially the same rotational speed as the output shaft 61.

[0110] The vehicle driving assembly 72 includes the actuation device 2. The actuation device 2 is designed to control the differential locking mechanism 46 and the shifting of gears in the gearbox 44. Accordingly, movements of the first and second shifting shafts 38, 40 are controlled by the actuation device 2. If present, also movement of the third shifting shaft 42 is controlled by the actuation device 2. The actuation device 2 is described in detail below with reference to Figs. 3a - 3d.

[0111] Figs. 3a - 3d schematically illustrate an actuation device 2 and parts thereof. Fig. 3a schematically shows a schematic perspective view of the actuation device 2. Figs. 3b - 3d show different views of a barrel cam 4 of the actuation device 2.

[0112] The actuation device 2 is configured to be utilised in a vehicle driving arrangement and accordingly, in a vehicle. The vehicle driving arrangement may be an arrangement 72 as discussed herein, e.g. with reference to Figs. 2a and 2b and the vehicle may be any of the vehicles discussed with reference to Fig. 1. Accordingly, in the following reference is also made to Figs. 1 - 2b.

[0113] The actuation device 2 is designed to control the differential locking mechanism 46 and the gearbox 44 of a vehicle 80. The actuation device 2 is composed of several components. These components include a barrel cam 4, an electric actuator 6, a first track follower 32, and a second track follower 34. The actuation device 2 is designed to control the rotation of the barrel cam 4, which in turn controls the operation of the differential locking mechanism 46 and the shifting of gears in the gearbox 44.

[0114] The barrel cam 4 has a rotational axis 8 and is provided with at least a first group of tracks 10 and a second group of tracks 16. The electric actuator 6 is operatively connected to the barrel cam 4 and controls its rotation about the rotational axis 8.

[0115] In the following, axial, radial and circumferential references relate to the rotational axis 8 of the barrel cam 4.

[0116] The first track follower 32 is configured to follow the first group of tracks 10 as the barrel cam

[0117] 4 is rotated about the rotational axis 8. Similarly, the second track follower 34 is configured to follow the second group of tracks 16 as the barrel cam 4 is rotated about the rotational axis 8. The first track follower 32 is designed to connect to a first shifting shaft 38 arranged to operate the differential locking mechanism 46, while the second track follower 34 is designed to connect to a second shifting shaft 40 arranged to shift at least a first gear 50 of the gearbox 44.

[0118] The barrel cam 4 is cylindrically shaped and has a rotational axis 8. The barrel cam 4 is provided with at least a first group of tracks 10 and a second group of tracks 16. The tracks on the barrel cam 4 are designed to guide the movement of the track followers 32, 34 as the barrel cam 4 is rotated about the rotational axis 8. The design and arrangement of the groups of tracks on the barrel cam 4 play a role in controlling the operation of the differential locking mechanism 46 and the shifting of gears in the gearbox 44.

[0119] The electric actuator 6 is operatively connected to the barrel cam 4 and is responsible for rotation of the barrel cam 4. The electric actuator 6 includes an electric motor 28 and a transmission system 30, which may include one or more of a set of gears, a chain or pulley drive, a worm drive, etc. The electric motor 28 is connected to the transmission system 30, which is designed to transmit the rotation of the electric motor 28 to the barrel cam 4. The electric motor 28 is designed to provide the necessary power and speed to drive the rotation of the barrel cam 4, thereby controlling the movement of the track followers 32, 34 along the first and second groups of tracks 10, 16 on the barrel cam 4. The transmission system 30 is designed to reduce the rotational speed of the electric motor 28, thereby controlling the speed and direction of rotation of the barrel cam 4. The transmission system 30 is designed to provide a mechanical advantage to the electric motor 28, thereby enabling the electric motor 28 to drive the rotation of the barrel cam 4 at a controlled speed and direction.

[0120] A control arrangement 75 is arranged to control the electric motor 28 and thus, is arranged to control the speed and direction of rotation of the barrel cam 4. The control arrangement 75 may form part of the control arrangement 75 discussed above with reference to the control of the electric machine 76. Alternatively, the control arrangement 75 for controlling the electric motor 28 may be a separate control arrangement.

[0121] The first group of tracks 10 includes a first main track 12 and at least one first side track 14, 14’, 14”. The first main track 12 extends circumferentially around the barrel cam 4. Each of the first side tracks 14, 14’, 14” is axially displaced from the first main track 12 and has a limited circumferential extension. Each of the first side tracks 14, 14’, 14” branches off from the first main track 12. The first track follower 32 is designed to follow the first group of tracks 10 as the barrel cam 4 is rotated about the rotational axis 8. That is, as the barrel cam 4 is rotated about the rotational axis 8, the first track follower 32 is arranged to follow the first main track 12 and the at least one first side track 14, 14’, 14” as discussed herein, inter alia as discussed below.

[0122] The first main track 12 extends circumferentially around the barrel cam 4. At least some portions of the first main track 12 are shallower than the at least one first side track 14, 14’, 14”.

[0123] The at least one first side track 14, 14’, 14” branches off from the first main track 12 and is axially displaced from the first main track 12. In the illustrated example there are provided three first side tracks 14, 14’, 14”. Each of the at least one first side track 14, 14’, 14” has a limited circumferential extension. Each of the at least one first side track 14, 14’, 14” is deeper than some portions of the first main track 12. This is particularly visible in Fig. 3d.

[0124] The second group of tracks 16 includes a second main track 18 and at least one second side track 20, 20’. The second main track 18 extends circumferentially around the barrel cam 4. Each of the second side tracks 20, 20’ is axially displaced from the second main track 18 and has a limited circumferential extension. Each of the second side tracks 20, 20’ branches off from the second main track 18.

[0125] The second track follower 34 is designed to follow the second group of tracks 16 as the barrel cam 4 is rotated about the rotational axis 8. That is, as the barrel cam 4 is rotated about the rotational axis 8, the second track follower 34 is arranged to follow the second main track 18 and the at least one second side track 20, 20’ as discussed herein, inter alia as discussed below.

[0126] The second main track 18 extends circumferentially around the barrel cam 4. At least some portions of the second main track 18 are shallower than the at least one second side track 20, 20’.

[0127] The at least one second side track 20, 20’ branches off from the second main track 18 and is axially displaced from the second main track 18. In the illustrated example there are provided two first side tracks 20, 20’. Each of the at least one second side track 20, 20’ has a limited circumferential extension. Each of the at least one second side track 20, 20’ is deeper than at least some portions of the second main track 18. This is particularly visible in Fig. 3d. In some configurations, such as in the illustrated example, the barrel cam 4 is provided with a third group of tracks 22. The third group of tracks 22 includes a third main track 24 and at least one third side track 26. The third main track 24 extends circumferentially around the barrel cam 4. The at least one third side track 26 is axially displaced from the third main track 24 and has a limited circumferential extension. The at least one third side track 26 branches off from the third main track 24.

[0128] A third track follower 36 is designed to follow the third group of tracks 22 as the barrel cam 4 is rotated about the rotational axis 8. That is, as the barrel cam 4 is rotated about the rotational axis 8, the third track follower 36 is arranged to follow the third main track 24 and the at least one third side track 26 as discussed herein, inter alia as discussed below.

[0129] The third main track 24 extends circumferentially around the barrel cam 4. At least some portions of the third main track 24 are shallower than the third side track 26.

[0130] The at least one third side track 26 branches off from the third main track 24 and is axially displaced from the third main track 24. The at least one third side track 26 has a limited circumferential extension. The at least one third side track 26 is deeper than the third main track 24. This is particularly visible in Fig. 3d.

[0131] In the illustrated example, each group of tracks 10, 16, 22 is by formed by at least partially circumferentially extending recesses in a body of the barrel cam 4.

[0132] The first track follower 32 is designed to follow the first group of tracks 10 on the barrel cam 4 as it is rotated about the rotational axis 8.

[0133] For instance, the first track follower 32 may be equipped with a pin or roller for accurate tracking of the first main track 12 and the at least one first side track 14, 14’, 14” on the barrel cam 4. The first track follower 32 may be biased radially inwardly against the barrel cam 4 to ensure reliable tracking in the first group of tracks 10.

[0134] The first track follower 32 is configured to follow bottom surfaces of the first group of tracks 10. Thus, the arrangement of the shallower portions of the first main track 12 and the deeper first side tracks 14, 14’, 14” enable the first track follower 32 to enter the first side tracks 14, 14’, 14” as the barrel cam 4 is rotated in a first direction 7 about the rotational axis 8. Further, the at least one first side track 14, 14’, 14” may branch off at an acute angle from the first main track 12 seen as the barrel cam 4 rotates in the first direction 7. Conversely, seen as the barrel cam 4 rotates in an opposite second direction 9, the at least one first side track 14, 14’, 14” extends at an obtuse angle to the first main track 12. Thus, entering and exiting the at least one first side track 14, 14’, 14” of the first track follower 32 may be supported by this acute / obtuse branching off of the at least one first side track 14, 14’, 14”.

[0135] Mentioned purely as an example, the at least one first side track 14, 14’, 14” may branch off from the first main track 12 at an angle within a range of 5 - 35 degrees.

[0136] The first track follower 32 is connected to the first shifting shaft 38, which is arranged to operate the differential locking mechanism 46. The first track follower 32 is designed to provide precise and synchronized linear movement of the first shifting shaft 38, thereby controlling the engaging and unengaging of the differential locking mechanism 46.

[0137] More specifically, as barrel cam 4 is rotated in the first direction 7 and the first track follower enters a first, a second, or a third of the at least one first side track 14, 14’, 14”, the first track follower 32 is axially displaced from the first main track 12. The first shifting shaft 38 is connected to the first track follower 32 and accordingly, is moved linearly a distance proportional to the axial displacement of the first track follower 32. This movement of the first shifting shaft 38 is transferred to the differential locking mechanism 46 for engagement thereof and thus, locking of the differential 74.

[0138] The second track follower 34 is designed to follow the second group of tracks 16 on the barrel cam 4 as it is rotated about the rotational axis 8.

[0139] For instance, the second track follower 34 may be equipped with a pin or roller for accurate tracking of the second main track 18 and the at least one second side track 20, 20’ on the barrel cam 4. The second track follower 32 may be biased radially inwardly against the barrel cam 4 to ensure reliable tracking in the second group of tracks 16.

[0140] The second track follower 34 is configured to follow bottom surfaces of the second group of tracks 16. Thus, the arrangement of the shallower portions of the second main track 18 and the deeper second side tracks 20, 20’ enable the second track follower 34 to enter the second side tracks 20, 20’ as the barrel cam 4 is rotated in the first direction 7 about the rotational axis 8. Further, the at least one second side track 20, 20’ may branch off at an acute angle from the second main track 18 seen as the barrel cam 4 rotates in the first direction 7. Conversely, seen as the barrel cam 4 rotates in the second direction 9, the at least one second side track 20, 20’ extends at an obtuse angle to the second main track 18. Thus, entering and exiting the at least one second side track 20, 20’ of the second track follower 34 may be supported by this acute / obtuse branching off of the at least one second side track 20, 20’.

[0141] Mentioned purely as an example, the at least one second side track 20, 20’ may branch off from the second main track 18 at an angle within a range of 5 - 35 degrees.

[0142] The second track follower 34 is connected to the second shifting shaft 40, which is arranged to shift at least a first gear 50 of the gearbox 44. The second track follower 34 is designed to provide precise and synchronized movement for engaging and disengaging the first gear 50.

[0143] Again, as barrel cam 4 is rotated in the first direction 7, now, the second track follower 34 enters a first or a second side track of the at least one second side track 20, 20’, the second track follower 34 is axially displaced from the first main track 12. As shown e.g. in Figs. 3b and 3c, the first side track 20 of the at least one second side track 20, 20’ is arranged at one axial side of the second main track 18 and the second side track 20’ of the at least one second side track 20, 20’ is arranged at an opposite side of the second main track 18. Accordingly, depending on which of the first and second side tracks 20, 20’ of the at least one second side track 20, 20’ the second track follower 34 enters, the second track follower 34 is axially displaced in one of two opposite axial directions.

[0144] The second shifting shaft 40 is connected to the second track follower 34 and accordingly, is moved linearly a distance, in one of the two opposite axial directions, proportional to the axial displacement of the second track follower 34. This movement of the second shifting shaft 40 is transferred to the relevant shifting sleeve 62 in the gearbox 44 to engage either the first gear 50 or the second gear 54.

[0145] The third track follower 36 is designed to follow the third group of tracks 22 on the barrel cam 4 as it is rotated about the rotational axis 8.

[0146] The third track follower 36 may be equipped with a pin or roller for accurate tracking of the third main track 24 and the at least one third side track 26 on the barrel cam 4. The third track follower 36 may be biased radially inwardly against the barrel cam 4 to ensure reliable tracking in the third group of tracks 22. The third track follower 36 is configured to follow bottom surfaces of the third group of tracks 22. Thus, the arrangement of the shallower portions of the third main track 24 and the deeper third side track 26 enable the third track follower 36 to enter the third side track 26 as the barrel cam 4 is rotated in the first direction 7 about the rotational axis 8.

[0147] Further, the at least one third side track 26 may branch off at an acute angle from the third main track 24 seen as the barrel cam 4 rotates in the first direction 7. Conversely, seen as the barrel cam 4 rotates in the second direction 9, the at least one third side track 26 extends at an obtuse angle to the third main track 24. Thus, entering and exiting the at least one third side track 26 of the third track follower 36 may be supported by this acute / obtuse branching off of the at least one third side track 26.

[0148] Mentioned purely as an example, the at least one third side track 26 may branch off from the third main track 24 at an angle within a range of 5 - 35 degrees.

[0149] The third track follower 36 is connected to a third shifting shaft 42, which is arranged to shift at least one further gear of the gearbox 44, such as a third gear 58 of the gearbox 44. The third track follower 36 is designed to provide precise and synchronized movement for engaging and disengaging the further gear of the gearbox 44.

[0150] Again, as barrel cam 4 is rotated in the first direction 7, now, the third track follower 36 enters the at least one third side track 26, the third track follower 36 is axially displaced from the third main track 24. The third shifting shaft 42 is connected to the third track follower 36 and accordingly, is moved linearly a distance proportional to the axial displacement of the third track follower 36.

[0151] The third shifting shaft 42 is connected to the third track follower 36 and is moved linearly by the movement of the third track follower 36, thereby controlling the shifting of the further gear of the gearbox 44. The movement of the third track follower 36 is transferred to the relevant shifting sleeve 62 in the gearbox 44 to engage e.g. the third gear 58.

[0152] The branching off of the side tracks 14, 14’, 14”, 20, 20’, 26 from the relevant main track 12, 18, 24 may be gradual i.e., the side track 14, 14’, 14”, 20, 20’, 26 branches off the main track 12, 18, 24 with an increasing angle further into the relevant side track 14, 14’, 14”, 20, 20’, 26. This so, to ensure a smooth transition from the main track 12, 18, 24 into the side track 14, 14’, 14”, 20, 20’, 26. With such a gradual branching off, the angle may relate to an angle between a tangent of the side track 14, 14’, 14”, 20, 20’, 26 and the relevant main track 12, 18, 24. Moreover, the above discussed angular ranges may relate to one of a maximum angle or a mean angle between the tangent of the side track 14, 14’, 14”, 20, 20’, 26 and the relevant main track 12, 18, 24.

[0153] As already touched upon above, the operation of the actuation device 2 involves the rotation of the barrel cam 4 in two directions about the rotational axis 8, the first direction 7 and the second direction 9.

[0154] The rotation of the barrel cam 4 controls the movement of the first and second track followers 32, 34 along the groups of tracks 10, 16 on the barrel cam 4. In some examples, such as in the illustrated example, the rotation of the barrel cam 4 also controls the movement of the third track follower 36 along the third group of tracks 22 on the barrel cam 4.

[0155] As the barrel cam 4 rotates in the first direction 7, the first track follower 32 enters one of the first, second, or third side tracks 14, 14’, 14” of the at least one first side track 14, 14’, 14” and the second track follower 34 enters one of the first or second side tracks 20, 20’ of the at least one the second side track 20, 20’. In some examples, such as in the illustrated example, the rotation of the barrel cam 4 in the first direction 7 also causes the third track follower 36 to enter the at least one third side track 26.

[0156] As the barrel cam 4 rotates in the second direction 9, the first track follower 32 follows the first main track 12 and does not enter any of the first side tracks 14, 14’, 14” and the second track follower 34 follows the second main track 18 and does not enter any second side tracks 20. Similarly, the rotation of the barrel cam 4 in the second direction 9 also causes the third track follower 36 to follow along the third main track 24 and not to enter the at least one third side track 26.

[0157] If one of the first, second, and / or third track followers 32, 34, 36 is positioned in one of the relevant side tracks 14, 14’, 14”, 20, 20’, 26, the rotation in the second direction 9 of the barrel cam 4, causes this / these track followers 32, 34, 36 to exit the relevant side track 14, 14’, 14”, 20, 20’, 26 and thus, to disengage the differential locking mechanism 46 and / or the relevant gear 50, 54, 58.

[0158] The side tracks 20, 20’, 26 of the second and third groups of tracks 16, 22 are offset from each other along the circumference of the barrel cam 4. Thus, the second track follower 34 can be brough to selectively enter one of the first and second side tracks 20, 20’ of the at least one second side track 20, 20’ or the third track follower 36 can be brough to enter the at least one third side track 26. Namely, by rotating the barrel cam 4 in the second direction 9 until the intended track follower 32, 34 is positioned at the relevant side track 20, 20’, 26, and thereafter rotating the barrel cam 4 in the first direction 7, a corresponding intended gear 50, 54, 58 is engaged.

[0159] It may be mentioned that rotating the barrel cam 4 in the second direction 9 with the electric actuator 6 to a position for engaging an intended gear 50, 54, 58 of the gearbox 44 can be done in parallel with synchronising the rotational speed of one half of a dog clutch 64 of the relevant gear 50, 54, 58 of the gearbox 44 with the electric machine 76.

[0160] Accordingly, the electric machine 76 may be configured to synchronize a rotational speed of one half of a dog clutch 64 of a gear of the gearbox 44 to be engaged while the barrel cam 4 is rotationally positioned by the electric actuator 6 to engage the gear of the gearbox 44 to be engaged.

[0161] In the illustrated example, each of the side tracks 20, 20’, 26 of the second and third groups of tracks 16, 22 overlaps in a circumferential direction partially with one side track 14, 14’, 14” of the first group of tracks 10. This enables a two-step functionality in the engagement of one of the gears 50, 54, 58 and engagement of the differential locking mechanism 46. In a first step the relevant gear 50, 54, 58 is engaged as explained in the third previous paragraph by rotating the barrel cam 4 in the first direction 7. Thus, each gear 50, 54, 58 may be engaged without the differential 74 being locked. In a second step, by continuing rotating the barrel cam 4 in the first direction 7, the first track follower 32 is brought to enter the corresponding partially overlapping at least one first side track 14, 14’, 14”. Thus, each gear 50, 54, 58 may be operated with the differential 74 locked.

[0162] More specifically, according to an example, the first side track 20 of the at least one second side track 20, 20’ extends along a first circumferential portion 11 of the barrel cam 4 and a first side track 14 of the at least one first side track 14, 14’, 14” extends along only part of the first circumferential portion 11 of the barrel cam 4.

[0163] Accordingly, by rotating the barrel cam 4 in the first direction 7 for the second track follower 34 to enter the first side track 20 of the at least one second side track 20, 20’ only a partial distance along the first circumferential portion 11 of the barrel cam 4, e.g. the first gear 50 is engaged in the gearbox 44 while the first track follower 32 does not enter the first side track 14 of the at least one first side track 14, 14’, 14” and the differential locking mechanism 46 remains disengaged. By rotating the barrel cam 4 further in the first direction 7, the second track follower 34 will continue following the first side track 20 of the at least one second side track 20, 20’ further along the first circumferential portion 11 of the barrel cam 4. This enables the first track follower 32 to enter the first side track 14 of the at least one first side track 14, 14’, 14” which causes the differential locking mechanism 46 to engage and lock the differential. Thus, the above-discussed two-step functionality is provided.

[0164] According to an example, a second side track 20' of the at least one second side track 20, 20’ extends along a second circumferential portion 13 of the barrel cam 4, and a second side track 14' of the at least one first side track 14, 14’, 14” extends along only part of the second circumferential portion 13 of the barrel cam 4.

[0165] Accordingly, by rotating the barrel cam 4 in the first direction 7 for the second track follower 34 to enter the second side track 20’ of the at least one second side track 20, 20’ only a partial distance along the second circumferential portion 13 of the barrel cam 4, e.g. the second gear 50 is engaged in the gearbox 44 while the first track follower 32 does not enter the second side track 14’ of the at least one first side track 14, 14’, 14” and the differential locking mechanism 46 remains disengaged. By rotating the barrel cam 4 further in the first direction 7, the second track follower 34 will continue following the second side track 20’ of the at least one second side track 20, 20’ further along the second circumferential portion 13 of the barrel cam 4. This enables the first track follower 32 to enter the second side track 14’ of the at least one first side track 14, 14’, 14” which causes the differential locking mechanism 46 to engage and lock the differential. Thus, the above-discussed two-step functionality is provided.

[0166] According to an example, the at least one third side track 26 extends along a third circumferential portion 15 of the barrel cam 4 and a third side track 14” of the at least one first side track 14, 14’, 14” extends along only part of the third circumferential portion 15 of the barrel cam 4.

[0167] Accordingly, by rotating the barrel cam 4 in the first direction 7 for the third track follower 36 to enter the at least one third side track 26 only a partial distance along the third circumferential portion 15 of the barrel cam 4, e.g. the third gear 58 is engaged in the gearbox 44 while the first track follower 32 does not enter the third side track 14” of the at least one first side track 14, 14’, 14” and the differential locking mechanism 46 remains disengaged. By rotating the barrel cam 4 further in the first direction 7, the third track follower 36 will continue following the at least one third side track 26 further along the third circumferential portion 15 of the barrel cam 4. This enables the first track follower 32 to enter the third side track 14” of the at least one first side track 14, 14’, 14” which causes the differential locking mechanism 46 to engage and lock the differential. Thus, the abovediscussed two-step functionality is provided.

[0168] Various alternatives of the actuation device 2 may be provided within the scope of the appended claims. To mention some examples:

[0169] - The third group of tracks 22 may be provided with a further third side track e.g., for shifting the fourth gear 59 indicated in Fig. 2b. For such a further side track a corresponding fourth side track of the at least one first side track may be provided, if differential locking capability in connection with the fourth gear 59 is desired.

[0170] - Further groups of tracks may be provided on the barrel cam 4 for shifting of further gears in the gearbox 44, if it is provided with such further gears.

[0171] - It may not be necessarily to provide a differential locking capability for each gear of the gearbox 44. Mentioned purely as an example, the for the third gear 58 there may not be required any possibility to lock the differential 74. In such case there need not be provided the third side track 14” of the at least one first side track.

[0172] A control arrangement 75 as discussed above with reference to Figs. 2b and 3a comprises a calculation unit which may take the form of substantially any suitable type of processor circuit or microcomputer, e.g. a circuit for digital signal processing (digital signal processor, DSP), a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The herein utilised expression calculation unit may represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. The control arrangement 75 may comprise a memory unit. The calculation unit is connected to the memory unit, which provides the calculation unit with, for example, the stored programme code and / or stored data which the calculation unit needs to enable it to do calculations. The calculation unit may also be adapted to storing partial or final results of calculations in the memory unit. The memory unit may comprise a physical device utilised to store data or programs, i.e. , sequences of instructions, on a temporary or permanent basis. The control arrangement 75 is connected inter alia to one or more of the electric machine 76, the electric actuator 6, rotational speed sensors (not shown), and / or position sensors (not shown), to enable control of the electric machine 76 and / or the actuation device 2. The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and / or "including" when used herein specify the presence of stated features, integers, actions, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and / or groups thereof.

[0173] It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

[0174] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0175] It is to be understood that the foregoing is illustrative of various examples and that the invention is defined only by the appended claims. A person skilled in the art will realize that the examples may be modified, and that different features of the examples may be combined to create examples other than those described herein, without departing from the scope of the invention, as defined by the appended claims.

Claims

CLAIMS1. An actuation device (2) for a differential locking mechanism (46) and a gearbox (44) of a vehicle (80), the actuation device (2) comprising: a barrel cam (4) having a rotational axis (8) and being provided with at least a first group of tracks (10) and a second group of tracks (16), an electric actuator (6) operatively connected to the barrel cam (4) for controlling a rotation of the barrel cam (4), a first track follower (32) configured to follow the first group of tracks (10) as the barrel cam (4) is rotated about the rotational axis (8), and a second track follower (34) configured to follow the second group of tracks (16) as the barrel cam (4) is rotated about the rotational axis (8), wherein the first track follower (32) is configured to connect to a first shifting shaft (38) arranged to operate the differential locking mechanism (46), and wherein the second track follower (34) is configured to connect to a second shifting shaft (40) arranged to shift at least a first gear (50) of the gearbox (44).

2. The actuation device (2) according to claim 1 , wherein the first group of tracks (10) comprises a first main track (12) and at least one first side track (14, 14’, 14”) branching off from the first main track (12), wherein the first main track (12) extends circumferentially around the barrel cam (4), wherein the at least one first side track (14, 14’, 14”) is axially displaced from the first main track (12) and has a limited circumferential extension, wherein the second group of tracks (16) comprises a second main track (18) and at least one second side track (20, 20’) branching off from the second main track (18), wherein the second main track (18) extends circumferentially around the barrel cam (4), and wherein the at least one second side track (20, 20’) is axially displaced from the second main track (18) and has a limited circumferential extension.

3. The actuation device (2) according to claim 2, wherein one or more portions of the first main track (12) are shallower than the at least one first side track (14, 14’, 14”), and wherein one or more portions of the second main track (18) are shallower than the at least one second side track (20, 20’).

4. The actuation device (2) according to claim 2 or 3, wherein rotation of the barrel cam (4) in a first direction (7) about the rotational axis (6) causes the first track follower (32) to enter the at least one first side track (14, 14’, 14”) and the second track follower (34) to enter the at least one second side track (20, 20’), and wherein rotation of the barrel cam (4) in a second direction (9) about the rotational axis (6) causes the first track follower (32) to exit the at leastone first side track (14, 14’, 14”) and / or to follow along the first main track (12) and the second track follower (34) to exit the at least one second side track (20, 20’) and / or to follow along the second main track (18).

5. The actuation device (2) according to any one of claims 2 to 4, wherein a first side track (20) of the at least one second side track (20, 20’) extends along a first circumferential portion (11) of the barrel cam (4), and wherein a first side track (14) of the at least one first side track (14, 14’, 14”) extends along only part of the first circumferential portion (11) of the barrel cam (4).

6. The actuation device (2) according to claim 5, wherein a second side track (20') of the at least one second side track (20, 20’) extends along a second circumferential portion (13) of the barrel cam (4), and wherein a second side track (14') of the at least one first side track (14, 14’, 14”) extends along only part of the second circumferential portion (13) of the barrel cam (4).

7. The actuation device (2) according to any one of claims 1 to 6, wherein the barrel cam (4) is provided with a third group of tracks (22), and wherein the actuation device (2) comprises a third track follower (36) configured to follow the third group of tracks (22) as the barrel cam (4) is rotated about the rotational axis (8), and wherein the third track follower (36) is configured to connect to a third shifting shaft (42) arranged to shift at least one further gear of the gearbox (44).

8. The actuation device (2) according to claim 7, wherein the third group of tracks (22) comprises a third main track (24) and at least one third side track (26) branching off from the third main track (24), wherein the third main track (24) extends circumferentially around the barrel cam (4), and wherein the at least one third side track (26) is axially displaced from the third main track (24) and has a limited circumferential extension,9. The actuation device (2) according to claim 8, wherein one or more portions of the third main track (24) are shallower than the at least one third side track (26).

10. The actuation device (2) according to claim 8 or 9, wherein rotation of the barrel cam (4) in a first direction (7) about the rotational axis (6) causes the third track follower (36) to enter the at least one third side track (26), and wherein rotation of the barrel cam (4) in a second direction (9) about the rotational axis (6) causes the third track follower (36) to exit the at least one third side track (26) and / or to follow along the third main track (24).

11. The actuation device (2) according to any one of claims 8 to 10, wherein a first side track (26) of the at least one third side track (26) extends along a third circumferential portion (15) of the barrel cam (4), and wherein a third side track (14”) of the at least one first side track (14, 14’, 14”) extends along only part of the third circumferential portion (15) of the barrel cam (4).

12. The actuation device (2) according to any one of the preceding claims, wherein the electric actuator (6) comprises an electric motor (28) and a transmission system (30), wherein the electric motor (28) is connected to the transmission system (30) for transmitting rotation of the electric motor (28) to the barrel cam (4).

13. The actuation device (2) according to any one of the preceding claims, comprising the first shifting shaft (38) and the second shifting shaft (40).

14. A vehicle driving assembly (72) for a vehicle (80), wherein the vehicle driving assembly (72) is configured to support at least two drive wheels (78) of the vehicle (80), wherein the vehicle driving assembly (72) comprises an axle beam (68), two drive shafts (70) arranged to drive the drive wheels (78), a gearbox (44), a differential (74), a differential locking mechanism (46), and an electric machine (76) configured to drive the two drive shafts (70) via the gearbox (44) and the differential (74), and an actuation device (2) according to any one of the preceding claims.

15. The vehicle driving assembly (72) wherein the electric machine (76) is configured to synchronize a rotational speed of one half of a dog clutch (64) of a gear of the gearbox (44) to be engaged while the barrel cam (4) is rotationally positioned by the electric actuator (6) to engage the gear of the gearbox (44) to be engaged.

16. A vehicle (80) comprising a vehicle driving assembly (72) according to claim 14 or 15.

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