In-wheel steering assembly, wheel, vehicle and method for steering a vehicle

Abstract

The invention relates to an in-wheel steering assembly, a wheel, a vehicle and a method for steering a vehicle, wherein the in-wheel steering assembly comprises a chassis interface, an inner hub supported on the chassis interface and defining a wheel axis, and an outer hub rotatable relative to said inner hub about said wheel axis, wherein the inner hub is pivotable about a pivot axis, wherein the pivot axis trails the wheel axis over a trail distance, wherein the in-wheel steering assembly further comprises a steering lever that is corotatable with the inner hub and extends inside the inner hub in a lever direction perpendicular to and away from the pivot axis and towards the wheel axis, wherein the in-wheel steering assembly is provided with a steering actuator for engaging the steering lever inside the inner hub and for imparting a steering moment on said steering lever about the pivot axis relative to the chassis interface.

Description

[0001] In-wheel steering assembly, wheel , vehicle and method for steering a vehicle

[0002] BACKGROUND

[0003] The invention relates to an in-wheel steering assembly, a wheel , a vehicle and a method for steering a vehicle .

[0004] NL 1038479 A discloses a bicycle, comprising a frame and control means for controlling the position of a pivotable steering wheel . The steering wheel is connected to the frame by means of an integrated steering wheel bearing which includes a wheel rotation bearing to enable the steering wheel to rotate about its central wheel axis , as well as a pivot bearing to enable the steering wheel to pivot about its pivot axis so as to control the direction of travel of the bicycle . The central part of the pivot bearing can be pulled to the right or to the left relative to the fixed frame around its pivot axis by two pulling cables . The flexibility of the pulling cables allows them to bridge the distance between the pivot bearing and the handlebars while following the top tube or the bottom tube of the frame . This is particularly convenient when the steering wheel bearing is used on a cargo bike, where the distance between the pivot bearing and the handlebars is relatively large . The resulting cargo bike configuration has a greater stability, improved driving characteristics and more freedom in choosing the position of the handlebars relative to the pivoting steering wheel .

[0005] EP 2 660 125 Bl discloses a hydraulic steering system for a motorcycle utilizing a hydraulically driven piston rod to drive a gear plate that turns the axial movement of the piston into a rotating movement of the steering axle, using a rack-and-pinion like transmission .

[0006] SUMMARY OF THE INVENTION

[0007] A disadvantage of the steering wheel bearing known from NL 1038479 A is that the pulling cables are connected to cable pulling brackets on the outside of the steering wheel bearing, where the pulling cables are exposed to water and dirt . The pulling cables may start to oxidize over time as a result of moisture ingress . Consequently, more friction needs to be overcome to move the pulling cables , which may reduce the responsiveness of the steering . Regular maintenance of the pulling cables is required .

[0008] Moreover, i f one of the pulling cables fails during the riding of the bicycle, the pivot bearing can no longer be controlled and the rider may be not be able to stop the bicycle in a safe manner .

[0009] For this reason, it is known to replace the pulling cables with a rigid, more reliable steering rod . However, such a steering rod is relative bulky and does not provide the same design freedom as the flexible pulling cables .

[0010] In NL 1038479 A the pivot axis intersects with the central wheel axis . Likewise , in EP 2 660 125 Bl , the steering axle intersects with the central wheel axis . In both cases , the steering system does not have a sel f-centering effect, resulting in unstable and twitchy steering behavior .

[0011] It is an obj ect of the present invention to provide an in-wheel steering assembly, a wheel , a vehicle and method for steering a vehicle, wherein the steering can be controlled in a more compact, stable, responsive and / or reliable manner .

[0012] According to a first aspect , the invention provides an in-wheel steering assembly for steering a vehicle, wherein the in-wheel steering assembly comprises a chassis interface for connecting the in-wheel steering assembly to a chassis of the vehicle , an inner hub supported on the chassis interface and defining a wheel axis , and an outer hub concentrically fitted around the inner hub and rotatable relative to said inner hub about said wheel axis , wherein the inner hub is pivotable relative to the chassis interface about a pivot axis perpendicular to the wheel axis , wherein the pivot axis trails the wheel axis over a trail distance , wherein the in-wheel steering assembly further comprises a steering lever that is corotatable with the inner hub and extends inside the inner hub in a lever direction perpendicular to and away from the pivot axis and towards the wheel axis , wherein the in-wheel steering assembly is provided with a steering actuator that is configured for engaging the steering lever inside the inner hub and for imparting a steering moment on said steering lever about the pivot axis relative to the chassis interface .

[0013] Compared to the known steering wheel bearing, where the pulling cables are connected to cable pulling brackets on the outside of the steering wheel bearing, the steering actuator of the in-wheel steering assembly according to the present invention interacts with the steering lever inside the inner hub . Consequently, the in-wheel steering assembly can be designed in a more compact manner . Moreover, by engaging the steering lever inside the inner hub, the steering moment can be imparted onto the steering lever relatively close to the pivot axis . This can be advantageous in terms of reducing tolerances and / or increasing responsiveness in the direction control of the vehicle . Furthermore, inside the inner hub, the steering actuator and / or the steering lever can be shielded more ef fectively from water and dirt, thereby increasing reliability and / or reducing maintenance .

[0014] The trail distance allows the wheel of the vehicle to pivot about the pivot axis in a position trailing the wheel axis , thereby causing the wheel to align in the direction of travel and greatly improving the stability of the wheel . The same trail distance, or at least a part thereof , can conveniently be used to ef fectively impart the steering moment on the steering lever . More in particular, by having the steering lever extend away from the pivot axis towards the wheel axis over at least a part of said trailing distance, the steering lever can be engaged by the steering actuator relatively close to or at the wheel axis , thus maintaining a relatively compact design while simultaneously providing stability . Moreover, because of the more central location of the steering actuator within the inner hub, the maximum steering angle that can be achieved between the inner hub and the steering actuator can effectively be increased .

[0015] Preferably, the trail distance is at least ten millimeters , preferably at least eleven millimeters and most preferably at least twelve millimeters .

[0016] In another preferred embodiment the steering lever extends inside the inner hub in a lever direction along a lever axis that intersects with the pivot axis . In other words , the lever axis and the pivot axis can be located in the same plane . Hence , the steering lever can be rotated symmetrically about the pivot axis in opposite steering directions .

[0017] In another embodiment the steering actuator is a linear actuator . The steering actuator can therefore act linearly on the steering lever, which linear action can be converted by the steering lever into a steering moment about the pivot axis .

[0018] In yet another embodiment the steering actuator is a hydraulic actuator . Hydraulic fluids are generally incompressible . Hence, the hydraulic actuator can be driven or displaced by hydraulic fluid in a direct and / or responsive manner .

[0019] Preferably, the in-wheel steering assembly comprises one or more connectors for connecting the steering actuator to a source of hydraulic fluid . The in-wheel steering assembly can therefore be easily assembled, disassembled, mounted or dismounted while being disconnected from the source of hydraulic fluid . Once the in-wheel steering assembly is in place , source of hydraulic fluid can be connected . More preferably, the one or more connectors are located at or in the chassis interface . The source of hydraulic fluid can thus be connected to the steering actuator via the chassis interface . As the chassis interface is connectable to the chassis of the vehicle, the chassis interface provides a convenient location for connecting to the source of hydraulic fluid as well , in particular providing opportunities for guiding the hydraulic fluid along the chassis towards the chassis interface .

[0020] In another embodiment the steering actuator is integrated in the chassis interface . By integrating the steering actuator in the chassis interface, the chassis interface can be used as a housing for the steering actuator along at least a part of its length . By locating the steering actuator internally relative to the chassis interface rather than externally, the steering actuator does not add to the outer dimensions of the chassis interface, thus allowing for more freedom of movement or an increased maximum steering angle of the inner hub about the pivot axis relative to the chassis interface . Moreover, the integration can also shield the steering actuator from ingress of water or dirt, thereby further increasing reliability and / or reducing maintenance .

[0021] In another embodiment the chassis interface comprises a shaft body extending through the inner hub along a shaft axis , wherein the steering actuator is configured for acting parallel to the shaft axis . Hence , the steering actuator can act on the steering lever in the same direction in which the shaft body extends through the inner hub . Hence , the steering actuator can be provided in an orientation predominantly in or parallel to the shaft body, allowing for at least partial integration or connection of the steering actuator in or to the shaft body . In particular, the steering actuator may coincide with the shaft axis , thereby using the shaft body as its housing along at least a part of its length, thereby again minimi zing the impact of the steering actuator on the outer dimensions of the chassis interface .

[0022] In another embodiment the steering actuator comprises a first steering chamber and a steering piston that is bidirectionally movable inside the first steering chamber in a stroke direction perpendicular to the pivot axis and transverse to the lever direction, wherein the steering lever is coupled to the steering piston for converting the bidirectional movement of the steering piston in the stroke direction into pivoting of the inner hub relative to the chassis interface about the pivot axis . By moving the steering piston bidirectionally, said steering piston can both push and pull on the steering lever, thereby allowing the steering piston to control the steering lever in both steering directions .

[0023] Preferably, the steering piston comprises a first steering piston end, a second steering piston end and a steering piston body extending between the first steering piston end and the second steering piston end, wherein the steering actuator comprises a second steering chamber opposite to the first steering chamber in the stroke direction, wherein the first steering chamber and the second steering chamber are configured for receiving the first steering piston end and the second steering piston end, respectively, wherein the steering lever is coupled to the steering piston at the steering piston body between the first steering piston end and the second steering piston end . The hydraulic fluids in both steering chambers can alternately push and pull the steering piston in the stroke direction, thereby effectively increasing or doubling the force that can be exerted onto the steering piston compared to a situation in which a single chamber is used . Moreover, one chamber of the two steering chambers is redundant such that, when one of the steering chambers loses pressure as a result of a hydraulic leak, the hydraulic fluid in the other chamber may still push and pull the steering piston . Hence , the vehicle can still be controlled safely in both steering directions until the hydraulic leak is repaired .

[0024] In an alternative embodiment the steering actuator comprises a first steering chamber and a first steering piston that is movable inside the first steering chamber in a stroke direction perpendicular to the pivot axis and transverse to the lever direction, wherein the steering actuator further comprises a second steering chamber, opposite to the first steering chamber in the stroke direction, and a second steering piston that is movable inside the second steering chamber in the stroke direction, wherein the steering lever is positioned between the first steering piston and the second steering piston in the stroke direction to be alternately displaced by the first steering piston and the second steering piston while converting the respective movements of the steering pistons in the stroke direction into pivoting of the inner hub relative to the chassis interface about the pivot axis . In this alternative embodiment, the two steering pistons can be used for alternately pushing the steering lever in opposite directions along the stroke direction .

[0025] In an embodiment that may be combined with any of the aforementioned alternatives with the first steering chamber, the steering actuator further defines a lever chamber that houses the steering lever, wherein the lever chamber and the first steering chamber both form parts of a closed hydraulic system, wherein the in-wheel steering assembly comprises a connecting member that corotatably connects the steering lever inside the lever chamber to the inner hub outside the lever chamber while sealing off the lever chamber relative to the steering actuator . By including the lever chamber in the closed hydraulic system, hydraulic fluid can be provided on both piston ends , thus ensuring more uni form lubrication, equalized friction and less risk of leakage to or contamination from the outside . Even if a small amount of hydraulic fluid leaks from the lever chamber to the outside, the chances of hydraulic fluid leaking from the first steering chamber into the lever chamber to the outside are even smaller .

[0026] Preferably, the connecting member extends coaxially to the pivot axis . Hence, the connecting member can be easily sealed relative to the steering actuator, for example by using an O-ring .

[0027] According to a second aspect , the invention provides a wheel comprising an in-wheel steering assembly according to any one of the embodiments of the first aspect of the invention . The wheel may be of fered with the in-wheel steering assembly pre-installed or as an add-on part . With the in-wheel steering assembly included in said wheel , the wheel has the same technical advantages as the in-wheel steering assembly according to the first aspect of the invention .

[0028] According to a third aspect , the invention provides a vehicle comprising at least one wheel according to the second aspect of the invention . As such, the vehicle has the same technical advantages as the aforementioned wheel .

[0029] In a preferred embodiment the vehicle is a bicycle or a cargo bike . More preferably, the chassis is a bicycle frame or a cargo bike frame . When the in-wheel steering assembly according to the first aspect of the invention is used in a bicycle or a cargo bike , the in-wheel steering assembly can replace a conventional fork and / or allow for a more compact frame that can absorb forces from the wheel more head-on or frontally .

[0030] In another embodiment the vehicle comprises a steering control and at least one control line for operationally connecting the steering control to the steering actuator . The steering actuator can thus be controlled remotely via the at least one control line . Preferably, the at least one control line is or comprises a hydraulic conduit . The hydraulic conduit provides great design freedom that is only limited by the flexibility of the conduit .

[0031] More preferably, the steering control comprises a steering input member for receiving a steering input and a steering output member between the steering input member and the at least one control line for converting the steering input into a displacement of hydraulic fluid through the at least one control line . The displacement of the hydraulic fluid directly controls the steering actuator in response to the steering input, thereby providing a more responsive and / or reliable steering . The hydraulic conduits can be connected to the steering actuator to form a closed hydraulic system . More in particular, the steering output member may be enclosed in the hydraulic system in a similar manner to the steering lever, to ensure uni form lubrication, equalized friction and less risk of leakage to or contamination from the outside .

[0032] Most preferably, the steering input member is a handlebar, a hand wheel , a j oystick, one or more buttons , or any other kind of suitable steering input member . A handlebar can be used on a bicycle, whereas a hand wheel is more common on a vehicle with more than two wheels , for example on a go- kart . Alternatively, other steering input members , as specified, may be used .

[0033] According to a fourth aspect , the invention provides a method for steering a vehicle using an in-wheel steering assembly according to any one of the embodiments of the first aspect of the invention, wherein the method comprises the step of : pivoting the inner hub relative to the chassis interface about the pivot axis by imparting a steering moment with the steering actuator on the steering lever about the pivot axis relative to the chassis interface .

[0034] The method relates to the practical implementation of the in-wheel steering assembly according to the first aspect of the invention for steering a vehicle , and therefore has the same technical advantages , which will not be repeated hereafter .

[0035] In a preferred embodiment of the method the steering moment is imparted hydraulically .

[0036] In a further embodiment of the method, the vehicle comprises a steering control , wherein the method further comprises the step of : hydraulically connecting the steering control to the steering actuator . The various aspects and features described and shown in the specification can be applied, individually, wherever possible . These individual aspects , in particular the aspects and features described in the attached dependent claims , can be made subj ect of divisional patent applications .

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings , in which : figure 1 shows an isometric view of a vehicle, in particular a cargo bike, with an in-wheel steering assembly according to a first embodiment of the invention; figure 2 shows an isometric view of the in-wheel steering assembly of figure 1 , isolated from the vehicle ; figure 3 shows an exploded view of the in-wheel steering assembly of figure 2 ; figure 4 shows an exploded view of a selection of components of the in-wheel steering assembly of figure 2 , from a lower angle ; figure 5 shows a cross section of the in-wheel steering assembly according to the line V-V in figure 2 ; figure 6 shows a cross section of the in-wheel steering assembly of figure 5 at a maximum steering angle ; figure 7 shows a cross section of an output member of a steering control according to line VI I-VI I in figure 1 ; figure 8 shows a cross section of the output member of the steering control of figure 7 at a maximum steering angle ; figure 9 shows a cross section of an alternative in-wheel steering assembly according to a second embodiment of the invention; figure 10 shows a cross section of a further alternative in-wheel steering assembly according to a third embodiment of the invention; figure 11 shows an isometric view of a further alternative in-wheel steering assembly according to a fourth embodiment of the invention; figure 12 shows a cross section of the further alternative in-wheel steering assembly according to the line XI I-XI I in figure 11 ; figure 13 shows a perspective view of an alternative steering control according to a fi fth embodiment of the invention; figure 14 shows a side view of the alternative steering control according to figure 13 ; and figure 15 shows a cross section of the alternative steering control according to the line XV-XV in figure 14 .

[0039] DETAILED DESCRIPTION OF THE INVENTION

[0040] Figure 1 shows a vehicle 1 according to a first embodiment of the invention . In this example, the vehicle 1 is a cargo bike . Alternatively, the vehicle 1 may be a bicycle, a go-kart or any other multi-wheeled vehicle .

[0041] The vehicle 1 has a driving direction D . Unless stated otherwise, the driving direction D refers to a forward direction of travel of the vehicle 1 .

[0042] The vehicle 1 comprises a chassis 10 , in this example a cargo bike frame, an a plurality of wheels 11 , 12 held by said chassis 10 . Each wheel 11 , 12 comprises a rim 13 and a tire 14 fitted around said rim 13 . In this example , the wheels 11 , 12 are spoked wheels , having spokes 15 extends radially outwards towards the rim 13 from the center of the respective wheel 11 , 12 . Alternatively, the rim 13 may extend towards the center of the respective wheel 11 , 12 itself , like a cast rim, a disk rim, an integrally formed rim or the like .

[0043] Considered in the driving direction D, the plurality of wheels 11 , 12 comprises a front wheel 11 and a rear wheel 12 . The front wheel 11 is pivotable about a steering axis , a swivel axis or pivot axis P to a chosen steering angle A relative to a neutral plane N, as shown in figure 6. The rear wheel 12 , as shown in figure 1 , is driven in a manner known per se .

[0044] The vehicle 1 further comprises an in-wheel steering assembly 2 for steering the vehicle 1 . In this example, the in-wheel steering assembly 2 is fitted to or provided as a pre-installed part of the front wheel 11 .

[0045] The vehicle 1 further comprises a steering control

[0046] 9 that is operationally connected to the in-wheel steering assembly 2 for controlling said in-wheel steering assembly 2 .

[0047] As shown in more detail in figures 2 and 3 , the inwheel steering assembly 2 comprises a holder, a carrier, a frame interface or a chassis interface 3 for mechanically connecting the in-wheel steering assembly 2 to the chassis

[0048] 10 of the vehicle 1 , as shown in figure 1 . In this example, the chassis interface 3 is formed like a shaft . In particular, the chassis interface 3 comprises a first interface end 31 , a second interface end 32 and a shaft body 30 extending between the first interface end 31 and the second interface end 32 along a shaft axis S . In this example , the shaft body 30 is configured for connecting to the chassis 10 of the vehicle 1 at the respective interface ends 31 , 32 . Moreover, in this example , the shaft body 30 is symmetrical or substantially symmetrical relative to the neutral plane N of the front wheel 11 . Alternatively, the shaft body 30 may be connected to the chassis 10 on one side only, like a cantilever .

[0049] As best seen in figure 5 , the chassis interface 3 is further provided with a pivot section 33 formed at and / or protruding from the shaft body 30 at or near the neutral plane N of the front wheel 11 . The pivot section 33 defines the pivot axis P of the front wheel 11 . Said pivot axis P extends perpendicular to the shaft axis S .

[0050] In the context of the present invention, an axis is perpendicular to another axis when the directions along which the respective axes extend are at a right angle to each other . The respective axes do not necessarily have to intersect . In particular, in this example, the pivot axis P is offset from, spaced apart from or trails the shaft axis S over a pivot offset XI in a trail direction T perpendicular to both the pivot axis P and the shaft axis S . The pivot offset XI is at least five millimeters , preferably at least eight millimeters , more preferably at least ten millimeters , and in this example approximately twelve millimeters .

[0051] As shown in figures 1 to 3 , the in-wheel steering assembly 2 is provided with an inner hub 4 that is supported on the chassis interface 3 . The inner hub 4 extends concentrically to and / or defines a wheel axis W . The wheel axis W extends perpendicular to the driving direction D and / or the pivot axis P . The inner hub 4 comprises an inner hub body 40 that extends concentrically about the wheel axis W . In this example , the inter hub body 40 is formed by a first hub hal f 41 and a second hub half 42 mated with suitable fasteners , such as bolts . Alternatively, the inner hub body 40 may be formed from an integral or monolithic piece .

[0052] As shown in figure 5 , the inner hub body 40 further defines an internal space H for accommodating and / or receiving the chassis interface 3 . In this example, the internal space H is formed by a through hole 43 that extends through the inner hub body 40 in or parallel to the wheel axis W . The through hole 43 is dimensioned or shaped to accommodate the chassis interface 3 at a range of steering angles A between the maximum steering angle, as shown in figure 6, and the neutral steering angle, as shown in figure 5. In this example , the maximum steering angle is approximately forty-one degrees .

[0053] As best seen in figure 5, the shaft body 30 of the chassis interface 3 extends through the inner hub 4 to connect to the chassis 10 of the vehicle 1 on opposite sides of the inner hub 4 .

[0054] As best seen by comparing figures 5 and 6, the inner hub 4 is mounted to or on the pivot section 33 of the chassis interface 3 so as to be swivable or pivotable relative to the chassis interface 3 about the pivot axis P . More specifically, as best seen in figure 3 , the in-wheel steering assembly 2 is provided with a first pivot bearing 61 and a second pivot bearing 62 aligned coaxially to the pivot axis P on opposite sides of the chassis interface 3 for connecting the chassis interface 3 to the inner hub 4 and for allowing pivoting of the inner hub 4 relative to the chassis interface 3 about said pivot axis P . In particular, the pivot bearings 61 , 62 are mounted to opposite sides of the pivot section 33 of the chassis interface 3 at or concentric to the pivot axis P . The inner hub 4 defines or is provided with a bearing recess 45 that confines the first pivot bearing 61 , the second pivot bearing 62 and the chassis interface 3 in a confinement direction parallel to the pivot axis P .

[0055] As shown in figure 3 , the in-wheel steering assembly 2 may optionally be provided with a pre-load spring 65 for pre-loading or biasing the pivot bearings 61 , 62 against the chassis interface 3 and a cover 66 enclosing the bearing recess 45 at the side of said pre-load spring 65 .

[0056] In this example , the pivot bearings 61 , 62 are ring bearings , ball bearings or roller bearings , and in particular tapered roller bearings . As such, the pivot bearings 61 , 62 can effectively take loads in both axial and radial directions , relative to the pivot axis P .

[0057] In this example, as shown in figure 5, the pivot axis P is offset from, spaced apart from or trails the wheel axis W over a trail distance X2 that is equal to or slightly larger than the pivot of fset XI . In particular, the trail distance X2 may exceed the pivot offset XI by at least one millimeter or at least two millimeters .

[0058] As shown in figures 1 to 3 , the in-wheel steering assembly 2 is further provided with an outer hub 5 that is concentrically mounted or fitted around the inner hub 4 . The outer hub 5 is rotatable relative to said inner hub 4 about said wheel axis W . The outer hub 5 is configured to be mounted or fitted at the center of the front wheel 11 and, in said center position, carries the spokes 15 ( if present ) , the rim 13 and the tire 15 . As such, the outer hub 5 facilitates rotation of the tire 15 about the wheel axis W, relative to the inner hub 4 . The outer hub 5 comprises an outer hub body 50 that is annular or at least partially annular to fit around the inner hub body 40 .

[0059] As best seen in figure 3 , the in-wheel steering assembly 2 is provided with a first wheel bearing 63 and a second wheel bearing 64 between the inner hub 4 and the outer hub 5 for allowing rotation of the outer hub 5 relative to the inner hub 4 about the wheel axis W . In this example, the wheel bearings 63 , 64 are ring bearings , ball bearings or roller bearings .

[0060] As shown in figure 3 , the in-wheel steering assembly 2 further comprises a steering arm or a steering lever 7 that rotates together with, in unison with, or is corotatable with the inner hub 4 about the pivot axis P . In other words , i f the steering lever 7 is moved, rotated, swiveled or pivoted about the pivot axis P, the inner hub 4 will be moved, rotated, swiveled or pivoted about the pivot axis P in the same direction and to the same extent . In this example, the inner hub 4 is provided with a lever slot 44 for receiving the steering lever 7 in a manner that fixes the orientation of the steering lever 7 relative to the inner hub 4 about the pivot axis P . Alternatively, the steering lever 7 may be fixed to the inner hub 4 with suitable fasteners or the steering lever 7 may be permanently fixed to, glued to, welded to or integrally formed with the inner hub 4 .

[0061] As best seen in figure 4 , the steering lever 7 comprises a first lever end 71 , a second lever end 72 opposite to the first lever end 71 and a lever body 70 extending between the first lever end 71 and the second lever end 72 in a lever direction L along a lever axis M . In this example, the lever direction L is perpendicular to and away from the pivot axis P and / or towards the wheel axis W . In other words , the steering lever 7 proj ects from the inner hub 4 and / or the pivot axis P towards the wheel axis W . The first lever end 71 is connected in a corotatable manner to the inner hub 4 , as previously discussed . At or near the second lever end 72 , the lever body 70 is provided with a pin slot 73 extending in the lever direction L . In this example, the pin slot 73 extends at least up to , across or crosses the wheel axis W in the lever direction L .

[0062] As best seen in figure 5, the in-wheel steering assembly 2 is further provided with a steering actuator 8 that is configured for interacting with the steering lever 7 inside the inner hub 4 . In particular, the steering actuator 8 engages the steering lever 7 inside the inner hub 4 for exerting, generating imparting a rotation, a swiveling movement , a pivoting movement, a moment of force, a steering force or a steering moment on said steering lever 7 about the pivot axis P relative to the chassis interface 3 .

[0063] In this example the steering actuator 8 is a linear actuator, in particular a hydraulic actuator . As best seen in figure 5, the steering actuator 8 comprises a first steering chamber 81 and a second steering chamber 82 that are formed inside the shaft body 30 of the chassis interface 3 for receiving a hydraulic fluid . The shaft body 30 thus forms a housing enclosing the respective steering chambers 81 , 82 . In other words , the steering actuator 8 is contained in, enclosed by and / or integrated in the chassis interface 3 . Alternatively, the steering actuator 8 may be arranged at least partially outside of the shaft body 30 and have its own housing (not shown) .

[0064] The steering actuator 8 further comprises a steering piston 83 that is slidably received in and / or bidirectionally movable inside the first steering chamber 81 and the second steering chamber 82 in a stroke direction Y . The first steering chamber 81 and the second steering chamber 82 are located opposite to each other in said stroke direction Y . In this example , the stroke direction Y is parallel to and / or coincides the shaft axis S . Consequently, the steering actuator 8 is configured for acting parallel to the shaft axis S . The stroke direction Y is also perpendicular to the pivot axis P, perpendicular to the neutral plane N and / or transverse to the lever direction L .

[0065] The in-wheel steering assembly 2 comprises connectors C for connecting the steering actuator to a source of hydraulic fluid . In this example, the connectors C are located at the respective interface ends 31 , 32 of the chassis interface 3 for connection to the source of hydraulic fluid via said chassis interface 3 .

[0066] The steering piston 83 comprises a first steering piston end 84 , a second steering piston end 85 and a steering piston body 86 extending between the first steering piston end 84 and the second steering piston end 85 . The first steering chamber 81 and the second steering chamber 82 are configured for receiving the first steering piston end 84 and the second steering piston end 85, respectively . The steering actuator 8 comprises a plurality of seals 87 , in particular O-rings , for hydraulically sealing the steering piston ends 84 , 85 relative to the respective steering chambers 81 , 82 .

[0067] The steering lever 7 is coupled to the steering piston 83 at the steering piston body 86 between the first steering piston end 84 and the second steering piston end 85 . In this example, the shaft body 30 is provided with a control aperture 34 for allowing the steering lever 7 to extend into the shaft body 30 up to the position of the steering piston 83 to engage said steering piston 83 . The control aperture 34 is dimensioned or shaped to allow for pivoting of the steering lever 7 about the pivot axis P .

[0068] Optionally, the steering lever 7 may be coupled to the shaft body 30 at said pivot axis P, for example via a pivot pin 35, as shown in figure 3 , that is insertable into the control aperture 34 along said pivot axis P . For this purpose, the steering lever 7 may be provided with a pivot aperture or pivot seat 74 for receiving said pivot pin 35.

[0069] As further shown in figure 4 , the steering piston 83 further comprises a steering pin 88 protruding from the steering piston body 86 in a direction parallel to the pivot axis P . As best seen in figure 5, the steering pin 88 is configured to be slidably received in the pin slot 73 of the steering lever 7 . Together, the steering pin 88 and the pin slot 73 form a pin-slot mechanism for converting the bidirectional movement of the steering piston 83 in the stroke direction Y into a rotation, swiveling or pivoting of the inner hub 4 relative to the chassis interface 3 about the pivot axis P, see figures 5 and 6.

[0070] As shown in figure 1 , the vehicle 1 comprises control lines KI , K2 for operationally connecting the steering control 9 to the steering actuator 8 in figure 5. In this example , said control lines KI , K2 are hydraulic conduits , in particular flexible tubes . The control lines KI , K2 are guided along the chassis 10 of the vehicle 1 to interconnect the steering control 9 and the in-wheel steering assembly 2 .

[0071] As further shown in figure 1 , the steering control 9 comprises a steering input member 91 for receiving a steering input . In this example, the steering input member 91 is a handlebar . The handlebar is rotatable about a control axis Z . Alternatively, the steering input member 91 may be a hand wheel or another type of manually operable steering input member . The steering control 9 further comprises a steering output member 92 between the steering input member 91 and the control lines KI , K2 for converting the steering input into a displacement of hydraulic fluid through the control lines KI , K2 .

[0072] As shown in more detail in figures 7 and 8 , the steering output member 92 comprises a cylindrical housing 93 that defines a first arcuate drive chamber 94 and a second arcuate drive chamber 95 for receiving hydraulic fluid . The steering output member 92 further comprises an arcuate drive piston 96 with a first drive piston end 98 and a second drive piston end 99 slidably received in the first arcuate drive chamber 94 and the second arcuate drive chamber 95 , respectively . In this example, the arcuate drive chambers 94 , 95 and the arcuate drive piston 96 are all concentric to or coaxial with the control axis Z . The arcuate drive piston 96 is further provided with a drive piston body 97 between the first drive piston end 98 and the second drive piston end 99 that is concentrically connected or connectable to the steering input member 91 to convert a rotation of the steering input member 91 , in particular about the control axis Z , into a displacement of hydraulic fluids from or into the respective arcuate drive chambers 94 , 95. Each of the control lines KI , K2 forms a closed circuit or a closed system of hydraulic fluid with a respective one of the arcuate drive chambers 94 , 95 and a respective one of the steering chambers 81 , 82 .

[0073] Figure 9 shows an alternative in-wheel steering assembly 102 according to a second embodiment of the invention, that dif fers from the aforementioned in-wheel steering assembly 2 in that its steering actuator 108 features a single steering chamber 181 and an alternative steering piston 183 that is slidably received in the single steering chamber 181 to be alternately pushed and pulled by hydraulic fluid from the side of the single steering chamber 181 only . Again, in this example, the steering actuator 108 is integrated in the chassis interface 103 , which has an alternative shaft body 130 that only defines the single steering chamber 181 rather than the two steering chambers 81 , 82 in figure 5.

[0074] Figure 10 shows a further alternative in-wheel steering assembly 202 according to a third embodiment of the invention, that dif fers from the aforementioned in-wheel steering assemblies 2 , 102 in that its steering actuator 208 features a first steering piston 283 and a second steering piston 383 that alternately push the steering lever 7 in opposite directions along the stroke direction Y . Each steering piston 283 , 383 is provided with a pushing surface 285 , 385 for physically abutting and / or pushing the steering lever 207 . In the absence of any pulling action, the steering lever 207 is modified as it does not require a pin slot at its second end 272 .

[0075] Figures 11 and 12 show a further alternative in- wheel steering assembly 302 according to a fourth embodiment of the invention, that differs from the aforementioned inwheel steering assemblies 2 , 102 , 202 in that, as best seen in figure 12 , its steering actuator 303 features an alternative shaft body 330 that defines a lever chamber 380 for housing or accommodating an alternative steering lever 307 . In contrast to the previously discussed steering levers 7 , 207 , the alternative steering lever 307 does not extend outside of the steering actuator 303 . Instead it is fully enclosed by the alternative shaft body 330 inside the lever chamber 380 . The lever chamber 380 , the first steering chamber 81 and the second steering chamber 82 form parts of a closed hydraulic system .

[0076] The further alternative in-wheel steering assembly 302 comprises a connecting member 335 that corotatably connects the steering lever 307 inside the lever chamber 380 to the inner hub 4 outside the lever chamber 380 while sealing off the lever chamber relative to the steering actuator 303 . The connecting member 335 replaces the previously described pivot pin 35. The connecting member 335 extends coaxially to the pivot axis P . In this example, the connecting member 335 is formed as a rectangular or square pin or key that is configured to engage a correspondingly shaped opening (not shown) in the inner hub 4 . Moreover, in this example, the connecting member 335 extends out of the alternative shaft body 330 on both sides to engage the inner hub 4 along the pivot axis P on both sides of said alternative shaft body 330 .

[0077] As shown in figure 11 , the in-wheel steering assembly 302 further comprises a circular bushing or filler 336 at the location where the connecting member 335 passes through the alternative shaft body 330 . Alternatively, the connecting member 335 itself may be circular, at least at the passage . As such, the alternative shaft body 330 can be easily sealed against the circular circumference of the filler 336 or the connecting member 335 to effectively seal off the lever chamber 380 , for example using an 0-ring . Figures 13-15 show an alternative steering control 409 according to a fifth embodiment of the invention, that dif fers from the aforementioned steering control 9 in that the steering output member 492 converts the steering input from the steering input member 491 into a displacement of hydraulic fluid through the control lines KI , K2 in a dif ferent manner . In particular, the steering output member 492 comprises a housing 493 that defines a first drive chamber 494 and a second drive chamber 495 extending coaxially inline with a control axis Z , rather than circumferentially about said control axis Z . Each drive chamber 494 , 495 is configured for receiving a drive piston 498 , 499 that can be reciprocated within the respective drive chamber 494 , 495 in or parallel to the control axis Z . Each drive piston 498 , 499 is connected to a cam 496, 497 that protrudes at least partially out of the drive chamber 494 , 495.

[0078] As best seen in figure 14 , the steering control 409 further comprises a profiled plate 500 that defines a first cam profile 501 and a second cam profile 502 opposite to the respective cams 496, 497 . The profiled member 500 is fixed relative to and / or corotatable with the steering input member 491 . Hence, the profiled member 500 rotates relative to the cams 496, 497 when the steering input member 491 is rotated . The cam profiles 501 , 502 are chosen to displace the cams 496 , 497 upon said rotation in accordance with the shape of the respective cam profile 501 , 502 . In this example, the cam profiles 501 , 502 are linear or substantially linear . Alternatively, the cam profiles 501 , 502 may be provided with curved sections , linear sections or combinations thereof , to vary the ratio between the steering input and the steering output along the respective cam profile 501 , 502 . The steering output may for example change at a relatively small rate to the steering input near the neutral position of the steering input member 491 and increase towards the more extreme steering angles , or vi ce versa .

[0079] Optionally, as shown in figures 14 and 15, the steering control 409 may be provided with a sealing cap 490 , shown in dashed lines only, to close of the area of the drive pistons 498 , 499 facing outwards , thereby allowing for the steering control 409 to be sealed on both sides of the drive pistons 498 , 499 in a similar manner to the sealing of the steering actuator 303 in figures 11 and 12 , thereby obtaining a fully closed hydraulic system or circuit between the steering control 409 , the control lines KI , K2 and the inwheel steering system 302 .

[0080] A method for steering the vehicle 1 of figure 1 using any one of the aforementioned in-wheel steering assemblies 2 , 102 , 202 will now be briefly be elucidated with reference to figures 5 to 7 .

[0081] Figure 5 shows the situation in which the inner hub 4 is arranged in a neutral orientation with the wheel axis W parallel to the shaft axis S and / or the lever axis M perpendicular to the shaft axis S . The piston 83 of the steering actuator 8 is located symmetrically between the two steering chambers 81 , 82 . There is an equal volume of hydraulic fluid in both steering chambers 81 , 82 . Moreover, the steering pin 88 is located in the neutral plane N . The configuration of the steering output member 92 in figure 7 corresponds to this neutral orientation, with each of the two arcuate drive chambers 94 , 95 being equal in volume .

[0082] Figure 6 shows the situation in which the inner hub 4 is pivoted relative to the chassis interface 3 about the pivot axis P by imparting a steering moment with the steering actuator 8 on the steering lever 7 about the pivot axis P relative to the chassis interface 3 . The situation as shown corresponds to a left turn relative to the driving direction D . The configuration of the steering output member 92 in figure 8 corresponds to this left turn steering action, with the first arcuate drive chamber 94 being reduced in volume in an equal amount to the increase in volume of the first steering chamber 81 , and with the second arcuate drive chamber 95 being increased in volume in an equal amount to a decrease in volume of the second steering chamber 82 .

[0083] It follows from the description above that , in this example, the steering moment is imparted hydraulically by simultaneously pulling and pushing on the piston 83 from both steering chambers 81 , 82 . Alternatively, the piston 183 may be pushed and pulled from one side only, as shown in figure 9, or the piston 283 may be pushed alternately from opposite sides , as shown in figure 10 .

[0084] It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention . From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention .

[0085] LIST OF REFERENCE NUMERALS

[0086] 1 vehicle

[0087] 10 chassis

[0088] 11 front wheel

[0089] 12 rear wheel

[0090] 13 rim

[0091] 14 tire

[0092] 15 spoke

[0093] 2 in-wheel steering assembly

[0094] 3 chassis interface

[0095] 30 shaft body

[0096] 31 first interface end

[0097] 32 second interface end

[0098] 33 pivot section

[0099] 34 control aperture

[0100] 35 pivot pin

[0101] 4 inner hub

[0102] 40 inner hub body

[0103] 41 first hub half

[0104] 42 second hub hal f

[0105] 43 through hole

[0106] 44 lever slot bearing recess outer hub outer hub body first pivot bearing second pivot bearing first wheel bearing second wheel bearing pre-load spring cover steering lever lever body first lever end second lever end pin slot pivot seat steering actuator first steering chamber second steering chamber steering piston first steering piston end second steering piston end steering piston body seal steering pin steering control steering input member steering output member housing first arcuate drive chamber second arcuate drive chamber arcuate drive piston drive piston body first drive piston end second drive piston end alternative in-wheel steering assembly chassis interface shaft body 108 steering actuator

[0107] 181 single steering chamber

[0108] 183 alternative piston

[0109] 202 further alternative in-wheel steering assembly

[0110] 207 steering lever

[0111] 272 second lever end

[0112] 283 first steering piston

[0113] 285 first pushing surface

[0114] 383 second steering piston

[0115] 385 second pushing surface

[0116] 302 further alternative in-wheel steering assembly

[0117] 303 steering actuator

[0118] 330 alternative shaft body

[0119] 335 connecting member

[0120] 336 filler

[0121] 307 alternative steering actuator

[0122] 409 alternative steering control

[0123] 490 sealing cap

[0124] 491 steering input member

[0125] 492 steering output member

[0126] 493 housing

[0127] 494 first drive chamber

[0128] 495 second drive chamber

[0129] 496 first cam

[0130] 497 second cam

[0131] 498 first drive piston

[0132] 499 second drive piston

[0133] 500 profiled member

[0134] 501 first cam profile

[0135] 502 second cam profile

[0136] A steering angle

[0137] C connector

[0138] D driving direction

[0139] H internal space

[0140] KI first control line

[0141] K2 second control line

[0142] L lever direction M lever axis

[0143] N neutral plane

[0144] P pivot axis

[0145] S shaft axis T trail direction

[0146] W wheel axis

[0147] XI pivot of fset

[0148] X2 trail distance

[0149] Y stroke direction Z control axis

Claims

C L A I M S1 . In-wheel steering assembly for steering a vehicle, wherein the in-wheel steering assembly comprises a chassis interface for connecting the in-wheel steering assembly to a chassis of the vehicle , an inner hub supported on the chassis interface and defining a wheel axis , and an outer hub concentrically fitted around the inner hub and rotatable relative to said inner hub about said wheel axis , wherein the inner hub is pivotable relative to the chassis interface about a pivot axis perpendicular to the wheel axis , wherein the pivot axis trails the wheel axis over a trail distance , wherein the in-wheel steering assembly further comprises a steering lever that is corotatable with the inner hub and extends inside the inner hub in a lever direction perpendicular to and away from the pivot axis and towards the wheel axis , wherein the in-wheel steering assembly is provided with a steering actuator that is configured for engaging the steering lever inside the inner hub and for imparting a steering moment on said steering lever about the pivot axis relative to the chassis interface .2 . In-wheel steering assembly according to claim 1 , wherein the trail distance is at least ten millimeters , preferably at least eleven millimeters and most preferably at least twelve millimeters .3 . In-wheel steering assembly according to any one of the preceding claims , wherein the steering lever extends inside the inner hub in a lever direction along a lever axis that intersects with the pivot axis .4 . In-wheel steering assembly according to any one of the preceding claims , wherein the steering actuator is a linear actuator .

5. In-wheel steering assembly according to any one of the preceding claims , wherein the steering actuator is a hydraulic actuator .

6. In-wheel steering assembly according to claim5, wherein the in-wheel steering assembly comprises one or more connectors for connecting the steering actuator to a source of hydraulic fluid .7 . In-wheel steering assembly according to claim6, wherein the one or more connectors are located at or in the chassis interface .8 . In-wheel steering assembly according to any one of the preceding claims , wherein the steering actuator is integrated in the chassis interface .

9. In-wheel steering assembly according to any one of the preceding claims , wherein the chassis interface comprises a shaft body extending through the inner hub along a shaft axis , wherein the steering actuator is configured for acting parallel to the shaft axis .10 . In-wheel steering assembly according to claim 9, wherein the steering actuator coincides with the shaft axis .11 . In-wheel steering assembly according to any one of the preceding claims , wherein the steering actuator comprises a first steering chamber and a steering piston that is bidirectionally movable inside the first steering chamber in a stroke direction perpendicular to the pivot axis and transverse to the lever direction, wherein the steering lever is coupled to the steering piston for converting the bidirectional movement of the steering piston in the stroke direction into pivoting of the inner hub relative to the chassis interface about the pivot axis .12 . In-wheel steering assembly according to claim 11 , wherein the steering piston comprises a first steering piston end, a second steering piston end and a steering piston body extending between the first steering piston end and the second steering piston end, wherein the steering actuator comprises a second steering chamber opposite to the first steering chamber in the stroke direction, wherein the first steering chamber and the second steering chamber are configured for receiving the first steering piston end and the second steering piston end, respectively, wherein thesteering lever is coupled to the steering piston at the steering piston body between the first steering piston end and the second steering piston end .13 . In-wheel steering assembly according to any one of claims 1-9 , wherein the steering actuator comprises a first steering chamber and a first steering piston that is movable inside the first steering chamber in a stroke direction perpendicular to the pivot axis and transverse to the lever direction, wherein the steering actuator further comprises a second steering chamber, opposite to the first steering chamber in the stroke direction, and a second steering piston that is movable inside the second steering chamber in the stroke direction, wherein the steering lever is positioned between the first steering piston and the second steering piston in the stroke direction to be alternately displaced by the first steering piston and the second steering piston while converting the respective movements of the steering pistons in the stroke direction into pivoting of the inner hub relative to the chassis interface about the pivot axis .14 . In-wheel steering assembly according to any one of claims 11-13 , wherein the steering actuator further defines a lever chamber that houses the steering lever, wherein the lever chamber and the first steering chamber both form parts of a closed hydraulic system, wherein the in-wheel steering assembly comprises a connecting member that corotatably connects the steering lever inside the lever chamber to the inner hub outside the lever chamber while sealing off the lever chamber relative to the steering actuator .

15. In-wheel steering assembly according to claim 14 , wherein the connecting member extends coaxially to the pivot axis .

16. Wheel comprising an in-wheel steering assembly according to any one of the preceding claims .17 . Vehicle comprising at least one wheel according to claim 16 .18 . Vehicle according to claim 17 , wherein thevehicle is a bicycle or a cargo bike .

19. Vehicle according to claim 18 , wherein the chassis is a bicycle frame or a cargo bike frame .20 . Vehicle according to any one of claims 17-19, wherein the vehicle comprises a steering control and at least one control line for operationally connecting the steering control to the steering actuator .21 . Vehicle according to claim 20 , wherein the at least one control line comprises a hydraulic conduit .22 . Vehicle according to claim 21 , wherein the steering control comprises a steering input member for receiving a steering input and a steering output member between the steering input member and the at least one control line for converting the steering input into a displacement of hydraulic fluid through the at least one control line .23 . Vehicle according to claim 22 , wherein the steering input member is a handlebar, a hand wheel , a j oystick, one or more buttons , or any other kind of suitable steering input member .24 . Method for steering a vehicle using an in-wheel steering assembly according to any one of claims 1-15, wherein the method comprises the step of : pivoting the inner hub relative to the chassis interface about the pivot axis by imparting a steering moment with the steering actuator on the steering lever about the pivot axis relative to the chassis interface .

25. Method according to claim 24 , wherein the steering moment is imparted hydraulically .

26. Method according to claim 24 or 25, wherein the vehicle comprises a steering control , wherein the method further comprises the step of : hydraulically connecting the steering control to the steering actuator .-o- o-o-o-o- o-o-o-

Images