Patent Description:
In modern bicycles there is increasing use of on-board equipments that facilitate the use of the bicycle. One of such on-board equipments comprising an electric motor that assists or at least partially replaces the propulsive action exerted on the pedals of the bicycle by the user. Bicycles equipped with such on-board equipments are also known as pedal assist bicycles or electric bicycles.

The electric motor used is usually a DC electric motor with voltages usually comprised between <NUM> and <NUM> Volt that can be integrated in the hub of one of the two wheels, most often in the rear one. In this case, the electric motor is arranged inside a hub body rotatably mounted on a hub shaft fixed with respect to the front fork (in the case of the hub of the front wheel) or with respect to the chain stay (in the case of the hub of the rear wheel) of the bicycle.

The activation at full power or at different power levels of the electric motor can be activated based on simple or even very articulated operating logics selected by the manufacturer of the electric motor, by the manufacturer of the bicycle or even by the user, just as such operating logics can be subjected to regulatory constraints of the country in which the bicycle is commercialized or used.

To this purpose, it is provided for the electric motor to be in electric connection with a control unit which comprises components and electronic circuits suitable for controlling the electric motor based on such operating logics. The control unit can be mounted directly on-board the electric motor or on-board the bicycle in remote position from the electric motor. The control unit is very often arranged in electric connection with one or more sensors mounted on-board the bicycle, like for example pedaling sensors, force sensors, rotation sensors or other types of sensors, and with one or more control devices configured to send signals representative of parameters and/or values used by the control unit for the correct implementation of the activation logic of the electric motor to the control unit.

The electric energy necessary for powering the electric motor is stored in one or more accumulators of electric charge, like for example rechargeable lithium ion batteries, arranged in suitable housings connected to the frame or other parts of the bicycle or arranged inside the frame of the bicycle.

The Applicant has observed that in the case in which the electric motor is integrated in the hub of a wheel, making a motorized hub, it is necessary to ensure one or more electric connections between the electric motor, the control unit, the possible sensors and control devices and the battery.

The Applicant has observed that it is necessary for electrical conductor elements, such as power cables, signal cables and electrical connectors, to reach the electric motor and optionally the control unit housed inside the hub body.

The Applicant has verified that a passage groove is usually formed in the hub shaft, carved from the solid piece, at a bearing mounted on the hub shaft and active on the hub body that houses the electric motor. The electrical conductor elements pass in such a groove thus passing beneath the bearing and reach the inside of the hub body. The electrical conductor elements are substantially fixed with respect to the hub shaft and can be connected to the electric motor, to the control unit, to the possible sensors and control devices and to the battery.

The Applicant has noted that such a solution does not allow the use of hub shafts configured for the quick release of the wheel, in other words hub shafts that comprise an inner through cavity designed to be engaged by a quick release axle that constrains the hub shaft to the front fork or to the chain stay of the bicycle.

The Applicant has verified that such hub shafts have a wall thickness not sufficient to form a passage groove for the electrical conductor elements, since in many cases the thickness of the cylindrical wall defined by the hub shaft is less than the thickness of the electrical conductor elements.

The Applicant has noted that even if the thickness of the cylindrical wall of the hub shaft were sufficient to make a passage groove, such a passage groove could excessively weaken the structure of the hub shaft with possible compromises to the functional integrity of the hub shaft.

The Applicant has also verified that it is not possible to use the inner cavity of the hub shaft for the passage of the electrical conductor elements since such an inner cavity must be used to house the quick release axle.

The Applicant has hypothesized to groove the bearing and in particular the inner ring of the bearing to form the space necessary for the passage of the electrical conductor elements. The Applicant has, however, noted that this could compromise the correct functionality of the bearing.

The Applicant has noted that if it is wished to equip a motorized hub with a hub shaft configured for quick release, the passage of the electrical conductor elements must avoid having a negative impact on the correct operation of the hub to preserve the functional integrity of the hub itself.

The Applicant has perceived that by providing a bearing of greater diameter than the diameter of the hub shaft, between the bearing and the hub shaft there would be a radial space able to be used for the passage of the electrical conductor elements without having to groove or perforate the hub shaft or the bearing.

The prior art documents <CIT> and <CIT> disclose the features of the preamble of claim <NUM>.

The present invention therefore relates to a motorized hub assembly for a bicycle wheel according to claim <NUM>.

The hub shaft can be fixed with respect to the front fork (in the case of a hub of the front wheel) or with respect to the chain stay (in the case of a hub of the rear wheel) of the bicycle through the use of a quick release axle inserted in the longitudinal through cavity of the hub shaft.

The first bearing can be selected with a diameter of its inner ring such that the distance in the radial direction that separates the inner ring from the hub shaft is sufficient to form a routing opening crossed by the electrical conductor elements.

Between the inner ring of the first bearing and the hub shaft, in the areas not engaged by the routing opening it is possible to provide any spacer body or support body that allows the inner ring to be connected to the hub shaft, therefore allowing a correct rotary coupling between hub shaft and hub body.

The rotation axis of the hub body is taken as reference for the elements that form part of the motorized hub assembly of the present invention; the indications of direction and similar, such as "axial", "radial" and "circumferential" will refer to this axis. The indications "outwards" and "inwards" referring to radial directions must be interpreted as away from the rotation axis or towards the rotation axis. The axial direction is parallel to the direction of the rotation axis and the indications "inwards" and "outwards" referring to axial directions must be interpreted, respectively, as towards a radial reference plane passing through a middle point of the hub body and as away from such a reference plane. The circumferential direction is meant to indicate an arched direction, and not necessarily perfectly circular, around the rotation axis.

The Applicant has noted that the first bearing transfers radial thrusts from the hub body to the hub shaft, transferring the stresses to which the rim of the wheel is subjected to the hub shaft and thus to the frame of the bicycle.

The Applicant has perceived that the routing opening provided between the first bearing and the hub shaft would prevent placing the first bearing in continuous circumferential contact with the hub shaft, causing a discontinuous support of the first bearing on the hub shaft at least at the routing opening.

The Applicant deems that such discontinuous support does not allow the first bearing to transfer radial thrusts coming from the hub body to the hub shaft in an identical manner along the entire circumferential extension thereof.

By providing a support body for the first bearing at least at the routing opening and configuring such a support body to withstand a thrust directed in a radially inner direction exerted by the first bearing, the circumferential continuity between the first bearing and the hub shaft is restored.

Preferably, said support body extends circumferentially around the entire hub shaft, said inner ring of the first bearing resting on said support body along the entire circumferential extension of the support body.

In this way, the support body allows the first bearing to rest uniformly along the entire inner ring, allowing the radial thrusts transferred to the first bearing to be distributed substantially uniformly on the inner ring.

Preferably, said support body has a radially outer resting surface for said inner ring of the first bearing, said radially outer resting surface being continuous.

Preferably, there are no interruptions or holes between any two points of the radially outer surface of the support body.

Preferably, an annular sealing gasket is provided axially outside the first bearing.

Preferably, said sealing gasket rests on said support body and is active between said support body and said hub body.

In this way, the sealing gasket prevents foreign bodies, water, mud or dirt from being able to reach the first bearing or being able to penetrate between the support body and the hub body.

Preferably, said support body comprises a radial passage axially outside said first bearing and defining a radial outlet for said routing opening; said electrical conductor elements crossing said radial passage.

The radial passage allows the electrical conductor elements to move away from the hub assembly in the radial direction or to create an electrical connection interface that can be engaged radially. In this way, the axial bulk of the hub assembly is not influenced by the presence of the electrical conductor elements.

In alternative embodiments, the support body can comprise an axial passage arranged outside said first bearing and defining an axial outlet for said routing opening; said electrical conductor elements crossing said axial passage.

Preferably, a cover is provided arranged at an axial end of the hub shaft; said cover axially closing said routing opening and being fixedly connected to said hub shaft.

The cover is preferably equipped with an axial through hole coaxial with the longitudinal through cavity of the hub shaft and is preferably configured to abut on the fork or on the chain stay of the bicycle.

Preferably, the cover is configured to cooperate with the quick release axle to constrain the hub shaft to the fork or to the chain stay of the bicycle.

Preferably, the radial passage of the support body is axially interposed between the cover and the first bearing.

The delimiting wall defines the width in the radial direction of the routing opening. The routing opening crossed by the electrical conductor elements extends between the delimiting wall and the hub shaft. A radially inner surface of the delimiting wall preferably directly faces the routing opening. A radially outer surface of the delimiting wall preferably defines at least one portion of the radially outer resting surface of the support body.

In a first embodiment, said support body preferably comprises a radially inner surface comprising a first portion and a second portion. Such a first portion is preferably radially spaced from said hub shaft and defines the radially inner surface of the delimiting wall. The second portion is preferably directly coupled with the hub shaft.

Preferably, said radially inner surface of the support body comprises two circumferentially spaced joining portions arranged between the first and the second portion, said routing opening being circumferentially delimited by said two joining portions.

The two joining portions define respective side walls that circumferentially limit the routing opening.

In the first embodiment, the routing opening is therefore preferably defined between the two joining portions of the radially inner surface of the support body, the delimiting wall of the support body and the hub shaft.

In a second embodiment, said support body comprises a substantially cylindrical radially inner surface spaced from said hub shaft.

Preferably, the radially inner surface comprises the radially inner surface of the delimiting wall.

In the second embodiment, said radially inner surface of the support body preferably comprises a coupling surface of the support body arranged in contact with a spacer body fixedly connected to the hub shaft.

The spacer body comprises a circumferential first end wall and a second circumferential end wall and extends around the hub shaft between said first and second circumferential end wall.

The routing opening is circumferentially delimited by said first and second circumferential end wall.

In the second embodiment, the routing opening is therefore preferably defined between the two end walls of the spacer, the delimiting wall of the support body and the hub shaft.

Preferably, the coupling surface of the support body comprises a threading to screw said support body onto a radially outer threaded surface of the spacer.

Preferably, the spacer is made from at least one portion of a stator of said electric motor. Such a stator portion can project axially from the hub body so as to be engaged by a cover or by another body configured to couple the hub shaft with the fork or with the chain stay of the bicycle.

Preferably, a second bearing having a radially inner ring is provided, said second bearing being arranged radially outside the hub shaft and rotatably coupling said hub shaft with said hub body.

The second bearing is preferably axially opposite the first bearing.

The inner ring of the second bearing preferably has a smaller diameter than the diameter of the inner ring of the first bearing, so that the inner ring of the second bearing can be directly in contact with the hub shaft.

Further features and advantages of the present invention will become clearer from the following detailed description of preferred embodiments thereof, made with reference to the attached drawings and given for indicating and not limiting purposes. In such drawings:.

With reference to the attached figures, a motorized hub assembly of a bicycle wheel in accordance with the present invention is indicated as a whole with reference numeral <NUM>.

The hub assembly <NUM> is configured to be mounted in a front or rear wheel of a bicycle; the example embodiment of <FIG> is specifically configured to be mounted in a rear wheel.

The hub assembly <NUM> comprises a hub body <NUM> rotatably mounted around a rotation axis X on a hub shaft <NUM>.

The hub body <NUM> has a substantially cylindrical shape and comprises two opposite axial ends 11a, 11b. At each axial end 11a, 11b a respective closing plate <NUM>, <NUM> of the hub body <NUM> is provided so that the hub body <NUM> makes an internally hollow body.

In the preferred embodiment of the invention, a closing plate <NUM> is in one piece with the hub body <NUM> and the other closing plate <NUM> is removably mounted on the hub body <NUM> preferably through suitable bolts, as outlined in <FIG>.

The hub body <NUM> can be made of a metallic material, for example aluminum or alloys thereof.

On a radially outer surface <NUM> of the hub body <NUM>, or on one or both of the closing plates <NUM>, <NUM>, spoke attachment flanges <NUM> are provided. The flanges <NUM> can be made in one piece with the hub body <NUM> or can be made as distinct pieces from the hub body <NUM> to then be stably associated with the hub body <NUM>.

A brake disc (not illustrated) can be mounted on the hub assembly <NUM> in axially outer position with respect to the spoke attachment flanges <NUM>, preferably on a suitable mounting portion (not illustrated).

In the case in which the hub assembly is configured to be mounted on a rear wheel, the hub body <NUM> can be associated with a free wheel <NUM> (<FIG>) for supporting a cogset of the rear gearshift of the bicycle. The free wheel <NUM> is mounted fixedly connected to the hub body <NUM> through a receiving seat <NUM> arranged at the axial end 11b of the hub body and preferably formed in the closing plate <NUM>, as schematically illustrated in <FIG>. The free wheel, when provided, is rotatably mounted on the hub shaft <NUM>.

The hub shaft <NUM> can be constrained to the fork or to the chain stay of a bicycle and does not rotate with respect to the frame of the bicycle.

To this purpose, the hub shaft <NUM> extends along a longitudinal axis and comprises a longitudinal through cavity 12a configured to receive a quick release axle. The quick release axle (not illustrated) typically comprises a rod having, at one of the opposite axial end portions thereof, an outer threading intended to be coupled with an outer threading made on a cap configured to axially abut against an outer wall of an arm of the fork or of the chain stay. At the opposite axial end portion, the rod comprises a locking lever rotating as a unit with the rod and pivoted to the rod through a cam mechanism. The locking lever is also in abutment against an abutment surface provided in the rod and intended to abut with the other arm of the fork or of the chain stay of the bicycle. The screwing of the rod into the cap results in the locking of the rod with respect to the arm of the fork or of the chain stay. The subsequent rotation of the locking lever causes, thanks to the cam mechanism, the forced axial abutment of the abutment surface against the other arm of the fork or of the chain stay and, consequently, the locking of the hub shaft on the fork or on the chain stay.

The rod of the quick release axle is slidably received inside the longitudinal through cavity 12a of the hub shaft <NUM>. The longitudinal through cavity 12a of the hub shaft <NUM> is defined by a cylindrical wall 12b of the hub shaft <NUM> having an inner surface 12c directly facing the inner cavity 12a and an outer surface 12d. The thickness of the cylindrical wall 12b, in other words the distance in the radial direction between the inner surface 12c and the outer surface 12d is preferably comprised between <NUM> millimeters and <NUM> millimeters, more preferably comprised between <NUM> and <NUM> millimeters.

Inside the hub body <NUM> an electric motor <NUM> is housed. The electric motor <NUM> is preferably a DC electric motor with power supply voltages comprised between <NUM> and <NUM> Volt. The electric motor <NUM> comprises a stator <NUM> and a rotor <NUM>, outlined in <FIG>. The stator <NUM> is fixedly connected to the hub shaft <NUM> and the rotor <NUM> is fixedly connected to the hub body <NUM>. By supplying electrical energy to the electric motor <NUM>, the rotor <NUM> is set in rotation with respect to the stator <NUM>, making the hub body <NUM> rotate.

In order to allow the electric motor <NUM> to be in electric connection with one or more electric accumulators, electrical conductor elements <NUM> are provided connected to the electric motor <NUM>. Such electrical connector elements <NUM> can also connect a control unit <NUM>, for example an electronic board, to one or more sensors and to one or more control devices. The control unit <NUM> is configured to actuate the electric motor <NUM> according to one or more predetermined operating logics preferably able to be set by a user through one or more control devices. The control unit <NUM> is mounted inside the hub body <NUM> and is in electric connection with the electric motor <NUM> to allow it to be driven.

The electrical conductor elements <NUM> can be electric power cables and possibly signal cables, for example made of metal and coated with an electrically insulating sheath, or they can be one or more electrical connectors configured to mechanically and electrically couple with other electrical connectors coming from the frame of the bicycle. The electrical conductor elements <NUM> can also be electric cables coupled on one side with the electric motor and on the opposite side with one or more electrical connectors.

In the example embodiment illustrated in <FIG>, <FIG> and <FIG>, the electrical conductor elements <NUM> are made from metallic cables coated with electrically insulating sheaths, whereas in the example embodiment illustrated in <FIG> and <FIG> the electrical conductor elements <NUM> are made from connectors.

The electrical conductor elements <NUM> do not rotate with the hub body <NUM>.

In order to allow the hub body <NUM> to rotate around the rotation axis X with respect to the hub shaft <NUM>, a first bearing <NUM> and a second bearing <NUM> are provided that are coaxial and active between the hub shaft <NUM> and the hub body <NUM>. The first <NUM> and the second bearing <NUM> are preferably rolling ball bearings of the radial type, in other words of the type in which the load force to be borne is substantially perpendicular to the rotation axis of the bearing (which coincides with the rotation axis X of the hub body <NUM>).

The second bearing <NUM> is preferably arranged close to the axial end 11b of the hub body <NUM> carrying the closing plate <NUM> mounted on the hub body <NUM>. The first bearing <NUM> is preferably arranged close to the other axial end 11a of the hub body <NUM>.

The second bearing <NUM> is preferably directly coupled with the hub shaft <NUM>. As shown in <FIG>, the second bearing <NUM> comprises an inner ring 24a and an outer ring 24b and a plurality of balls 24c radially interposed between the inner ring 24a and the outer ring 24b, so as to make the outer ring 24b rotatable with respect to the inner ring 24a. The inner ring 24a preferably directly rests on the outer surface 12d of the hub shaft <NUM>. The outer ring 12b is inserted into a seat formed in the hub body <NUM>.

The first bearing <NUM> comprises an inner ring 23a and an outer ring 23b and a plurality of balls 23c radially interposed between the inner ring 23a and the outer ring 23b, so as to make the outer ring 23b rotatable with respect to the inner ring 23a.

As shown in <FIG>, the inner ring 23a of the first bearing <NUM> has a greater diameter than the diameter of the inner ring 24a of the second bearing <NUM>, so that the inner ring 23a of the first bearing <NUM> is radially spaced from the hub shaft <NUM>. The inner ring 23a of the first bearing <NUM> is not in direct contact with the hub shaft <NUM>. The outer ring 23b of the first bearing <NUM> is stably constrained in a seat formed in the hub body <NUM>.

Between the inner ring 23a of the first bearing <NUM> and the hub shaft <NUM> a routing opening <NUM> (better illustrated in <FIG> and <FIG>) crossed by the electrical conductor elements <NUM> is provided.

The routing opening <NUM> crosses the hub body <NUM> in the axial direction, placing the inside of the hub body <NUM> in communication with the outside of the hub body <NUM>. The routing opening <NUM> has a limited extension in the circumferential direction, in other words it has a circumferential extension of less than <NUM>°. In the preferred embodiment of the invention, the extension in the circumferential direction of the routing opening is comprised between <NUM>° and <NUM>°, preferably between <NUM>° and <NUM>°, for example about <NUM>°.

The routing opening <NUM> extends, in the radial direction, between the hub shaft <NUM> and a support body <NUM>. The support body <NUM> is arranged radially inside the first bearing <NUM> and has the function of abutting in the radial direction against the first bearing <NUM> at least in the portion engaged by the routing opening <NUM>. As illustrated in <FIG> and <FIG>, the inner ring 23a of the first bearing <NUM> is in direct contact with the support body <NUM> allowing the first bearing <NUM> to discharge radial forces onto the support body <NUM>. The routing opening <NUM> is delimited in the radially outer direction by a delimiting wall <NUM> of the support body <NUM>.

In the preferred embodiment of the invention, the support body <NUM> is active on the inner ring 23a of the first bearing <NUM> for the entire circumferential extension thereof and has a radially outer resting surface 26a that is contacted by the inner ring 23a of the first bearing <NUM>. The radially outer surface 26a of the support body <NUM> is a substantially cylindrical continuous surface matched to the inner ring 23a of the first bearing <NUM>.

In a first embodiment of the support body <NUM>, illustrated in <FIG>, <FIG> and <FIG>, the support body <NUM> comprises a radially inner surface <NUM> (<FIG> and <FIG>) having a first portion 28a and a second portion 28b. The first portion 28a coincides with a radially inner surface of the delimiting wall <NUM>. Such a first portion 28a directly faces the routing opening <NUM> and has a circumferential extension equal to the circumferential extension of the routing opening <NUM>. The second portion 28b of the radially inner surface <NUM> of the support body <NUM> is in direct contact with the hub shaft <NUM>, in particular with the outer surface 12d of the hub shaft <NUM>. The support body <NUM> is directly mounted on the hub shaft <NUM> with possible mechanical interference. The support body <NUM> is directly in contact with the hub shaft <NUM> for part of the circumferential extension of the hub shaft <NUM> excluding the part of the hub shaft <NUM> engaged by the routing opening <NUM>. In order to avoid the support body <NUM> being able to rotate with respect to the hub shaft <NUM>, the hub shaft <NUM> and the support body <NUM> are coupled together through a shape coupling. Such a shape coupling can comprise a substantially flat portion of the radially inner surface <NUM> of the support body <NUM> counter-shaped to a flat portion 12e (partially visible in <FIG>) of the outer surface 12d of the hub shaft <NUM>.

The radially inner surface <NUM> of the support body <NUM> comprises two joining portions <NUM> (illustrated in <FIG>) that join the first portion 28a and the second portion 28b of the radially inner surface <NUM>. The two joining portions <NUM> make two steps, which are configured like two side walls, which circumferentially delimit the routing opening <NUM>. The support body <NUM> is macroscopically configured like an annular body that has a groove defining the routing opening <NUM>.

The support body <NUM> also has, at the radially outer support surface 26a, a shoulder <NUM> facing axially towards the hub body <NUM>. The shoulder <NUM> has an annular shape and axially abuts the first bearing <NUM> directly contacting the inner ring 23a of the first bearing <NUM>, as better illustrated in <FIG>.

In a second embodiment of the support body <NUM>, illustrated in <FIG> and <FIG>, the support body <NUM> comprises a substantially cylindrical radially inner surface <NUM> radially spaced from the hub shaft <NUM>. The radially inner surface of the delimiting wall <NUM> is comprised in the radially inner surface <NUM>. The radially inner surface <NUM> is not in contact, at any point, with the hub shaft <NUM> but is in contact with a spacer body <NUM> through a coupling surface <NUM>. As schematically illustrated in <FIG>, the coupling surface <NUM> comprises a threading <NUM> and the spacer body <NUM> comprises a threading <NUM> arranged on a radially outer surface thereof 32b. The threadings <NUM>, <NUM> of the coupling surface and of the spacer body <NUM> are configured to couple so as to be able to screw the support body <NUM> on the spacer body <NUM>. In order to make it possible to easily screw the support body <NUM> on the spacer body <NUM>, the support body <NUM> comprises an axially outer portion 26b equipped with walls counter-shaped to a mounting tool.

As shown in <FIG>, the spacer body <NUM> is directly mounted on the hub shaft <NUM> so that it cannot rotate with respect to the hub shaft <NUM>. To this purpose, the hub shaft <NUM> and the spacer body <NUM> are coupled together through a shape coupling. Such a shape coupling can comprise a radially inner surface 32a of the spacer body <NUM> having a substantially flat portion matched to a flat portion 12e (<FIG>) of the outer surface 12d of the hub shaft <NUM>.

As shown in <FIG>, the spacer body <NUM> comprises a first circumferential end wall <NUM> and a second circumferential end wall <NUM> that define the circumferential limits of the routing opening <NUM>. At the routing opening <NUM> the spacer body <NUM> is not in contact with the hub shaft <NUM>.

The spacer body <NUM> is made from the stator <NUM> or from a stator portion <NUM> of the electric motor <NUM>, which thus projects axially outside of the hub body <NUM>.

In both embodiments of the support body <NUM>, the hub assembly <NUM> comprises an annular sealing gasket <NUM> axially outside the first bearing <NUM>. The annular sealing gasket <NUM> can be an oil seal, a dust guard or an oil seal that integrates a dust guard and has the function of preventing the entry of foreign bodies, water, mud or dirt in the first bearing <NUM>. The annular sealing gasket <NUM> is arranged radially between the hub body <NUM> and the support body <NUM> and is preferably in axial contact with the outer ring 23b of the first bearing <NUM>.

The support body <NUM> also comprises a radial passage <NUM> axially outside the first bearing <NUM> that has the function of allowing the electrical conductor elements <NUM> to exit the hub assembly <NUM> in the radial direction. The radial passage <NUM> is made from a hole or a through opening in the delimiting wall <NUM> of the support body <NUM> formed in axially outer position to the axial position occupied by the first bearing <NUM>. In the attached figures, the radial passage <NUM> is illustrated in the first embodiment of the support body <NUM>, however it could also be provided in relation to the second embodiment of the support body <NUM>.

At the radial passage <NUM> a buffer <NUM> is provided (<FIG> and <FIG>) arranged radially outside the radial passage <NUM> at the delimiting wall <NUM>. The buffer <NUM> is arranged axially outside the first bearing <NUM> and comprises a radial hole that allows the passage of the electrical conductor elements <NUM>. The buffer <NUM> prevents foreign bodies, water, mud or dirt from being able to enter into the radial passage <NUM>, therefore acting as sealing gasket. In the attached figures, the buffer <NUM> is illustrated in the first embodiment of the support body <NUM>, however it could also be provided in relation to the second embodiment of the support body <NUM>.

The hub assembly <NUM> also comprises a cover <NUM> mounted at an axial end of the hub shaft <NUM>. The cover <NUM> axially delimits the routing opening <NUM>, as shown in <FIG>. The cover <NUM> comprises an axial through hole <NUM> coaxial with the longitudinal through cavity 12a of the hub shaft <NUM>. The axial hole <NUM> is configured to receive the quick release axle and allow the mounting of the hub assembly <NUM> on the fork or on the chain stay of the bicycle. The cover <NUM> is made fixed with respect to the hub shaft <NUM> through a grub screw <NUM> that radially crosses the cover <NUM> and that inserts into a blind hole or a groove <NUM> of the support body <NUM>. The blind hole or the groove <NUM> is formed on the support body <NUM> in a position not engaged by the routing opening <NUM>, as illustrated in <FIG>. The grub screw <NUM> also makes it possible to mount the cover <NUM> with an unequivocal orientation with respect to the support body <NUM> and thus with respect to the hub shaft <NUM>. The cover <NUM> axially contacts the buffer <NUM> holding it axially in position. In the attached figures, the cover <NUM> is illustrated in the first embodiment of the support body <NUM>, however it could also be provided in relation to the second embodiment of the support body <NUM>.

The mounting of the hub assembly <NUM> provides for mounting the first bearing <NUM> on the hub body <NUM> coupling the outer ring 23b stably with the hub body <NUM>.

In the case of the first embodiment of the support body <NUM>, the latter is arranged inside the first bearing <NUM> with the inner ring 23a in contact on the radially outer resting surface 26a of the support body <NUM>. The shoulder <NUM> is arranged in axial abutment on the first bearing <NUM>. In the case of the second embodiment of the support body <NUM>, the latter is coupled with the stator <NUM> of the electric motor <NUM> (or is part of the same or is the stator <NUM> itself).

At this point, the electric motor <NUM> and the control unit <NUM> are inserted in the hub body <NUM> through the axial end 11b of the latter equipped with the removable closing plate <NUM>. The electric motor <NUM> is pre-wired with the electrical conductor elements <NUM>. The electrical conductor elements <NUM> are made to pass radially inside the first bearing <NUM>.

In the case of the first embodiment of the support body <NUM>, the electrical conductor elements <NUM> are routed through the routing opening <NUM> that is partially formed by the support body <NUM> already arranged in position inside the first bearing <NUM>.

In the case of the second embodiment of the support body <NUM>, the insertion of the electric motor <NUM> determines the positioning of the spacer body <NUM> in position radially inside the first bearing <NUM>, at least partially making the routing opening <NUM>. The electrical conductor elements <NUM> are made to pass through the partially formed routing opening <NUM>.

If the buffer <NUM> is present, the electrical conductor elements <NUM> are previously routed therethrough and positioned axially outside the first bearing <NUM> through the radial passage <NUM>.

Once the electric motor <NUM> and the control unit <NUM> have been inserted in the hub body <NUM>, the hub shaft <NUM> is inserted inside the hub body <NUM>.

In the case of the first embodiment of the support body <NUM>, the hub shaft <NUM> is inserted in the support body <NUM> so that the radially outer surface 12d of the hub shaft <NUM> contacts the radially inner surface <NUM> of the support body <NUM>. In this step, the orientation of the hub shaft <NUM> with respect to the support body <NUM> is unequivocal through the effect of the shape coupling between the radially inner surface <NUM> of the support body <NUM> and the radially outer surface 12d of the hub shaft <NUM>. The routing opening <NUM> is thus completely defined once the hub shaft <NUM> has been inserted in the hub body <NUM>.

In the case of the second embodiment of the support body <NUM>, the hub shaft <NUM> is inserted in the support body <NUM> so that the radially outer surface 12d of the hub shaft <NUM> contacts the radially inner surface 32a of the spacer body <NUM>. In this step, the orientation of the hub shaft <NUM> with respect to the spacer body <NUM> is unequivocal through the effect of the shape coupling between the radially inner surface 32a of the spacer body <NUM> and the radially outer surface 12d of the hub shaft <NUM>.

Once the hub shaft <NUM> has been positioned, the closing plate <NUM> is mounted on the open axial end (through which the electric motor <NUM> and the control unit <NUM> were inserted) of the hub body <NUM>. The second bearing <NUM>, the inner ring 24a of which contacts the radially outer surface 12d of the hub shaft <NUM>, was pre-engaged on the closing plate <NUM>.

In the case of the second embodiment of the support body <NUM>, the support body <NUM> is thus mounted by screwing it on the spacer body <NUM>. Such a coupling takes the radially outer resting surface 26a of the support body <NUM> in contact with the inner ring 23a of the first bearing <NUM>.

The assembly of the hub assembly <NUM> is completed by coupling the cover <NUM>, when provided, with the support body <NUM>.

Claim 1:
Motorized hub assembly (<NUM>) for a bicycle wheel comprising:
a hub shaft (<NUM>) extending along a longitudinal axis;
at least one first bearing (<NUM>) having a radially inner ring (23a) and arranged radially outside the hub shaft (<NUM>);
a hub body (<NUM>) radially external to the hub shaft (<NUM>) and mounted rotatably, about a rotation axis (X), on the hub shaft (<NUM>) through said first bearing (<NUM>);
an electric motor (<NUM>) arranged inside the hub body (<NUM>);
a routing opening (<NUM>) crossed by electrical conductor elements (<NUM>) connected to said electric motor (<NUM>), said routing opening (<NUM>) being arranged radially between the inner ring (23a) of the first bearing (<NUM>) and the hub shaft (<NUM>);
a support body (<NUM>) provided at least at the routing opening (<NUM>) and radially interposed between the inner ring (23a) of the first bearing (<NUM>) and the routing opening (<NUM>); said support body (<NUM>) being configured to withstand a thrust directed in a radially inner direction exerted by the first bearing (<NUM>) and said inner ring (23a) of the first bearing (<NUM>) resting on said support body (<NUM>);
characterised in that
said support body (<NUM>) has a delimiting wall (<NUM>) for said routing opening (<NUM>); said routing opening (<NUM>) being radially defined between said delimiting wall (<NUM>) and said hub shaft (<NUM>); and the hub shaft (<NUM>) comprising a longitudinal through cavity (12a) configured to receive a quick release axle.