Free hub for bicycle

Abstract

The utility model relates to a free wheel hub for a bicycle, comprising a drive device and a wheel hub sleeve, each of which is mounted on a wheel hub shaft so as to be rotatable about a common axis of rotation, a locking body mechanism having at least one locking body, which is mounted in a radial locking body recess so as to be adjustable between a locking position and a release position, and a pre-tensioning device, the locking body recess is arranged in one of the drive device and the hub sleeve, and the other of the drive device and the hub sleeve has a radial gear train or is connected to the gear train in a rotationally fixed manner, and wherein the surface of the locking body has a coupling surface, which is arranged on the surface of the locking body in a rotationally fixed manner. The locking body has a coupling surface which bears against an abutment surface of the locking body recess in the locking position, and the engagement section of the locking body engages into the gear train such that a torque is transmitted from the drive device to the hub sleeve via the coupling surface when the drive device rotates about the axis of rotation in the first direction of rotation, and wherein the coupling surface engages into the engagement section of the locking body in the first direction of rotation about the axis of rotation. In the release position, the locking body allows the hub sleeve to rotate relative to the drive in the first rotational direction, and wherein more than half of the coupling surface is designed as a flat region.

Description

Technical Field

[0001] The utility model relates to a free hub for a bicycle, and more precisely to a free hub, comprising: a drive device and a hub sleeve, which are supported on a hub shaft in a manner that enables them to rotate around a common axis of rotation; and a locking body mechanism having at least one locking body supported in a radially extending locking body recess in a manner that enables adjustment between a locking position and a release position; and a preloading device configured to preload the locking body towards the locking position.

[0002] Wherein, the locking body recess is provided in one of the components of the drive device and the hub sleeve, and the other of the components of the drive device and the hub sleeve has a radial transmission gear system or is connected to the transmission gear system in an anti-rotation manner. Wherein, the surface of the locking body has a coupling surface, which abuts against the abutment surface of the locking body recess in the locking position, and the engaging section of the locking body engages with the transmission gear system, such that when the drive device rotates around the axis of rotation in a first rotational direction, torque is transmitted from the drive device to the hub sleeve through the coupling surface. Wherein, the locking body does not engage with the transmission gear system in the release position, and allows the hub sleeve to rotate relative to the drive device in the first rotational direction, so that the hub sleeve can overrun the drive device in the first rotational direction.

[0003] That is to say, there are two alternative solutions in terms of the layout of the transmission gear system and the locking body recess. According to the first alternative, the locking body recess is provided in the hub sleeve as one of the components, and the drive device as the other component has a transmission gear system or is connected to the transmission gear system in an anti-rotation manner. According to the second alternative, the locking body recess is provided in the drive device as one of the components, and the hub sleeve as the other component has a transmission gear system or is connected to the transmission gear system in an anti-rotation manner.

[0004] Wherein, the concept of "anti-rotation" relates to rotation around the common axis of rotation of the drive device and the hub sleeve. Background Art

[0005] For example, the publication DE 4025708 A1 discloses a free hub. Among them, the locking bodies are all rotatably adjustable locking pawls, which have relatively small cylindrical coupling surfaces.

[0006] The disadvantage of such rotationally moving pawls is that either the transmitted force is small or a larger structure is required, because the force vector of such pawls has a relatively high radial component, which requires support by the housing component that serves as a receptacle.

[0007] An axial freewheel that transfers torque from a drive device to a hub sleeve via an axial gear system can transfer a large force with a smaller size, but has a high manufacturing cost. For example, a bicycle hub with an axial freewheel is described in EP 3984764 A1. The axial freewheel is also called a sprocket freewheel. SUMMARY OF THE UTILITY MODEL

[0008] In view of this, the purpose of the present utility model is to further develop free hubs of the same type, making them easy to adjust according to different requirements in terms of torque to be transferred, and having the characteristics of being light, small, and low-cost.

[0009] For this purpose, a free hub is proposed. Various embodiments of the present utility model are as follows:

[0010] Embodiment 1. A free hub for a bicycle, the free hub comprising:

[0011] A drive device and a hub sleeve, which are respectively supported on a hub shaft in a manner capable of rotating around a common axis of rotation,

[0012] A locking body mechanism having at least one locking body, the locking body being supported in a radial locking body recess in a manner capable of being adjusted between a locking position and a release position, and

[0013] A preloading device configured to preload the locking body towards the locking position, wherein the locking body recess is provided in one of the members of the drive device and the hub sleeve, and the other of the members of the drive device and the hub sleeve has a radial transmission gear system or is non-rotatably connected to the transmission gear system,

[0014] Wherein, the surface of the locking body has a coupling surface, the coupling surface abuts against the abutment surface of the locking body recess in the locking position, and the engaging section of the locking body engages with the transmission gear system, so that when the drive device rotates around the axis of rotation in a first rotational direction, torque is transferred from the drive device to the hub sleeve through the coupling surface, and wherein the locking body allows the hub sleeve to rotate relative to the drive device in the first rotational direction in the release position,

[0015] Wherein, more than half of the coupling surface is constructed as a flat area.

[0016] Embodiment 2. The free hub according to Embodiment 1,

[0017] Wherein, the entire coupling surface adopts a flat construction scheme, and the locking body is a locking slider that can be adjusted between the locking position and the release position by a translational movement.

[0018] Example 3. The freewheel according to Example 1,

[0019] wherein the coupling surface consists of a flat region and a curved region, in particular a cylindrical region, and the curved region is configured to rotatably support the locking body during the pivoting movement of the locking body as a locking pawl between the locking position and the release position.

[0020] Example 4. The freewheel according to any one of the above embodiments,

[0021] wherein the flat region of the coupling surface forms an angle of not more than 30°, preferably not more than 20°, and more preferably not more than 10° with a perpendicular line from the center point of the flat region to the rotation axis.

[0022] Example 5. The freewheel according to any one of the above embodiments,

[0023] wherein the preloading device includes a spring configured to preload several locking bodies, preferably all locking bodies, of the locking body mechanism towards the respective locking positions.

[0024] Example 6. The freewheel according to any one of the above embodiments, wherein the locking body mechanism, the preloading device, and the driving device and the component of the hub sleeve on which the at least one locking body notch (22) is provided can be pre-assembled to form a first assembly, and the preloading device holds the locking body mechanism on the component.

[0025] Example 7. The freewheel according to Example 6, wherein the locking body is configured as a locking slider that can be adjusted between the locking position and the release position by a translational movement, and the locking body notch tapers radially inwards, and the preloading device preloads the locking slider radially inwards.

[0026] Example 8. The freewheel according to any one of the above embodiments, wherein the engaging section of the locking body has two or more arms configured to engage in adjacent tooth gaps of the transmission gear system in the locking position.

[0027] Embodiment 9. The overrunning clutch according to any one of the above embodiments, wherein the locking body mechanism has several groups of locking bodies, and the locking bodies are supported in corresponding locking body recesses distributed in a certain manner around the periphery of the component, such that for each of the groups, in the locked position, when the transmission gear train is in an appropriate rotational position, the locking bodies of the corresponding group simultaneously engage with the transmission gear train, while the locking bodies of different groups cannot simultaneously engage with the transmission gear train.

[0028] Embodiment 10. The overrunning clutch according to any one of the above embodiments, wherein the flat area of the coupling surface is more than twice, preferably more than three times, and particularly preferably more than five times the tooth contact area of the surface of the locking body, where the tooth contact area is the area of the surface of the locking body that makes planar contact with the leading tooth surface of the transmission gear train along the first rotational direction in the locked position.

[0029] Embodiment 11. The overrunning clutch (10) according to Embodiment 10, wherein a perpendicular line passing through the center point of the tooth contact area and perpendicular to the tooth contact area intersects the flat area of the coupling surface, preferably at the center point of the flat area. According to the present invention, more than half of the coupling surface is constructed as a flat area for efficiently transmitting force or torque from the drive device to the hub sleeve.

[0030] The locking body mechanism may include several locking bodies respectively supported in corresponding locking body recesses, for example, depending on the torque to be transmitted, including two, three, four or six locking bodies, and these locking bodies preferably adopt the same construction scheme to simplify manufacturing.

[0031] Therefore, whenever the features of "the locking body" or "the locking body recess" or "the at least one locking body" or "the at least one locking body recess" are described in this application, it can be understood that for a locking body mechanism including several locking bodies, unless otherwise specified, the corresponding features preferably apply to several locking bodies, and particularly preferably apply to all the locking bodies of the locking body mechanism or the corresponding locking body recesses.

[0032] Preferably, the locking body recess is formed in the hub sleeve, and the transmission gear train is provided on the drive device. The advantage of this is that the transmission gear train can be manufactured together with the flywheel type part (Kassettenprofil) of the drive device in a cost-effective manner in a single manufacturing process.

[0033] Among the alternative basic structures that have not been excluded, the locking body is supported in a locking body recess on the drive device. This basic structure is more costly because, in this case, a high-strength ring part with a transmission gear system, which is made of special steel for example, needs to be fixed to a hub sleeve that is usually made of a lighter and less strong material such as aluminum.

[0034] In one technical solution, the entire coupling surface can adopt a flat construction scheme, in which the locking body can be supported in the locking body recess in such a way that it can move translationally between a locking position and a release position as a locking slider.

[0035] The advantage of this is that the force vector for transmitting rotational motion acts almost only tangentially and can have only a very small radial component. In this way, similar to an overrunning clutch, a larger force can be transmitted with a smaller size, and the manufacturing cost is reduced.

[0036] However, the locking slider may tilt in the locking body recess, which requires a high precision of the stop surface.

[0037] Therefore, in order to achieve a more stable support, in an alternative construction scheme, the coupling surface of the locking body consists of the flat area and a curved area, in particular a cylindrical area, where the curved area is used to rotatably support the locking body during the pivoting motion of the locking body implemented as a locking pawl between the locking position and the release position. The cylindrical area can in particular transition tangentially to the flat area. This variant is also referred to as a smooth pawl below, and it combines the advantages of a slider lock (i.e., a larger engagement surface and a mainly tangential engagement angle) with the advantages of a pawl (i.e., stable support and low precision requirements for the pawl seat).

[0038] Tests show that when the inclination angle of the leading tooth surface of the transmission gear system on the steel drive device in the first rotational direction is set appropriately, in most applications, if the area of the leading tooth surface in the first rotational direction is large enough, it is sufficient for only two pawls to engage in separate tooth gaps respectively.

[0039] In the case where the engagement section of the locking pawl consists of a single arm that engages in only a single tooth gap, in particular, in order to achieve the interaction with this locking pawl, it can be proposed that for at least one tooth part, preferably for several or all tooth parts of the radial transmission gear system, the vertical line perpendicular to the leading tooth surface in the first rotational direction and passing through the center point of this tooth surface does not intersect the trailing tooth surface of the same tooth part in the first rotational direction, which reduces the risk of the tooth part being sheared during operation.

[0040] Embodiments in which the locking body mechanism includes both a locking slider and a locking pawl are not excluded either.

[0041] The flat coupling surface may have a certain size such that the contact pressure per unit area is significantly reduced. This can reduce the number of pawls of the locking body mechanism, or / and use a material with reduced strength for the locking body, for example, using AL6082-T6 to replace the otherwise necessary AL 7075-T6.

[0042] In particular, the flat area of the coupling surface may be more than twice, preferably more than three times, and particularly preferably more than five times the tooth contact area of the surface of the locking body, where the tooth contact area is the area on the surface of the locking body that makes planar contact with the leading tooth surface of the transmission gear system in the locking position along the first rotation direction.

[0043] To reasonably transmit force or torque within the locking body, preferably, a vertical line passing through the center point of the tooth contact area and perpendicular to the tooth contact area of the surface of the locking body intersects the flat area of the coupling surface of the locking body, and particularly preferably intersects at or near the center point of the flat area. This particularly applies to the case where the engaging section of the locking body consists of only a single arm configured to engage only one tooth gap of the transmission gear system.

[0044] To efficiently transmit torque, preferably, the flat area of the coupling surface and the perpendicular line from the center point of this flat area to the rotation axis form an angle not greater than 30°, preferably not greater than 20°, and further preferably not greater than 10°.

[0045] Wherein, the locking body may particularly have a constant cross-sectional shape perpendicular to the direction extending parallel to the rotation axis of the free hub in the installed state, or at least be based on such a constant cross-sectional shape.

[0046] The spring suspension of the locking body can be achieved through different configurations of the preloading device, which may include elements selected from the following range or consist of them: compression spring, helical compression spring, helical spring coil, worm spring (Wurmfeder), snap ring, rubber spring, cellulose spring, Sylomer spring, or a combination of the above.

[0047] For each locking body, the preloading device may include an independent spring corresponding to each locking body, such as a helical compression spring, in order to particularly preload each individual locking body towards the locking position in a targeted manner.

[0048] However, to reduce the number of components and simplify the installation, as an alternative, the preloading device may include a spring that preloads the several locking bodies towards the locking position, preferably including a single spring for all the locking bodies of the locking body mechanism.

[0049] In the latter case, the locking slider preferably uses a Wurmfederring, which pre-tightens the locking slider radially inwards. For the locking pawl, a snap ring can also be used, which acts on the pawl from the radial outside or from the radial inside, so as to pre-tighten the pawl respectively towards the locking position along the pivoting direction.

[0050] To simplify installation, the locking body mechanism, the pre-tensioning device, and the component (drive device or hub sleeve) provided with the at least one locking body notch can be pre-assembled into a first assembly, wherein the pre-tensioning device holds the locking body mechanism on the component, thus preventing the locking body from falling out of the corresponding locking body notch. This first assembly can be sleeved onto the other component with the transmission gear system along the common axis of rotation, or the first assembly can be inserted into the other component, depending on whether the transmission gear system is radially outwards or radially inwards.

[0051] In an embodiment using a locking slider, the above solution can be achieved, for example, as follows: the at least one locking body notch tapers radially inwards, and the pre-tensioning device (such as a Wurmfederring) pre-tightens the at least one locking slider radially inwards, and then presses the locking slider into its seat in the notch in a loss-preventing manner.

[0052] In order to better divide the force introduced into or derived from the locking body (depending on whether the locking body notch is provided in the drive device or the hub sleeve), or in order to increase the resultant force that can be transmitted, the engaging section of the at least one locking body can have two or more arms, which are configured to engage in the adjacent tooth gaps of the radial transmission gear system in the locking position.

[0053] In the case where the locking body is constructed as a locking slider, this construction scheme is particularly preferably adopted, because in this way the tilting moment acting on the locking body can also be reduced and the support can be stabilized thereby.

[0054] Compared with the pawl, it is easier to achieve a neat engagement with two or more arms when using a slider, because in a pure translational motion, all arms travel the same length of stroke. The adverse angular relationships of the rotating pawl are avoided, and high precision is not required.

[0055] In principle, a locking pawl with more than one arm can be used, but the manufacturing must be very precise, because depending on the principle of rotary engagement, in the same time, the outer arm needs to travel a greater distance, and its engagement speed is therefore higher. In this case, the bases and guides of the pawl and the engagement gear system and their dimensional tolerances all need to be designed very strictly and manufactured with high precision.

[0056] As described above, preferably, the locking body mechanism has several locking bodies, preferably of the same type, and correspondingly several locking body notches are provided, which are distributed around the periphery of the component provided with these locking body notches, so as to distribute the force or torque of the drive device to the locking bodies.

[0057] Based on the number of locking bodies and the number of teeth of each locking body, different applications can be modularly realized and a lightweight structure can be achieved. For example, when the hub sleeve is the same, according to the corresponding torque of a specific application, a racing bike hub can be realized by two locking bodies, an MTB hub can be realized by three locking bodies, and an eMTB hub or a freight bike hub can be realized by six locking bodies. Among them, depending on the specific application, each locking body notch can remain empty. Among them, the locking body can especially be a locking slider respectively having two teeth.

[0058] According to a preferred embodiment, the locking body notches are distributed in such a way that the locking bodies can be simultaneously engaged with the transmission gear train, so that during the rotation of the drive device in the first rotation direction, the force to be transmitted or the torque to be transmitted is evenly distributed to all the locking bodies.

[0059] However, after the drive device starts to rotate in the first rotation direction, in order to reduce the maximum rotation angle required until the torque is actually transmitted to the hub sleeve, the locking body mechanism can have several groups of locking bodies, which are distributed and supported in the corresponding locking body notches around the periphery of the one component in such a way that for each of the groups, in the locked position, when the transmission gear train is in an appropriate rotation position, the locking bodies of the corresponding group are simultaneously engaged with this transmission gear train, while the locking bodies of different groups cannot be simultaneously engaged with the transmission gear train.

[0060] For this purpose, the angular pitch of the directly adjacent teeth of the transmission gear train can have a constant preset value, and for each group, the mutual angular pitch between the locking bodies of the corresponding group is equal to an integer multiple of the preset value, while the mutual angular pitch between the locking bodies of different groups is different from an integer multiple of the preset value by a fraction of the preset value. If the locking body mechanism consists of n groups, this fraction can be m / n, where m is a natural number greater than zero but less than n. In the case of using 2 groups, this fraction can especially be 1 / 2, in the case of using 3 groups it can be 1 / 3 or / and 2 / 3, and so on.

[0061] In addition, a solution where one group or several groups or all groups are composed of a single locking body is not excluded. Preferably, all groups have the same number of locking bodies.

[0062] The applicant reserves the right to claim protection for a bicycle having a free hub according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The present invention is described below in conjunction with several embodiments shown in the accompanying drawings.

[0064] Figure 1 is a perspective view of a first embodiment of a free hub according to the present utility model,

[0065] Figure 2 for Figure 1 A three-quarter longitudinal section of an object,

[0066] Figure 3 for Figure 1 A cross-sectional view of an object with the cutting plane being at Figure 1 The section plane perpendicular to the axis of rotation shown in and denoted by III-III,

[0067] Figure 4 and Figure 5 for Figure 3 A partial enlarged view of the invention, wherein the locking pawl constructed as a flat pawl is shown in a locked position or in a released position, respectively,

[0068] Figure 6 and Figure 7 for Figure 1 Different views of an object, wherein the hub shaft and the drive device are not shown,

[0069] Figure 8 and Figure 9 for Figure 1 Different views of an object, wherein the hub shaft and the hub sleeve are not shown,

[0070] Figures 10 to 12 for Figure 1 Different views of one of the locking pawls of the free hub in FIG.

[0071] Figure 13 and Figure 14 The second embodiment of the free wheel hub according to the utility model is Figure 4 and Figure 5 The corresponding illustration, which shows the slightly modified shape and spring suspension of the locking pawl,

[0072] Figure 15 and Figure 16 The third embodiment of the free wheel hub according to the utility model is Figure 4 and Figure 5 A corresponding illustration, in which a locking body designed as a locking slide is shown,

[0073] Figure 17Cross-sectional view corresponding to the fourth embodiment of the freewheel hub according to the present utility model, including a locking slider, and Figure 3 corresponding cross-sectional view. Detailed description of the specific implementation

[0074] For the sake of clarity, not all features are labeled with reference numerals in each drawing. Instead, only those features necessary for explaining the corresponding drawing are labeled first. This is especially applicable when a drawing contains multiple features of the same type.

[0075] The same or corresponding features of different embodiments are denoted by the same reference numerals, and when describing other embodiments, the description mainly focuses on the differences from the first embodiment, and other aspects refer to the description of the first embodiment.

[0076] Figure 1 Perspective view of the first embodiment of the freewheel hub 10 according to the present utility model, and Figure 2 Three-quarter longitudinal sectional view of the same hub.

[0077] In the present application, unless otherwise specified, concepts such as "axial" and "radial" are always relative to the longitudinal axis L of the freewheel hub 10, which coincides with the common rotation axis X and, in the installed state, with the rear wheel axle of the bicycle.

[0078] The freewheel hub 10 includes a hub shaft 12, which can be fixedly installed on the bicycle frame in a known manner. The hub sleeve 14 is supported on the hub shaft 12 by two rolling bearings 11 and 13, and the drive device 16 is supported on the hub shaft 12 by another two rolling bearings 15 and 17, respectively, in a rotatable manner about the common rotation axis X.

[0079] The drive device 16 can be connected to a pinion mechanism (not shown here) in a conventional manner, and torque can be introduced into the drive device 16 through the pinion mechanism. The hub sleeve 14 has two spoke flanges 23, 25 for connecting to the spokes of the rear wheel (also not shown here).

[0080] The longitudinal end 16e1 of the drive device 16 facing the hub sleeve 14 extends into the hub sleeve 14. In the axial region of the hub where the hub sleeve 14 and the drive device 16 overlap, a locking body mechanism 18 is provided inside the freewheel hub 10. A locking body 20 of the locking body mechanism is shown in cross-section in Figure 2 .

[0081] The cover ring 19 prevents dirt and / or moisture from entering the radial gap between the drive device 16 and the hub sleeve 14.

[0082] From Figure 3As can be seen most clearly from the cross-sectional view, in order to support the locking body 20, the hub sleeve 14 has three radially distributed locking body notches 22 around the circumference of the hub sleeve 14 here.

[0083] To reduce the weight, three additional notches 27 are provided circumferentially in the hub sleeve 14 between the locking body notches, each of which has a support protrusion 29 provided therein.

[0084] The locking body 20, which is configured as a locking pawl 50 here, is supported in the corresponding locking body notch 22 in a pivotable manner between a locking position and a release position, and is pre-tensioned and held in the hub sleeve 14 by a retaining ring 61 of a pre-tensioning device 24 towards the locking position.

[0085] In the illustrated example, among the three locking pawls 50, the locking pawls at the 12 o'clock position and the 8 o'clock position are in the locking position, in which the engaging section 33 of the corresponding locking pawl 50 engages with the radial transmission tooth system 26 at the longitudinal end 16e1 of the drive device 16, and the radial transmission tooth system 26 is provided on the outer circumference of the drive device 16, while the locking pawl at the 4 o'clock position is in the release position due to its angular position relative to the drive device 16, in which the locking pawl 50 does not engage with the transmission tooth system 26. Here, this is mainly used to illustrate the locking position and the release position in the same drawing. Figure 3 Figure 3

[0086] Different from the illustration, the three locking body notches 22 can also be preferably arranged such that all the locking bodies are always in the locking position or the release position simultaneously.

[0087] Figure 4 and Figure 5 are Figure 3 partial enlarged views of, in which, Figure 4 the locking body 20 in the locking position is shown, Figure 5 the locking body 20 in the release position is shown.

[0088] When selecting the Figures 3 to 5 section plane, it is made to extend centrally through the groove 30 of the locking body 20, and the retaining ring 61 is accommodated in the groove.

[0089] During the rotation of the drive device 16 in the first rotation direction R1, the torque is transmitted from the drive device 16 to the hub sleeve 14 and then to the rear wheel of the bicycle through those locking pawls 50 in the locking position.

[0090] However, the hub sleeve 14 may overrun the drive device 16 in the first rotational direction R1, which is equivalent to the hub sleeve 14 rotating relative to the drive device 16 in the first rotational direction R1, or equivalent to the drive device 16 rotating relative to the hub sleeve 14 contrary to the first rotational direction R1, because in this movement, the engaging section 33 of the locking pawl 50 can slide over the rear, flatter tooth surface 26.2 of the transmission gear system 26 in the first rotational direction R1, or the locking pawl 50 repeatedly moves from the tooth surface 26.2 into the release position during rotation.

[0091] From Figure 4 It can be seen most clearly that in the locked position, the locking body 20 abuts with a part of its surface (here called the coupling surface 35) against the corresponding abutment surface 45 of the recess 22, wherein, in the illustrated example, the coupling surface 35 consists of a region 37 curved in an outwardly convex cylindrical shape and a flat region 36, the curved region being for pivotally supporting the locking body 20, and the flat region being for transmitting torque to the hub sleeve 14 when the drive device 16 rotates in the first rotational direction R1. Correspondingly, the abutment surface 45 of the locking body recess 22 consists of an inwardly concave cylindrical curved support region 47 and a flat region 46.

[0092] In Figure 4 the cross-sectional view, the curved region 37 extends between the marked points P1 and P2, and the flat region extends between the points P2 and P3.

[0093] The size and inclination of the flat region 36 are selected to achieve efficient torque transmission while stably supporting the locking body 20. According to the present invention, the flat region 36 occupies more than half of the coupling surface 35.

[0094] The angle α between the flat region 36 and the perpendicular line L from the center point M of the flat region 36 to the rotation axis X is preferably not greater than 30°, so as to efficiently transmit the tangential component of the introduced force.

[0095] In an example as Figure 4 shown, the flat region 36 of the coupling surface 35 is more than five times the tooth contact region 65, and the tooth contact region 65 is the region of the surface of the locking body 20 that makes planar contact with the front tooth surface 26.1 of the radial transmission gear system 26 in the first rotational direction R1 in the locked position.

[0096] Furthermore, in the illustrated example, in order to achieve favorable force transmission, the perpendicular line F perpendicular to the tooth contact region 65 and passing through the center point N of the tooth contact region 65 intersects the flat region 36 of the coupling surface 35 of the locking body 20, and preferably intersects at or near the center point M of the flat region 36.

[0097] For technical reasons, the deformation of the catch 61 caused by the locking body 20 cannot be shown when creating the drawings. However, based on the overlapping areas of the catch 61 and the locking body 20 in Figure 4 and Figure 5 , the deformation of the catch 61 and the resulting forces can be inferred.

[0098] Accordingly, Figure 4 the minimal overlap in indicates that the pretensioning device 24 is largely relaxed in the locking position of the locking body 20 and only slightly presses the locking body 20 radially outwards into the concave-cylindrical curved bearing area 47 of the locking body recess 22, thereby holding the locking body on the hub sleeve 14.

[0099] If the hub sleeve 14 exceeds the drive device 16 in the first rotational direction R1 from the position shown in Figure 4 , the locking pawl 50 rotates clockwise from the locking position into the release position via the tooth flank 26.2, as shown in Figure 5 . Among them, as shown in Figure 5 , the position of the pivot S of the adjusting movement of the locking pawl 50 between the locking position and the release position is defined by the cylindrical-curved bearing area 47 of the locking body recess 22.

[0100] In Figure 5 , it can be seen that the overlapping area O between the catch 61 and the locking body 20 increases significantly, which means that the catch 61 is deformed to a certain extent by the locking body 20, causing the catch to press against the bottom 39 of the groove 30 in the right-side area of the locking body 20 as shown in Figure 5 , thereby pre-tensioning the locking body 20 and causing it to pivot counterclockwise back to the locking position.

[0101] From Figure 5 it can also be seen that in the shown example, the tooth height and inclination of the leading tooth flank 26.1 of the radial transmission tooth system 26 of the drive device 16 in the first rotational direction R1 are selected in such a way that the vertical line G perpendicular to the leading tooth flank 26.1 in the first rotational direction and passing through the center point Q of the tooth flank 26.1 does not intersect the trailing tooth flank 26.2 of the same tooth part in the first rotational direction R1, thereby reducing the risk of the tooth part being sheared during operation.

[0102] For a locking body with more than one arm 31, the leading tooth flank 26.1 in the first rotational direction may have a greater slope or a smaller tooth height, because in this case, the forces acting on the transmission tooth system during operation are distributed to different arms.

[0103] Since the catch 61 holds the locking body mechanism 18 on the hub sleeve 14 and prevents the locking body 20 from falling out of the locking body recess 22, the aforementioned components can be pre-assembled into a first assembly 41, in Figure 6 andFigure 7 The first component is shown from different perspectives. As can be seen in these views, the hub sleeve 14 has grooves 14n or 29n for receiving and guiding the snap ring 61 both in the region between the notches 22, 27 and in the region of the support protrusion 29.

[0104] It can also be seen from these drawings that the notches 22, 27 not only open radially inwards, but also axially at the longitudinal end 14e1 of the hub sleeve 14 facing the drive device 16 in the installed state, but these notches are covered by the cover part 19 in the fully installed state ( Figure 1 )

[0105] Figure 8 and Figure 9 The overrunning clutch of the first embodiment is shown from different perspectives, with the hub shaft and the hub sleeve not shown. As shown, the locking bodies 10 can be grouped into two different groups 18.1 and 18.2 here, where group 18.1 has two locking bodies and group 18.2 has only one locking body.

[0106] The locking bodies 20 are distributed in such a way that for each of these two groups, when the transmission gear train is in the appropriate rotational position, all the locking bodies of the corresponding group engage the transmission gear train simultaneously, while the locking bodies of different groups cannot engage the transmission gear train simultaneously.

[0107] Thereby, for a transmission gear train 26 with a preset number of teeth, after the drive device 16 starts to rotate in the first rotational direction R1, the maximum time required before torque is transmitted to the hub sleeve 14 can be shortened.

[0108] In practice, in this case, all groups preferably have the same number of locking bodies, such as one, two or three locking bodies, and in this example, the different groups are mainly used to show the locking and release positions in a single cross-sectional view.

[0109] Finally, in Figures 10 to 12 the locking body 20 configured as a "flat ratchet" in the first embodiment is shown again separately and from different perspectives.

[0110] As shown, the locking body 20 has two flat and parallel side walls 32, 34, and, disregarding the groove 30, has the same cross-sectional shape for all cutting planes parallel to the side walls 32, 34.

[0111] In the top view of the side wall 32 as Figure 12 shown, the basic shape of the locking body 20 is a nearly equilateral triangle with a rounded tip, and the engaging section 33 projects from this basic shape in the form of an extension of one of the sides of the triangle.

[0112] Compared with a conventional pawl in which the latching section is directly adjacent to a generally cylindrical support section, the locking body according to the present utility model has a larger coupling surface of the flat area 36 for more efficient torque transmission, and the name "flat pawl" proposed herein is derived therefrom.

[0113] Figures 13 to 17 More embodiments of the present utility model are shown.

[0114] Figure 13 and Figure 14 correspond roughly to Figure 4 and Figure 5 , namely enlarged cross-sectional views of the locking body in the locked position and the released position respectively, and an embodiment variant is shown, in which each locking pawl 50 is pre-tensioned towards the locked position by an independent helical compression spring 42. That is, the pre-tensioning device 24 consists of the entire helical compression spring 42 in this case.

[0115] Among them, different from the first embodiment, based on the shapes of the locking pawl 50 and the locking pawl notch, there are two spring positioning schemes, namely, selectively positioned in the first spring receiving portion 43 or the second spring receiving portion 53, and these spring receiving portions are formed at different positions in the locking body notch 22.

[0116] Correspondingly, the locking body 20 has two bearing surfaces 44, 54, and depending on the selected spring receiving portions 43, 53, in the released position of the locking body 20, the correspondingly positioned helical spring applies pressure to these bearing surfaces, thereby pre-tensioning the locking body towards the locked position.

[0117] In Figures 15 to 17 the third and fourth embodiments, different from the first two embodiments, the locking body 20 is not constructed as a locking pawl, but as a locking slider 40.

[0118] Figure 15 and Figure 16 show the third embodiment of the present utility model in a manner corresponding to Figure 4 and Figure 5 . Similar to the second embodiment, a helical compression spring is provided for each locking body 20, which presses against the recessed bearing surface 51 in the released position of the locking body ( Figure 16 ), thereby pre-tensioning the locking body 20 towards the locked position ( Figure 15 ), but the difference from the second embodiment is that the adjustment movement is a translational movement.

[0119] In the locking slider solution as shown in Figures 15 to 17 , the entire coupling surface 35 of each locking body 20 is constructed flat, and thus is the same as the flat area 36.

[0120] Different from the embodiments described above, the engaging section 33 of the locking slider 40 shown in these drawings does not have only one engaging arm, but has two engaging arms 31 which engage into adjacent tooth gaps 27 of the transmission gear train 26, such that the force transmitted by the drive device 16 to the locking body 20 in the locked position during rotation of the drive device 16 in the first rotational direction R1 is divided onto two abutment surfaces of the engaging arms 31.

[0121] In such as Figure 15 and Figure 16 In the example shown, during the movement between the locked position and the released position, the translational movement of the locking slider 40 is not completely radial, but is slightly inclined corresponding to the slope of the steeper tooth surface 26.1 of the transmission gear train 26, and the movement is guided by two substantially parallel side walls 22s of the locking body notch 22.

[0122] To prevent the locking slider 40 from radially inwardly falling out of the locking body notch 22 during installation, an intercepting protrusion 52 is preferably provided on the radially inner edge of the locking slider notch 22 that is forward in the first rotational direction R1. In this case, an insertion notch 55 additionally provided on the radially inner edge of the locking slider notch 22 that is rearward in the first rotational direction R1 can facilitate the insertion of the locking slider 40.

[0123] In Figure 17 In the embodiment of, six locking sliders 40 each having two engaging arms 31 are provided. Different from the example of Figure 15 and Figure 16 These engaging arms are radially inwardly pre-tensioned towards the locked position by a single worm spring coil 59 acting as a pre-tensioning device. In this example, the locking body notch 22 tapers slightly radially inwardly, so the pre-tensioning device 24 also holds the locking body 20 on the hub sleeve 14 in this example.

[0124] It should be added that the locking body notch is provided on one of the components of the drive device and the hub sleeve, and is provided on the hub sleeve in all the embodiments shown here, while the transmission gear train is provided on the other of the components of the drive device and the hub sleeve, and is provided on the drive device in all the embodiments shown. However, the opposite layout can also be adopted.

[0125] The overrunning clutch according to the present invention has the characteristics of being light, small and low-cost, and is very easy to adjust according to different requirements. In this way, in particular, several advantages of the novel gentle pawls and locking sliders described here can be combined with traditional rotary locking pawls.

Claims

1. A freewheel hub (10) for a bicycle, the freewheel hub comprising: a drive device (16) and a hub sleeve (14) which are respectively supported on a hub shaft (12) in a manner capable of rotating about a common axis of rotation (X), a locking body mechanism (18) having at least one locking body (20), the locking body being supported in a radially extending locking body recess (22) in a manner capable of being adjusted between a locking position and a release position, and a preloading device (24) configured to preload the locking body (20) towards the locking position, wherein the locking body recess (22) is provided in one of the components of the drive device (16) and the hub sleeve (14), and the other of the components of the drive device (16) and the hub sleeve (14) has a radially extending transmission tooth system (26) or is non-rotatably connected to the transmission tooth system (26), wherein a surface of the locking body (20) has a coupling surface (35), the coupling surface (35) abuts against a contact surface (45) of the locking body recess (22) in the locking position, and a latching section (33) of the locking body (20) latches into the transmission tooth system (26), such that when the drive device (16) rotates about the axis of rotation (X) in a first rotational direction (R1), torque is transmitted from the drive device (16) to the hub sleeve (14) through the coupling surface (35), and wherein the locking body (20) allows the hub sleeve (14) to rotate relative to the drive device (16) in the first rotational direction (R1) in the release position, characterized in that more than half of the coupling surface (35) is constructed as a flat area (36).

2. The freewheel hub according to claim 1, It is characterized in that the entire coupling surface (35) has a flat construction, and the locking body (20) is a locking slider (40) and can be adjusted between the locking position and the release position by a translational movement.

3. The freewheel hub according to claim 1, It is characterized in that the coupling surface (35) consists of the flat area (36) and a curved area (37), wherein the curved area (37) is used to rotatably support the locking body during a pivoting movement of the locking body (20) as a locking pawl (50) between the locking position and the release position.

4. The freewheel hub according to claim 3, It is characterized in that the curved area (37) is a cylindrical area.

5. The freewheel hub (10) according to any one of claims 1 to 4, It is characterized in that the flat area (36) of the coupling surface (35) forms an angle (α) of not more than 30° with a perpendicular line (L) from the center point (M) of the flat area (36) to the axis of rotation (X).

6. The freewheel hub (10) according to claim 5, It is characterized in that the angle (α) is not more than 20°.

7. The freewheel hub (10) according to claim 6, It is characterized in that the angle (α) is not more than 10°.

8. The freewheel hub (10) according to any one of claims 1 to 4, It is characterized in that wherein the preloading device (24) includes a spring configured to preload a plurality of locking bodies (20) of the locking body mechanism (18) towards corresponding locking positions.

9. The freewheel hub (10) according to claim 8, It is characterized in that wherein the spring is configured to preload all of the locking bodies (20) of the locking body mechanism (18) towards corresponding locking positions.

10. The freewheel hub (10) according to any one of claims 1 to 4, characterized in that, The locking body mechanism (18), the preloading device (24), and the member of the hub sleeve (14) among these components on which the at least one locking body notch (22) is provided can be pre-assembled to form a first assembly (41), wherein the preloading device (24) holds the locking body mechanism (18) on the member.

11. The freewheel hub (10) according to claim 10, characterized in that, The locking body (20) is configured as a locking slider (40) capable of being adjusted between the locking position and the release position by a translational movement, and wherein the locking body notch (22) tapers radially inwards, and the preloading device (24) preloads the locking slider (40) radially inwards.

12. The freewheel hub (10) according to any one of claims 1 to 4, characterized in that, The engaging section (33) of the locking body has two or more arms (31) configured to engage into adjacent tooth gaps (27) of the transmission gear system (26) in the locking position.

13. The freewheel hub (10) according to any one of claims 1 to 4, characterized in that, The locking body mechanism (18) has several groups (18.1, 18.2) of locking bodies (20), and the locking bodies (20) are supported in corresponding locking body notches (22) distributed around the periphery of the member in such a way that for each of the groups (18.1, 18.2), in the locking position, when the transmission gear system (26) is in an appropriate rotational position, the locking bodies (20) of the corresponding group (18.1, 18.2) all simultaneously engage into the transmission gear system (26), while the locking bodies (20) of different groups (18.1, 18.2) cannot simultaneously engage into the transmission gear system (26).

14. The freewheel hub (10) according to any one of claims 1 to 4, characterized in that, The flat area (36) of the coupling surface (35) is more than twice the tooth contact area (65) of the surface of the locking body (20), wherein the tooth contact area (65) is the area of the surface of the locking body (20) that makes planar contact with the leading tooth surface (26.1) of the transmission gear system (26) along the first rotational direction (R1) in the locking position.

15. The freewheel hub (10) according to claim 14, characterized in that, The flat area (36) of the coupling surface (35) is more than three times the tooth contact area (65) of the surface of the locking body (20).

16. The freewheel hub (10) according to claim 15, characterized in that, The flat area (36) of the coupling surface (35) is more than five times the tooth contact area (65) of the surface of the locking body (20).

17. The freewheel hub (10) according to claim 14, characterized in that, A vertical line (F) perpendicular to the tooth contact area (65) and passing through the center point (N) of the tooth contact area (65) intersects the flat area (36) of the coupling surface (35).

18. The freewheel hub (10) according to claim 17, characterized in that, The vertical line (F) intersects the flat area (36) of the coupling surface (35) at the center point (M) of the flat area (36).

Images