Rear wheel hub, in particular for bicycles

Abstract

A hub for bicycles, having an axle and a shell, two bearing units arranged substantially between the hub axle and the hub shell, and a rotor rotatably supported relative to the hub axle for receiving a sprocket the rotor, and a freewheel having two toothed disc units with biased tooth faces for transmitting the drive torque from the rotor to the hub shell. The two toothed disc units are disposed around the hub axle upon assembly, they are, at idle, disposed transverse to the hub axle. At least one toothed disc unit includes a toothed disc having a hole, a radial wall and an axial toothed wall, wherein an inner diameter of the hole is smaller at the axial wall than an inner dimension in the radial wall to form a receiving space at the toothed disc between the clear inner diameter of the axial wall and the radial wall.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and embodiments of the present invention can be taken from the embodiment which will now be explained with reference to the accompanying drawings.

FIG. 1 is a cross-section of a rear wheel hub according to the invention;

FIG. 2 is an exploded view in perspective of the hub according to FIG. 1;

FIG. 3 is a top plan view of a toothed disc of the rear wheel hub according to FIG. 1;

FIG. 4 is a side view of the toothed disc according to FIG. 3;

FIG. 5 is a cross-section of a first embodiment of the toothed disc according to FIG. 3;

FIG. 6 is a cross-section of a second embodiment of the toothed disc according to FIG. 3;

FIG. 7 is a schematic cross-section of a third embodiment of the toothed disc according to FIG. 3;

FIG. 8 is a schematic cross-section of a fourth embodiment of the toothed disc according to FIG. 3; and

FIG. 9 is a detail of the labyrinth seal between the rotor and the hub shell of the hub according to FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the rear wheel hub 1 according to the invention will now be described with reference to the accompanying drawings.

The rear wheel hub 1 according to the invention illustrated in FIG. 1 of a rear wheel comprises a stationary hub axle 2. The hub shell 3 is supported by bearings 4 to be rotatable relative to the hub axle 2.

Between the rotor 5, which serves to receive a sprocket cluster, and the hub shell 3 a freewheel 6 is disposed comprising in this case two toothed discs 7 as toothed disc units. The outside surface of the rotor 5 is provided with engaging dogs 34 which comprise on the outer surface longitudinal grooves parallel to the longitudinal direction 10 or the symmetry axis of the hub. The longitudinal grooves (see FIG. 2) allow to reduce the weight of the rotor and thus of the entire hub so as to still further reduce the relatively low weight of the hub.

The hub shell 3 in this embodiment comprises two radially disposed flanges 3a and 3b provided with bores 3c which serve for receiving spokes to connect the hub 1 with a rim.

The radially outward ends of the flanges 3a and 3b are configured to be convex such that the material is higher at the outer face of each hub flange than in the center region of this hub flange. Thus, much material is present at particularly stressed positions while the less stressed radially outward ends of the flanges 3a and 3b are convex in contour 3d or convex in cross-section so as to save material there and to save weight overall.

The hub axle 2 is configured hollow. The clear inner diameter 26 is larger than the outer diameter 27 of the hub 1 which is received in a dropout of a bicycle. In this case the hub comprises at its ends 28 and 29 an adapter ring or limit stop 30 and 31 each which are attached to the hub axle 2 when assembling the hub 1. The limit stops 30 and 31 are provided at the axially outwardly ends which are received in the dropouts. The diameter 27 of the receiving sections is smaller than the inner diameter 26 of the hollow hub axle 2.

Both limit stops have O-rings in their interiors for clamping the limit stops on the hub axle. The entire hub can be assembled and dismantled manually, by hand, without employing any tool.

The limit stop 30 positioned on the left in FIG. 1 comprises on the hub side a radial double flange 32 which comprises two annular flanges 32a and 32b. Between the two flanges an expansion chamber 33 is provided extending annularly around the hub axle. As humidity or dirt hits the outer flange 32a and passes through the gap, the flow rate is considerably reduced in the expansion chamber 33 since the flow will fan out and expand. In this way it is substantially reliably prevented that humidity penetrates further till the second gap at the second flange 32b or even passes through the second gap at the second flange 32b. During a ride any entering humidity is displaced radially outwardly. In standstill, condensate will collect at the bottom due to gravity and escape outward so as to provide reliable protection.

The labyrinth seal 36 on the other side between the rotor and the hub shell 3 is shown in detail in FIG. 9. A first sealing gap 37 is disposed radially outwardly. During a ride any water entering is displaced radially outwardly due to centrifugal forces. If during cleaning e.g. with a water jetting system, water should ever enter through the first sealing gap 37 the flow rate will be considerably reduced in the expansion chamber 38. The expansion chamber 38 is followed by a second sealing gap 39. The sealing gap 39 is delimited by a conically extending wall section 40 which increases in diameter in the direction toward the hub shell 3. The sealing effect is thus considerably improved since any humidity entering is displaced radially outwardly due to centrifugal forces. In standstill, water condensation will collect at the radially inward end of the conical wall section 40 from where it can drip out.

If any humidity should ever pass through the second sealing gap, an elastomer seal 41 is provided downstream.

An exploded view in perspective is shown in FIG. 2. As can be seen, the entire hub can be assembled by hand without any tool. The springs 9a and 9b of the biasing devices bias the toothed discs 7 of the freewheel device 6 toward one another.

FIG. 3 is a top plan view of a toothed disc 7, while FIG. 4 is a side view. FIGS. 5 to 8 show different cross-sectional views of conceivable embodiments of the toothed disc units or toothed discs 7.

The toothed discs 7 have a center through hole 11. The axial wall 13 is provided with a tooth face 8 with axial toothing 14. The axial toothings 14 of two toothed discs 7 interact to transmit drive torque in one rotational direction while in the other rotational direction the freewheel function is fulfilled. One or both toothed discs 7 will be displaced axially outwardly such that the tooth surfaces 8 slide past one another.

The appropriate outer walls of the radial walls 12 are provided with an outer toothing 24 which interacts with an inner toothing of a threaded sleeve 25 or with an inner toothing of the rotor 5. Axial displacement is possible in each case while each toothed disc is non-rotatably received.

The toothed disc 7 illustrated in FIG. 7 consists of multiple parts comprising, an axial disc 22 with the axial wall 13 and the axial toothing 14, and a ring sleeve 23 provided with the radial wall 12, and a disc 44. The parts 22 and 23 are non-rotatably connected with one another. They may be configured as one-piece as illustrated in FIG. 8. The additional disc 44 may be provided which is biased by the springs 9a and 9b of the biasing device.

The entire toothed disc 7 is approximately U-shaped in cross-section with the legs 20 and 21 of the “U” extending radially inwardly.

In each case the axial wall 13 has a clear inner diameter 15 and a clear inner dimension 16 which is larger than the clear inner diameter 15. In all of the embodiments this will create at one or both of the toothed discs a receiving space 17 which is delimited radially inwardly through the clear inner diameter 15 and radially outwardly through the clear inner dimension 16. The clear inner dimension 16 is in particular the clear inner diameter in the region of the radial wall 12.

The receiving space 17 may be provided with a receiving ring configured in different shapes and made from different materials. A ring 18 approximately rectangular in cross-section may for example be provided as illustrated in the left half of FIG. 5. Also, a profiled receiving ring 18a may be provided comprising e.g. groove-shaped recesses or a comb-like cross-section.

The material of the receiving ring is in particular a lightweight material e.g. light metal. Preferably the ring 18 effects sound-damping at specific frequencies such that sounds can be adjusted. This allows to configure the hub including acoustic aspects.

A ring of plastic foam or the like is also conceivable. A particularly low weight can be achieved by employing an air-filled ring or no ring at all.

On the whole the invention will further reduce by another 10% the relatively low total weight of the hub while the operational reliability and durability are not reduced. The acoustic properties can concurrently be adapted to the customers' wishes.

Another advantage is the higher response rate since the toothed discs are considerably reduced in weight and can thus accelerate significantly faster while the spring forces of the springs 9a and 9b of the biasing device 9 remain unchanged.

Claims

1. A hub, in particular for bicycles and the like, comprising: a hub axle,a hub shell arranged substantially concentric with said hub axle,at least two bearing units which are arranged substantially between said hub axle and said hub shell such that said hub shell is rotatably supported relative to said hub axle,a rotor which is rotatably supported relative to said hub axle and configured such that at least one sprocket can be arranged on said rotor,a freewheel device which is arranged between said rotor and said hub shell and which comprises two toothed disc units whose tooth faces are urged toward one another by a biasing device, for transmitting the drive torque from the rotor to the hub shell,wherein said two toothed disc units are disposed around the hub axle and in a correctly assembled hub they are, at least in the idle state, disposed transverse to the longitudinal direction of said hub axle, andat least one toothed disc unit having a toothed disc with a through hole and a radial wall and an axial wall having axial toothing, wherein the clear inner diameter of the through hole is smaller at the axial wall than a clear inner dimension in the region of the radial wall such that a receiving space is formed at the toothed disc unit around the hub axle between the clear inner diameter of the axial wall and the clear inner dimension of the radial wall.

2. The rear wheel hub according to claim 1 wherein at least one toothed disc unit is supported floating.

3. The rear wheel hub according to claim 2 wherein both of the toothed disc units are supported floating.

4. The rear wheel hub according to claim 1, wherein at least one receiving ring is received in the receiving space.

5. The rear wheel hub according to claim 4 wherein the receiving ring consists of a material selected from a group of materials comprising light metals, plastic and fiber-reinforced plastic.

6. The rear wheel hub according to claim 1, wherein the receiving ring effects a damping of vibrations.

7. The rear wheel hub according to claim 1, wherein the receiving ring is structured and configured such that resonance can be adjusted.

8. The rear wheel hub according to claim 1, wherein at least one toothed disc unit is U-shaped in cross-section with the legs of the U-shaped cross-section extending radially inwardly.

9. The rear wheel hub according to claim 1, wherein the toothed disc unit comprises at least one axial disc and one ring sleeve.

10. The rear wheel hub according to claim 1, wherein each toothed disc unit has a radially arranged outer profile which outer profile of the one toothed disc unit interacts with an inner profile of a threaded sleeve which is arranged in the hub shell and wherein the outer profile of the other toothed disc unit interacts with an inner profile in the rotor so as to enable axial displacement of each toothed disc while allowing transmission of the drive torque between the one toothed disc unit and the hub shell, and between the other toothed disc unit and the rotor.

11. The rear wheel hub according to claim 1, wherein the hub axle is configured hollow and has a larger inner diameter than the outer diameter of the hub which is provided for being inserted into a dropout at a bicycle frame.

12. The rear wheel hub according to claim 1, wherein at least one end of the hub axle is provided with a separate adapter ring comprising a diameter section provided for being inserted into a dropout at a bicycle frame to retain the hub in the bicycle frame.

13. The rear wheel hub according to claim 12, wherein the adapter ring comprises a double flange which in conjunction with the hub shell achieves a non-contact sealing of the hub shell.

14. The rear wheel hub according to claim 13, wherein each flange of the double flange comprises a narrow sealing gap while an expansion chamber is present between the two flanges.

15. The rear wheel hub according to claim 1, wherein the rotor is provided with radially outwardly extending engaging means which serve to non-rotatably attach sprockets wherein at least one engaging means comprises at least one longitudinal groove.

16. The rear wheel hub according to claim 1, wherein between the rotor and the hub shell a labyrinth seal is provided which comprises a sealing gap facing radially outwardly and which is followed by a radially inwardly expansion chamber which is followed radially inwardly by a second sealing gap.

17. The rear wheel hub according to claim 16, wherein the second sealing gap is delimited by a conical rotor wall section whose diameter increases toward the hub shell.

18. The rear wheel hub according to claim 1, wherein the hub shell comprises at least one hub flange for attaching spokes and extends radially outwardly from the hub shell wherein the radially outward end is concave in cross-section.

19. A rear wheel having a rim and a rear wheel hub and connecting elements between the rim and the rear wheel hub which rear wheel hub comprises: a hub axle,a hub shell arranged substantially concentric with said hub axle,at least two bearing units which are arranged substantially between said hub axle and said hub shell such that said hub shell is rotatably supported relative to said hub axle,a rotor which is rotatably supported relative to said hub axle and is configured such that at least one sprocket can be arranged on said rotor,a freewheel device which is arranged between said rotor and said hub shell and comprises two toothed disc units whose tooth faces are urged toward one another by a biasing device for transmitting the drive torque from the rotor to the hub shell,wherein said two toothed disc units are disposed around the hub axle and in a correctly assembled hub they are, at least in the idle state, disposed transverse to the longitudinal direction of said hub axle, andat least one toothed disc unit includes a toothed disc having a through hole and a radial wall and an axial wall having axial toothing wherein the clear inner diameter of the through hole is smaller at the axial wall than a clear inner dimension in the region of the radial wall such that a receiving space is formed at the toothed disc unit around the hub axle between the clear inner diameter of the axial wall and the clear inner dimension of the radial wall.