GB2275512A - A multi-speed bicycle hub drive having a single selection sleeve - Google Patents

Abstract

The drive comprises an intermediate gear (2), a control gear (1) and a coupling means (4, 4a, 7) for the selective non-rotational coupling of a first planet carrier (24) of the intermediate gear (2) and or a ring gear (2) of the intermediate gear (2) with either of planet carrier (31) of the control gear (1) or a ring gear (27) of the control gear (1). The coupling means comprises a single coupling sleeve (7). Carrier plates (4, 4a) be moved in axial direction by sliding blocks (12, 12a) for the selective non-rotatable coupling of the carriers and ring gears. The drive is configured to have low or "hill" ratios and may have up to ten speeds. <IMAGE>

Description

A MULTI-SPEED HUB DRIVE The present invention relates to a multi-speed hub drive for bicycles or suchlike, comprising an intermediate gear with a first sun wheel non-rotatably connected to a hub axle, a first planet carrier rotatably arranged on the hub axle, at least one first planet wheel rotatably arranged on the first planet carrier and constantly meshing with the first sun wheel and a first hollow wheel arranged concentrically to the hub axle, said first hollow wheel being non-rotatably connected to a driver; a control gear spaced from the intermediate gear in one axial direction of the hub axle with at least one second sun wheel, which may be non-rotatably connected to the hub axle, a second planet carrier rotatably arranged on the hub axle with at least one second planet wheel, which constantly meshes with the at least one second sun wheel and a second hollow wheel arranged coaxially to the hub axle; and comprising a coupling means for selective non-rotational coupling of the first planet carrier and the first hollow wheel with either the second planet carrier or the second hollow wheel respectively.

Such a multi-speed hub drive is known, for example, -from DE-3834431 Al. IN this multi-speed hub drive, a hollow wheel and a planet carrier of an intermediate gear may be non-rotatably connected selectively to a hollow wheel or a planet carrier of a control gear via a coupling means. The number of speed selections provided by the control gear may thus be doubled by providing the intermediate gear. In this multi-speed hub drive, the coupling means comprising two coupling sleeves arranged to rotate around a hub axle.

The two coupling sleeves are movable in an axial direction so that one of the coupling sleeves may selectively be coupled either to the planet carrier or to the hollow wheel of the intermediate gear, and the other coupling sleeve may selectively be coupled either to the planet carrier or hollow wheel of the control gear. The two coupling sleeves overlap one another, one of the coupling sleeves having splines or longitudinal toothing on its outer periphery and the other coupling sleeve having corresponding splines or internal longitudinal toothing. The two coupling sleeves constantly mesh via these tooth arrangements and are non-rotatably connected to one another, while being movable relative to one another in an axial direction parallel to the hub axle.

However, this coupling means has the disadvantage that an increased amount of material is required for the coupling means because the two coupling sleeves overlap, thus resulting in an increase in the overall weight of the hub drive. Since one of the coupling sleeves must be provided with a larger outside diameter, this also restricts the space available for the other structural parts of the hub drive. There is also the possibility that, at least in the maximum extended relative position of the two coupling sleeves, the two coupling sleeves may tilt slightly towards one another, even in the case of a neutral gear selection, which means that an increased frictional resistance must be overcome during a shift in gear.

In contrast to this, the object of the present invention is to provide a multi-speed hub drive, in which the coupling means is constructed to ensure smoothrunning between the intermediate gear and the control gear as well as being of low weight and compact.

The object is achieved according to the invention is that the coupling means comprises a single coupling sleeve, which is rotatably arranged on the hub axle and fixed in axial direction; a first carrier element, which is non-rotatably supported on the coupling sleeve and may be removed in an axial direction by means of a first operating means, for the selective non-rotatable coupling of either the first planet carrier or the first hollow wheel to the coupling sleeve; and a second carrier element, which is non-rotatably supported on the coupling sleeve and may be moved in an axial direction by a second operating means, for the selective non-rotatable coupling of the second planet carrier or the second hollow wheel to the coupling sleeve. Since a single coupling sleeve is provided, the overlap area of the two coupling sleeves known from the prior art is avoided, so that on the one hand the overall weight of the coupling means may be reduced and on the other hand the space taken up by the coupling sleeve inside the hub drive is minimised, thus making more space available for the arrangement of other structural parts. The carrier elements may be moved in an axial direction on the coupling sleeve and are rotationally fixed, so that transmission of driving power results in the transmission of torque between the coupling sleeve and the carrier elements acting exclusively in a peripheral direction. Tilting of the coupling sleeve relative to the carrier elements may therefore be avoided and hence no additional friction forces are generated during the gear shift.

So that the intermediate gear and the control gear may be connected by the coupling sleeve in a particularly simple manner, it is proposed that the coupling sleeve is arranged in an axial direction between the intermediate gear and the control gear.

If the first and second carrier elements comprise first and second carrier plates, then the dynamically balanced configuration of the carrier elements ensures that no balance errors are generated by the coupling means during operation of the multi-speed hub drive. The plate-type configuration of the carrier elements may also assist in centring the coupling sleeve.

To ensure that the connection between the carrier plates and the coupling sleeve is rotationally fixed by a simple means, it is proposed that one outer periphery of the coupling sleeve is provided with splines, and that the inner peripheries of each of the first and second carrier plates are provided with internal splines, which constantly mesh in each case with the coupling sleeve splines. This ensures that the driving or braking force acting between the carrier plates and the coupling sleeve on a plurality of teeth is distributed, which means that load concentrations resulting in deformation of the structural part may be avoided.

If the end section adjacent to the intermediate gear and/or the end section of the coupling sleeve adjacent to the control gear is/are provided with a plurality of slots running in axial direction, which are preferably open towards the respective end of the coupling sleeve, and if a first or second carrier is arranged radially inside the coupling sleeve to be movable in an axial direction, whereby arm sections of the first or second carrier each pass radially through the slots in the end section adjacent to the intermediate gear or in the end section of the coupling sleeve adjacent to the control gear and are fixedly connected to the first or second carrier plate respectively, it is possible to operate the carrier plates in a simple manner by means of the carriers. In this case, no peripherally directed forces occur between the arm sections of the carriers and the side faces of the slots in the coupling sleeve, since these forces are transmitted by the carrier plates. The arms of the drivers inside the slots may therefore run without substantial friction. It is possible to easily assemble the coupling means by simply sliding the corresponding carrier laterally into the coupling sleeve, because the slots are preferably open towards the ends of the coupling sleeves. These slots may also be produced at low expense.

Because the first or second carrier may be moved in an axial direction by the first or second operating means against the biassing of a spring element to axially shift the first or second carrier plate, the operating means need merely urge the respective carriers in an axial direction, the movement of the carriers in an axially opposed direction being effected by the spring element. In this way, a substantially simple configuration of the operating means may be achieved.

The rotationally fixed connection between the respective elements may be achieved in simple manner in that the first or second carrier plate is provided on one outer periphery with radially outwardly directed teeth, which, when the first or second carrier plate is in a first coupling position, engage with teeth provided on the first planet carrier or the second planet carrier, and couple the first- or second carrier plate nonrotatably to the first or second planet carrier respectively, and which when the first or second carrier plate is in a second coupling position, engage with teeth provided on a toothed disc or with the second hollow wheel, and couple the first or second carrier plate non-rotatably to the toothed disc or second hollow wheel respectively, whereby the toothed disc constantly engages with teeth provided on the hollow wheel via teeth .. . .

provided on the outer periphery of the toothed disc. As already mentioned, a further consequence of such a structure is that the coupling sleeve may be supported on the respective planet carriers or hollow wheel or toothed disc by means of the carrier plate, and is thus substantially centred in its radial position. No additional support or centring means are therefore required inside the coupling sleeve, thus allowing further structural elements of the multi-speed hub drive to be disposed in the area formed between the coupling sleeve and the hub axle.

If the teeth on the first or second planet carrier are provided with oblique guards, an additional force is generated during the gear shift between the carrier plates and the respective planet carriers, which is directed axially and pushes the toothed disc into the next respective speed selection which avoids a neutral position being selected during a gear change. The oblique guards also allow a smooth engagement of the teeth of the respective carrier plate with the planet carrier to be achieved.

Because the toothed sleeve or the second hollow wheel may be shifted axially against the biassing of a spring element, the carrier plates are permitted to continue to rotate relative to the hollow wheel or the toothed sleeve during a gear shift until a tooth of the carrier plate stands opposite a corresponding recess in the second hollow wheel or the toothed sleeve, and the toothed sleeve can shift further axially to engage with the corresponding carrier plate. This prevents any possible axial blocking of the carriers plates with subsequent jolting during a gear shift of the multi-speed hub drive.

To ensure the greatest possible stability of the coupling sleeve, as well as permitting joint overlapping of the slots in the two end sections of the coupling sleeve, it is proposed that the slots adjacent to the control gear and the slots adjacent to the intermediate gear are shifted in relation to one another in a peripheral direction.

The first and second operating means may be structured in a particularly simple and inexpensive manner in that the first and second operating means comprise shift pins, which are each guided in a central hole in the hub axle, and sliding blocks, which are fixedly connected to the shift pins and pass through an axial slot in the hub axle, and against which the respective first or second carrier abut.

If the spring element acts between the first and second carriers and biases each of these in such a way that the first and second carrier plates are disposed in their first coupling positions, it is ensured that the two carrier plates assume a previously defined gear shift position as a-result of the spring bias, whereby only one spring element is required to bias the two carrier plates.

To provide a large number of gear selections, it is proposed that the control gear comprises a five-speed gear. In this case, it is preferred that the control gear comprises two control gear sun wheels of different diameter, which may be selectively connected to the hub axle at a radial projection on the hub axle by a blocking means so that they are rotationally fixed, and that the planet wheel is a doubly stepped planet wheel, the teeth of each step of which constantly mesh with one of the control gear sun wheels, and wherein, in addition, the teeth of one of the steps of the planet wheel constantly meshes with the second hollow wheel.

In order to minimise as far as possible the number of guide openings for the sliding blocks in the hub axle and thus increase the stability of the hub axle, it is proposed that the blocking means comprises a sliding block and a gear shift sleeve, and that the sliding block of the blocking means and the sliding block of the second operating means are guided in the same axial slot in the hub axle.

The invention is explained in further details below on the basis of an example of a ten-speed hub with a back-pedal braking system for bicycles shown in the drawings.

Figure 1 shows a longitudinal part section of a ten-speed hub made in accordance with the invention with control gear and intermediate gear; Figure 2 shows a coupling sleeve made in accordance with the invention; Figure 3 shows a chart indicating the speed selection ranges of the individual sliding blocks.

The ten-speed hub according to the invention is composed of a control gear 1 and an intermediate gear or transmission 2, wherein a coaxial coupling sleeve 7 is provided as a multi-functional part to form the connection between the two gear units 1 and 2. The hub has a conventional structure with an axle 17, around which the gear units 1 and 2 are grouped in the form of planetary gears. A hub sleeve 3 with the usual spoke flanges forms the outer periphery. Said hub sleeve 3 is mounted in a known manner on an adjustable bearing cone 28 and on a drive means, referred to here as "hollow wheel" 20, said hollow wheel in turn being rotatably connected to the axle 17 via the fixed bearing cone or bearing flange 38. The hollow wheel 20 belonging to the intermediate gear 2 is provided with internal teeth 35, and is connected to the sun wheel teeth 37 on the axle 17 via planet gears 36. These planet gears 36 are rotatably mounted on axles 39 coaxially arranged in a planet gear carrier 24. A crown-wheel arrangement of teeth 5a is also arranged coaxially on the face of the planet gear carrier to point towards the axle 17, these teeth having oblique surfaces 25 on their axial end. Teeth 5a mesh with teeth 4b of a carrier plate 4a engaging into them, the latter teeth 4b connecting with grooves 8 of a coupling sleeve 7 via their radially internal teeth 6a so as to be axially movable. The coupling sleeve 7 has at least two slots 10 extending in the direction of the groove, through which slots 10 a star-shaped carrier ila engages and is coupled axially to the carrier plate 4a on the outside, whereas on the inside it abuts a sliding block 12a on one side,. being held in this position by a spring 41. Therefore, if the sliding block 12a with a shift pin 16 in its axial slot 10 moves back and forth, e.g. towards adjustable bearing cone 28 in Figure 1, then carrier lia follows this and, with its external teeth 4b, moves from teeth 5a via the oblique surfaces 25 to engage in teeth 23 of the toothed disc 22, the external teeth 23a of which engage permanently in teeth 21 of the hollow wheel 20. This is achieved by means of a spring 42, which acts as a connection between the two gears and eases the gear selection process by brief spring deflection in the case of shift resistances when sliding the carrier plate 4a into the teeth 23. The direct gear of transmission 2 is selected, when the carrier plate 4a is coupled by its tooth 4b to internal teeth 23 of the toothed disc 22. Hence, the driving power passes from outside directly via the hollow wheel 20, the toothed disc 22, the carrier plate 4a onto the coupling sleeve 7, thus bypassing the intermediate gear.

Transmission of the lower ratio "hill" gear with its transmission of torque passing via the hollow wheel 20, planet wheel 36, planet carrier 24, carrier plate 4a onto the coupling sleeve 7 is such that it approximately halves the speeds which may be selected with the control gear 1, i.e. produces a hub drive transmission ratio, which in each case lies about in the middle between two directly consecutive transmission ratios of the control gear 1.

The description so far has related to the gear change between low ratio "hill" gear and direct transmission of the intermediate gear 2, which must be coordinated with the gear change of the control gear 1.

Description of the five-speed control gear 1, known per se, is restricted here to the function of the five speeds, naming the parts concerned. Torque is transmitted into the control gear 1 via the coupling sleeve 7 coupled to the intermediate gear 2 and via the carrier plate 4, which may be moved on this by means of a sliding block 12. Its teeth 6 engage permanently into the grooves 8 and its radially arranged external teeth 4b are coupled with teeth 5 connected to a web or support frame 26 of the planet carrier 31. The carrier plate 4 is connected to a carrier 11 in such a way that it may be moved axially in both directions by the latter. The carrier 11 abuts the sliding block 12 which is controlled from outside via a shift pin 15. The carrier plate 4 is star-shaped and passes through the coupling sleeve 7 at its slots 9, thus enabling the transmission of control movements from the sliding block 12 to the carrier plate 4.

The high-ratio "fast" gear of the five-speed control gear 1 is selected'when the planet carrier31 is driven via the carrier plate 4 and the stepped planet wheel 32 is supported on the larger sun wheel 34 which is coupled for this purpose to axial teeth 43 on axle 17 by moving the sliding block 13 towards the adjustable bearing cone 28. The quicker turning hollow wheel 27 transmits the movement via the ratchet 44 onto the hub sleeve 3.

The low-ratio "fast" gear is selected by moving the sliding block 13 to the right in Figure 1 by means of the shift sleeve 14 by which the sun wheel 34 is decoupled from the axial teeth 43 and the sun wheel 33 is pushed into the axial teeth 43 by a spring 45 and fixed.

The drive of the hollow wheel 27 and therefore of the hub sleeve 3 starts to move quickly, but at a low transmission ratio.

Direct coupling of the hub sleeve 3 with the coupling sleeve 7, thus bypassing the planetary gear is achieved by moving the sliding block 12 to the right by means of selector rod 15, by which the hollow wheel 27 is connected by its teeth 27a to the teeth 4b of the carrier plate 4. The ratchet 44 drives the hub sleeve 3 as previously described.

The low ratio "hill" gear is selected by reversing the drive conditions in the planetary gear. The drive must now run via the hollow wheel 27 to produce lower sleeve rotational speeds 'via the geared-down planet carrier 31. Therefore, if the sliding block 12 is moved a further stage towards the fixed bearing flange 38, then the carrier plate 4 moves the hollow wheel 27 and the ratchet 44 with it towards the fixed bearing flange by means of its teeth 4b, which abut an axial stop in teeth 27a, by which the ratchet 44 is raised on an oblique element 46 and rendered ineffective. Hence, torque is transmitted from the carrier plate 4 via the hollow wheel 27., the stepped planet gears 32, which are still supported on the sun wheel 33, planet carrier 31, brake cone 30 and via a ratchet 47 arranged on the latter onto the hub sleeve 3. In the case of the high ratio "fast" gears, this ratchet 47 is outrun in both cases because the rotational speed of the planet carrier 31 lags behind that of the hollow wheel 27.

Finally, the low ratio "high hill" gear is selected by moving the sliding block 13 towards the adjustable bearing cone 28 where it was previously positioned for the high ratio "fast" gear. Movement is transmitted against the spring 45, which biasses the two sun wheels 33 and 34 against the sliding block 13.

In the back-pedal braking process, the flow of force passes through. the teeth connections of the respectively selected speeds either directly - in the high ratio "fast" gears - onto the planet carrier, as shown in Figure 1, or in standard gear and the low ratio "hill" gears, is transmitted via the hollow wheel 27 onto the planet carrier 31.

While the ratchets 44 and 47 are outrun, the brake cone 30 which is screwed to the left via a coarse thread 48 causes the brake casing 29 to spread apart and initiate braking by abutting against the hub sleeve 3.

The ten-speed hub with three sliding blocks according to the invention is controlled from both ends of the axle 17, whereby the five-speed hub 1 must be coordinatedly selected by means of the shift pin 15 and the shift sleeve 14, and the intermediate gear 2 is controlled by the shift pin 16. The shift sequence is shown in the chart in Figure 3. This shows how the two sun wheels must be shifted by sliding block 13, the fivespeed part of the control gear 1 by sliding block 12 and the intermediate gear 2 by sliding block 12a to achieve a stepped gear sequence. It is certainly an advantage for the rider of a bicycle equipped with such a gear hub, if means to ensure a correct gear sequence are built into the control system, top,rovide an operational advantage over chain gears which use a separate selector for each chain shift.

The chart according to Figure 3 is based on the possibility of providing a a further gear between each of the speeds of the control gear 1 because of the correspondingly low reduction of the hill gear of the intermediate gear 2. Therefore, the following shift sequence results in the case of the shown control gear with five speeds.

The high ratio "fast" gear is the tenth gear, in which the control gear 1 is shifted to the high-ratio "fast" gear and the intermediate gear 2 to direct gear.

in ninth gear, the control gear 1 is again shifted to the high-ratio "fast" gear and the intermediate gear 2 to the "hill" gear. In eighth gear, the control gear 1 is shifted to low-ratio "fast" gear and the intermediate gear 2 to direct gear, and so on until in the lowest "hill" gear, first gear, in which the control gear 1 is shifted to the low "hill" gear and the intermediate gear 2 to "hill" gear.

In the case of the other transmission ratio of the intermediate gear 2, another shift sequence is also conceivable, e.g. as in the case of chain gear shift with one switchable gear wheel pair corresponding to the chainwheel associated with the pedal crank and another switchable gear wheel pair corresponding to the hub sprockets.

The described embodiment has three sliding blocks 12, 12a and 13, which are adequate in full operation, but increase the expense of the external control system. It is known from earlier publications, e.g. DE 3440067 and DE 3440068, that five speeds may also be selected with a single sliding block, if additional expense is taken into account for the control system inside the hub.

It is possible to construct a hub which is expensive because of this internal arrangement and at the same time save such expense by means of the intermediate gear within the scope of this invention. Instead of a hub having three sliding blocks, this would result in a hub with two control inputs to the hub gear via two sliding blocks, in which case each control input is arranged in each axle end.

A further development of the invention which simplifies this construction may provide for the two sliding blocks to be controlled form one side only, i.e.

to attach an inverter to only one shaft end, which when compared to figure 1, controls the ten-speed hub via a shift sleeve similar to 14 and a selector rod similar to 15, and is thus operated by a single control cable.

Claims (16)

1. A multi-speed hub drive for bicycles or suchlike comprising: an intermediate gear with a first sun wheel nonrotatably connected to a hub axle, a first planet carrier rotatably arranged on said hub axle, at least one first planet wheel rotatably arranged on said first planet carrier and constantly meshing with said first sun wheel and a first hollow wheel arranged concentrically to said hub axle, said first hollow wheel being non-rotatably connected to a driver; a control gear- spaced from said intermediate gear in one axial direction of said hub axle with at least one second sun wheel, which may be non-rotatably connected to said hub axle, a second planet carrier rotatably arranged on said hub axle with at least one second planet wheel, which constantly meshes with said at least one second sun wheel and a second hollow wheel arranged coaxially to said hub axle; a coupling means for selective non-rotational coupling of said first planet carrier and said first hollow wheel with either said second planet carrier or said second hollow wheel wherein, said coupling means comprises: a single coupling sleeve which is rotatably arranged on said hub axle and is axially fixed; a first carrier element which is non-rotatably supported on said coupling sleeve and may be axially moved by means of a first operating means, for the selective non-rotatable coupling of either said first planet carrier or said first hollow wheel to said coupling sleeve; and a second carrier element which is non-rotatably supported on said coupling sleeve and may be moved in axial direction by a second operating means, for the selective non-rotatable -coupling of said second planet carrier or said second hollow wheel to said coupling sleeve.

2. A multi-speed hub drive according to Claim 1, wherein the coupling sleeve is arranged in an axial direction between the intermediate gear and the control gear.

3. A multi-speed hub drive according to Claim 1 or 2, wherein the first and second carrier elements comprise first and second carrier plates.

4. A multi-speed hub drive according to Claim 3, wherein an outer periphery of the coupling sleeve is provided with splines, and that the inner peripheries of each of the first and second carrier plates are provided with internal splines, which constantly mesh in each case with the longitudinal toothing on the coupling sleeve.

5. A multi-speed hub drive according to Claim 4, wherein the end section adjacent to the intermediate gear and/or the end section of the coupling sleeve adjacent to the control gear is/are provided with a plurality of slots running in axial direction, which are preferably open towards the respective end of said coupling sleeve; and that a first or second carrier is arranged radially inside said coupling sleeve to be movable in an axial direction, whereby arm sections of said first or second carrier each pass radi-ally through the slots in the end section adjacent to said intermediate gear or in the end section of said coupling sleeve adjacent to said control gear and are fixedly connected to the first or second carrier plate respectively.;

6. A multi-speed hub drive according to Claim 5, wherein the first or second carrier may be moved in an axial direction by the first or second operating means against the action of force of a spring element to axially shift said first or second carrier plate.

7. A multi-speed hub drive according to one of Claims 3 to 6, wherein the first or second carrier plate is provided on -one outer periphery with teeth pointing radially outwards, which, when said first or second carrier plate is in a first coupling position, engage with teeth provided on the first planet carrier or the second planet carrier respectively, and couple said first or second carrier plate non-rotatable to said first or second planet carrier respectively, and which when said first or second carrier plate is in a second coupling position, engage with teeth provided on a toothed disc or with the second hollow wheel, and couple said first or second carrier plate non-rotatably to said toothed disc or second hollow wheel respectively, whereby said toothed disc constantly engages with teeth provided on the hollow wheel via teeth provided on the outer periphery of said toothed disc.

8. A multi-speed hub drive according to Claim 7, wherein the teeth are provided with oblique guards on the first or second planet carrier.

9. A multi-speed hub drive according to Claim 7 or 8, wherein the toothed sleeve or the second hollow wheel may be shifted axially against the biassing action of a spring element.

10. A multi-speed hub drive according to one of Claims 5 to 9, wherein the slots adjacent to the control gear and the slots adjacent to the intermediate gear are shifted in relation to one another in a peripheral direction.

11. A multi-speed hub drive according to one of Claims 1 to 10, wherein the first and second operating means comprise shift pins which are each guided in a central hole in the hub axle and sliding blocks, which are fixedly connected to said shift pins and pass through an axial slot in said hub axle and against which the respective first or second carriers abut.

12. A multi-speed hub drive according to one of Claims 6 to 11, wherein the spring element acts between the first and second carriers and biases each of these in such a way that the first and second carrier plates are disposed in their first coupling positions.

13. A multi-speed hub drive' according to one of Claims 1 to 12, wherein the control gear comprises a five-speed gear.

14. A multi-speed hub drive according to one of Claims 1 to 13, wherein the- control gear comprises two control gear sun wheels of different diameter, which may be selectively connected to the hub axle at a radial projection on said hub axle by a blocking means so that they are rotationally fixed, and that the planet wheel is a doubly stepped planet wheel, the teeth of each step of said planet wheel constantly meshing with said control gear sun wheels, and wherein, in addition, the teeth of one of the steps of said planet wheel constantly meshes with the second hollow wheel.

15. A multi-speed hub drive according to Claim 14, wherein the blocking means comprises a sliding block and a gear shift sleeve and that said sliding block of said blocking means and the sliding block of the second operating means are guided in the same axial slot in the hub axle.

16. A multi-speed hub drive substantially as described herein with reference to any one or more of the Figures of the accompanying drawings.