Planetary bottom bracket gearbox for a bicycle or e-bike

Abstract

A planetary bottom bracket gearbox for a bicycle or pedelec (1) is proposed, comprising a crankshaft (WAn) as the drive, a gearbox output shaft (WAb) as the driven shaft, and further shafts (W1, W2, W3, W4, W5, W6, W7), as well as a first gearbox switching group (3) and a second gearbox switching group (4), wherein the first gearbox switching group (3) comprises a first planetary gear set (RS1) and a second planetary gear set (RS2), to which four switching elements (B1, B2, K1, K2) are assigned, and wherein the second gearbox switching group (4) comprises at least one planetary gear set (RS3, RS4). Furthermore, a bicycle or pedelec (1) with a bottom bracket gearbox is proposed.

Description

The present invention relates to a bottom bracket transmission of planetary construction for a bicycle or a pedelec having a transmission input shaft as drive and a transmission output shaft as output and having further shafts, and having a first transmission shift group and a second transmission shift group, to which a plurality of planetary gear sets and shift elements are assigned. The invention further relates to a bicycle or pedelec with the bottom bracket transmission.For example, from the publication DE 10 2021 204 634 B3, such a transmission in a pedal crank housing for a bicycle is known. The transmission comprises three planetary gear sets, to which four shift elements are assigned, in order to realize at least four gears.DE 10 2022 209 136 B3 (post-published) relates to a bottom bracket transmission of planetary design for a bicycle or pedelec with a pedal crankshaft as drive and a transmission output shaft as output, and at least four further shafts and three planetary gear sets. Five shift elements are provided to implement at least six gears.DE 10 2016 225 141 A1 relates to a transmission for a bicycle having a planetary set, an electric machine and a transmission, which has a transmission input shaft. A sun gear of the planetary gear set is connectable to the electric machine, a carrier to a pedal crankshaft and a ring gear to the transmission input shaft.DE 10 2016 225 162 A1 relates to a pedal bearing transmission for a bicycle, having a shift transmission with a shift transmission input shaft and a shift transmission output shaft. The transmission includes a minus planetary gear set and a plus planetary gear set, wherein elements of the first planetary gear set are connected to the transmission input and output shafts and an element of the second planetary gear set is connected to the transmission output shaft.DE 10 2022 203 240 B3 relates to a bottom bracket transmission of planetary design for a bicycle or pedelec with a crank shaft as drive and a transmission output shaft as output, as well as at least four further shafts and three planetary gear sets. At least five shift elements are provided in order to realize at least six gears.DE 10 2022 203 245 B3 relates to a bottom bracket transmission of planetary design for a bicycle or pedelec with a crank shaft as drive and a transmission output shaft as output, as well as at least five further shafts and three planetary gear sets. At least six shift elements are provided in order to realize at least six gears.The object of the present invention is to propose a bottom bracket transmission and a bicycle or pedelec with the bottom bracket transmission, which have the smallest possible construction outlay with properties improved compared to the prior art.This object is achieved according to the invention by the subject matter having the features of patent claims 1 and 15, respectively. Advantageous and claimed developments are evident from the dependent claims and the description and the drawings.Thus, a bottom bracket transmission of planetary construction for a bicycle or a pedelec is proposed. The bottom bracket transmission has a crank shaft as the drive and a transmission output shaft as the output and further shafts, wherein the output is preferably effected via a sprocket, a belt wheel or the like. Furthermore, the bottom bracket transmission comprises a first transmission shift group and a second transmission shift group, wherein the first transmission shift group comprises a first planetary gear set and a second planetary gear set, to which four shift elements are assigned, wherein the second transmission shift group comprises at least one third planetary gear set, to which at least two shift elements are assigned, wherein a first shaft as input shaft of the first transmission shift group 3 is connected to a third element of the first planetary gear set, wherein a fifth shaft as output shaft of the first transmission shift group is connected to a second element of the first planetary gear set, wherein a first element of the first planetary gear set is connected to a third element of the second planetary gear set, wherein a second element of the second planetary gear set can be fixed via a first shift element to a housing or to a stationary component or the like and can be connected via a fifth shift element to the third element of the first planetary gear set, and wherein a first element of the second planetary gear set is fixable to the housing via a second shift element and is connectable to the second element of the first planetary gear set via a sixth shift element.In this way, with the above-described connection of the first transmission shift group, in the proposed bottom bracket transmission with only two planetary gear sets provided and only four shift elements provided, a particularly simple and compact construction is realized in the bottom bracket transmission. In addition, particularly low component loads and an advantageously high toothing efficiency arise due to the geometric transmission range in the bottom bracket transmission compared to the known transmission.For the mechanical connection of elements, for example rotary elements or the like of the two planetary gear sets in the two transmission shift groups, preferably, in addition to the drive and output, further shafts or shaft-like elements are used, wherein the term shaft is not to be understood exclusively as a cylindrical, rotatably mounted machine element for transmitting torques, but rather also to be understood as general connection elements which connect the individual gear set elements to one another for transmitting torque.The axial sequence of the two transmission shift groups can be interchanged in the case of the proposed bottom bracket transmission. Consequently, the first transmission shift group is connected upstream or downstream of the second transmission shift group between the transmission input shaft or the crankshaft and the transmission output shaft of the bottom bracket transmission. In an upstream arrangement of the first transmission shift group, a pedal crank of the pedal bearing transmission connected to the transmission input shaft or pedal crankshaft is connected to the first shaft as a kind of input shaft of the first transmission shift group, and the fifth shaft of the first transmission shift group is connected on the input side to the second transmission shift group. It is possible for the pedal crankshaft and the first shaft to be embodied in one piece or in multiple pieces. In a downstream arrangement of the first transmission shift group, the first shaft is connected on the output side to the second transmission shift group and the fifth shaft of the first transmission shift group is connected to the transmission output shaft. It is possible for the transmission output shaft and the fifth shaft to be embodied in one piece or in multiple pieces.In the proposed bottom bracket transmission, an arbitrarily designed multi-stage second transmission shift group can be combined with the first transmission shift group as a treaded transmission. The second transmission shift group can preferably be designed as a two-speed transmission or two-speed group or as a four-speed transmission or four-speed group and the first transmission shift group as a four-speed transmission or four-speed group, so that, for example, an eight-speed transmission or else a sixteen-speed transmission is realized as a bottom bracket transmission. However, other gear numbers can also be realized in the transmission shift groups, so that the bottom bracket transmission can also realize more or less. Depending on the boundary conditions and requirements of the bottom bracket transmission, gears can also be omitted. In this way, the wheel set can be optimized to the required transmission ratios (gear jumps, spreading, etc.) or also to the type of shifting operations, as to how many shifting elements are involved.In order to connect the second transmission shift group, it can be provided, in order to achieve a particularly simple and compact structure of the bottom bracket transmission, that in the second transmission shift group, a third planetary gear set is provided as a two-gear group, to which a third shift element and a seventh shift element are assigned, wherein a second element of the third planetary gear set is connected to the bottom bracket shaft or to the fifth shaft of the first transmission shift group, that a first element of the third planetary gear set can be fixed to the housing via the third shift element, and wherein a third element of the third planetary gear set is connected to the first shaft of the first transmission shift group or to the transmission output shaft.In order to connect the second transmission shift group, it can be provided, in order to achieve a particularly simple and compact structure of the bottom bracket transmission, that in the second transmission shift group, the third planetary gear set and a fourth planetary gear set are provided as a four-speed group, to which the third shift element, a fourth shift element, the seventh shift element and an eighth shift element are assigned, wherein the second element of the third planetary gear set is connected to the bottom crank shaft or to the fifth shaft of the first transmission shift group, that the first element of the third planetary gear set can be fixed to the housing via the third shift element, and that the third element of the third planetary gear set is connected to a second element of the fourth planetary gear set, that a third element of the fourth planetary gear set can be fixed to the housing via a fourth shift element, and a first element of the fourth planetary gear set is connected to the first shaft of the first transmission shift group or to the transmission output shaft.For blocking the third planetary gear set in the second transmission shift group, two elements of the third planetary gear set can be connected to one another via the seventh shift element, so that a total of three different blocking variants result in the third planetary gear set.For blocking the fourth planetary gear set in the second transmission shift group, two elements of the fourth planetary gear set can be connected to one another via the eighth shift element, so that a total of three different blocking variants result in the fourth planetary gear set.Within the scope of the invention, it is provided in the proposed bottom bracket transmission with the two transmission shift groups that the shift elements provided can be designed as brakes, freewheel brakes, clutches and / or freewheels. An advantageous variant of the invention provides that the first shifting element is designed as a freewheel brake, that the second shifting element, the third shifting element and the fourth shifting element are each designed as a positive brake, that the fifth shifting element is designed as a positive clutch, and / or that the sixth shifting element, the seventh shifting element and the eighth shifting element are each designed as a freewheel.The shifting elements embodied as brakes and clutches are preferably embodied as form-locking shifting elements, for example as cost-effective brake claws or shifting claws or the like, for example with a toothed brake ring and a corresponding pawl. Brakes as shift elements have the advantage that they can be easily reached for actuation from the outside. In the case of clutches designed as freewheels, it is advantageous if the brakes are designed, for example, as one-way brakes, in order to prevent the transmission from blocking when the direction of rotation is reversed at the input or at the output. Preferably, non-actively switchable or actuatable freewheels are used as freewheels. This has the advantage that no switching actuation is required in the passive switching elements. The non-operable one-way clutch transmits a torque when it locks in the lock-up direction state. No torque is transmitted in the opposite direction of rotation, since the freewheel does not block in the overrun drive state. However, it is conceivable that actively switchable freewheels or also actively switchable freewheel brakes are also used.A preferred embodiment of the invention can provide that at least one of the planetary gear sets provided is designed as a minus planetary gear set, resulting in an arrangement which is particularly advantageous in terms of installation space. It is also conceivable for one of the planetary gear sets to be designed as a plus planetary gear set.A minus planetary gear set can preferably be transferred into a plus planetary gear set if the planetary gear carrier and ring gear connection on this gear set is interchanged with one another and the amount of the stationary transmission ratio is increased by 1. A minus planetary gear set has planetary gears rotatably mounted on its planetary gear carrier, which mesh with the sun gear and the ring gear of this planetary gear set, so that the ring gear rotates in the direction opposite to the sun gear rotation direction when the planetary gear carrier is held stationary and the sun gear rotates. A plus planetary gear set has inner and outer planetary gears rotatably mounted on its planetary gear carrier and in meshing engagement with one another, wherein the sun gear of this planetary gear set meshes with the inner planetary gears and the ring gear of this planetary gear set meshes with the outer planetary gears, so that the ring gear rotates in the same direction of rotation as the sun gear direction when the planetary gear carrier is held stationary and the sun gear rotates.This means for the person skilled in the art that in the individual gearsets designed as minus planetary gearsets, a first element or gearset element is designed as a sun gear, a second element is designed as a planet carrier or carrier, and a third element is designed as a ring gear. Furthermore, this means that in an individual gearset designed as a plus planetary gearset, the first element is designed as a sun gear, the second element is designed as a ring gear, and the third element is designed as a planet carrier or carrier.Furthermore, in the proposed bottom bracket transmission, it is conceivable that stepped planets are used both in a minus planetary gear set and in a plus planetary gear set. In the case of a minus stepped planetary gear set, the assignment of the elements or the gear set elements is maintained as in the case of a conventional minus planetary gear set. In a positive stepped planetary gearset, it is provided that the first element is designed as a first sun gear, the second element as a second sun gear and the third element as a planet carrier, or that the first element is designed as a first ring gear, the second element as a second ring gear and the third element as a planet carrier.In order to further optimize the control of the proposed bottom bracket transmission, it is provided that at least one torque sensor or the like is provided on the drive and / or on the output.In order to electrically support the drive in the proposed bottom bracket transmission, at least one electric machine or the like can be connected or connectable or permanently or releasably coupled to the drive or to the crank shaft or transmission input shaft and / or to the output or to the transmission output shaft. The electric machine can preferably be arranged axially parallel to the pedal crankshaft or transmission input shaft, while the planetary gear sets are arranged coaxially to the pedal crankshaft or transmission input shaft.A further aspect of the present invention claims a bicycle or pedelec with the above-described bottom bracket transmission. This results in the advantages and further advantages already described.The present invention is explained in more detail below with reference to the drawings.The following are shown: FIG. 1 shows a schematic basic view of a bottom bracket transmission according to the invention on a bicycle or a pedelec with a first transmission shift group connected upstream of a second transmission shift group; FIG. 2 shows a schematic basic view of the bottom bracket transmission according to the invention with the first transmission shift group connected downstream of the second transmission shift group; FIG. 3 shows a shift pattern with four shiftable gears of the first transmission shift group in the bottom bracket transmission; FIG. 4 shows a schematic basic view of a planetary gear set as a minus planetary gear set; FIG. 5 shows a schematic basic view of a planetary gear set as a plus planetary gear set; FIG. 6 shows a schematic basic view of a planetary gear set as a minus stepped planetary gear set; FIG. 7 shows a schematic basic view of a planetary gear set as a plus stepped planetary gear set with two sun gears; FIG. 8 shows a schematic basic view of a planetary gear set as a plus stepped planetary gear set with two ring gears; FIG. 9 shows a schematic basic view of the bottom bracket transmission with an embodiment of the second transmission shift group, which is connected downstream of the first transmission shift group as a four-speed transmission, as a two-speed transmission with a first locking variant in a third planetary gear set of the second transmission shift group; FIG. 10 shows a schematic basic view of the bottom bracket transmission with an embodiment of the second transmission shift group, which is connected downstream of the first transmission shift group as a four-speed transmission, as a two-speed transmission with a second blocking variant in the third planetary gear set of the second transmission shift group; FIG. 11 shows a schematic basic view of the bottom bracket transmission with an embodiment of the second transmission shift group, which is connected downstream of the first transmission shift group as a four-speed transmission, as a two-speed transmission with a third locking variant in the third planetary gear set of the second transmission shift group; FIG. 12 is a shift pattern of the eight speed pedal bearing transmission according to FIGS. 9 to 11; FIG. 13 shows a schematic basic view of the bottom bracket transmission with an embodiment of the second transmission shift group, which is connected downstream of the first transmission shift group as a four-speed transmission, as a four-speed transmission with a first locking variant in a third planetary gear set and with a first locking variant in a fourth planetary gear set of the second transmission shift group; FIG. 14 shows a schematic basic view of the bottom bracket transmission with an embodiment of the second transmission shift group, which is connected downstream of the first transmission shift group as a four-speed transmission, as a four-speed transmission with a first locking variant in a third planetary gear set and with a second locking variant in the fourth planetary gear set of the second transmission shift group; FIG. 15 shows a schematic basic view of the bottom bracket transmission with an embodiment of the second transmission shift group, which is connected downstream of the first transmission shift group as a four-speed transmission, as a four-speed transmission with a first locking variant in a third planetary gear set and with a third locking variant in the fourth planetary gear set of the second transmission shift group; FIG. 16 is a shift pattern of the sixteen speed pedal bearing transmission according to FIGS. 13 to 15 ; FIG. 17 shows a schematic basic view of the bottom bracket transmission according to FIG. 1 with a torque sensor indicated by way of example on the drive; FIG. 18 shows a schematic basic view of the bottom bracket transmission according to FIG. 17 with an electric machine arranged by way of example on the drive; FIG. 19 shows a schematic basic view of the bottom bracket transmission according to FIG. 17 with an electric machine arranged by way of example on the output; and FIG. 20 shows a schematic basic view of the bottom bracket transmission according to FIG. 17 with a freewheel in front of the crank shaft.FIGS. 1 to 20 show various embodiments and designs or shift patterns of a bottom bracket transmission according to the invention in planetary construction only by way of example. FIG. 1 shows, by way of example, a bicycle or pedelec 1 with the bottom bracket transmission, which is only indicated schematically.The pedal transmission is shown in a housing or pedal housing 2 with a pedal crank with pedals as a pedal crank shaft WAn, wherein the pedal crank shaft WAn is connected on the input side to one of the transmission shift groups 3, 4. Furthermore, the bottom bracket transmission comprises a transmission output shaft WAb as output with a not further illustrated chain wheel or belt wheel, which is connected on the output side to one of the transmission shift groups 3, 4. The bottom bracket transmission comprises a multi-stage first transmission shift group 3 and a multi-stage second transmission shift group 4, wherein the first transmission shift group 3 has a first planetary gear set RS 1 and a second planetary gear set RS 2, to which a first shift element B 1 as a freewheel brake, a second shift element B 2 as a positive brake, a fifth shift element K 1 as a positive clutch and a sixth shift element K 2 as a freewheel are assigned, and wherein the second transmission shift group 4 has, depending on the design, a third planetary gear set RS 3 and / or a fourth planetary gear set RS 4, to which a third shift element B 3 as a positive brake and a seventh shift element K 3 as a freewheel and / or a fourth shift element B 4 as a positive brake and an eighth shift element K 4 as a freewheel are assigned. The two transmission shift groups 3, 4 form virtually two subtransmissions which can be interconnected with one another in any desired sequence with respect to the force flow direction between the pedal crankshaft WAn and the transmission output shaft WAb.Independently of the respective variant embodiments, it is provided in the bottom bracket transmission that a first shaft W 1 as input shaft of the first transmission shift group 3 is connected to a third element of the first planetary gear set RS 1, wherein a fifth shaft W 5 as output shaft of the first transmission shift group 3 is connected to a second element of the first planetary gear set RS 1, wherein a first element of the first planetary gear set RS 1 is connected to a third element of the second planetary gear set RS 2, wherein a second element of the second planetary gear set RS 2 can be fixed to the housing 2 via the first shift element B 1 and can be connected to the third element of the first planetary gear set RS 1 via the fifth shift element K 1, and wherein a first element of the second planetary gear set RS 2 can be fixed to the housing 2 via the second shift element B 2 and can be connected to the second element of the first planetary gear set RS 1 via the sixth shift element K 2.In FIGS. 1 and 2 and also 9 to 11 and 13 to 15 and 17 to 20, the planetary gear sets RS 1, RS 2, RS 3, RS 4 provided are each designed as minus planetary gear sets which are advantageous in terms of installation space. In this case, it is provided that a sun gear SR 1, SR 2, SR 3, SR 4 is provided as the first element, a carrier or planet carrier PT 1, PT 2, PT 3, PT 4 is provided as the second element, and a ring gear HR 1, HR 2, HR 3, HR 4 is provided as the third element in the planetary gear sets RS 1, RS 2, RS 3, RS 4.FIG. 1 shows an embodiment variant of the bottom bracket transmission in which the first transmission shift group 3 is connected upstream of the second transmission shift group 4. In detail, in the first embodiment variant according to FIG. 1, it is provided that the first shaft W 1 as input shaft of the first transmission shift group 3 is connected to the pedal crankshaft WAn or is formed integrally therewith, that the first shaft W 1 is connected to the ring gear HR 1 of the first planetary gear set RS 1, that the fifth shaft W 5 is connected on the input side to the second transmission shift group 4, that the fifth shaft W 5 as output shaft of the first transmission shift group 3 is connected to the planet carrier PT 1 of the first planetary gear set RS 1, that the sun gear SR 1 of the first planetary gear set RS 1 is connected to the ring gear HR 2 of the second planetary gear set RS 2 via a fourth shaft W 4, that the planet carrier PT2 of the second planetary gear set can be fixed to the housing 2 via a second shaft W2 when the first shift element B1 is locked and can be connected to the ring gear HR1 of the first planetary gear set RS1 via the first shaft W1 when the fifth shift element K1 is closed, and that the sun gear SR2 of the second planetary gear set RS2 can be fixed to the housing 2 via a third shaft W3 when the second shift element B2 is closed and can be connected to the planet carrier PT1 of the first planetary gear set RS1 via the fifth shaft W5 when the sixth shift element K2 is locked.FIG. 2 shows an embodiment variant of the bottom bracket transmission, in which the first transmission shift group 3 is arranged downstream of the second transmission shift group 4. In detail, in the embodiment variant according to FIG. 2, it is provided that the pedal crankshaft WAn is connected on the input side to the second transmission shift group 4, that the first shaft W 1 as input shaft of the first transmission shift group 3 is connected on the output side to the second transmission shift group 4, that the first shaft W 1 is connected to the ring gear HR 1 of the first planetary gear set RS 1, that the fifth shaft W 5 as output shaft of the first transmission shift group 3 is connected to the transmission output shaft WAb or is formed integrally therewith, that the fifth shaft W 5 as output shaft of the first transmission shift group 3 is connected to the planetary gear carrier PT 1 of the first planetary gear set RS 1, the sun gear SR1 of the first planetary gear set RS1 is connected via the fourth shaft W4 to the ring gear HR2 of the second planetary gear set RS2, the planet carrier PT2 of the second planetary gear set RS2 is fixable via the second shaft W2 to the housing 2 when the first shift element B1 is locked and is connectable via the first shaft W1 to the ring gear HR1 of the first planetary gear set RS1 when the fifth shift element K1 is closed, and in that the sun gear SR2 of the second planetary gear set R2 can be fixed to the housing 2 via the third shaft W3 when the second shift element B2 is closed and can be connected to the planet carrier PT1 of the first planetary gear set RS1 via the fifth shaft W5 when the sixth shift element K2 is locked.FIG. 3 shows a shift pattern for the first transmission shift group 3 as a four-speed transmission. This results in four gears V 1, V 2, V 3, V 4 being able to be realized by the first transmission shift group 3. The shift pattern specifies the shift elements B 1, B 2, K 1, K 2 used for the respective gear V 1, V 2, V 3, V 4. Here, an X in the case of the freewheel K 2 or the freewheel brake B 1 as shift elements in the shift pattern means that the freewheel or the freewheel brake are locked. This works automatically without external actuation. Further, in a brake B 2 or a clutch K 1 as a shift element in the shift pattern, an X means that the brake B 2 or the clutch K 1 is closed. This functions via a suitable actuator system. An empty field in the case of the freewheel K 2 or the freewheel brake B 1 means that they do not block. An empty field in the brake B 2 or the clutch K 1 means that they are open.In detail, it follows from the shift pattern according to FIG. 3 that, for the realization or shifting of a first gear V 1, the first shift element B 1 designed as a free-wheeling brake and the sixth shift element K 2 designed as a free-wheeling brake block, that, for the shifting of a second gear V 2, the first shift element B 1 designed as a free-wheeling brake blocks and the second shift element B 2 designed as a brake is closed, that, for the shifting of a third gear V 3, the fifth shift element K 1 designed as a clutch is closed and the sixth shift element K 2 designed as a free-wheeling clutch blocks, and / or that, for the shifting of a fourth gear V 4, the second shift element B 2 designed as a brake and the fifth shift element K 1 designed as a clutch are closed.FIG. 4 shows, by way of example, a minus planetary gear set in which the first element is designed as a sun gear 1-SR, the second element is designed as a planet carrier 2-PT and the third element is designed as a ring gear 3-HR.FIG. 5 shows, by way of example, a plus planetary gear set in which the first element is designed as a sun gear 1-SR, the second element is designed as a ring gear 2-HR and the third element is designed as a planet carrier 3-PT.FIG. 6 shows, by way of example, a minus stepped planetary gearset in which the first element is designed as a sun gear 1-SR, the second element as a planet carrier 2-PT and the third element as a ring gear 3-HR.FIG. 7 shows, by way of example, a plus stepped planetary gearset in which the first element is designed as a first sun gear 1-SRA, the second element as a second sun gear 2-SRB and the third element as a planet carrier 3-PT.FIG. 8 shows, by way of example, a further embodiment of a positive stepped planetary gearset in which the first element is designed as a first ring gear 1-HRA, the second element as a second ring gear 2-HRB and the third element as a planet carrier 3-PT.The possible embodiments illustrated in FIGS. 4 to 8 with reference to a planetary gear set can be implemented on the specific planetary gear sets RS 1, RS 2, RS 3, RS 4 of the bottom bracket transmission according to the invention.FIGS. 9 to 11 show the bottom bracket transmission by way of example with a first transmission shift group 3 as a four-speed transmission group and with a second transmission shift group 4 as a two-speed transmission group, wherein the first transmission shift group 3 is connected upstream of the second transmission shift group 4. However, it is easily possible that the order of the transmission shift groups 3, 4 can be interchanged. The second transmission shift group 4 comprises the third planetary gear set RS 3, to which the third shift element B 3 and the seventh shift element K 3, K 3 I, K 3 II are assigned.In detail, for the connection of the second transmission shift group 4 to the first transmission shift group 3 in FIGS. 9 to 11, it is provided that in the second transmission shift group 4 the planet carrier PT 3 of the third planetary gear set RS 3 is connected to the fifth shaft W 5 as output shaft of the first transmission shift group 3, that the sun gear SR 3 of the third planetary gear set RS 3 can be fixed to the housing 2 via a sixth shaft W 6 when the third shift element B 3 is closed, that the ring gear HR 3 of the third planetary gear set RS 3 is connected via a seventh shaft W 7 or directly to the transmission output shaft WAb.For blocking the third planetary gear set RS 3, within the scope of a first blocking variant shown in FIG. 9, the ring gear HR 3 is connected to the sun gear SR 3 of the third planetary gear set RS 3 when the seventh shift element K 3 is blocked in a first arrangement variant of the seventh shift element K 3.In a second blocking variant of the third planetary gear set RS 3 illustrated in FIG. 10, the sun gear SR 3 of the third planetary gear set RS 3 is connected in I with the planetary carrier PT 3 of the third planetary gear set RS 3 when the seventh shift element K 3 is blocked in a second arrangement variant of the seventh shift element K 3 I.In a third blocking variant of the third planetary gear set RS 3 illustrated in FIG. 11, the ring gear HR 3 of the third planetary gear set RS 3 is connected in II with the planet carrier PT 3 of the third planetary gear set RS 3 when the seventh shift element K 3 is locked in a third arrangement variant of the seventh shift element K 3 II.FIG. 12 shows a shift pattern for the bottom bracket transmission with the first transmission shift group 3 as a four-speed transmission and with the second transmission shift group 4 as a two-speed transmission. It follows from this that 4 x 2, i.e. eight gears V 1, V 2, V 3, V 4, V 5, V 6, V 7, V 8, can be realized. The shift pattern shows the shift elements B 1, B 2, B 3, K 1, K 2, K 3, K 3 I, K 3 II used for the respective gear V 1, V 2, V 3, V 4, V 5, V 6, V 7, V 8. Here, an X in the freewheels K 2, K 3 or the freewheel brake B 1 as shift elements in the shift pattern means that the freewheels or the freewheel brake block. This works automatically without external actuation. Further, in a brake B 2, B 3 or a clutch K 1 as a shift element in the shift pattern, an X means that the brake B 2, B 3 or the clutch K 1 is closed. This functions via a suitable actuator system. An empty field in the freewheels K 2, K 3, K 3 I, K 3 II or the freewheel brake B 1 means that they do not block. An empty field in the brakes or the clutch B 2, B 3, K 1 means that they are open.In detail, it follows from the shift pattern according to FIG. 12 that, for the realization or shifting of a first gear V 1, the first shift element B 1 designed as a free-wheeling brake, the sixth shift element K 2 designed as a free-wheeling brake and the seventh shift element K 3, K 3 I, K 3 II block, that, for the shifting of a second gear V 2, the first shift element B 1 designed as a free-wheeling brake blocks and the second shift element B 2 designed as a brake is closed and the seventh shift element K 3, K 3 I, K 3 II designed as a free-wheeling brake blocks, that, for shifting a third gear V3, the first shift element B1 designed as a free-wheeling brake is locked and the third shift element B3 designed as a brake is closed and the sixth shift element K2 designed as a free-wheeling lock, that for shifting a fourth gear V4, the first shift element B1 designed as a free-wheeling brake is locked and the second shift element B2 and the third shift element B3 designed as a brake are closed, that for shifting a fifth gear V5, the fifth shift element K1 designed as a clutch is closed and the sixth shift element K2 designed as a free-wheeling lock and the seventh shift element K3, K3 I, K3 II designed as a free-wheeling lock, that for shifting a sixth gear V 6, the second shifting element B 2 designed as a brake and the fifth shifting element K 1 designed as a clutch are closed and the seventh shifting element K 3, K 3 I, K 3 II designed as a freewheel are locked, that for shifting a seventh gear V 7, the third shifting element B 3 designed as a brake and the fifth shifting element K 1 designed as a clutch are closed and the sixth shifting element K 2 designed as a freewheel are locked, and / or that for shifting an eighth gear V 8, the second shifting element B 2 designed as a brake, the third shifting element B 3 designed as a brake and the fifth shifting element K 1 designed as a clutch are closed.FIGS. 13 to 15 show the bottom bracket transmission by way of example with a first transmission shift group 3 as a four-speed transmission group and with a second transmission shift group 4 as a four-speed transmission group, the first transmission shift group 3 being connected upstream of the second transmission shift group 4. However, it is easily possible that the order of the transmission shift groups 3, 4 can be interchanged. The second transmission shift group 4 comprises the third planetary gear set RS 3 and the fourth planetary gear set RS 4, to which the third shift element B 3, the fourth shift element B 4, the seventh shift element K 3, K 3 I, K 3 II and the eighth shift element K 4, K 4 I, K 4 II are assigned.In detail, for the connection of the second transmission shift group 4 to the first transmission shift group 3 in FIGS. 13 to 15, it is provided that in the second transmission shift group 4 the planet carrier PT 3 of the third planetary gear set RS 3 is connected to the fifth shaft W 5 as output shaft of the first transmission shift group 3, that the sun gear SR 3 of the third planetary gear set RS 3 can be fixed to the housing 2 via the sixth shaft W 6 when the third shift element B 3 is closed, that the ring gear HR 3 of the third planetary gear set RS 3 is connected to the planet carrier PT 4 of the fourth planetary gear set RS 4 via the seventh shaft, that the ring gear HR 4 of the fourth planetary gear set RS 4 can be fixed to the housing 2 when the fourth shift element B 4 is closed, and that the sun gear SR 4 of the fourth planetary gear set RS 4 is connected to the transmission output shaft WAb. Furthermore, the first blocking variant of the third planetary gear set RS 3 is shown by way of example via the seventh shift element K 3, wherein the two further blocking variants of the third planetary gear set RS 3 already described above are likewise possible.For blocking the fourth planetary gear set RS 4, within the scope of a first blocking variant shown in FIG. 13, the ring gear HR 4 of the fourth planetary gear set RS 4 is connected to the sun gear SR 4 of the fourth planetary gear set RS 4 in a first arrangement variant of the eighth shifting element K 4 when the eighth shifting element K 4 is blocked.In a second blocking variant of the fourth planetary gear set RS 4 illustrated in FIG. 14, the planet carrier PT 4 of the fourth planetary gear set RS 4 is connected in I with the sun gear SR 4 of the fourth planetary gear set RS 4 when the eighth shift element K 4 is blocked in a second arrangement variant of the eighth shift element K 4.In a third blocking variant of the fourth planetary gear set RS 4 illustrated in FIG. 15, the ring gear HR 4 of the fourth planetary gear set RS 4 is connected in II with the planetary gear carrier PT 4 of the fourth planetary gear set RS 4 when the eighth shift element K 4 is locked in a third arrangement variant of the eighth shift element K 4.FIG. 16 shows a shift pattern for the bottom bracket transmission with the first transmission shift group 3 as a four-speed transmission and with the second transmission shift group 4 as a four-speed transmission. It follows from this that 4×4, i.e. sixteen gears V 1, V 2, V 3, V 4, V 5, V 6, V 7, V 8, V 9, V 10, V 11, V 12, V 13, V 14, V 15, V 16, can be realized. The shift pattern specifies the switching elements B 1, B 2, B 3, B 4, K 1, K 2, K 3, K 3 I, K 3 II, K 4, K 4 I, K 4 II used for the respective gear V 1, V 2, V 3, V 4, V 7, V 8, V 9, V 10, V 11, V 12, V 13, V 14, V 15, V 16. Here, an X in the freewheels K 2, K 3, K 3 I, K 3 II, K 4, K 4 I, K 4 II or the freewheel brake B 1 as shift elements in the shift pattern means that the freewheels or the freewheel brake block. This works automatically without external actuation. Further, in a brake B 2, B 3, B 4 or a clutch K 1 as a shift element in the shift pattern, an X means that the brake B 2, B 3, B 4 or the clutch K 1 is closed. This functions via a suitable actuator system. An empty field in the freewheels K 2, K 3, K 3 I, K 3 II, K 4, K 4 I, K 4 II or the freewheel brake B 1 means that they do not block. An empty field in the brakes or the clutch B 2, B 3, B 4, K 1 means that they are open.In detail, it follows from the shift pattern according to FIG. 16 that, for the realization or shifting of a first gear V 1, the first shift element B 1 designed as a free-wheeling brake, the sixth shift element K 2 designed as a free-wheeling brake, the seventh shift element K 3, K 3 I, K 3 II designed as a free-wheeling brake and the eighth shift element K 4, K 4 I, K 4 II block, that, for the shifting of a second gear V 2, the first shift element B 1 designed as a free-wheeling brake blocks and the second shift element B 2 designed as a brake is closed and the seventh shift element K 3, K 3 I, designed as a free-wheeling brake, K3 II and the eighth shift element K4, K4 I, K4 II designed as a freewheel block that, for shifting a third gear V3, the first shift element B1 designed as a freewheel brake blocks and the third shift element B3 designed as a brake is closed, and the sixth shift element K2 designed as a freewheel and the eighth shift element K4, K4 I, K4 II block that, for shifting a fourth gear V4, the first shift element B1 designed as a freewheel brake blocks, and the second shift element B2 designed as a brake and the third shift element B3 designed as a brake are closed, and the eighth shift element K4 designed as a freewheel block, K4 I, K4 II inhibits that, for shifting a fifth gear V5, the fifth shift element K1 designed as a clutch is closed, and the sixth shift element K2 designed as a freewheel, the seventh shift element K3, K3 I, K3 II designed as a freewheel and the eighth shift element K4, K4 I, K4 II inhibit that, for shifting a sixth gear V6, the second shift element B2 designed as a brake and the fifth shift element K1 designed as a clutch are closed, and the seventh shift element K3, K3 I, designed as a freewheel are closed, K3 II and the eighth shift element K4, K4 I, K4 II designed as a freewheel block that, for the shifting of a seventh gear V7, the third shift element B3 designed as a brake and the fifth shift element K1 designed as a clutch are closed, and the sixth shift element K2 designed as a freewheel and the eighth shift element K4, K4 I, K4 II block that, for the shifting of an eighth gear V8, the second shift element B2 designed as a brake, the third shift element B3 designed as a brake and the fifth shift element K1 designed as a clutch are closed, and the eighth shift element K4, K4 I, designed as a freewheel block, K4 II blocks that, for shifting a ninth gear V9, the first shifting element B1 designed as a free-wheeling brake blocks and the fourth shifting element B4 designed as a brake is closed and the sixth shifting element K2 designed as a free-wheeling and the seventh shifting element K3, K3 I, K3 designed as a free-wheeling block, that, for shifting a tenth gear V10, the first shifting element B1 designed as a free-wheeling brake blocks and the second shifting element B2 designed as a brake and the fourth shifting element B4 designed as a brake are closed and the seventh shifting element K3, K3 I, K3 II designed as a free-wheeling block, wherein, for shifting an eleventh gear V11, the first shifting element B1 designed as a free-wheeling brake is locked, and the third shifting element B3 designed as a brake and the fourth shifting element B4 designed as a brake are closed, and the sixth shifting element K2 designed as a free-wheeling brake is locked, that, for shifting a twelfth gear V12, the first shifting element B1 designed as a free-wheeling brake is locked, and the second shifting element B2, the third shifting element B3 designed as a brake and the fourth shifting element B4 designed as a brake are closed, that, for shifting a thirteenth gear V13, the fourth shifting element B4 designed as a brake and the fifth shifting element K1 designed as a clutch are closed, and the sixth shifting element K2 designed as a free-wheeling and the seventh shifting element K3, K3 I, designed as a free-wheeling clutch are closed, K3 II block that, for shifting a fourteenth gear V14, the second shifting element B2, the fourth shifting element B4 and the fifth shifting element K1 designed as a brake are closed and the seventh shifting element K3, K3 I, K3 II designed as a freewheel are closed, that, for shifting a fifteenth gear V15, the third shifting element B3, the fourth shifting element B4 and the fifth shifting element K1 designed as a brake are closed and the sixth shifting element K2 designed as a freewheel are locked, and / or that, for shifting a sixteenth gear V16, the second shifting element B2, the third shifting element B3 designed as a brake are closed, the fourth shift element B 4 designed as a brake and the fifth shift element K 1 designed as a clutch are closed.FIG. 17 shows an embodiment of the bottom bracket transmission according to the invention with reference to FIG. 1, in which a torque sensor 5 is connected or connectable to the pedal crankshaft or to the transmission input shaft WAn. For example, a disk-shaped torque sensor 5 can be arranged at the transmission input. However, the torque sensor 5 can also be implemented in a different manner.FIGS. 18 and 19 each show an embodiment of the bottom bracket transmission according to the invention with an additional electric machine EM on the basis of FIG. 17. The electric machine EM can be connected to the pedal crankshaft WAn, as is indicated in FIG. 18. It is also conceivable for the electric machine EM to be linked to the transmission output shaft WAb, as shown in FIG. 19. The electric machine EM is preferably arranged axially parallel to the pedal crankshaft or transmission input shaft WAn. However, a coaxial arrangement of the electric machine EM with respect to the pedal crankshaft would also be possible. Independently of this, it is advantageous to connect the electric machine EM via a freewheel F 0 or the like, so that no losses are caused by the co-rotating electric machine EM during operation without the electric machine EM.FIG. 20 shows an embodiment of the bottom bracket transmission according to the invention with reference to FIG. 17 with an additional freewheel F 1 between the crank and the transmission input of the bottom bracket transmission. In this way, in the event of a pedaling interruption, the freewheel can open and decouple the pedal crank from the inertial masses of the gear wheel set and in particular of the electric machine EM, so that no mass forces can be perceptible at the pedal.Reference numerals denote reference numerals1 Bicycle or Pedelec 2 Housing or bottom bracket housing 3 First transmission shift group 4 Second transmission shift group 5 Torque sensor EM Electric machine F 0 Freewheel for electric machine F 1 Additional freewheel SR 1 Sun gear of the first planetary gear set PT 1 Planet carrier of the first planetary gear set HR 1 Ring gear of the first planetary gear set SR 2 Sun gear of the second planetary gear set PT 2 Planet carrier of the second planetary gear set HR 2 Ring gear of the second planetary gear set SR 3 Sun gear of the third planetary gear set PT 3 Planet carrier of the third planetary gear set HR 3 Ring gear of the third planetary gear set SR 4 Sun gear of the fourth planetary gear set PT 4 Planet carrier of the fourth planetary gear set HR 4 Ring gear of the fourth planetary gear set RS 1 First planetary gear set rs2 second planetary gear set RS3 third planetary gear set RS4 fourth planetary gear set WAn transmission input shaft or pedal crankshaft WAb transmission output shaft W1 first shaft W2 second shaft W3 third shaft W4 fourth shaft W5 fifth shaft W6 sixth shaft W7 seventh shaft V1 first gear of the pedal transmission V2 second gear of the pedal transmission V3 third gear of the pedal transmission V4 fourth gear of the pedal transmission V5 fifth gear of the pedal transmission V6 sixth gear of the pedal transmission V7 seventh gear of the pedal transmission V8 eighth gear of the pedal transmission V9 ninth gear of the pedal transmission V10 Tenth gear of the bottom bracket transmission V 11 eleventh gear of the bottom bracket transmission V 12 twelfth gear of the bottom bracket transmission V 13 thirteenth gear of the bottom bracket transmission V 14 fourteenth gear of the bottom bracket transmission V 15 fifteenth gear of the bottom bracket transmission V 16 sixteenth gear of the bottom bracket transmission B 1 first shifting element B 2 second shifting element B 3 third shifting element B 4 fourth shifting element K 1 fifth shifting element K 2 sixth shifting element K 3 seventh shifting element configured as free wheel in a first arrangement variant K 3 I seventh shifting element configured as free wheel in a second arrangement variant k3 II seventh shift element embodied as a freewheel in a third arrangement variant K4 eighth shift element embodied as a freewheel in a first arrangement variant K4 I eighth shift element embodied as a freewheel in a second arrangement variant K4 II eighth shift element embodied as a freewheel in a third arrangement variant 1-SR first element as a sun gear 2-PT second element as a planet carrier 2-HR second element as a ring gear 3-HR third element as a ring gear 3-PT third element as a planet carrier 1-SRA first element as a first sun gear 2-SRB second element as a second sun gear 1-HRA first element as a first ring gear 2-HRB first element as a second ring gear

Claims

Bottom bracket transmission in planetary construction for a bicycle or a pedelec (1), having a crank shaft (WAn) as drive, having a transmission output shaft (WAb) as output and having further shafts (W1, W2, W3, W4, W5, W6, W7) and having a first transmission shift group (3) and a second transmission shift group (4), wherein the first transmission shift group (3) comprises a first planetary gear set (RS1) and a second planetary gear set (RS2), to which four shift elements (B1, B2, K1, K2) are assigned, wherein the second transmission shift group (4) comprises at least one planetary gear set (RS3, RS4), to which at least two shift elements (B3, B4, K3, K3 I, K3 II, K4, K4 I, K4 II) wherein a first shaft (W1) as input shaft of the first transmission shift group (3) is connected to a third element of the first planetary gear set (RS1), wherein a fifth shaft (W5) as output shaft of the first transmission shift group (3) is connected to a second element of the first planetary gear set (RS1), wherein a first element of the first planetary gear set (RS1) is connected to a third element of the second planetary gear set (RS2), wherein a second element of the second planetary gear set (RS2) can be fixed to a housing (2) via a first shift element (B1) and can be connected to the third element of the first planetary gear set (RS1) via a fifth shift element (K1), and wherein a first element of the second planetary gear set (RS2) can be fixed to the housing (2) via a second shift element (B2) and can be connected to the second element of the first planetary gear set (RS1) via a sixth shift element (K2).Bottom bracket transmission according to Claim 1, characterized in that the first transmission shift group (3) is arranged upstream or downstream of the second transmission shift group (4).Bottom bracket transmission according to one of the preceding claims, characterized in that the second transmission shift group (4) comprises at least one third planetary gear set (RS3), to which at least one third shift element (B3) and a seventh shift element (K3, K3 I, K3 II) are assigned, wherein a second element of the third planetary gear set (RS3) is connected to the crank shaft (WAn) or to the fifth shaft (W5) of the first transmission shift group (3), and in that a first element of the third planetary gear set (RS3) can be fixed to the housing (2) via a third shift element (B3), and a third element of the third planetary gear set (RS 3) is connected to the first shaft (W 1) of the first transmission shift group (3) or to the transmission output shaft (WAb).Pedal transmission according to either of Claims 1 and 2, characterized in that the second transmission shift group (4) comprises at least one third planetary gear set (RS3) and one fourth planetary gear set (RS4), to which at least one third shift element (B3), one fourth shift element (B4), one seventh shift element (K3, K3 I, K3 II) and one eighth shift element (K4, K4 I, K4 II) are assigned, a second element of the third planetary gear set (RS3) being connected to the pedal crankshaft (WAn) or to the fifth shaft (W5) of the first transmission shift group (3), a first element of the third planetary gear set (RS3) is fixable to the housing (2) via a third shift element (B3), and a third element of the third planetary gear set (RS3) is connected to a second element of the fourth planetary gear set (RS4), a third element of the fourth planetary gear set (RS4) is fixable to the housing (2) via a fourth shift element (B4), and a first element of the fourth planetary gear set (RS4) is connected to the first shaft (W1) of the first transmission shift group (3) or to the transmission output shaft (WAb).Bottom bracket transmission according to one of the preceding claims, characterized in that in the second transmission shift group (4) for blocking the third planetary gear set (RS3), two elements of the third planetary gear set (RS3) can be connected to one another via the seventh shift element (K3, K3 I, K3 II).Bottom bracket transmission according to one of the preceding claims, characterized in that in the second transmission shift group (4) for blocking the fourth planetary gear set (RS4), two elements of the fourth planetary gear set (RS4) can be connected to one another via the eighth shift element (K4, K4 I, K4 II).Pedal transmission according to one of the preceding claims, characterized in that the first shift element (B1) is designed as a freewheel brake, in that the second shift element (B2), the third shift element (B3) and the fourth shift element (B4) are each designed as a positively locking brake, in that the fifth shift element (K1) is designed as a positively locking clutch, and / or in that the sixth shift element (K2) and the seventh shift element (K3) and the eighth shift element (K4) are each designed as a freewheel.Bottom bracket transmission according to one of the preceding claims, characterized in that the first planetary gear set (RS1) and / or the second planetary gear set (RS2) and / or the third planetary gear set (RS3) and / or the fourth planetary gear set (RS4) are each designed as a minus planetary gear set.Pedal transmission according to Claim 8, characterized in that, in the case of a minus planetary gear set, the first element is designed as a sun wheel (SR1, SR2, SR3, SR4), the second element is designed as a planet wheel carrier (PT1, PT2, PT3, PT4) and the third element is designed as a ring wheel (HR1, HR2, HR3, HR4).Bottom bracket transmission according to one of the preceding claims, characterized in that the first planetary gear set (RS1) and / or the second planetary gear set (RS2) and / or the third planetary gear set (RS3) and / or the fourth planetary gear set (RS4) are each designed as a plus planetary gear set.Pedal transmission according to Claim 10, characterized in that, in the case of a positive planetary gear set, the first element is designed as a sun wheel (SR1, SR2, SR3, SR4), the second element is designed as a ring wheel (HR1, HR2, HR3, HR4) and the third element is designed as a planet wheel carrier (PT1, PT2, PT3, PT4. Over).Pedal transmission according to one of the preceding claims, characterized in that a torque sensor (5) is connected to the pedal crankshaft (WAn).Pedal transmission according to one of the preceding claims, characterized in that at least one electric machine (EM) is connected or can be connected to the pedal crankshaft (WAn) or to the transmission output shaft (WAb).Pedal bearing transmission according to Claim 13, characterized in that the electric machine (EM) is arranged axially parallel to the pedal crankshaft (WAn).Bicycle or pedelec (1) with the bottom bracket transmission according to one of the preceding claims.

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