Planetary bottom bracket gearbox for a bicycle or e-bike

Abstract

The present invention relates to a planetary bottom bracket gearbox for a bicycle or pedelec (1), with a crankshaft (WAn) as the drive and a gearbox output shaft (WAb) as the driven shaft, as well as further shafts (W1, W2, W3, W4, W5, W6), with three planetary gear sets (RS1, RS2, RS3), and with six switching elements (B1, B2, B3, K1, K2, K3, K3 I , K3 II ) for realizing multiple gears (G1, G2, G3, G4, G5, G6, G7, G8), wherein a first gear shift group (3) is assigned a first planetary gear set (RS1) and a second planetary gear set (RS2) as well as a first shift element (B1), a second shift element (B2), a fourth shift element (K1) and a fifth shift element (K2), wherein a second gear shift group (4) is assigned a third planetary gear set (RS3) as well as a third shift element (B3) and a sixth shift element (K3, K3 I , K3 II). are assigned. Furthermore, the invention relates to a bicycle or pedelec (1) with a bottom bracket gearbox.

Description

[0001] The present invention relates to a planetary bottom bracket gear for a bicycle or pedelec, comprising a pedal crankshaft as the input and a transmission output shaft as the output, as well as additional shafts, with three planetary gear sets, and with six shifting elements for implementing multiple gears. Furthermore, the invention relates to a bicycle or pedelec with the bottom bracket gear.

[0002] For example, from the publication DE 10 2022 207 262 B3, a planetary bottom bracket gear for a bicycle or pedelec is known. The bottom bracket gear has a pedal crankshaft as the input and a transmission output shaft as the output, as well as at least five additional shafts, wherein the output is preferably via a chain wheel, a belt wheel, or the like. Furthermore, the bottom bracket gear comprises three planetary gear sets arranged coaxially to the pedal crankshaft and six shifting elements for implementing at least eight gears in the bottom bracket gear. Furthermore, a first sub-transmission with a first planetary gear set is provided, wherein a first shifting element and a fourth shifting element are assigned to the first sub-transmission.Furthermore, a second sub-transmission with a second planetary gear set and a third planetary gear set is provided as a positive planetary gear set, wherein a second shifting element, a third shifting element, a fifth shifting element, and a sixth shifting element are assigned to the second sub-transmission. To interlock the first planetary gear set, two elements of the first planetary gear set can be connected to one another via the fourth shifting element.

[0003] Furthermore, the publications DE 10 2022 203 245 B3, DE 10 2022 207 261, and DE 10 2022 209 136 disclose a planetary bottom bracket gear for a bicycle or pedelec, as well as a bicycle or pedelec with the planetary bottom bracket gear. Furthermore, the publication DE 10 2022 207 394 B3 discloses a planetary bottom bracket gear for a bicycle, as well as a bicycle with the planetary bottom bracket gear.

[0004] The present invention is based on the object of proposing a bottom bracket gear and a bicycle or pedelec with the bottom bracket gear, which have the lowest possible construction effort with improved properties compared to the prior art.

[0005] The problem is solved by the subject matter of the independent patent claims. Advantageous and claimed developments emerge from the dependent claims, the description, and the drawings.

[0006] Thus, a planetary bottom bracket gear for a bicycle or pedelec is proposed. The bottom bracket gear comprises a crankshaft as the input and a transmission output shaft as the output, as well as additional shafts, with the output preferably being provided via a sprocket, a belt pulley, or the like. Furthermore, the bottom bracket gear comprises three planetary gear sets and six shifting elements for implementing, for example, eight gears in the proposed bottom bracket gear.In order to realize a particularly effective and space-saving design for the bottom bracket gear, a first gear shifting group and a second gear shifting group are provided, wherein a first planetary gear set and a second planetary gear set as well as a first shifting element, a second shifting element, a fourth shifting element and a fifth shifting element are assigned to the first gear shifting group, wherein a third planetary gear set as well as a third shifting element and a sixth shifting element are assigned to the second gear shifting group, wherein either the pedal crankshaft is connected to a second element of the second planetary gear set, the transmission output shaft is connected to a third element of the third planetary gear set, a first element of the first planetary gear set is connected to a housing orcan be fixed to any stationary component and can be connected to the second element of the second planetary gear set and to the pedal crankshaft via the fourth switching element, a second element of the first planetary gear set can be fixed to the housing via a second switching element and can be connected to the third element of the second planetary gear set and to the second element of the third planetary gear set via the fifth switching element or the pedal crankshaft is connected to a second element of the third planetary gear set, the transmission output shaft is connected to a third element of the second planetary gear set, a first element of the first planetary gear set is connected to a housing orcan be fixed to any stationary component and can be connected to the second element of the second planetary gear set and to the third element of the third planetary gear set via the fourth shifting element, a second element of the first planetary gear set can be fixed to the housing via a second shifting element and can be connected to the third element of the second planetary gear set and to the transmission output shaft via the fifth shifting element, wherein a first element of the second planetary gear set is connected to a third element of the first planetary gear set, wherein a first element of the third planetary gear set can be fixed to the housing via a third shifting element, and wherein, in order to block the third planetary gear set, two elements of the third planetary gear set can be connected to one another via the sixth shifting element.

[0007] The proposed bottom bracket transmission thus essentially consists of two gear shift groups or group transmissions, whereby the first gear shift group can, for example, form a 4-speed group, while the second gear shift group can, for example, form a 2-speed group, so that a total of eight gears can be realized. The axial order of the two coupled gear shift groups can be interchanged in the proposed bottom bracket transmission. Accordingly, the first gear shift group is connected upstream or downstream of the second gear shift group between the transmission input shaft or the pedal crankshaft and the transmission output shaft of the bottom bracket transmission. In this way, with the above-described connection of the only three provided planetary gear sets and the only six provided shift elements, a particularly simple and compact design is realized in the proposed bottom bracket transmission.In addition, there is particularly low component load and an advantageously high gearing efficiency due to the geometric gear ratio series in the bottom bracket gear.

[0008] For the mechanical connection of elements, for example rotating elements or the like of the planetary gear sets, in addition to the input and output, further shafts or shaft-like elements are preferably used, whereby the term shaft does not exclusively refer to a cylindrical, rotatably mounted machine element for transmitting torque, but rather also to general connecting elements which connect the individual gear set elements to one another for torque transmission.

[0009] In the second gear shift group of the proposed bottom bracket transmission, various blocking variants of the third planetary gear set are possible via the sixth shift element, which is preferably designed as a freewheel, in three different arrangement variants of the sixth shift element.

[0010] Within the scope of a first blocking variant of the third planetary gear set, it is provided that the third element is connectable or connected to the first element of the third planetary gear set when the sixth shifting element is blocked in the first arrangement variant. In a second blocking variant of the third planetary gear set, it is provided that the second element is connectable or connected to the first element of the third planetary gear set when the sixth shifting element is blocked in the second arrangement variant. Furthermore, in a third blocking variant of the third planetary gear set, the second element is connectable or connected to the third element of the third planetary gear set when the sixth shifting element is blocked in the third arrangement variant.

[0011] Regardless of the locking variants, in the bottom bracket transmission with the first transmission group upstream of the second transmission group, it is provided that the pedal crankshaft is connected to the second element of the second planetary gear set, that the transmission output shaft is connected directly or additionally via a sixth shaft to the third element of the third planetary gear set, that the first element of the second planetary gear set is connected via a fourth shaft to the third element of the first planetary gear set, that the first element of the first planetary gear set can be fixed to the housing via a first shaft when the first switching element is locked and can be connected to the pedal crankshaft and to the second element of the second planetary gear set when the fourth switching element is closed,that the second element of the first planetary gear set can be fixed to the housing via a second shaft when the second shifting element is closed and can be connected to the third element of the second planetary gear set and to the second element of the third planetary gear set via a fifth shaft when the fifth shifting element is locked, and that the first element of the third planetary gear set can be fixed to the housing via a third shaft when the third shifting element is closed.

[0012] In the bottom bracket transmission with the second transmission group upstream of the first transmission group, it is provided that the pedal crankshaft is connected to the second element of the third planetary gear set, that the transmission output shaft is connected directly or additionally via a fifth shaft to the third element of the second planetary gear set, that the first element of the second planetary gear set is connected via a fourth shaft to the third element of the first planetary gear set, that the first element of the first planetary gear set can be fixed to the housing via a first shaft when the first shifting element is locked and can be connected via a sixth shaft to the third element of the third planetary gear set and to the second element of the second planetary gear set when the fourth shifting element is engaged,that the second element of the first planetary gear set can be fixed to the housing via a second shaft when the second shifting element is closed and can be connected to the third element of the second planetary gear set and to the transmission output shaft via a fifth shaft when the fifth shifting element is locked, and that the first element of the third planetary gear set can be fixed to the housing via a third shaft when the third shifting element is closed.

[0013] Within the scope of the present invention, the proposed bottom bracket transmission with the two gear shift groups provides that the provided shifting elements can be designed as brakes, freewheel brakes, clutches, and / or freewheels. An advantageous embodiment of the invention provides that the first shifting element is designed as a freewheel brake, that the second shifting element and the third shifting element are each designed as a positive-locking brake, that the fourth shifting element is designed as a positive-locking clutch, and that the fifth shifting element and the sixth shifting element are each designed as a freewheel.

[0014] The switching elements designed as brakes and clutches are preferably designed as positive-locking switching elements, for example as cost-effective brake or switching claws or the like, for example with a toothed brake ring and a corresponding switching pawl. Brakes as switching elements have the advantage that they are easily accessible for operation 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 gear from jamming when the direction of rotation at the input or output is reversed. Freewheels that cannot be actively switched or actuated are preferably used as freewheels. This has the advantage that no switching operation is required for the passive switching elements. The non-actuable freewheel transmits a torque when it is locked in the blocking direction.No torque is transmitted in the opposite direction of rotation, as the freewheel does not lock in the overrunning drive state. However, it is conceivable that actively switchable freewheels or actively switchable freewheel brakes could also be used.

[0015] A preferred embodiment of the invention can provide for at least one of the planetary gear sets to be designed as a negative planetary gear set, resulting in a particularly space-efficient arrangement. It is also conceivable for one of the planetary gear sets to be designed as a positive planetary gear set.

[0016] A negative planetary gear set can preferably be converted into a positive planetary gear set if the planet carrier and ring gear connections on this gear set are swapped and the amount of the stationary gear ratio is increased by 1. A negative planetary gear set has rotatably mounted planet gears on its planet carrier, which mesh with the sun gear and the ring gear of this planetary gear set, so that the ring gear rotates in the opposite direction to the sun gear rotation when the planet carrier is held stationary and the sun gear is rotating.A plus planetary gear set has inner and outer planetary gears that are rotatably mounted on its planetary gear carrier and mesh with one another, with the sun gear of this planetary gear set meshing with the inner planetary gears and the ring gear of this planetary gear set meshing with the outer planetary gears, so that the ring gear rotates in the same direction of rotation as the sun gear when the planetary gear carrier is held stationary and the sun gear is rotating.

[0017] For those skilled in the art, this means that in the case of single gear sets designed as a negative planetary gear set, a first element or gear set element is designed as a sun gear, a second element as a planetary gear carrier or web, and a third element as a ring gear. Furthermore, this means that in a single gear set designed as a positive planetary gear set, the first element is designed as a sun gear, the second element as a ring gear, and the third element as a planetary gear carrier or web.

[0018] Furthermore, with the proposed bottom bracket gear, it is conceivable for stepped planetary gears to be used in both a negative planetary gear set and a positive planetary gear set. In a negative stepped planetary gear set, the assignment of the elements or gear set elements remains the same as in a conventional negative planetary gear set. In a positive stepped planetary gear set, it is provided that the first element is designed as the first sun gear, the second element as the second sun gear, and the third element as the planet gear carrier, or that the first element is designed as the first ring gear, the second element as the second ring gear, and the third element as the planet gear carrier.

[0019] In order to further optimize the control of the proposed bottom bracket gear, it is provided that at least one torque sensor or the like is provided on the drive and / or on the output.

[0020] To electrically assist the drive in the proposed bottom bracket transmission, at least one electric motor or the like can be connected or connectable to the drive or to the pedal crankshaft or transmission input shaft and / or to the output or to the transmission output shaft, or can be permanently or detachably coupled. Preferably, the electric motor can 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.

[0021] A further aspect of the present invention claims a bicycle or pedelec with the above-described bottom bracket gear. This results in the advantages already described and further advantages.

[0022] The present invention is further explained below with reference to the drawings.

[0023] They show: Fig. 1 a schematic principle view of a bottom bracket gear according to the invention on a bicycle or a pedelec with a first gear shift group connected upstream of a second gear shift group with a first blocking variant of a third planetary gear set in the second gear shift group; Fig. 2 a schematic principle view of the bottom bracket transmission with the first transmission group upstream of the second transmission group with a second blocking variant of the third planetary gear set in the second transmission group; Fig. 3 a schematic principle view of the bottom bracket transmission with the first transmission group upstream of the second transmission group with a third blocking variant of the third planetary gear set in the second transmission group; Fig. 4 a schematic principle view of the bottom bracket transmission with the second transmission group upstream of the first transmission group with the first blocking variant of the third planetary gear set in the second transmission group; Fig. 5 a schematic principle view of the bottom bracket transmission with the second transmission group upstream of the first transmission group with the second blocking variant of the third planetary gear set in the second transmission group; Fig. 6 a schematic principle view of the bottom bracket transmission with the second transmission group upstream of the first transmission group with the third blocking variant of the third planetary gear set in the second transmission group; Fig. 7 a gearshift diagram with eight switchable gears of the bottom bracket gearbox; Fig. 8 a schematic principle view of a planetary gear set as a minus planetary gear set; Fig. 9 a schematic principle view of a planetary gear set as a plus planetary gear set; Fig. 10 a schematic principle view of a planetary gear set as a minus-step planetary gear set; Fig. 11 a schematic principle view of a planetary gear set as a plus-stepped planetary gear set with two sun gears; Fig. 12 a schematic principle view of a planetary gear set as a plus-stepped planetary gear set with two ring gears; Fig. 13 a schematic diagram of the bottom bracket gear according to Fig. 1 with an exemplary torque sensor on the drive; Fig. 14 a schematic diagram of the bottom bracket gear according to Fig. 13 with an electric machine arranged on the drive as an example; Fig. 15 a schematic diagram of the bottom bracket gear according to Fig. 13 with an electric machine arranged as an example at the output; and Fig. 16 a schematic diagram of the bottom bracket gear according to Fig. 13 with a freewheel provided between the pedal crankshaft and the gearbox input shaft.

[0024] In the Fig. 1 to 16 show various design variants and embodiments or a circuit diagram of a bottom bracket gear according to the invention in planetary design merely by way of example. Fig. 1 shows an example of a bicycle or pedelec 1 with the bottom bracket gear, only schematically indicated.

[0025] The bottom bracket gear is shown in a housing or bottom bracket shell 2 with a pedal crankshaft or pedal crank with pedals, wherein the pedal crankshaft WAn is connected on the input side to one of the gear shift groups 3, 4. Furthermore, the bottom bracket gear comprises a gear output shaft WAb as an output with a chain or belt wheel (not shown in detail). The bottom bracket gear comprises a multi-stage first gear shift group 3 and a multi-stage second gear shift group 4, wherein the first gear shift group 3 has a first planetary gear set RS1 and a second planetary gear set RS2, to which a first shifting element B1, a second shifting element B2, a fourth shifting element K1, and a fifth shifting element K2 are assigned, and wherein the second gear shift group 4 has a third planetary gear set RS3, to which a third shifting element B3 and a sixth shifting element K3, K3 I , K3 IIThe two gearshift groups 3, 4 essentially form two sub-gearboxes that can be interconnected in any order with respect to the direction of power flow between the pedal crankshaft WAn and the gear output shaft WAb.

[0026] Regardless of the respective design variants, the bottom bracket transmission is provided with either the pedal crankshaft WAn being connected to a second element of the second planetary gear set RS2, the transmission output shaft WAb being connected to a third element of the third planetary gear set, a first element of the first planetary gear set RS1 being fixable to a housing 2 via a first switching element B1 and connectable to the second element of the second planetary gear set RS2 and to the pedal crankshaft WAn via the fourth switching element K1, a second element of the first planetary gear set RS1 being fixable to the housing 2 via a second switching element B2 and connectable to the third element of the second planetary gear set RS2 and to the second element of the third planetary gear set RS3 via the fifth switching element K2, or the pedal crankshaft WAn being connected to a second element of the third planetary gear set RS3,the transmission output shaft WAb is connected to a third element of the second planetary gear set RS2, wherein a first element of the first planetary gear set RS1 can be fixed to a housing 2 via a first shifting element B1 and can be connected to the second element of the second planetary gear set RS2 and to the third element of the third planetary gear set RS3 via the fourth shifting element K1, a second element of the first planetary gear set RS1 can be fixed to the housing 2 via a second shifting element B2 and can be connected to the third element of the second planetary gear set RS2 via the fifth shifting element K2 to the transmission output shaft WAb, wherein a first element of the second planetary gear set RS2 is connected to a third element of the first planetary gear set RS1, wherein a first element of the third planetary gear set RS3 can be fixed to the housing 2 via a third shifting element B3,and wherein, for blocking the third planetary gear set RS3, two elements of the third planetary gear set RS3 are connected via the sixth switching element K3, K3, I , K3 II can be connected to each other.

[0027] In the Fig. 1 to 6, the three proposed planetary gear sets RS1, RS2, and RS3 are each designed as space-saving negative planetary gear sets. The first element of the planetary gear sets RS1, RS2, and RS3 is a sun gear SR1, SR2, and SR3, the second element is a carrier or planetary gear carrier PT1, PT2, and PT3, and the third element is a ring gear HR1, HR2, and HR3.

[0028] In Fig. Figure 1 shows a first locking variant for the third planetary gear set RS3 of the second gear shift group 4 of the bottom bracket transmission, with the first gear shift group 3 being connected upstream of the second gear shift group 4. In detail, the crankshaft WAn is connected to a planetary gear carrier PT2 of the second planetary gear set RS2, the transmission output shaft WAb is connected via a sixth shaft W6 to a ring gear HR3 of the third planetary gear set RS3, a sun gear SR2 of the second planetary gear set RS2 is connected via a fourth shaft W4 to a ring gear HR1 of the first planetary gear set RS1, a sun gear SR1 of the first planetary gear set RS1 can be fixed to the housing 2 via a first shaft W1 when the first shifting element B1 is locked, and can be connected to the crankshaft WAn and to the planetary gear carrier PT2 of the second planetary gear set RS2 when the fourth shifting element K1 is engaged.that a planetary gear carrier PT1 of the first planetary gear set RS1 can be fixed to the housing 2 via a second shaft W2 when the second shifting element B2 is closed, and can be connected to a ring gear HR2 of the second planetary gear set RS2 and to a planetary gear carrier PT3 of the third planetary gear set RS3 via a fifth shaft W5 when the fifth shifting element K2 is locked, that a sun gear SR3 of the third planetary gear set RS3 can be fixed to the housing 2 via a third shaft W3 when the third shifting element B3 is closed, and that in the first blocking variant of the third planetary gear set RS3, the ring gear HR3 of the third planetary gear set RS3 can be connected to the sun gear SR3 of the third planetary gear set RS3 when the sixth shifting element K3 is locked in the first arrangement variant.

[0029] In Fig. 2 shows a second blocking variant for the third planetary gear set RS3 of the second gear shift group 4 of the bottom bracket transmission, wherein the first gear shift group 3 is connected upstream of the second gear shift group 4.

[0030] In contrast to the Fig. 1 and described above, the planetary gear carrier PT3 of the third planetary gear set RS3 is in the second blocking variant with the sixth switching element K3 locked I in the second arrangement variant connected to the sun gear SR3 of the third planetary gear set RS3.

[0031] In Fig. 3 shows a third blocking variant for the third planetary gear set RS3 of the second gear shift group 4 of the bottom bracket transmission, wherein the first gear shift group 3 is connected upstream of the second gear shift group 4. In contrast to the Fig. 1 and Fig. 2 and described above, the planetary gear carrier PT3 of the third planetary gear set RS3 is in the context of the third blocking variant with the sixth switching element K3 locked II in the third arrangement variant connected to the ring gear HR3 of the third planetary gear set RS3.

[0032] In Fig. Figure 4 shows the first interlocking variant for the third planetary gear set RS3 of the second gear shift group 4 of the bottom bracket transmission, with the second gear shift group 4 being connected upstream of the first gear shift group 3. In detail, the crankshaft WAn is connected to the planetary gear carrier PT3 of the third planetary gear set RS3, the transmission output shaft WAb is connected via the fifth shaft W5 to the ring gear HR2 of the second planetary gear set RS2, the sun gear SR2 of the second planetary gear set RS2 is connected via the fourth shaft W4 to the ring gear HR1 of the first planetary gear set RS1,that the sun gear SR1 of the first planetary gear set RS1 can be fixed to the housing 2 via the first shaft W1 when the first shifting element B1 is locked, and can be connected to the ring gear HR3 of the third planetary gear set RS3 and to the planet carrier PT2 of the second planetary gear set RS2 via the sixth shaft W6 when the fourth shifting element K1 is closed, that the planet carrier PT1 of the first planetary gear set RS1 can be fixed to the housing 2 via the second shaft W2 when the second shifting element B2 is closed, and can be connected to the ring gear HR2 of the second planetary gear set RS2 and to the transmission output shaft WAb via the fifth shaft W5 when the fifth shifting element K2 is locked,that the sun gear SR3 of the third planetary gear set RS3 can be fixed to the housing 2 via the third shaft W3 when the third shifting element B3 is closed, and that in the first blocking variant of the third planetary gear set RS3, the ring gear HR3 of the third planetary gear set RS3 can be connected to the sun gear SR3 of the third planetary gear set RS3 when the sixth shifting element K3 is locked in the first arrangement variant.

[0033] In Fig. 5 shows a second blocking variant for the third planetary gear set RS3 of the second gear shift group 4 of the bottom bracket transmission, wherein the second gear shift group 4 is connected upstream of the first gear shift group 3. In contrast to the Fig. 4 and described above, the planetary gear carrier PT3 of the third planetary gear set RS3 is in the second blocking variant with the sixth switching element K3 locked Iin the second arrangement variant connected to the sun gear SR3 of the third planetary gear set RS3.

[0034] In Fig. 6 shows a third blocking variant for the third planetary gear set RS3 of the second gear shift group 4 of the bottom bracket transmission, wherein the second gear shift group 4 is connected upstream of the first gear shift group 3. In contrast to the Fig. 4 and Fig. 5 and described above, the planetary gear carrier PT3 of the third planetary gear set RS3 is in the context of the third blocking variant with the sixth switching element K3 locked II in the third arrangement variant connected to the ring gear HR3 of the third planetary gear set RS3.

[0035] In Fig. Figure 7 shows a shifting diagram for the bottom bracket transmission as an eight-speed transmission, with the first gear shifting group 3 being designed as a 4-speed group and the second gear shifting group 4 as a 2-speed group, so that a total of eight gears G1, G2, G3, G4, G5, G6, G7, G8 are realized. The shifting diagram shows the shifting elements B1, B2, K1, K2, K3, K3 used for the respective gears G1, G2, G3, G4, G5, G6, G7, G8. I , K3 II , K4. An X for the freewheels K2, K3, K3 I , K3 II and the freewheel brake B1 as switching elements in the circuit diagram, which lock the freewheels and the freewheel brake. This works automatically without external activation. Furthermore, an X for a brake B2, B3, and a clutch K1 as a switching element in the circuit diagram means that the brake B2, B3, and the clutch K1 are engaged. This works via a suitable actuator.

[0036] In detail, the circuit diagram according to Fig. 7, that to realize or switch a first gear G1, the first switching element B1 designed as a freewheel brake, the fifth switching element K2 designed as a freewheel and the sixth switching element K3 designed as a freewheel, K3 I , K3 II are locked, that to realize a second gear G2 the fourth switching element K1 designed as a clutch is closed and the fifth switching element K2 designed as a freewheel and the sixth switching element K3 designed as a freewheel, K3 I , K3 IIare locked, that to realize a third gear G3 the first switching element B1 designed as a freewheel brake is locked and the third switching element B3 designed as a brake is closed and the fifth switching element K2 designed as a freewheel is locked, that to realize a fourth gear G4 the third switching element B3 designed as a brake is closed and the fourth switching element K1 designed as a clutch is closed and the fifth switching element K2 designed as a freewheel is locked, that to realize a fifth gear G5 the first switching element B1 designed as a freewheel brake is locked and the second switching element B2 designed as a brake is closed and the sixth switching element K3 designed as a freewheel, K3 I , K3 IIis locked, that to realize a sixth gear G6 the second switching element B2 designed as a brake is closed and the fourth switching element K1 designed as a clutch is closed and the sixth switching element K3 designed as a freewheel, K3 I , K3 II is locked, that in order to realize a seventh gear G7 the first switching element B1 designed as a freewheel brake is locked and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are closed, and / or that in order to realize an eighth gear G8 the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are closed and the fourth switching element K1 designed as a clutch is closed.

[0037] In Fig. Figure 8 shows an example of a minus planetary gear set in which the first element is designed as a sun gear 1-SR, the second element as a planet gear carrier 2-PT and the third element as a ring gear 3-HR.

[0038] In Fig. Figure 9 shows an example of a plus planetary gear set in which the first element is designed as a sun gear 1-SR, the second element as a ring gear 2-HR and the third element as a planet gear carrier 3-PT.

[0039] In Fig. 10 shows an example of a minus-stepped planetary gear set in which the first element is designed as a sun gear 1-SR, the second element as a planet gear carrier 2-PT and the third element as a ring gear 3-HR.

[0040] In Fig. 11 shows an example of a plus-stepped planetary gear set in which the first element is designed as the first sun gear 1-SRA, the second element as the second sun gear 2-SRB and the third element as the planet gear carrier 3-PT.

[0041] In Fig. 12 shows, by way of example, a further embodiment of a plus-stepped planetary gear set, 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 gear carrier 3-PT.

[0042] The Fig. The possible designs shown in Figures 8 to 12 using a planetary gear set can be implemented on the specific planetary gear sets RS1, RS2, RS3 of the bottom bracket gear according to the invention.

[0043] In Fig. 13 is an embodiment of the bottom bracket gear according to the invention based on 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 designed in a different way.

[0044] In the Fig. 14 and Fig. 15 is an embodiment of the bottom bracket gear according to the invention based on Fig. 13 with an additional electric machine EM. The electric machine EM can be connected to the pedal crankshaft WAn, as shown in Fig. 14. It is also conceivable that the electric machine EM is connected to the transmission output shaft WAb, as shown in Fig. 15. 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 to the pedal crankshaft would also be possible. Irrespective of this, it is advantageous to connect the electric machine EM via a freewheel F0 or similar device so that, when operating without the electric machine EM, no losses are caused by the co-rotating electric machine EM.

[0045] In Fig. 16 is an embodiment of the bottom bracket gear according to the invention based on Fig. 13 is shown with an additional freewheel F1 between the pedal crank and the input of the bottom bracket transmission. This allows the freewheel to open when pedaling is interrupted, decoupling the pedal crank from the inertial masses of the gear set and, in particular, the electric motor EM, so that no inertial forces are felt at the pedal. Reference symbol 1 bicycle or pedelec 2 Housing or bottom bracket shell 3 first gearshift group 4 second gearshift group 5 Torque sensor EM electric machine F0 Freewheel for electric machine F1 additional freewheel SR1 sun gear of the first planetary gear set PT1 planetary gear carrier of the first planetary gear set HR1 ring gear of the first planetary gear set SR2 sun gear of the second planetary gear set PT2 planetary gear carrier of the second planetary gear set HR2 ring gear of the second planetary gear set SR3 sun gear of the third planetary gear set PT3 planetary gear carrier of the third planetary gear set HR3 ring gear of the third planetary gear set RS1 first planetary gear set RS2 second planetary gear set RS3 third planetary gear set WAn gearbox input shaft or crankshaft WAB gearbox output shaft W1 first wave W2 second wave W3 third wave W4 fourth wave W5 fifth wave W6 sixth wave W0 fixed housing connection G1 first gear of the bottom bracket gearbox G2 second gear of the bottom bracket gearbox G3 third gear of the bottom bracket gearbox G4 fourth gear of the bottom bracket gearbox G5 fifth gear of the bottom bracket gearbox G6 sixth gear of the bottom bracket gearbox G7 seventh gear of the bottom bracket gearbox G8 eighth gear of the bottom bracket gearbox B1 first switching element designed as a freewheel brake B2 second switching element designed as a brake B3 third switching element designed as a brake K1 fourth switching element designed as a clutch K2 fifth switching element designed as a freewheel K3 sixth switching element designed as a freewheel in a first arrangement variant K3 I sixth switching element designed as a freewheel in a second arrangement variant K3 II sixth switching element designed as a freewheel in a third variant 1-SR first element as sun gear 2-PT second element as planetary gear carrier 2-HR second element as ring gear 3-HR third element as ring gear 3-PT third element as planetary gear carrier 1-SRA first element as first sun gear 2-SRB second element as second sun gear 1-HRA first element as first ring gear 2-HRB first element as second ring gear

Claims

[1] Bottom bracket gear in planetary design for a bicycle or a pedelec (1), with a pedal crankshaft (WAn) as input and a transmission output shaft (WAb) as output and further shafts (W1, W2, W3, W4, W5, W6), with three planetary gear sets (RS1, RS2, RS3), and with six switching elements (B1, B2, B3, K1, K2, K3, K3 I , K3 II ) for realizing several gears (G1, G2, G3, G4, G5, G6, G7, G8) and having a first transmission shift group (3) and a second transmission shift group (4), wherein the first transmission shift group (3) is assigned a first planetary gear set (RS1) and a second planetary gear set (RS2) as well as a first shifting element (B1), a second shifting element (B2), a fourth shifting element (K1) and a fifth shifting element (K2), wherein the second transmission shift group (4) is assigned a third planetary gear set (RS3) as well as a third shifting element (B3) and a sixth shifting element (K3, K3 I , K3 II), wherein either the pedal crankshaft (WAn) is connected to a second element of the second planetary gear set (RS2), the transmission output shaft (WAb) is connected to a third element of the third planetary gear set (RS3), a first element of the first planetary gear set (RS1) can be fixed to a housing (2) via a first switching element (B1) and can be connected to the second element of the second planetary gear set (RS2) and to the pedal crankshaft (WAn) via a second switching element (B2) and can be connected to the third element of the second planetary gear set (RS2) and to the second element of the third planetary gear set (RS3) via the fifth switching element (K2), or the pedal crankshaft (WAn) is connected to a second element of the third planetary gear set (RS3),the transmission output shaft (WAb) is connected to a third element of the second planetary gear set (RS2), a first element of the first planetary gear set (RS1) can be fixed to a housing (2) via a first shifting element (B1) and can be connected to the second element of the second planetary gear set (RS2) and to the third element of the third planetary gear set (RS3) via the fourth shifting element (K1), a second element of the first planetary gear set (RS1) can be fixed to the housing (2) via a second shifting element (B2) and can be connected to the third element of the second planetary gear set (RS2) and to the transmission output shaft (WAb) via the fifth shifting element (K2), wherein a first element of the second planetary gear set (RS2) is connected to a third element of the first planetary gear set (RS1), wherein a first element of the third planetary gear set (RS3) can be fixed to the housing (2) via a third shifting element (B3),and wherein, for blocking the third planetary gear set (RS3), two elements of the third planetary gear set (RS3) are connected via the sixth shift element (K3, K3, I , K3 II ) can be connected to each other. [2] Bottom bracket gear according to claim 1, characterized by that in a first blocking variant of the third planetary gear set (RS3), the third element of the third planetary gear set (RS3) can be connected to the first element of the third planetary gear set (RS3) in a first arrangement variant when the sixth shift element (K3) is blocked. [3] Bottom bracket gear according to claim 1, characterized by that in a second blocking variant of the third planetary gear set (RS3), the second element of the third planetary gear set (RS3) with the sixth shift element (K3) locked I ) in a second arrangement variant can be connected to the first element of the third planetary gear set (RS3). [4] Bottom bracket gear according to claim 1, characterized bythat in a third blocking variant of the third planetary gear set (RS3), the second element of the third planetary gear set (RS3) with the sixth shift element (K3) locked II ) in a third arrangement variant can be connected to the third element of the third planetary gear set (RS3). [5] Bottom bracket gear according to one of the preceding claims, characterized bythat the pedal crankshaft (WAn) is connected to the second element of the second planetary gear set (RS2), that the transmission output shaft (WAb) is connected directly or via a sixth shaft (W6) to the third element of the third planetary gear set (RS3), that the first element of the second planetary gear set (RS2) is connected via a fourth shaft (W4) to the third element of the first planetary gear set (RS1), that the first element of the first planetary gear set (RS1) can be fixed to the housing (2) via a first shaft (W1) when the first shifting element (B1) is locked and can be connected to the pedal crankshaft (WAn) and to the second element of the second planetary gear set (RS2) when the fourth shifting element (K1) is closed,that the second element of the first planetary gear set (RS1) can be fixed to the housing (2) via a second shaft (W2) when the second shifting element (B2) is closed and can be connected to the third element of the second planetary gear set (RS2) and to the second element of the third planetary gear set (RS3) via a fifth shaft (W5) when the fifth shifting element (K2) is locked, and that the first element of the third planetary gear set (RS3) can be fixed to the housing (2) via a third shaft (W3) when the third shifting element (B3) is closed. [6] Bottom bracket gear according to one of claims 1 to 5, characterized bythat the pedal crankshaft (WAn) is connected to the second element of the third planetary gear set (RS3), that the transmission output shaft (WAb) is connected directly or via a fifth shaft (W5) to the third element of the second planetary gear set (RS2), that the first element of the second planetary gear set (RS2) is connected via a fourth shaft (W4) to the third element of the first planetary gear set (RS1), that the first element of the first planetary gear set (RS1) can be fixed to the housing (2) via a first shaft (W1) when the first shifting element (B1) is locked and can be connected to the third element of the third planetary gear set (RS3) and to the second element of the second planetary gear set (RS2) via a sixth shaft (W6) when the fourth shifting element (K1) is closed,that the second element of the first planetary gear set (RS1) can be fixed to the housing (2) via a second shaft (W2) when the second shifting element (B2) is closed and can be connected to the third element of the second planetary gear set (RS2) and to the transmission output shaft (WAb) via a fifth shaft (W5) when the fifth shifting element (K2) is locked, and that the first element of the third planetary gear set (RS3) can be fixed to the housing (2) via a third shaft (W3) when the third shifting element (B3) is closed. [7] Bottom bracket gear according to one of the preceding claims, characterized by that the first switching element (B1) is designed as a freewheel brake, that the second switching element (B2) and the third switching element (B3) are each designed as a positive-locking brake, that the fourth switching element (K1) is designed as a positive-locking clutch, and / or that the fifth switching element (K2) and the sixth switching element (K3, K3 I , K3 II) are each designed as a freewheel. [8] Bottom bracket gear according to one of the preceding claims, characterized by that the first planetary gear set (RS1) and / or the second planetary gear set (RS2) and / or the third planetary gear set (RS3) is designed as a minus planetary gear set. [9] Bottom bracket gear according to claim 8, characterized by that in a minus planetary gear set the first element is designed as a sun gear (SR1, SR2, SR3), the second element as a planet gear carrier (PT1, PT2, PT3) and the third element as a ring gear (HR1, HR2, HR3). [10] Bottom bracket gear according to one of the preceding claims, characterized by that the first planetary gear set (RS1) and / or the second planetary gear set (RS2) and / or the third planetary gear set (RS3) is designed as a plus planetary gear set. [11] Bottom bracket gear according to claim 10, characterized bythat in a plus planetary gear set the first element is designed as a sun gear (SR1, SR2, SR3), the second element as a ring gear (HR1, HR2, HR3) and the third element as a planet gear carrier (PT1, PT2, PT3). [12] Bottom bracket gear according to one of the preceding claims, characterized by that a torque sensor (5) is connected to the pedal crankshaft (WAn). [13] Bottom bracket gear according to one of the preceding claims, characterized by that at least one electrical machine (EM) is connected or connectable to the pedal crankshaft (WAn) or to the transmission output shaft (WAb). [14] Bottom bracket gear according to claim 13, characterized by that the electric machine (EM) is arranged axially parallel to the pedal crankshaft (WAn). [15] Bottom bracket gear according to one of the preceding claims, characterized bythat to realize a first gear (G1), the first switching element (B1) designed as a freewheel brake, the fifth switching element (K2) designed as a freewheel and the sixth switching element (K3, K3 I , K3 II ) are locked, that in order to realize a second gear (G2) the fourth switching element (K1) designed as a clutch is closed and the fifth switching element (K2) designed as a freewheel and the sixth switching element (K3, K3 I , K3 II) are locked, that in order to realize a third gear (G3) the first switching element (B1) designed as a freewheel brake is locked and the third switching element (B3) designed as a brake is closed and the fifth switching element (K2) designed as a freewheel is locked, that in order to realize a fourth gear (G4) the third switching element (B3) designed as a brake is closed and the fourth switching element (K1) designed as a clutch is closed and the fifth switching element (K2) designed as a freewheel is locked, that in order to realize a fifth gear (G5) the first switching element (B1) designed as a freewheel brake is locked and the second switching element (B2) designed as a brake is closed and the sixth switching element (K3, K3 I , K3 II) is locked, that in order to realize a sixth gear (G6) the second switching element (B2) designed as a brake is closed and the fourth switching element (K1) designed as a clutch is closed and the sixth switching element (K3, K3 I , K3 II ) is locked, that in order to realize a seventh gear (G7) the first switching element (B1) designed as a freewheel brake is locked and the second switching element (B2) designed as a brake and the third switching element (B3) designed as a brake are closed, and / or that in order to realize an eighth gear (G8) the second switching element (B2) designed as a brake and the third switching element (B3) designed as a brake are closed and the fourth switching element (K1) designed as a clutch is closed. [16] Bicycle or pedelec (1) with the bottom bracket gear according to one of the preceding claims.

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