Planetary bottom bracket gearbox for a bicycle or e-bike

Abstract

Bottom bracket gearbox in planetary design for a bicycle or a pedelec (1), with a gearbox input shaft (WAn) as drive, with a gearbox output shaft (WAb) as output, with a multi-stage main gearbox (3) and with at least one gearbox shift group (4), wherein the transmission shift group (4) comprises two planetary gear sets (RS1, RS2) and four shift elements (B1, B2, K1, K2), wherein a second element of the first planetary gear set (RS1) is connected to a first shaft (W1), wherein a first element of the first planetary gear set (RS1) is connected via a fourth shaft (W4) to a second element of the second planetary gear set (RS2), wherein a third element of the first planetary gear set (RS1) is connected to a fifth shaft (W5), wherein a first element of the second planetary gear set (RS2) can be fixed via a third shaft (W3) and via a second switching element (B2) designed as a brake, wherein the third shaft (W3) can be connected to the first shaft (W1) via a sixth switching element (K2) designed as a clutch or freewheel, wherein a third element of the second planetary gear set (RS2) can be fixed via a second shaft (W2) and via a first switching element (B1) designed as a brake and wherein the second shaft (W2) can be connected to the first shaft (W1) via a fifth switching element (K1) designed as a clutch or freewheel, wherein the main gearbox (3) either additionally - includes a third planetary gear set (RS3) and two switching elements (B3, K3), or - includes a third planetary gear set (RS3) and a fourth planetary gear set (RS4) as well as three switching elements (B3, B4, K3), or - includes a third planetary gear set (RS3) and a fourth planetary gear set (RS4) as well as four switching elements (B3, B4, K3, K4), characterized in that each of the planet gear sets (RS1, RS2, RS3, RS4) is designed as a minus stepped planet gear set, wherein in a minus stepped planet gear set the first element is designed as a sun gear (SR1, SR2, SR3, SR4), the second element as a planet carrier (PT1, PT2, PT3, PT4) and the third element as a ring gear (HR1, HR2, HR3, HR4).

Description

[0001] The present invention relates to a planetary bottom bracket gear for a bicycle or pedelec, comprising a transmission input shaft as the drive and a transmission output shaft as the output, a multi-stage main transmission, and at least one gear shift group. Furthermore, the invention relates to a bicycle or pedelec with the bottom bracket gear.

[0002] For example, from the publication DE 10 2018 208 380 A1, a 16-speed bottom bracket gear in planetary design for a bicycle or a pedelec with a four-speed main gear is known, to which a front-mounted gear set and a rear-mounted gear set, each with two gear stages, are assigned.

[0003] DE 10 2018 208 387 A1 shows a multi-stage transmission in planetary design for a bicycle or a pedelec with a transmission input shaft as input and a transmission output shaft as output, with at least four planetary gear sets, wherein at least four freewheel clutches and at least four brakes are provided for realizing at least sixteen gears.

[0004] DE 10 2021 208 705 A1 shows a gear set arrangement for a planetary gear of a bicycle formed from a planetary assembly, a stationary component, two brakes and two freewheel clutches.

[0005] DE 10 2016 225 165 A1 discloses a transmission for a bicycle with a manual transmission connected to a bottom bracket crankshaft and having a manual transmission output shaft, as well as an electric motor. The transmission includes a superposition gearing arranged downstream of the manual transmission.

[0006] 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.

[0007] This object is achieved according to the invention by the subject matter having the features of the independent patent claims. Advantageous and claimed developments emerge from the subclaims and the description, as well as the drawings.

[0008] Thus, a bottom bracket gear in planetary design for a bicycle or a pedelec is proposed, having a transmission input shaft as the drive, a transmission output shaft as the output, a multi-stage main transmission, and at least one transmission shifting group, wherein the transmission shifting group has two planetary gear sets and four shifting elements, wherein a second element of the first planetary gear set is connected to a first shaft, wherein a first element of the first planetary gear set is connected to a second element of the second planetary gear set via a fourth shaft, wherein a third element of the first planetary gear set is connected to a fifth shaft, wherein a first element of the second planetary gear set can be locked via a third shaft and via a second shifting element designed as a brake, wherein the third shaft can be connected to the first shaft via a sixth shifting element designed as a clutch or freewheel,wherein a third element of the second planetary gear set can be fixed via a second shaft and via a first switching element designed as a brake, and wherein the second shaft can be connected to the first shaft via a fifth switching element designed as a clutch or freewheel.

[0009] In this way, the above-described connection of the gear shifting group in the proposed bottom bracket transmission, with only two planetary gear sets and only four shifting elements in the gear shifting group, achieves a particularly simple and compact design for the bottom bracket transmission. In addition, this results in particularly low component loads and an advantageously high gear efficiency due to the geometric gear ratio series in the bottom bracket transmission.

[0010] For the mechanical connection of elements of the two planetary gear sets in the transmission group, preferably only five additional shafts or shaft-like elements are used in addition to the input and output, whereby the term shaft does not exclusively refer to a cylindrical, rotatably mounted machine element for transmitting torque, but rather also includes general connecting elements that connect the individual gear set elements to one another for torque transmission.

[0011] The axial order of the main gearbox and gearshift group can be reversed in the proposed bottom bracket gearbox. Accordingly, the gearshift group is arranged upstream or downstream of the main gearbox between the gearbox input shaft and the gearbox output shaft. With an upstream arrangement of the gearshift group, a pedal crank of the bottom bracket gearbox, which is connected to the gearbox input shaft, is connected to the first shaft, essentially acting as the gearbox input shaft of the gearshift group, and the fifth shaft of the gearshift group is connected on the input side to the multi-stage main gearbox. It is possible for the gearbox input shaft and the first shaft to be designed as one or more parts. With a downstream arrangement of the gearshift group, the first shaft is connected to the main gearbox on the output side, and the fifth shaft of the gearshift group is connected to the gearbox output shaft.It is possible that the transmission output shaft and the fifth shaft are designed as one piece or in multiple pieces.

[0012] The proposed bottom bracket transmission can utilize any multi-stage main transmission of planetary design with at least one additional planetary gear set and at least two additional shifting elements. Preferably, the main transmission can be designed as a two-speed, three-speed, or four-speed transmission and thus have one or two additional planetary gear sets with two to four additional shifting elements.

[0013] One possible embodiment of the invention may provide for the main transmission to be designed as a two-speed transmission with a third planetary gear set and two shift elements. The two-speed main transmission may be located upstream or downstream of the transmission shift group.

[0014] In the two-speed main transmission, it is provided that a second element of the third planetary gear set is connected to the transmission input shaft or to the fifth shaft of the transmission shift group, that a first element of the third planetary gear set can be fixed via a third shift element designed as a brake and can be connected to a third element of the third planetary gear set via a seventh shift element designed as a clutch or freewheel, and that the third element of the third planetary gear set is connected to the transmission output shaft or to the first shaft of the transmission shift group.

[0015] A further embodiment of the invention may provide for the main transmission to be designed as a three-speed transmission with a third planetary gear set and a fourth planetary gear set, as well as with three shift elements. The three-speed main transmission may be located upstream or downstream of the transmission shift group.

[0016] In the three-speed main transmission, it is provided that a second element of the third planetary gear set is connected to the transmission input shaft or to the fifth shaft of the transmission shift group, that a first element of the third planetary gear set and a first element of the fourth planetary gear set are connected to the transmission output shaft or to the first shaft of the transmission shift group, that a third element of the third planetary gear set can be locked via a third shift element designed as a brake and is connected to a second element of the fourth planetary gear set, and that a third element of the fourth planetary gear set can be locked via a fourth shift element designed as a brake and can be connected to the transmission output shaft or to the first shaft of the transmission shift group via a seventh shift element designed as a clutch or freewheel.

[0017] A further embodiment of the invention may provide for the main transmission to be designed as a four-speed transmission with a third planetary gear set and a fourth planetary gear set, as well as four shift elements. The four-speed main transmission may be located upstream or downstream of the transmission shift group.

[0018] Within the framework of a first variant of the four-speed main transmission, it is provided that a second element of the third planetary gear set is connected to the transmission input shaft or to the fifth shaft of the transmission shift group, that a first element of the third planetary gear set can be locked via a third shifting element designed as a brake and can be connected to a third element of the third planetary gear set and to a second element of the fourth planetary gear set via a seventh shifting element designed as a clutch or freewheel, that the third element of the third planetary gear set is connected to the second element of the fourth planetary gear set,that a third element of the fourth planetary gear set can be locked via a fourth switching element designed as a brake and can be connected to the transmission output shaft or to the first shaft of the transmission shift group via an eighth switching element designed as a clutch or freewheel, and that a first element of the fourth planetary gear set is connected to the transmission output shaft or to the first shaft of the transmission shift group.

[0019] In a second variant of the four-speed main transmission, it is provided that a second element of the third planetary gear set is connected to the transmission input shaft or to the fifth shaft of the transmission shift group, that a first element of the third planetary gear set is connected to the transmission output shaft or to the first shaft of the transmission shift group, that a 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 locked via a third switching element designed as a brake and can be connected to the transmission input shaft or to the fifth shaft of the transmission shift group via a seventh switching element designed as a clutch or freewheel, and that a first element of the fourth planetary gear set can be locked via a fourth switching element designed as a brake and can be connected to the transmission output shaft or to the first shaft of the transmission shift group via an eighth switching element designed as a clutch or freewheel.

[0020] According to the invention, each of the planetary gear sets is 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, although this is not according to the invention.

[0021] 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.

[0022] 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.

[0023] According to the invention, the proposed bottom bracket gear train provides for stepped planetary gears to be used in each negative 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, 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 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.

[0024] Within the scope of the present invention, in the proposed bottom bracket transmission with the main transmission and the transmission shifting group, it is provided that the first shifting element and / or the second shifting element and / or the third shifting element and / or the fourth shifting element are each designed as a positive-locking brake and / or that the fifth shifting element and / or sixth shifting element and / or seventh shifting element and / or eighth shifting element are each designed as a freewheel.

[0025] The switching elements designed as brakes are preferably designed as positive-locking switching elements, for example as cost-effective switching dogs 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. Since the provided freewheels are used as clutches, it is advantageous if the brakes are designed, for example, as single-action brakes in order to prevent the gear from blocking 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] The present invention is further explained below with reference to the drawings.

[0030] They show: Fig. 1 a schematic principle view of a first embodiment of a bottom bracket gear according to the invention on a bicycle or a pedelec with a gear shift group connected upstream of a main gearbox; Fig. 2 a schematic principle view of a binding variant of the first embodiment of the bottom bracket gear according to Fig. 1; Fig. 3 a schematic principle view of a second embodiment of the bottom bracket transmission with the gear shift group connected downstream of the main transmission; Fig. 4 a shift diagram with the four switchable gears of the gear group in the bottom bracket gearbox; Fig. 5 a schematic principle view of a planetary gear set as a minus planetary gear set; Fig. 6 a schematic principle view of a planetary gear set as a plus planetary gear set; Fig. 7 a schematic principle view of a planetary gear set according to the invention as a minus-step planetary gear set; Fig. 8 a schematic principle view of a planetary gear set as a plus-stepped planetary gear set with two sun gears; Fig. 9 a schematic principle view of a planetary gear set as a plus-stepped planetary gear set with two ring gears; Fig. 10 a schematic principle view of the bottom bracket transmission with a first embodiment of the main transmission downstream of the transmission group as a two-speed transmission; Fig. 11 a schematic principle view of the bottom bracket transmission with the first embodiment of the main transmission upstream of the transmission group as a two-speed transmission; Fig. 12 a circuit diagram of the bottom bracket gear according to the Fig. 10 and Fig. 11; Fig. 13 a schematic principle view of the bottom bracket transmission with a second embodiment of the main transmission downstream of the transmission group as a three-speed transmission; Fig. 14 a schematic principle view of the bottom bracket transmission with the first embodiment of the main transmission upstream of the transmission group as a three-speed transmission; Fig. 15 a circuit diagram of the bottom bracket gear according to the Fig. 13 and Fig. 14; Fig. 16 a schematic principle view of the bottom bracket transmission with a third embodiment of the main transmission downstream of the transmission group as a four-speed transmission; Fig. 17 a schematic principle view of the bottom bracket transmission with the first embodiment of the main transmission upstream of the transmission group as a four-speed transmission; Fig. 18 a circuit diagram of the bottom bracket gear according to the Fig. 16 and Fig. 17; Fig. 19 a schematic principle view of the bottom bracket transmission with an alternative third embodiment of the main transmission downstream of the transmission group as a four-speed transmission; Fig. 20 a schematic principle view of the bottom bracket transmission with the alternative first embodiment of the main transmission upstream of the transmission shift group as a four-speed transmission; Fig. 21 a circuit diagram of the bottom bracket gear according to the Fig. 19 and Fig. 20; Fig. 22 a schematic diagram of the bottom bracket gear according to Fig. 1 with an exemplary torque sensor on the drive; Fig. 23 a schematic diagram of the bottom bracket gear according to Fig. 22 with an electric machine arranged on the drive as an example; Fig. 24 a schematic principle view of the bottom bracket gear according to Fig. 22 with an electric machine arranged as an example at the output; and Fig. 25 a schematic diagram of the bottom bracket gear according to Fig. 22 with a freewheel provided between the pedal crankshaft and the gearbox input shaft.

[0031] In the Fig. 1 to 25, various design variants and embodiments or switching schemes of a bottom bracket gear according to the invention in planetary design are shown merely by way of example. Fig. 1 shows an example of a bicycle or pedelec 1 with the bottom bracket gear, only schematically indicated.

[0032] The bottom bracket transmission is shown in a housing or bottom bracket shell 2 with a pedal crankshaft or pedal crank with pedals, wherein the pedal crankshaft is connected to a transmission input shaft WAn. Furthermore, the bottom bracket transmission comprises a transmission output shaft WAb as the output with a chain or belt pulley (not shown in detail). Furthermore, a multi-stage main transmission 3 and a transmission shift group 4 are provided, wherein the transmission shift group 4 has a first planetary gear set RS1 and a second planetary gear set RS2, as well as four shift elements B1, B2, K1, K2. The main transmission 3 and the transmission shift group 4 essentially form two sub-transmissions.

[0033] Regardless of the respective design variants, the transmission shift group 4 is provided with a second element of the first planetary gear set RS1 being connected to a first shaft W1, the first shaft W1 being connected to the transmission input shaft WAn in the case of an upstream transmission shift group 4 or on the output side to the main transmission 3 in the case of a downstream transmission shift group 4, a first element of the first planetary gear set RS1 being connected via a fourth shaft W4 to a second element of the second planetary gear set RS2, a third element of the first planetary gear set RS1 being connected to a fifth shaft W5, the fifth shaft W5 being connected to the transmission output shaft WAb in the case of a downstream transmission shift group 4 or on the input side to the main transmission 3 in the case of an upstream transmission shift group 4,wherein a first element of the second planetary gear set RS2 is lockable via a third shaft W3 and via a second shifting element B2 designed as a brake, wherein the third shaft W3 is connectable to the first shaft W1 via a sixth shifting element K2 designed as a clutch or freewheel, wherein a third element of the second planetary gear set RS2 is lockable via a second shaft W2 and via a first shifting element B1 designed as a brake, and wherein the second shaft W2 is connectable to the first shaft W1 via a fifth shifting element K1 designed as a clutch or freewheel.

[0034] In the Fig. 1 to 3, the two planetary gear sets RS1, RS2 are each designed as space-efficient negative planetary gear sets. The first element of the planetary gear sets RS1, RS2 is a sun gear SR1, SR2, the second element is a planetary gear carrier PT1, PT2, and the third element is a ring gear HR1, HR2.

[0035] In the Fig. 1 and Fig. 2 shows two different binding variants, which differ in the geometric position of the elements of the planetary gear sets RS1, RS2 and the switching elements B1, B2, K1, K2 as well as the shafts W1, W2, W3, W4, W5, but have identical connections of the elements of the planetary gear sets RS1, RS2 and the switching elements B1, B2, K1, K2 as well as the shafts W1, W2, W3, W4, W5.

[0036] In Fig. 1 and Fig. 2 shows a first embodiment of the bottom bracket gear, in which the gear shift group 4 is connected upstream of the multi-stage main gear 3. In detail, the first embodiment according to Fig. 1 and Fig. 2, it is provided that the planetary gear carrier PT1 of the first planetary gear set RS1 is connected via the first shaft W1 or directly to the transmission input shaft Wan, that the sun gear SR1 of the first planetary gear set RS1 is connected via the fourth shaft W4 to the planetary gear carrier PT2 of the second planetary gear set RS2, that the ring gear HR1 of the first planetary gear set RS1 is connected to the fifth shaft W5, that the fifth shaft W5 is connected on the input side to the main transmission 3, that the sun gear SR2 of the second planetary gear set RS2 can be fixed to the housing 2 via the third shaft W3 and via the second shifting element B2 designed as a brake, that the third shaft W3 can be connected via the sixth shifting element K2 designed as a clutch or freewheel to the first shaft W1 or directly to the transmission input shaft WAn and to the planetary gear carrier PT1 of the first planetary gear set RS1,that the ring gear HR2 of the second planetary gear set RS2 can be fixed to the housing 2 via the second shaft W2 and via the first switching element B1 designed as a brake, and wherein the second shaft W2 can be connected to the first shaft W1 or directly to the transmission input shaft WAn and to the planetary gear carrier PT1 of the first planetary gear set RS1 via the fifth switching element K1 designed as a clutch or freewheel.

[0037] In Fig. 3 shows a second embodiment of the bottom bracket transmission, in which the gear shift group 4 is connected downstream of the multi-stage main transmission 3. In detail, the second embodiment according to Fig. 3, it is provided that the planetary gear carrier PT1 of the first planetary gear set RS1 is connected to the first shaft W1, that the first shaft W1 is connected on the output side to the main transmission 3, that the sun gear SR1 of the first planetary gear set RS1 is connected via the fourth shaft W4 to the planetary gear carrier PT2 of the second planetary gear set RS2, that the ring gear HR1 of the first planetary gear set RS1 is connected to the fifth shaft W5, that the fifth shaft W5 is connected to the transmission output shaft WAb, that the sun gear SR2 of the second planetary gear set RS2 can be fixed to the housing 2 via the third shaft W3 and via the second switching element B2 designed as a brake, that the third shaft W3 can be connected to the first shaft W1 and to the planetary gear carrier PT1 of the first planetary gear set RS1 via the sixth switching element K2 designed as a clutch or freewheel,that the ring gear HR2 of the second planetary gear set RS2 can be fixed to the housing 2 via the second shaft W2 and via the first switching element B1 designed as a brake, and wherein the second shaft W2 can be connected to the first shaft W1 and to the planetary gear carrier PT1 of the first planetary gear set RS1 via the fifth switching element K1 designed as a clutch or freewheel.

[0038] In Fig. Figure 4 shows a shift diagram for transmission shift group 4 as a four-speed transmission. This means that four gears V1, V2, V3, and V4 can be realized with the transmission shift group. The shift elements B1, B2, K1, and K2 used for the respective gear V1, V2, V3, and V4 are specified in the shift diagram. An X for the freewheels K1 and K2 as shift elements in the shift diagram means that the freewheels are locked. This works automatically without external activation. Furthermore, an X for a brake B1 and B2 as a shift element in the shift diagram means that the brake B1 and B2 is applied. This works via a suitable actuator.

[0039] In detail, the circuit diagram according to Fig. 4, that for shifting a first gear V1, the first shifting element B1 designed as a brake and the second shifting element B2 designed as a brake are open, with the fifth shifting element K1 designed as a freewheel and the sixth shifting element K2 designed as a freewheel locking; that for shifting a second gear V2, the first shifting element B1 designed as a brake is open and the second shifting element B2 designed as a brake is closed, with the fifth shifting element K1 designed as a freewheel locking and the sixth shifting element K2 designed as a freewheel not locking; that for shifting a third gear V3, the first shifting element B1 designed as a brake is closed and the second shifting element B2 designed as a brake is open, with the fifth shifting element K1 designed as a freewheel not locking and the sixth shifting element K2 designed as a freewheel locking;and / or that for shifting a fourth gear V4, the first shifting element B1 designed as a brake and the second shifting element B2 designed as a brake are closed, whereby the fifth shifting element K1 designed as a freewheel and the sixth shifting element K2 designed as a freewheel do not lock.

[0040] In Fig. 5 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.

[0041] In Fig. 6 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.

[0042] In Fig. 7 shows a minus stepped planetary gear set according to the invention, 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.

[0043] In Fig. 8 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.

[0044] In Fig. 9 shows an example of 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.

[0045] The Fig. The possible designs shown in Figures 5 to 9 using a planetary gear set can be implemented on the specific planetary gear sets RS1, RS2, RS3, RS4 of the bottom bracket gear according to the invention.

[0046] In the Fig. Figures 10 to 21 illustrate various exemplary embodiments of the bottom bracket transmission, with the proposed planetary gear sets RS1, RS2, RS3, RS4 of the main transmission 3 and the transmission shift group 4 each being designed as space-saving minus planetary gear sets in the proposed bottom bracket transmission. It is provided that a sun gear SR1, SR2, SR3, SR4 is provided as the first element, a planet gear carrier PT1, PT2, PT3, PT4 is provided as the second element, and a ring gear HR1, HR2, HR3, HR4 is provided as the third element for the planetary gear sets RS1, RS2, RS3, RS4.

[0047] In the Fig. 10 to 12, a first embodiment of the invention is shown, in which the main transmission 3 is designed as a two-speed transmission with a third planetary gear set RS3 and two shift elements B3 and K3. The two-speed main transmission 3 is in Fig. 10 of the transmission group 4, while the two-speed main transmission 3 in Fig. 11 is connected upstream of the transmission group 4.

[0048] In the two-speed main gearbox 3 according to Fig. 10 and Fig. 11 it is provided that the planet gear carrier PT3 of the third planetary gear set RS3 is connected to the transmission input shaft WAn or to the fifth shaft W5 of the transmission shift group 4, that the sun gear SR3 of the third planetary gear set RS3 can be fixed to the housing 2 via a sixth shaft W6 and via a third shift element B3 designed as a brake, that the sixth shaft W6 can be connected to the ring gear HR3 of the third planetary gear set RS3 via a seventh shift element K3 designed as a clutch or freewheel and via a seventh shaft W7, and that the ring gear HR3 of the third planetary gear set RS3 is connected to the transmission output shaft WAb or to the first shaft W1 of the transmission shift group 4. The connections of the two planetary gear sets RS1 and RS2 of the transmission shift group 4 have already been described.

[0049] In Fig. 12 is an example of a circuit diagram for the Fig. 10 and Fig. 11 shows the embodiment of the bottom bracket gear according to the invention. Because the gear shift group 4 has four gears and the main gear 4 has two gears, this results in a total of 4x2 = 8 shiftable gears G1 to G8. The shifting diagram shows the shifting elements B1, B2, B3, K1, K2, K3 used for the respective gears G1 to G8. An X for a freewheel K1, K2, K3 as a shifting element in the shifting diagram means that the freewheel is locked. This functions automatically without external activation. Furthermore, an X for a brake B1, B2, B3 as a shifting element in the shifting diagram means that the brake B1, B2, B3 is closed. This functions via a suitable actuator.

[0050] In detail, the circuit diagram according to Fig. 12, that to realize a first gear G1, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are opened, wherein the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel are locked.

[0051] It follows that in order to realize a second gear G2, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are opened and the second switching element B2 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock and the sixth switching element K2 designed as a freewheel does not lock.

[0052] It follows that in order to realize a third gear G3, the first switching element B1 designed as a brake is closed and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel does not lock and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock.

[0053] It follows that in order to realize a fourth gear G4, the first switching element B1 designed as a brake and the second switching element B2 designed as a brake are closed and the third switching element B3 designed as a brake is open, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel do not lock and the seventh switching element K3 designed as a freewheel locks.

[0054] It follows that in order to realize a fifth gear G5, the first switching element B1 designed as a brake and the second switching element B2 designed as a brake are opened and the third switching element B3 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel lock and the seventh switching element K3 designed as a freewheel does not lock.

[0055] It follows that in order to realize a sixth gear G6, the first switching element B1 designed as a brake is open and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel locks and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock.

[0056] It follows that in order to implement a seventh gear G7, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are closed and the second switching element B2 designed as a brake is open, wherein the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel locks, and / or that in order to implement an eighth gear G8, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are closed, wherein the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock.

[0057] In the Fig. 13 to 15, a second embodiment of the invention is shown, in which the main transmission 3 is designed as a three-speed transmission with a third planetary gear set RS3 and a fourth planetary gear set RS4 as well as three shift elements B3, B4 and K3. The three-speed main transmission 3 is in Fig. 13 of the gearbox group 4, while the three-speed main gearbox 3 in Fig. 14 is connected upstream of the transmission group 4.

[0058] With the three-speed main gearbox 3 according to Fig. 13 and Fig. 14, it is provided that the planetary gear carrier PT3 of the third planetary gear set RS3 is connected to the transmission input shaft WAn or to the fifth shaft W5 of the transmission shift group 4, that the sun gear SR3 of the third planetary gear set RS3 and the sun gear SR4 of the fourth planetary gear set RS4 are connected via an eighth shaft W8 or directly to the transmission output shaft WAb or to the first shaft W1 of the transmission shift group 4, that the ring gear HR3 of the third planetary gear set RS3 can be fixed to the housing 2 via a sixth shaft W6 and a third shifting element B3 designed as a brake, that the sixth shaft W6 is connected to the planetary gear carrier PT4 of the fourth planetary gear set RS4, and that the ring gear HR4 of the fourth planetary gear set RS4 can be fixed to the housing 2 via a seventh shaft W7 and a fourth shifting element B4 designed as a brake,that the ring gear HR4 of the fourth planetary gear set RS4 can be connected to the transmission output shaft WAb or to the first shaft W1 of the transmission switching group 4 via a seventh switching element K3 designed as a clutch or freewheel.

[0059] In Fig. 15 is an example of a circuit diagram for the Fig. 13 and Fig. 14 shows the embodiment of the bottom bracket gear according to the invention. Because the gear shift group 4 has four gears and the main gear 4 has three gears, this results in a total of 4x3 = 12 shiftable gears G1 to G12. The shifting diagram shows the shifting elements B1, B2, B3, B4, K1, K2, K3 used for the respective gears G1 to G12. An X for a freewheel K1, K2, K3 as a shifting element in the shifting diagram means that the freewheel is locked. This functions automatically without external activation. Furthermore, an X for a brake B1, B2, B3, B4 as a shifting element in the shifting diagram means that the brake B1, B2, B3, B4 is closed. This functions via a suitable actuator.

[0060] In detail, the circuit diagram according to Fig. 15, that to realize a first gear G1, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, wherein the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel are locked.

[0061] It follows that in order to realize a second gear G2, the first switching element B1 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened and the second switching element B2 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock and the sixth switching element K2 designed as a freewheel does not lock.

[0062] It follows that in order to realize a third gear G3, the first switching element B1 designed as a brake is closed and the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel does not lock and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock.

[0063] It follows that in order to realize a fourth gear G4, the first switching element B1 designed as a brake and the second switching element B2 designed as a brake are closed and the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are open, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel do not lock and the seventh switching element K3 designed as a freewheel locks.

[0064] It follows that in order to realize a fifth gear G5, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are opened and the fourth switching element B4 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel lock and the seventh switching element K3 designed as a freewheel does not lock.

[0065] It follows that in order to realize a sixth gear G6, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are opened and the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel locks and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock.

[0066] It follows that in order to realize a seventh gear G7, the first switching element B1 designed as a brake and the fourth switching element B4 designed as a brake are closed and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are open, whereby the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel locks.

[0067] It follows that in order to realize an eighth gear G8, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are closed and the third switching element B3 designed as a brake is opened, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock.

[0068] It follows that in order to realize a ninth gear G9, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are opened and the third switching element B3 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel lock and the seventh switching element K3 designed as a freewheel does not lock.

[0069] It follows that in order to realize a tenth gear G10, the first switching element B1 designed as a brake and the fourth switching element B4 designed as a brake are opened and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel is locked and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel are not locked.

[0070] It follows that in order to achieve an eleventh gear G11, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are closed and the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are opened, wherein the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel locks, and / or in order to achieve a twelfth gear G12, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake are opened and the third switching element B3 designed as a brake are closed and the fourth switching element B4 designed as a brake is opened, wherein the fifth switching element K1 designed as a freewheel,the sixth switching element K2, which is designed as a freewheel, and the seventh switching element K3, which is designed as a freewheel, do not lock.

[0071] In the Fig. 16 to 21, a third embodiment of the invention is shown, in which the main transmission 3 is designed as a four-speed transmission with a third planetary gear set RS3 and a fourth planetary gear set RS4 as well as four shift elements B3, B4, K3 and K4. The four-speed main transmission 3 is in Fig. 16 and Fig. 19 of the gearbox group 4, while the four-speed main gearbox 3 in Fig. 17 and Fig. 20 is connected upstream of the transmission switching group 4.

[0072] In a first variant of the four-speed main gearbox 3 according to Fig. 16 and Fig. 17, it is provided that the planetary gear carrier PT3 of the third planetary gear set RS3 is connected to the transmission input shaft WAn or to the fifth shaft W5 of the transmission shift group 4, that the sun gear SR3 of the third planetary gear set RS3 can be fixed to the housing 2 via a sixth shaft W6 and via a third switching element B3 designed as a brake, that the sun gear SR3 of the third planetary gear set RS3 can be connected to the ring gear HR3 of the third planetary gear set RS3 and to the planetary gear carrier PT4 of the fourth planetary gear set RS4 via a seventh switching element K3 designed as a clutch or freewheel and via a seventh shaft W7,that the ring gear HR4 of the fourth planetary gear set RS4 can be fixed to the housing 2 via an eighth shaft W8 via a fourth switching element B4 designed as a brake and can be connected to the transmission output shaft WAb or to the first shaft W1 of the transmission shift group 4 via an eighth switching element K4 designed as a clutch or freewheel, and that the sun gear SR4 of the fourth planetary gear set RS4 is connected via a ninth shaft W9 or directly to the transmission output shaft WAb or to the first shaft W1 of the transmission shift group 4.

[0073] In Fig. 18 is an example of a circuit diagram for the Fig. 16 and Fig. 17 shows the embodiment of the bottom bracket gear according to the invention. Because the gear shift group 4 has four gears and the main gear 4 has four gears, this results in a total of 4 x 4 = 16 shiftable gears G1 to G16. The shifting diagram shows the shifting elements B1, B2, B3, B4, K1, K2, K3, K4 used for the respective gears G1 to G16. An X for a freewheel K1, K2, K3, K4 as a shifting element in the shifting diagram means that the freewheel is locked. This functions automatically without external activation. Furthermore, an X for a brake B1, B2, B3, B4 as a shifting element in the shifting diagram means that the brake B1, B2, B3, B4 is closed. This functions via a suitable actuator.

[0074] In detail, the circuit diagram according to Fig. 18, that to realize a first gear G1, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, wherein the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel are locked.

[0075] It follows that in order to realize a second gear G2, the first switching element B1 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened and the second switching element B2 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock and the sixth switching element K2 designed as a freewheel does not lock.

[0076] It follows that in order to realize a third gear G3, the first switching element B1 designed as a brake is closed and the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel does not lock and the sixth switching element K2 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock.

[0077] It follows that in order to realize a fourth gear G4, the first switching element B1 designed as a brake and the second switching element B2 designed as a brake are closed and the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel do not lock and the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock.

[0078] It follows that in order to realize a fifth gear G5, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are opened and the third switching element B3 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock and the seventh switching element K3 designed as a freewheel does not lock.

[0079] It follows that in order to realize a sixth gear G6, the first switching element B1 designed as a brake and the fourth switching element B4 designed as a brake are opened and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock.

[0080] It follows that in order to realize a seventh gear G7, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are closed and the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock.

[0081] It follows that in order to realize an eighth gear G8, the first switching element B1 designed as a brake, 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 B4 designed as a brake is open, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock and the eighth switching element K4 designed as a freewheel locks.

[0082] It follows that in order to realize a ninth gear G9, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are opened and the fourth switching element B4 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock and the eighth switching element K4 designed as a freewheel does not lock.

[0083] It follows that in order to realize a tenth gear G10, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are opened and the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock and the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock.

[0084] It follows that in order to realize an eleventh gear G11, the first switching element B1 designed as a brake and the fourth switching element B4 designed as a brake are closed and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock.

[0085] It follows that in order to realize a twelfth gear G12, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are closed and the third switching element B3 designed as a brake is opened, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock and the seventh switching element K3 designed as a freewheel locks.

[0086] It follows that in order to realize a thirteenth gear G13, the first switching element B1 designed as a brake and the second switching element B2 designed as a brake are opened and the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel lock and the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock.

[0087] It follows that in order to realize a fourteenth gear G14, the first switching element B1 designed as a brake is open and the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel is locked and the sixth switching element K2 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel are not locked.

[0088] It follows that in order to achieve a fifteenth gear G15, the first switching element B1 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed and the second switching element B2 designed as a brake is opened, whereby the fifth switching element K1 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel locks, and / or in order to achieve a sixteenth gear G16, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel,the seventh switching element K3, which is designed as a freewheel, and the eighth switching element K4, which is designed as a freewheel, do not lock.

[0089] In a second variant of the four-speed main gearbox 3 according to Fig. 19 and Fig. 20, it is provided that the planetary gear carrier PT3 of the third planetary gear set RS3 is connected to the transmission input shaft WAn or to the fifth shaft W5 of the transmission shift group 4, that the sun gear SR3 of the third planetary gear set RS3 is connected via a ninth shaft W9 or directly to the transmission output shaft WAb or to the first shaft W1 of the transmission shift group 4, that the ring gear HR3 of the third planetary gear set RS3 is connected via an eighth shaft W8 to the planetary gear carrier PT4 of the fourth planetary gear set RS4, that the ring gear HR4 of the fourth planetary gear set RS4 can be fixed to the housing 2 via a sixth shaft W6 and via a third shifting element B3 designed as a brake, that the ring gear HR4 of the fourth planetary gear set RS4 can be connected to the transmission input shaft WAn or to the fifth shaft W5 via a seventh shifting element K3 designed as a clutch or freewheel,that the sun gear SR4 of the fourth planetary gear set RS4 can be fixed to the housing 2 via a seventh shaft W7 and via a fourth switching element B4 designed as a brake, and that the sun gear SR4 of the fourth planetary gear set RS4 can be connected to the transmission output shaft WAb or to the first shaft W1 of the transmission switching group 4 via an eighth switching element K4 designed as a clutch or freewheel.

[0090] In Fig. 21 is an example of a circuit diagram for the Fig. 19 and Fig. 20 shows the embodiment of the bottom bracket gear according to the invention. Because the gear shift group 4 has four gears and the main gear 4 has four gears, this results in a total of 4x4 = 16 shiftable gears G1 to G16. The shifting diagram shows the shifting elements B1, B2, B3, B4, K1, K2, K3, K4 used for the respective gears G1 to G16. An X for a freewheel K1, K2, K3, K4 as a shifting element in the shifting diagram means that the freewheel is locked. This functions automatically without external activation. Furthermore, an X for a brake B1, B2, B3, B4 as a shifting element in the shifting diagram means that the brake B1, B2, B3, B4 is closed. This functions via a suitable actuator.

[0091] In detail, the circuit diagram according to Fig. 21, that to realize a first gear G1, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, wherein the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel are locked.

[0092] It follows that in order to realize a second gear G2, the first switching element B1 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened and the second switching element B2 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock and the sixth switching element K2 designed as a freewheel does not lock.

[0093] It follows that in order to realize a third gear G3, the first switching element B1 designed as a brake is closed and the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel does not lock and the sixth switching element K2 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock.

[0094] It follows that in order to realize a fourth gear G4, the first switching element B1 designed as a brake and the second switching element B2 designed as a brake are closed and the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel do not lock and the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock.

[0095] It follows that in order to realize a fifth gear G5, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are opened and the fourth switching element B4 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock and the eighth switching element K4 designed as a freewheel does not lock.

[0096] It follows that in order to realize a sixth gear G6, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are opened and the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock and the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock.

[0097] It follows that, in order to realize a seventh gear G7, the first switching element B1 designed as a brake and the fourth switching element B4 designed as a brake are closed and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are open, whereby the fifth switching element K1 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel lock.

[0098] It follows that in order to realize an eighth gear G8, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are closed and the third switching element B3 designed as a brake is opened, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock and the seventh switching element K3 designed as a freewheel locks.

[0099] It follows that in order to realize a ninth gear G9, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are opened and the third switching element B3 designed as a brake is closed, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock and the seventh switching element K3 designed as a freewheel does not lock.

[0100] It follows that in order to realize a tenth gear G10, the first switching element B1 designed as a brake and the fourth switching element B4 designed as a brake are opened and the second switching element B2 designed as a brake and the third switching element B3 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel and the eighth switching element K4 designed as a freewheel are locked and the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel are not locked.

[0101] It follows that in order to realize an eleventh gear G11, the first switching element B1 designed as a brake and the third switching element B3 designed as a brake are closed and the second switching element B2 designed as a brake and the fourth switching element B4 designed as a brake are opened, whereby the fifth switching element K1 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel and the eighth switching element K4 designed as a freewheel lock.

[0102] It follows that in order to realize a twelfth gear G12, the first switching element B1 designed as a brake, 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 B4 designed as a brake is opened, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel and the seventh switching element K3 designed as a freewheel do not lock and the eighth switching element K4 designed as a freewheel locks.

[0103] It follows that in order to realize a thirteenth gear G13, the first switching element B1 designed as a brake and the second switching element B2 designed as a brake are opened and the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel and the sixth switching element K2 designed as a freewheel lock and the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock.

[0104] It follows that in order to realize a fourteenth gear G14, the first switching element B1 designed as a brake is open and the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel is locked and the sixth switching element K2 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel are not locked.

[0105] It follows that in order to achieve a fifteenth gear G15, the first switching element B1 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed and the second switching element B2 designed as a brake is opened, whereby the fifth switching element K1 designed as a freewheel, the seventh switching element K3 designed as a freewheel and the eighth switching element K4 designed as a freewheel do not lock and the sixth switching element K2 designed as a freewheel locks, and / or in order to achieve a sixteenth gear G16, the first switching element B1 designed as a brake, the second switching element B2 designed as a brake, the third switching element B3 designed as a brake and the fourth switching element B4 designed as a brake are closed, whereby the fifth switching element K1 designed as a freewheel, the sixth switching element K2 designed as a freewheel,the seventh switching element K3, which is designed as a freewheel, and the eighth switching element K4, which is designed as a freewheel, do not lock.

[0106] In Fig. Figure 22 shows an embodiment of the bottom bracket transmission according to the invention based on the first embodiment variant, 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.

[0107] In the Fig. 23 and Fig. 24 shows an embodiment of the bottom bracket gear according to the invention based on the first embodiment variant with an additional electric machine EM. The electric machine EM can be connected to the pedal crankshaft WAn, as shown in Fig. 23. It is also conceivable that the electric machine EM is connected to the transmission output shaft WAb, as shown in Fig. 24. 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 the like, so that during operation without the electric machine EM, no losses are caused by the co-rotating electric machine EM.

[0108] In Fig.Figure 25 shows an embodiment of the bottom bracket transmission according to the invention based on the first embodiment variant with an additional freewheel F1 between the pedal crankshaft and the transmission input shaft WAn. In this way, the freewheel can open when pedaling is interrupted and decouples the pedal crankshaft from the inertial masses of the transmission 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 multi-stage main gearbox 4 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 SR4 sun gear of the fourth planetary gear set PT4 planetary gear carrier of the fourth planetary gear set HR4 ring gear of the fourth planetary gear set SRA first sun gear in Plus-step gear set SRB second sun gear for plus-step gear set HRA first ring gear for Plus-stepped gear set HRB second ring gear for plus-step gear set RS1 first planetary gear set RS2 second planetary gear set RS3 third planetary gear set RS4 fourth planetary gear set WAn crankshaft WAB gearbox output shaft W1 first wave W2 second wave W3 third wave W4 fourth wave W5 fifth wave W6 sixth wave W7 seventh wave W8 eighth wave W9 ninth wave V1 first gear in the gearbox group V2 second gear in the gearbox group V3 third gear in the gearbox group V4 fourth gear in the gearbox group 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 G9 ninth gear of the bottom bracket gearbox G10 tenth gear of the bottom bracket gearbox G11 eleventh gear of the bottom bracket gearbox G12 twelfth gear of the bottom bracket gearbox G13 thirteenth gear of the bottom bracket gearbox G14 fourteenth gear of the bottom bracket gearbox G15 fifteenth gear of the bottom bracket gearbox G16 sixteenth gear of the bottom bracket gearbox B1 first switching element designed as a brake B2 second switching element designed as a brake B3 third switching element designed as a brake B4 fourth switching element designed as a brake K1 fifth switching element designed as a clutch or freewheel K2 sixth switching element designed as a clutch or freewheel K3 seventh switching element designed as a clutch or freewheel K4 eighth switching element designed as clutch or freewheel 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] Planetary bottom bracket gear for a bicycle or a pedelec (1), with a gear input shaft (WAn) as drive, with a gear output shaft (WAb) as output, with a multi-stage main gear (3) and with at least one gear shift group (4), wherein the transmission shift group (4) has two planetary gear sets (RS1, RS2) and four shift elements (B1, B2, K1, K2), wherein a second element of the first planetary gear set (RS1) is connected to a first shaft (W1), wherein a first element of the first planetary gear set (RS1) is connected via a fourth shaft (W4) to a second element of the second planetary gear set (RS2), wherein a third element of the first planetary gear set (RS1) is connected to a fifth shaft (W5), wherein a first element of the second planetary gear set (RS2) can be fixed via a third shaft (W3) and via a second switching element (B2) designed as a brake, wherein the third shaft (W3) is connectable to the first shaft (W1) via a sixth switching element (K2) designed as a clutch or freewheel, wherein a third element of the second planetary gear set (RS2) can be fixed via a second shaft (W2) and via a first switching element (B1) designed as a brake and wherein the second shaft (W2) is connectable to the first shaft (W1) via a fifth switching element (K1) designed as a clutch or freewheel, wherein the main gear (3) is either additionally - comprises a third planetary gear set (RS3) and two shift elements (B3, K3), or - comprises a third planetary gear set (RS3) and a fourth planetary gear set (RS4) as well as three shift elements (B3, B4, K3), or - a third planetary gear set (RS3) and a fourth planetary gear set (RS4) as well as four shift elements (B3, B4, K3, K4), characterized bythat each of the planetary gear sets (RS1, RS2, RS3, RS4) is designed as a minus stepped planetary gear set, wherein in a minus stepped planetary gear set the first element is designed as a sun gear (SR1, SR2, SR3, SR4), the second element is designed as a planet gear carrier (PT1, PT2, PT3, PT4) and the third element is designed as a ring gear (HR1, HR2, HR3, HR4). [2] Bottom bracket gear according to claim 1, characterized by that the gearshift group (4) is connected upstream or downstream of the main gearbox (3). [3] Bottom bracket transmission according to claim 1, provided that the main transmission (3) comprises a third planetary gear set (RS3) and two switching elements (B3, K3), characterized by that a second element of the third planetary gear set (RS3) is connected to the transmission input shaft (WAn) or to the fifth shaft (W5) of the transmission shift group (4), that a first element of the third planetary gear set (RS3) can be fixed via a third switching element (B3) designed as a brake, that the third element of the third planetary gear set (RS3) is connected to the transmission output shaft (WAb) or to the first shaft (W1) of the transmission shift group (4), and that the third planetary gear set can be locked together by connecting two of the three elements of the planetary gear set via a seventh switching element (K3) designed as a clutch or freewheel. [4] Bottom bracket transmission according to claim 1, provided that the main transmission (3) comprises a third planetary gear set (RS3) and a fourth planetary gear set (RS4) as well as three switching elements (B3, B4, K3), characterized by that a second element of the third planetary gear set (RS3) is connected to the transmission input shaft (WAn) or to the fifth shaft (W5) of the transmission shift group (4), that a first element of the third planetary gear set (RS3) and a first element of the fourth planetary gear set (RS4) are connected to the transmission output shaft (WAb) or to the first shaft (W1) of the transmission shift group (4), that a third element of the third planetary gear set (RS3) can be locked via a third switching element (B3) designed as a brake and is connected to a second element of the fourth planetary gear set (RS4), that a third element of the fourth planetary gear set (RS4) can be locked via a fourth switching element (B4) designed as a brake, and that the third planetary gear set and the fourth planetary gear set can be blocked via a seventh switching element (K3) designed as a clutch or freewheel by connecting two of the four shafts (w5 to w8). [5] Bottom bracket transmission according to claim 1, provided that the main transmission (3) comprises a third planetary gear set (RS3) and a fourth planetary gear set (RS4) as well as four switching elements (B3, B4, K3, K4), characterized by that a second element of the third planetary gear set (RS3) is connected to the transmission input shaft (WAn) or to the fifth shaft (W5) of the transmission shift group (4), that a first element of the third planetary gear set (RS3) can be fixed via a third switching element (B3) designed as a brake, that the third planetary gear set can be locked together via a seventh switching element (K3) designed as a clutch or freewheel by connecting two of the three elements of the planetary gear set, that the third element of the third planetary gear set (RS3) is connected to the second element of the fourth planetary gear set (RS4), and that a third element of the fourth planetary gear set (RS4) can be locked via a fourth switching element (B4) designed as a brake that the fourth planetary gear set can be locked together via an eighth switching element (K4) designed as a clutch or freewheel by connecting two of the three elements of the planetary gear set, and that a first element of the fourth planetary gear set (RS4) is connected to the transmission output shaft (WAb) or to the first shaft (W1) of the transmission shift group (4). [6] Bottom bracket transmission according to claim 1, provided that the main transmission (3) comprises a third planetary gear set (RS3) and a fourth planetary gear set (RS4) as well as four switching elements (B3, B4, K3, K4), characterized by that a second element of the third planetary gear set (RS3) is connected to the transmission input shaft (WAn) or to the fifth shaft (W5) of the transmission shift group (4), that a first element of the third planetary gear set (RS3) is connected to the transmission output shaft (WAb) or to the first shaft (W1) of the transmission shift group (4), that a third element of the third planetary gear set (RS3) is connected to a second element of the fourth planetary gear set (RS4), that a third element of the fourth planetary gear set (RS4) can be locked via a third switching element (B3) designed as a brake and can be connected to the transmission input shaft (WAn) or to the fifth shaft (W5) of the transmission switching group (4) via a seventh switching element (K3) designed as a clutch or freewheel, and that a first element of the fourth planetary gear set (RS4) can be fixed via a fourth switching element (B4) designed as a brake and can be connected to the transmission output shaft (WAb) or to the first shaft (W1) of the transmission switching group (4) via an eighth switching element (K4) designed as a clutch or freewheel. [7] Bottom bracket gear according to one of the preceding claims, characterized by that the first switching element (B1) and / or the second switching element (B2) and / or the third switching element (B3) and / or the fourth switching element (B4) are each designed as a positive-locking brake and / or that the fifth switching element (K1) and / or the sixth switching element (K2) and / or seventh switching element (K3) and / or the eighth switching element (K4) are each designed as a non-actively actuable freewheel. [8] Bottom bracket gear according to one of the preceding claims, characterized bythat a torque sensor (5) is connected to the transmission input shaft (Wan). [9] 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 transmission input shaft (WAn) or the transmission output shaft (WAb). [10] Bottom bracket gear according to claim 9, characterized by that the electric machine (EM) is arranged axially parallel to the pedal crankshaft and / or transmission input shaft (WAn). [11] Bottom bracket gear according to one of the preceding claims, characterized by that the planetary gear sets (RS1, RS2, RS3, RS4) are arranged coaxially to the pedal crankshaft and / or transmission input shaft (Wan). [12] Bicycle or pedelec (1) with a bottom bracket gear according to one of the preceding claims.

Images