Planetary-type bottom-bracket transmission for a bicycle or a pedelec

Patent metadata

Field	Value
Publication number	US-12428105-B2
Application number	US-202418944536-A
Country	US
Kind code	B2
Filing date	Nov 12, 2024
Priority date	Nov 13, 2023
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

A planetary-type bottom-bracket transmission for a bicycle or a pedelec includes a pedal crank shaft, a transmission output shaft, further shafts, and a first transmission shift group and a second transmission shift group. The first transmission shift group and the second transmission shift group are coupled to each other for implementing a plurality of gear ratios. The first transmission shift group includes a two-step stepped planetary gear set that is assigned a first shifting element, a second shifting element and a fifth shifting element.

First claim

The invention claimed is:

1. A planetary-type bottom-bracket transmission for a bicycle or a pedelec ( 1 ), comprising:
a pedal crank shaft (WAn) as an input;
a transmission output shaft (WAb) as an output;
a plurality of shafts (W 1 , W 2 , W 3 , W 4 , W 5 , W 6 ); and
a first transmission shift group ( 3 ) and a second transmission shift group ( 4 ) that are coupled together to implement a plurality of gear ratios (G 1 , G 2 , G 3 , G 4 , G 5 , G 6 , G 7 , G 8 , G 9 , G 10 , G 11 , G 12 ), the first transmission shift group ( 3 ) comprising a two-step stepped planetary gear set (StRS) assigned a first shifting element (B 1 ), a second shifting element (B 2 ), and a fifth shifting element (F 1 I, F 1 II, F 1 III, F 1 IV, F 1 V, F 1 VI), the second transmission shift group ( 4 ) comprising a first planetary gear set (RS 1 ) and a second planetary gear set (RS 2 ) assigned a third shifting element (B 3 ), a fourth shifting element (B 4 ), and a sixth shifting element (F 2 I, F 2 II, F 2 III, F 2 IV, F 2 V, F 2 VI),
wherein a stepped planet gear carrier (SPT) of the stepped planetary gear set (StRS 1 ) is connected to the pedal crank shaft (WAn) or to a sixth shaft (W 6 ) of the plurality of shafts as an output shaft of the second transmission shift group ( 4 ),
wherein a ring gear (HR 1 . 1 ) of the stepped planetary gear set (StRS) is connected to a second element of the first planetary gear set (RS 1 ) or to the transmission output shaft (WAb),
wherein a second sun gear (SR 1 . 2 ) of the stepped planetary gear set (StRS) is fixable to a casing ( 2 ) by the first shifting element (B 1 ),
wherein a first sun gear (SR 1 . 1 ) of the stepped planetary gear set (StRS) is fixable to the casing ( 2 ) by the second shifting element (B 2 ),
wherein, to interlock the stepped planetary gear set (StRS), two elements of the stepped planetary gear set (StRS) are connectable by the fifth shifting element (F 1 I, F 1 II, F 1 III, F 1 IV, F 1 V, F 1 VI),
wherein a first element of the first planetary gear set (RS 1 ) is connected to a first element of the second planetary gear set (RS 2 ),
wherein the first element of the first planetary gear set (RS 1 ) and the first element of the second planetary gear set (RS 2 ) are jointly connected to the stepped planet gear carrier (SPT) of the stepped planetary gear set (StRS) or to the transmission output shaft (WAb),
wherein a third element of the first planetary gear set (RS 1 ) is fixable to the casing ( 2 ) by the third shifting element (B 3 ),
wherein a third element of the second planetary gear set (RS 2 ) is fixable to the casing ( 2 ) by the fourth shifting element (B 4 ),
wherein the third element of the first planetary gear set (RS 1 ) is connected to the second element of the second planetary gear set (RS 2 ), and
wherein, to interlock the first planetary gear set (RS 1 ) and the second planetary gear set (RS 2 ), two shafts of the plurality of shafts connected to elements of the first planetary gear set (RS 1 ) and of the second planetary gear set (RS 2 ) are connectable by the sixth shifting element (F 2 I, F 2 II, F 2 III, F 2 IV, F 2 V, F 2 VI).

2. The bottom-bracket transmission of claim 1 , wherein the first transmission shift group ( 3 ) is connected upstream or downstream of the second transmission shift group ( 4 ).

3. The bottom-bracket transmission of claim 1 , wherein:
the stepped planet gear carrier (SPT) of the stepped planetary gear set (StRS 1 ) is connected to the pedal crank shaft (WAn) or to the sixth shaft (W 6 ) as the output shaft of the second transmission shift group ( 4 );
the ring gear (HR 1 . 1 ) of the stepped planetary gear set (StRS) is connected via a fifth shaft (W 5 ) of the plurality of shafts to the second element of the first planetary gear set (RS 1 ) or to the transmission output shaft (WAb);
the second sun gear (SR 1 . 2 ) of the stepped planetary gear set (StRS) is fixable to the casing ( 2 ) via a first shaft (W 1 ) of the plurality of shafts when the first shifting element (B 1 ) is engaged;
the first sun gear (SR 1 . 1 ) of the stepped planetary gear set (StRS) is fixable to the casing ( 2 ) via a second shaft (W 2 ) of the plurality of shafts when the second shifting element (B 2 ) is engaged;
to interlock the stepped planetary gear set (StRS), the two elements of the stepped planetary gear set (StRS) are connectable when the fifth shifting element (F 1 I, F 1 II, F 1 III, F 1 IV, F 1 V, F 1 VI) is locked;
the first element of the first planetary gear set (RS 1 ) is connected to the first element of the second planetary gear set (RS 2 );
the first element of the first planetary gear set (RS 1 ) and the first element of the second planetary gear set (RS 2 ) are jointly connected to the stepped planet gear carrier (SPT) of the stepped planetary gear set (StRS) or to the transmission output shaft (WAb);
the third element of the first planetary gear set (RS 1 ) is fixable to the casing ( 2 ) via a third shaft (W 3 ) of the plurality of shafts when the third shifting element (B 3 ) is engaged;
the third element of the second planetary gear set (RS 2 ) is fixable to the casing ( 2 ) via a fourth shaft (W 4 ) of the plurality of shafts when the fourth shifting element (B 4 ) is engaged;
the third element of the first planetary gear set (RS 1 ) is connected via the third shaft (W 3 ) to the second element of the second planetary gear set (RS 2 ); and
to interlock the first planetary gear set (RS 1 ) and the second planetary gear set (RS 2 ), the two shafts (WAb, W 3 , W 4 , W 5 ) connected to the elements of the first planetary gear set (RS 1 ) and of the second planetary gear set (RS 2 ) are connectable when the sixth shifting element (F 2 I, F 2 II, F 2 III, F 2 IV, F 2 V, F 2 VI) is locked.

4. The bottom-bracket transmission of claim 1 , wherein one or both of:
the first shifting element (B 1 ), the second shifting element (B 2 ), the third shifting element (B 3 ), and the fourth shifting element (B 4 ) are each a respective positively locking brake; and
the fifth shifting element (F 1 I, F 1 II, F 1 III, F 1 IV, F 1 V, F 1 VI) and the sixth shifting element (F 2 I, F 2 II, F 2 III, F 2 IV, F 2 V, F 2 VI) are each a respective freewheel.

5. The bottom-bracket transmission of claim 1 , wherein one or both of the first planetary gear set (RS 1 ) and the second planetary gear set (RS 2 ) is configured as a minus planetary gear set.

6. The bottom-bracket transmission of claim 5 , wherein, for each minus planetary gear set, the first element is a respective sun gear (SR 1 , SR 2 ), the second element is a respective planet gear carrier (PT 1 , PT 2 ), and the third element is a respective ring gear (HR 1 , HR 2 ).

7. The bottom-bracket transmission of claim 1 , wherein one or both of the first planetary gear set (RS 1 ) and the second planetary gear set (RS 2 ) is configured as a plus planetary gear set.

8. The bottom-bracket transmission of claim 7 , wherein, for each plus planetary gear set, the first element is a respective sun gear (SR 1 , SR 2 ), the second element is a respective ring gear (HR 1 , HR 2 ), and the third element is a respective planet gear carrier (PT 1 , PT 2 ).

9. The bottom-bracket transmission of claim 1 , further comprising a torque sensor ( 5 ) connected to the pedal crank shaft (WAn).

10. The bottom-bracket transmission of claim 1 , further comprising an electric machine (EM) connected or connectable to the pedal crank shaft (WAn) or to the transmission output shaft (WAb).

11. The bottom-bracket transmission of claim 10 , wherein the electric machine (EM) is arranged axially parallel to the pedal crank shaft (WAn).

12. The bottom-bracket transmission o

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Beck Stefan
• Wechs Michael
• Kutter Fabian
• Martin Thomas
• Riedisser Thomas

Classifications

• B62M11/18

  with a plurality of planetary gear units · CPC title

• B62M6/55

  power-driven at crank shafts parts · CPC title

• B62J45/411

  Torque sensors · CPC title

• B62J45/421

  at the pedal crank · CPC title

• F16H2200/2069

  using two freewheel mechanism · CPC title