Compact bicycle drive for an electrically drivable bicycle
In an embodiment a bicycle drive includes a pedal crankshaft configured to input mechanical drive power, an electric machine coupleable to the pedal crankshaft configured to input electric drive power and/or output generator power and a Wolfrom transmission interposed in a torque flow between the electric machine and the pedal crankshaft.
1 . A bicycle drive comprising:
a pedal crankshaft configured to input mechanical drive power;
an electric machine coupleable to the pedal crankshaft and configured to provide drive power and/or generator power; and
a Wolfrom transmission interposed between the electric machine and the pedal crankshaft,
wherein the Wolfrom transmission comprises a sun gear coupled to a rotor of the electric machine, a planet gear meshing with the sun gear, a fixed first ring gear meshing with the planet gear, and a second ring gear meshing with the planet gear and coupleable to the pedal crankshaft,
wherein the planet gear is relatively rotatably held on a planet carrier, and
wherein the planet carrier is relatively rotatably mounted on the sun gear.
2 . The bicycle drive of claim 1 , wherein the electric machine and the Wolfrom transmission are arranged coaxially with respect to the pedal crankshaft side by side in an axial direction.
3 . The bicycle drive of claim 1 , wherein the electric machine and the Wolfrom transmission are disposed within a housing, wherein the pedal crankshaft protrudes from the housing on both axial sides of the housing, and wherein the electric machine comprises the rotor supported on the housing.
4 . The bicycle drive of claim 1 , wherein the electric machine and the Wolfrom transmission are disposed within a housing, wherein the pedal crankshaft protrudes from the housing on both axial sides of the housing, and wherein the electric machine comprises the rotor supported on the pedal crankshaft.
5 . The bicycle drive of claim 1 , wherein the electric machine and the Wolfrom transmission are disposed within a housing, wherein the pedal crankshaft protrudes from the housing on both axial sides of the housing, and wherein the electric machine comprises the rotor supported on the housing and on the pedal crankshaft.
6 . The bicycle drive of claim 1 , wherein the sun gear has an axially projecting hub, and wherein the hub is connected in a rotationally fixed manner.
7 . The bicycle drive of claim 1 , wherein the planet gear meshing with the first ring gear and with the second ring gear has a constant diameter and a constant number of teeth.
8 . The bicycle drive of claim 1 , wherein the second ring gear has a radially inwardly projecting disc, and wherein the disc is coupleable to the pedal crankshaft.
9 . The bicycle drive of claim 8 , wherein the disc includes a disc hub radially inwardly surrounding a planet gear.
10 . The bicycle drive of claim 1 , wherein the second ring gear has a radially inwardly projecting disc, and wherein the disc is coupleable to the pedal crankshaft via a freewheel.
11 . The bicycle drive of claim 1 , wherein the second ring gear includes a radially inwardly offset and axially projecting bearing collar for fitting a ring gear bearing provided radially outwardly of the bearing collar for supporting the second ring gear on a housing.
12 . The bicycle drive of claim 1 , wherein the planet carrier is relatively rotatably mounted on a hub of the sun gear.
13 . A bicycle drive comprising:
a pedal crankshaft configured to input mechanical drive power;
an electric machine coupleable to the pedal crankshaft and configured to provide drive power and/or generator power; and
a Wolfrom transmission interposed between the electric machine and the pedal crankshaft,
wherein the Wolfrom transmission comprises a sun gear coupled to a rotor of the electric machine, a planet gear meshing with the sun gear, a fixed first ring gear meshing with the planet gear, and a second ring gear meshing with the planet gear and coupleable to the pedal crankshaft,
wherein the sun gear has an axially projecting hub, and
wherein the hub is connected in a rotationally fixed manner, via a plug-in toothing, to the rotor of the electric machine.
14 . The bicycle drive of claim 13 , wherein the electric machine and the Wolfrom transmission are disposed within a housing, wherein the pedal crankshaft protrudes from the housing on both axial sides of the housing, and wherein the electric machine comprises the rotor supported on the housing and on the pedal crankshaft.
15 . The bicycle drive of claim 13 , wherein the planet gear meshing with the first ring gear and with the second ring gear has a constant diameter and a constant number of teeth.
16 . The bicycle drive of claim 13 , wherein the second ring gear has a radially inwardly projecting disc, and wherein the disc is coupleable to the pedal crankshaft.
17 . The bicycle drive of claim 16 , wherein the disc includes a disc hub radially inwardly surrounding a planet gear.
18 . The bicycle drive of claim 13 , wherein the second ring gear has a radially inwardly projecting disc, and wherein the disc is coupleable to the pedal crankshaft via a freewheel.
19 . The bicycle drive of claim 13 , wherein the second ring gear includes a radially inwardly offset and axially projecting bearing collar for fitting a ring gear bearing provided radially outwardly of the bearing collar for supporting the second ring gear on a housing.
20 . The bicycle drive of claim 13 , wherein the planet gear is relatively rotatably held on a planet carrier, and wherein the planet carrier is relatively rotatably mounted on the hub.