Means of transport that can be simultaneously driven electromotively and by human muscular power
A means of transport, in particular a pedelec, which can be driven by means of drive energy produced electromotively and by human muscular power, comprising a drive unit in which an electric drive motor and a harmonic drive transmission are nested one inside the other, thereby saving space.
1 . A means of transport that can be simultaneously driven electromotively and by human muscular power, with a drive unit, the drive unit comprising:
an input shaft for transmitting drive energy generated from human muscular power;
an output shaft for delivering drive energy to a travel unit;
a harmonic drive transmission arranged around a rotation axis and having a wave generator, a flexspline and a ring gear;
an electric drive motor arranged around the rotation axis and having a stator and a rotor, wherein drive energy of the electric drive motor is transmittable to the output shaft via the harmonic drive transmission,
wherein the flexspline is configured as a sleeve extending in an axial direction of the rotation axis, which is connected on one axial side to a rotary bearing and toward another axial side has an engagement region for the wave generator, wherein a sleeve cavity is provided between the rotary bearing and the wave generator, as seen in the axial direction of the rotation axis, and
wherein the electric drive motor is arranged in the axial direction of the rotation axis at least partially in the sleeve cavity of the flexspline of the harmonic drive transmission with respect to an axial extent of the stator along the rotation axis.
2 . The means of transport according to claim 1 , wherein the wave generator, the flexspline and the ring gear of the harmonic drive transmission are arranged overlapping one another in a gearing plane perpendicular to the rotation axis, and the flexspline is mounted rotatably with respect to a counter bearing in a bearing plane perpendicular to the rotation axis, wherein the electric drive motor is arranged between the gearing plane and the bearing plane.
3 . The means of transport according to claim 1 , wherein a speed and/or rotation angle sensor is provided at the electric drive motor.
4 . The means of transport according to claim 1 , wherein a rotary bearing for the output shaft and a rotary bearing for the input shaft are arranged in a common shaft bearing plane perpendicular to the rotation axis.
5 . The means of transport according to claim 1 , wherein the electric drive motor and the harmonic drive transmission are arranged coaxially to one other around the rotation axis.
6 . The means of transport according to claim 1 , wherein the input shaft is connected to the output shaft in a co-rotating manner at least in one direction of rotation, and the energy provided through human muscular power is transmitted to the output shaft.
7 . The means of transport according to claim 1 , wherein the flexspline of the harmonic drive transmission is mounted on a stationary housing part via a freewheel.
8 . The means of transport according to claim 7 , wherein the freewheel is switchable or the flexspline and the stationary housing part are connectable in a co-rotating manner by a separate clutch unit, such that the electric drive motor is operable as a generator which receives drive energy from the ring gear and converts the drive energy into electrical energy.
9 . The means of transport according to claim 7 , wherein a rotary bearing is arranged between a counter bearing and the flexspline of the harmonic drive transmission in a bearing plane perpendicular to the rotation axis such that the rotary bearing overlaps with a freewheel.
10 . The means of transport according to claim 1 , wherein the wave generator, the flexspline and the ring gear of the harmonic drive transmission are arranged in a gearing plane perpendicular to the rotation axis together with a rotary bearing for the rotor of the electric drive motor.
11 . The means of transport according to claim 1 , wherein in the axial direction along the rotation axis, a shaft bearing plane, a gearing plane of the harmonic drive transmission, and a bearing plane of the flexspline of the harmonic drive transmission are arranged in succession.
12 . The means of transport according to claim 1 , wherein the drive unit is configured as a center drive unit or the drive unit is configured as a hub drive unit.
13 . The means of transport according to claim 1 , wherein a maximum extent of the drive unit along the rotation axis is not more than 100 mm.
14 . The means of transport according to claim 1 , wherein a control unit for controlling the electric drive motor is provided, which comprises at least one of the following features:
the control unit is arranged together with a rotary bearing for a crankshaft in an electronics bearing plane perpendicular to the rotation axis;
the control unit is connected to a rotation angle and/or speed and/or torque sensor at the input shaft;
the control unit is connected to a travel speed sensor;
the control unit is connected to a speed and/or rotation angle sensor at the electric drive motor;
the control unit is connected to an amperemeter for the electric drive motor;
the control unit controls the speeds and torques of the electric drive motor such that the drive energy, including the energy obtained from human muscular power, at the output shaft corresponds to the energy requirement of the drive unit;
the control unit controls the speed of the electric drive motor in proportion to the travel speed;
the control unit activates a drive support function or a brake function depending on the direction of rotation of a shaft driven by human muscular power;
the control unit is connected to a suspension travel sensor of the means of transport and at least partially compensates a pedal kickback caused by compression of a suspension of the means of transport by controlling the electric drive motor;
the control unit is connected to a display unit which is visible from the outside through a viewing window in the drive unit;
the control unit brings the input shaft into a starting position by controlling the electric drive motor.
15 . The means of transport according to claim 1 , comprising at least one of the following features:
the means of transport is an electric bicycle, pedelec, e-bike, cargo bike or transport bike;
the means of transport comprises a frame;
the means of transport comprises an electrical energy storage device;
the means of transport comprises a front wheel and a rear wheel;
the front wheel is steerable;
the means of transport comprises pedals which are rotatable about a pedaling axis via crank arms.
16 . The means of transport according to claim 1 , wherein the means of transport is a pedelec.