A drive unit for a means of locomotion drivable simultaneously by drive energy provided by human muscular strength and by electric motors, comprising - an input shaft for transmitting drive energy generated from human muscular strength, - an output shaft for delivering drive energy to a travel unit, - a harmonic drive gearing arranged around a rotation axis and having a first wave generator, a first 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 can be transmitted to the output shaft via the harmonic drive gearing, the drive unit being characterized by: - a harmonic variation gearing arranged in the drive train between the input shaft and the output shaft and having a second wave generator, a second flexspline and a ring gear, the harmonic variation gearing being arranged such that it receives the drive energy of the input shaft obtained from human muscular strength and transmits it to the output shaft of the drive unit, - an electric variation motor with a stator and a rotor, the drive energy of which is likewise introduced into the harmonic variation gearing, wherein the summed energy from human muscular strength and the electric variation motor can be transmitted to the output shaft by the harmonic variation gearing, wherein the ring gear of the harmonic drive gearing and the ring gear of the harmonic variation gearing are configured in a co-rotating manner relative to each other and transmit the summed drive energy from human muscular strength, the electric drive motor and the electric variation motor to the output shaft. - an input shaft for transmitting drive energy generated from human muscular strength, - an output shaft for delivering drive energy to a travel unit, - a harmonic drive gearing arranged around a rotation axis and having a first wave generator, a first 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 can be transmitted to the output shaft via the harmonic drive gearing, the drive unit being characterized by: - a harmonic variation gearing arranged in the drive train between the input shaft and the output shaft and having a second wave generator, a second flexspline and a ring gear, the harmonic variation gearing being arranged such that it receives the drive energy of the input shaft obtained from human muscular strength and transmits it to the output shaft of the drive unit, - an electric variation motor with a stator and a rotor, the drive energy of which is likewise introduced into the harmonic variation gearing, wherein the summed energy from human muscular strength and the electric variation motor can be transmitted to the output shaft by the harmonic variation gearing, - a harmonic variation gearing arranged in the drive train between the input shaft and the output shaft and having a second wave generator, a second flexspline and a ring gear, the harmonic variation gearing being arranged such that it receives the drive energy of the input shaft obtained from human muscular strength and transmits it to the output shaft of the drive unit, - an electric variation motor with a stator and a rotor, the drive energy of which is likewise introduced into the harmonic variation gearing, wherein the summed energy from human muscular strength and the electric variation motor can be transmitted to the output shaft by the harmonic variation gearing, wherein the ring gear of the harmonic drive gearing and the ring gear of the harmonic variation gearing are configured in a co-rotating manner relative to each other and transmit the summed drive energy from human muscular strength, the electric drive motor and the electric variation motor to the output shaft.