Speed-changing and differential transmission and motor and transmission unit

A motor and transmission unit, comprising:

• an electric motor having a motor output shaft configured as a hollow shaft;
• a speed-changing and differential transmission including a housing, an input shaft, two output shafts, a differential section, a speed-changing section, and a coupling device;
• said two output shafts of said speed-changing and differential transmission being disposed coaxially with said input shaft of said speed-changing and differential transmission, said differential section being configured as a spur wheel differential, said speed-changing section having two planetary stages, namely an input stage and a load stage, said input stage having a sun wheel, an annulus, a planet carrier, and at least one planet wheel, said sun wheel of said input stage being operatively connected to said input shaft of said speed-changing and differential transmission, said load stage having a sun wheel, an annulus, a planet carrier and at least one planet wheel, said annulus of said load stage being fixed in relation to said housing, said sun wheel of said load stage being operatively connectable to said at least one planet wheel of said input stage via said planet carrier of said input stage for defining a first operative connection, said at least one planet wheel of said load stage being operatively connectable to said annulus of said input stage via said planet carrier of said load stage for defining a second operative connection, one of the first and the second operative connection being configured as a selectable connection and a respective other one of the first and the second operative connection being configured as a fixed connection, said coupling device being configured to provide the selectable connection such that said annulus of said input stage can be operatively coupled to and decoupled from said planet carrier of said load stage or such that said sun wheel of said load stage can be operatively coupled to and decoupled from said planet carrier of said input stage;
• and
• said speed-changing and differential transmission being flanged coaxially to said electric motor, said motor output shaft of said electric motor being connected to said input shaft of said speed-changing and differential transmission, one of said two output shafts of said speed-changing and differential transmission passing coaxially through said motor output shaft of said electric motor.