Electric motor
An electric motor having a cooling channel which leads through an interior space surrounded by a stator and a housing comprises a first housing component, which forms a base opposite a first axial end of the stator, and a second housing component opposite a second axial end of the stator as a cover, and the first housing component has an inlet and an outlet for cooling liquid and an inner part which projects into the stator. The inner part forms a sleeve, in which the first end of the shaft is arranged, and the inner part also forms an annular space which is arranged between the stator and the sleeve, wherein a cooling channel section for cooling the stator extends in this annular space, and wherein at least one bearing of the shaft is arranged in the sleeve.
1 . An electric motor comprising
a stator, which comprises stator windings,
a rotor surrounding the stator and comprising permanent magnets,
a shaft connected to the rotor,
a housing surrounding the rotor and the stator, and
a cooling channel which leads through an interior space surrounded by the stator, wherein
the shaft has a first end, which is arranged in the housing, and a second end, which protrudes out of the housing,
the housing comprises a first housing component, which forms a base opposite a first axial end of the stator, and a second housing component opposite a second axial end of the stator as a cover, and
the first housing component has an inlet and an outlet for cooling liquid and an inner part which projects into the stator,
the inner part forms a sleeve, in which the first end of the shaft is arranged, and the inner part also forms an annular space which is arranged between the stator and the sleeve, wherein a cooling channel section for cooling the stator extends in this annular space,
the shaft has different diameters and the shaft is mounted in the sleeve formed by the inner part with a first bearing, which is arranged closer to the first end of the shaft than a second bearing and has a smaller bearing inner diameter than the second bearing, and wherein the first bearing is a fixed bearing and the second bearing is a floating bearing.
2 . The electric motor according to claim 1 , wherein the floating bearing is resiliently pressed against a stop formed by the shaft.
3 . The electric motor according to claim 1 , wherein the floating bearing is pressed by a spring washer against a stop formed by the shaft.
4 . The electric motor according to claim 1 , wherein an insert is arranged in the annular space, which together with the inner part defines the cooling channel section.
5 . The electric motor according to claim 4 , wherein the first housing component carries a plate which encloses the insert in the annular space.
6 . The electric motor according to claim 5 , wherein the plate forms a base of the sleeve.
7 . The electric motor according to claim 5 , wherein the plate defines a further cooling channel section between itself and the insert, and the first housing component carries a printed circuit board with control electronics for controlling the power supply to the stator windings, the printed circuit board carrying, on a side facing the plate, an electronic component which bears against the plate.
8 . The electric motor according to claim 7 , wherein the plate carries protrusions on a side facing away from the electronic component, which protrusions project into the further cooling channel section.
9 . The electric motor according to claim 7 , wherein the further cooling channel section is arranged upstream of the cooling channel for cooling the stator.
10 . The electric motor according to claim 1 , wherein the inner part has a cylindrical or a conical outer surface which defines a cone angle of less than 20°.
11 . The electric motor according to claim 1 , wherein a sealing ring is arranged between the first housing component and the second housing component.
12 . The electric motor according to claim 1 , wherein the rotor has a stack of laminations, to the inside of which the permanent magnets are attached, and a carrier, via which the stack of laminations is connected to the shaft.
13 . The electric motor according to claim 12 , wherein the carrier has an opening through which the shaft projects.
14 . The electric motor according to claim 1 , wherein the shaft protrudes from the second housing component.
15 . The electric motor according to claim 4 , wherein the insert has at least one rib which extends in the circumferential direction and along which the cooling channel section for cooling the stator runs.
16 . The electric motor according to claim 1 , wherein the first housing component has at least one rib which extends in the axial direction in the annular space and along which the cooling channel section for cooling the stator runs.