Axial flux motor with air cooling system

An axial flux electric motor comprising:

• a) a motor shaft defining a longitudinal axis of rotation about which the motor shaft is rotatable;
• b) a stator assembly including a plurality of electromagnets spaced circumference about the longitudinal axis of rotation, the electromagnets each including a stator core about which a wire coil is wound, the stator cores each including a core body which extends along a core axis between first and second opposite axial ends, the core axes being parallel to the longitudinal axis of rotation, the first axial ends defining first end faces that face in a first axial direction and the second axial ends defining second end faces that face in a second axial direction opposite from the first axial direction, the wire coils being wound about the core axes between the first and second axial ends, wherein the first and second opposite axial ends of each stator core are adapted to define opposite magnetic poles of each corresponding electromagnet;
• c) a rotor assembly coupled to the motor shaft, the rotor assembly and the motor shaft being adapted to rotate together relative to the stator assembly about the longitudinal axis of rotation, the rotor assembly including a first rotor including a first rotor plate and a plurality of first permanent magnets carried by the first rotor plate, the first permanent magnets being circumferentially spaced about the longitudinal axis of rotation and having first permanent magnet end faces positioned to oppose the first axial end faces of the stator cores, the first permanent magnet end faces being spaced from the first axial end faces of the stator cores by a first air gap, the rotor assembly also including a second rotor including a second rotor plate and a plurality of second permanent magnets carried by the second rotor plate, the plurality of second permanent magnets being circumferentially spaced about the longitudinal axis of rotation and having second permanent magnet end faces positioned to oppose the second axial end faces of the stator cores, the second permanent magnet end faces being spaced from the second axial end faces of the stator cores by a second air gap, the rotor assembly further including a hub radially inward from the stator cores, wherein the first and second rotor plates each include an inner portion defining the hub, an outer portion encircling the permanent magnets, and a connection portion extending from the inner portion to the outer portion at an oblique angle, wherein the hub is configured to capture a bearing assembly between the hub and the stator assembly, wherein the inner portions of the first rotor plate and the second rotor plate are coupled together;
• and
• d) the first and second rotor plates being configured for moving cooling air through the first and second air gaps, wherein the cooling air flows axially into one or more passageways extending axially relative to the longitudinal axis of rotation and turns such that the cooling air flows radially out of the axial flux electric motor through one or more outlets located radially relative to the longitudinal axis of rotation, wherein the one or more passageways comprise first and second sidewalls through the connection portions of the first and second rotor plates, the entire length of the first and second sidewalls are both oriented obliquely relative to the longitudinal axis of rotation.

An axial flux electric motor comprising:

• a) a housing assembly arranged along a longitudinal axis, the housing assembly comprising one or more air outlets on a circumferential outer wall of the housing assembly;
• b) a stator assembly mounted within the housing assembly, the stator assembly including a plurality of stator cores with wire coils, the stator assembly defining first and second axial faces;
• and
• c) a rotor assembly mounted within the housing assembly, the rotor assembly being rotatable with respect to the stator assembly and including an output shaft extending out of the housing assembly, the rotor assembly including a first rotor part carrying a first plurality of permanent magnets facing and spaced from the stator assembly first axial face to define a first air gap and a second rotor part carrying a second plurality of permanent magnets facing and spaced from the stator assembly second axial face to define a second air gap, the first rotor part including a first air-movement feature extending through the first rotor part and configured to, when the first rotor part is rotating, draw air into the housing assembly and through the first air gap, the rotor assembly further including a hub radially inward from the stator cores, wherein the first and second rotor parts each include an inner portion defining the hub, an outer portion encircling the permanent magnets, and a connection portion extending from the inner portion to the outer portion at an oblique angle, wherein the hub is configured to capture a bearing assembly between the hub and the stator assembly, wherein the inner portions of the first rotor part and the second rotor part are coupled together;
• d) wherein the first air-movement feature extends axially relative to the longitudinal axis of the housing assembly and comprises at least one aperture extending through the connection portion of the first rotor part, the at least one aperture having a centerline oriented obliquely relative to the longitudinal axis along the entire length of the at least one aperture;
• and
• e) wherein the air is drawn axially through the at least one aperture into the rotor assembly and moves axially through the first rotor part, and subsequently passes radially through an interstitial space to the first air gap, and exits the axial flux electric motor radially through the one or more air outlets in fluid communication with the first air gap.