Systems and methods for direct winding heat exchanger in motor
A system includes a rotor core; a rotor stack extending circumferentially from the rotor core, the rotor stack including: a first end; a second end opposite to the first end; and a first slot in the rotor stack, the first slot extending from the first end to the second end; and a hairpin cooling pipe in the first slot of the rotor stack.
1 . A system comprising a rotor including:
a rotor core;
a rotor stack extending circumferentially from the rotor core, the rotor stack including:
a first end;
a second end opposite to the first end;
a first slot in the rotor stack, the first slot extending from the first end to the second end;
flattened copper wires in the first slot;
a first cooling channel and a second cooling channel in the first slot, wherein the first cooling channel and the second cooling channel are proximate to and radially outward of a respective pair of the flattened copper wires;
a hairpin cooling pipe in the first cooling channel and the second cooling channel in the first slot of the rotor stack, wherein the hairpin cooling pipe includes:
a first elongated portion in the first cooling channel;
a second elongated portion parallel to the first elongated portion in the second cooling channel; and
a U-shaped connector connecting the first elongated portion to the second elongated portion at the first end of the rotor stack;
an inlet circuit extending circumferentially around the rotor at the first end of the rotor; and
an outlet circuit extending circumferentially around the rotor at the first end of the rotor.
2 . The system of claim 1 , further including:
a second slot extending from the first end of the rotor stack to the second end of the rotor stack.
3 . The system of claim 1 , wherein the first elongated portion of the hairpin cooling pipe is fluidly connected to the inlet circuit and the second elongated portion of the hairpin cooling pipe is fluidly connected to the outlet circuit.
4 . The system of claim 1 , further including:
a pump,
a filter; and
a heat exchanger, wherein the pump, the filter, and the heat exchanger are fluidly connected to the inlet circuit of the rotor stack.
5 . The system of claim 1 , further including:
a sump, wherein the sump is fluidly connected to the outlet circuit of the rotor stack.
6 . The system of claim 1 , wherein the rotor stack includes a first lamination and a second lamination, the first slot extends through the first lamination and the second lamination, and the hairpin cooling pipe is provided in the first slot in the first lamination and the second lamination.
7 . The system of claim 1 , further including:
a stator, wherein the rotor core and the rotor stack are provided inside the stator,
wherein the system is provided as a vehicle including the stator, the rotor core, and the rotor stack.
8 . The system of claim 1 , wherein the hairpin cooling pipe includes a porous inner surface.
9 . The system of claim 8 , wherein the porous inner surface includes a porous layer formed by a sintering process.
10 . The system of claim 1 , wherein the hairpin cooling pipe includes an electrical insulation layer on an outer surface of the hairpin cooling pipe.
11 . The system of claim 1 , wherein the first slot further includes a liquid configured to cool the flattened copper wires, the liquid being one of automatic transmission fluid or water-ethylene glycol.
12 . The system of claim 1 , wherein the first cooling channel and the second cooling channel are configured to perform direct cooling of the flattened copper wires.
13 . The system of claim 1 , further including an inverter including a power module, wherein the inverter is configured to convert DC power from a battery to AC power to power a drive motor including the rotor.
14 . The system of claim 13 , further including the battery, wherein the inverter is bidirectional and is configured to convert AC power to DC power during regenerative braking.
15 . The system of claim 1 , wherein the rotor core extends along a rotor axis, and the first slot extends in a direction parallel to the rotor axis.
16 . The system of claim 1 , wherein the hairpin cooling pipe is hollow, and a second end of the first elongated portion is in fluid connection with a second end of the second elongated portion.
17 . The system of claim 16 , wherein the second end of the first elongated portion is connected to the inlet circuit and the second end of the second elongated portion is connected to the outlet circuit.