An electrical rotating machine includes a laminated stator core having a first axial duct to convey a cooling air stream generated by a turbomachine through the laminated stator core to a rear stator winding overhang, and a second axial duct to return the cooling air stream from the rear stator winding overhang back through the laminated stator core. An air guide is attached to the laminated stator core on a side of the rear stator winding overhang to redirect the cooling air stream via the rear stator winding overhang. Radial slots between the ducts and an air gap between the laminated stator core and a rotor are spaced from one another at an axial distance which decreases toward a turbomachine-distal side of the laminated stator core so as to compensate a temperature gradient caused by the one-sided cooling.

A rotor shaft for an electric machine includes a rotor shaft main body and a rotor shaft core which is arranged therein and which is connected to the rotor shaft main body. The rotor shaft comprises a substantially axially running cooling cavity configured to conduct a cooling fluid, and the rotor shaft core is composed of a different material than the rotor shaft main body.

Increase in weight of a rotary electric machine including a low-speed rotor in which a spacer made of metal is provided between a plurality of magnetic pole pieces, can be suppressed. The rotary electric machine includes a stator, a first rotor provided so as to be rotatable with respect to the stator, and a second rotor provided coaxially with the first rotor. The first rotor includes a plurality of magnetic pole pieces disposed so as to be arranged in the circumferential direction, a plurality of spacers respectively disposed between the plurality of magnetic pole pieces, two dampers respectively disposed at both end portions in the axial direction, and a fastening tool for fastening each spacer to a corresponding clamper. The spacer has a cavity portion. The spacer and the fastening tool are electrically insulated from each other.

Presented are oleophilic surface treatments for electric machines, methods for making/using such electric machines, and vehicles employing traction motors having stator windings with oleophilic treatments on select surfaces. An electric machine includes an outer housing with a direct-cooling thermal management system fluidly connected to the housing to circulate thereto a coolant fluid. A stator assembly, which is attached to the housing, includes a stator core with one or more electromagnetic windings mounted to the stator core. A rotor assembly is movably mounted to the hosing adjacent the stator assembly. The rotor assembly includes a rotor core with one or more magnets mounted to the rotor core spaced, e.g., across an air gap, from the winding(s). Select components of the stator assembly have a target surface with an oleophilic surface treatment that enlarges the target surface's wetted area and increases a coolant mass of the coolant fluid contacting the target surface.

An electronic assembly includes a flexible printed circuit board (PCB) circumferentially disposed around a motor and a thermal management assembly (TMA) thermally connected to the flexible PCB. One or more switching semiconductor devices are disposed on a first surface of the flexible PCB. The TMA includes a cooling jacket, at least one jacket manifold formed through the cooling jacket and a thermal compensation base layer thermally coupled to the cooling jacket. The cooling jacket is mounted around a circumference of the motor and has a mounting surface concentric with the circumference of the motor. The mounting surface is coupled to the first surface of the flexible PCB. The at least one jacket manifold has a fluid inlet and a fluid outlet defining a fluid flow area therebetween. The thermal compensation base layer is thermally coupled to the cooling jacket and the one or more switching semiconductor devices.

A trimmer includes a handle assembly, a power mechanism installed at one end of the handle assembly, and a blade assembly connected to the power mechanism. The power mechanism has a housing assembly, a motor received in the housing assembly, and a power transmission assembly mounted on the housing assembly. The motor is an external rotor motor with a diameter greater than or equal to 50 mm. The power transmission assembly has pinion coaxially sleeved on an output shaft of the motor and a big gear meshing with the small gear, and a transmission ratio of the small gear to the big gear is less than 6. By such arrangement, the trimmer can obtain the best output effect under a condition that the output power of the motor is unchanged.

A motor assembly includes a motor, a housing including a housing space to house the motor, oil in a vertically lower region of the housing space, and an oil passage to lead the oil from the vertically lower region of the housing space through the motor to the vertically lower region of the housing space. The oil passage includes a first oil passage extending through an inside of the motor, and a second oil passage extending through an outside of the motor. One of the first oil passage and the second oil passage includes a cooler to cool the oil therein.

A method for determining a state of an electric motor having a stator (2) and a rotor (3) rotatably mounted relative to the stator (2) is disclosed. Due to a rotary motion of the rotor (3), a pressure difference (p) relative to an environment (15) of the electric motor (1, 1′, 1″, 1′″) is caused in an air space (16) inside the electric motor (1, 1′, 1″, 1′″). Here, in a normal state of the electric motor (1, 1′, 1″, 1′″), the pressure difference depends on an actual rotational speed (n) of the rotor (3). A corresponding electric motor suitable for carrying out this method is disclosed, wherein the electric motor may be part of a fan.

Various methods and systems are provided for a system for cooling an electric motor. The cooling system includes a primary coolant passage through a rotor shaft linked to a plurality of secondary passages though lamination stacks of a rotor configured to receive coolant at a central region of the lamination stacks.

In one exemplary embodiment, a gas turbine engine is provided. The gas turbine engine defines a radial direction, an axial direction, and an axis extending along the axial direction of the gas. The gas turbine engine includes: a shaft configured to rotate about the axis; an electric machine comprising a rotor coupled to and rotatable with the shaft and a stator, the rotor defining an end along the axial direction; and a cooling manifold rotatable with the rotor and positioned at the end of the rotor, the cooling manifold configured to receive a flow of cooling fluid and provide the cooling fluid to the stator during operation of the gas turbine engine.