An electric machine including a rotor shaft having an inner shaft core with a first composition and an outer shaft portion surrounding at least some of the inner shaft core. The outer shaft portion is fabricated from a material having a different composition than the inner shaft core. For example, the inner shaft core could be fabricated from a material having high thermal conductivity, such as copper, while the outer shaft portion is fabricated from a material with lesser thermal conductivity, but greater strength, for example steel. The two-material shaft with a highly thermally conductive core serves to conduct heat from the interior of the electric machine to the housing, or to an exterior apparatus or structure.

An electromechanical drive system for a mechanical power load. The system includes an electric motor connectable to an electric power source, a first transmission connected at one side with a first end of the shaft of the electric motor and connectable at the other end with a load, an electric power generator, and a second transmission connected at one side with a second end of the shaft of the electric motor, which extends in a direction opposite to that of the first end of the shaft of the electric motor, and which is connected at the other side with the electric power generator, wherein the electric power generator is electrically connectable via a switch with a power source and the electric motor, such that the electric current from the power generator can be directed either to electric power source or to an electric motor, with which charging of the electric power source is achieved when a need of the load for mechanical power is reduced.

An electromechanical drive system for a mechanical power load. The system includes an electric motor connectable to an electric power source, a first transmission connected at one side with a first end of the shaft of the electric motor and connectable at the other end with a load, an electric power generator, and a second transmission connected at one side with a second end of the shaft of the electric motor, which extends in a direction opposite to that of the first end of the shaft of the electric motor, and which is connected at the other side with the electric power generator, wherein the electric power generator is electrically connectable via a switch with a power source and the electric motor, such that the electric current from the power generator can be directed either to electric power source or to an electric motor, with which charging of the electric power source is achieved when a need of the load for mechanical power is reduced.

A first bracket in an electric motor includes an inflow path through which outside air flows inside, and an outflow path through which the air having flowed in flows outside. A stator core included in the electric motor includes a first ventilation path that is coupled with the inflow path and a second ventilation path that is coupled with the outflow path. A second bracket includes a third ventilation path that forms a flow path from the first ventilation path to the second ventilation path positioned symmetrically to the first ventilation path with respect to a plane containing a rotation axis. The air having flowed into the inside of the electric motor through the inflow path passes, in order, through the first ventilation path, the third ventilation path, and the second ventilation path, and flows out to the outside of the electric motor through the outflow path.

An e-charger includes a motor case that encases the motor and an outer housing that houses the motor case. The e-charger additionally includes a cooling system with passages cooperatively defined by the outer housing and the motor case. First and second longitudinal passages extend between the first and second ends of the motor, and a second longitudinal passage extends between the second and first ends of the motor. The end passage fluidly connects the first and second longitudinal passage. The cooling system is configured for directing flow of the coolant from the inlet, through the first longitudinal passage in a first longitudinal direction with respect to the axis, through the end passage, and back through the second longitudinal passage in a second longitudinal direction with respect to the axis.

An e-charger includes a motor case that encases the motor and an outer housing that houses the motor case. The e-charger additionally includes a cooling system with passages cooperatively defined by the outer housing and the motor case. First and second longitudinal passages extend between the first and second ends of the motor, and a second longitudinal passage extends between the second and first ends of the motor. The end passage fluidly connects the first and second longitudinal passage. The cooling system is configured for directing flow of the coolant from the inlet, through the first longitudinal passage in a first longitudinal direction with respect to the axis, through the end passage, and back through the second longitudinal passage in a second longitudinal direction with respect to the axis.

According to the method, either CO2-free air or pure nitrogen N2 is pumped into the cooling circuit selectively depending on system parameters. To this end, the method ensures that the air injection rate is high enough that, under normal conditions, the hydrogen concentration in the tank and in the riser remains below 2% H2. On air injection, the oxygen O2 (>2 ppm) in the cooling water reacts with the copper in the cooling ducts and a layer of copper oxide forms on the inner walls of said ducts. No reaction is triggered by the injection of nitrogen N2. The CO2 content in the injection air and, at the same time, also the H2 content in the exhaust air are continuously measured and monitored, and an alarm is triggered if adjustable limit values are exceeded. The equipment for performing the method comprises an electronic control unit (65) with an input field and display as a control box, and a pump and a pipe circuit for drawing air in from the riser. The control unit (65) can evaluate all the measured data from the sensors and analysers connected to the pipe and can at least check the CO2 content in the supply air and the H2 content in the riser (13) and display the hydrogen leakage.

A stator assembly for an electric machine may have a stator including a stator core and a plurality of stator windings, which has a cooling system for cooling the stator, where the cooling system includes a cooling shell 10 encompassing the stator core, which is thermally coupled to the stator core, where the cooling system has a supply line connected to the cooling shell at the intake end and a return line connected to the cooling shell at the outlet end, where the cooling system has at least one coolant pump and one coolant container, where the coolant pump is connected to the supply line in the flow path between the coolant container and the cooling shell in order to supply coolant to the cooling shell through the supply line.

A stator assembly for an electric machine may have a stator including a stator core and a plurality of stator windings, which has a cooling system for cooling the stator, where the cooling system includes a cooling shell 10 encompassing the stator core, which is thermally coupled to the stator core, where the cooling system has a supply line connected to the cooling shell at the intake end and a return line connected to the cooling shell at the outlet end, where the cooling system has at least one coolant pump and one coolant container, where the coolant pump is connected to the supply line in the flow path between the coolant container and the cooling shell in order to supply coolant to the cooling shell through the supply line.

An electric machine including a shaft, a rotor back assembly surrounding a portion of the shaft, and two or more permanent magnets radially positioned around the perimeter of the rotor back assembly. The electric machine also includes a rotor fan with multiple fan blades formed in an exterior surface of the rotor back assembly and one or more ventilation channels extending through the rotor back assembly. Methods of exporting heat from an electric machine, wither from a machine housing or through the shaft is also disclosed. The heat exportation methods feature the circulation of a fluid with the rotor fan through the ventilation channels and into contact with the housing, or exporting heat from the rotor back assembly through the shaft.