A brushless motor is at least partially located in a hermetically sealed space. An electric work machine includes a brushless motor, an output unit, a motor case, a lead wire, and a first seal. The brushless motor includes a stator, a rotor rotatable with respect to the stator, and a rotor shaft fixed to the rotor. The output unit is drivable by the rotor shaft. The motor case includes an internal space and a wiring passage. The internal space accommodates the stator and the rotor. The lead wire is located in the wiring passage connecting the internal space and an external space of the motor case. The first seal seals between the lead wire and the motor case.

An electric work machine is drivable appropriately when a brushless motor generates heat. The electric work machine includes a brushless motor including a stator, a rotor rotatable with respect to the stator, and a rotor shaft fixed to the rotor, an output unit drivable by the rotor shaft, a motor case accommodating the stator and the rotor, and a cooling fan located outside the motor case and rotatable by the rotor shaft.

An electric work machine is drivable appropriately when a brushless motor generates heat. The electric work machine includes a brushless motor including a stator, a rotor rotatable with respect to the stator, and a rotor shaft fixed to the rotor, an output unit drivable by the rotor shaft, a motor case accommodating the stator and the rotor, and a cooling fan located outside the motor case and rotatable by the rotor shaft.

An axial flux motor and a method for operating the same, in particular for driving at least one leaf element of a door, of a gate, of a window, of a person separation device and/or of a partition wall system, include a magnet unit and having a coil unit, with the magnet unit being designed so as to be rotatable about a rotational axis, and with a gap being designed between the magnet unit and the coil unit. An actuation unit is provided, with which the gap between the magnet unit and the coil unit is variable, in particular enlargeable.

A method for magnetizing a soft magnet in a rotor of a variable-flux memory motor (VFMM) includes: generating a first pulse of electric current that has a duration of equal to or more than 0.1 millisecond (ms) and equal to or less than 2 ms; and applying the first pulse to a stator winding of the VFMM to set a magnetization state of the soft magnet to a first magnetization state.

A permanent magnet motor is provided that produces variable magnetic flux. The motor may include two different types of permanent magnets with different coercivities. The magnetic state of one of the magnets may be altered during use. In one state, the effective magnetic flux of the motor is greater, and in another state, the effective magnetic flux of the motor is less.

An axial-flux generator for fluid turbines has a continuously variable generator that is constructed of a pair of rotors that move radially across a stator resulting in varying torque and varying power output. In one embodiment the rotors are normally held proximal to the center of a stator by spring tension. The stator is larger than the normally held position of the rotors. As the angular velocity of the rotors increases, the rotors move radially toward the perimeter of the stator, thus encountering a greater stator surface area providing increased torque, increased power generation and a higher-rated output speed when used with a fluid turbine.

An electromagnetic rotary drive includes a rotor including a magnetically effective core surrounded by a stator. The stator has poles arranged around the magnetically effective core and each of the poles is delimited by an end face. The rotor is capable of being magnetically driven without contact in an operating state about an axial direction, and is capable of being magnetically levitated without contact with respect to the stator. The rotor is configured to be magnetically levitated in a radial plane and is passively magnetically stabilized in the axial direction against tilting. The magnetically effective core has a rotor height which is a maximum extension of the magnetically effective core in the axial direction, the rotor height being greater than a stator pole height defined by a maximum extension of the end faces in the axial direction.

An electric machine includes a rotor, a stator, and an air gap formed between a magnetic device of the rotor and the stator. For the selective setting of the air gap, movement devices implemented by piezoelectric stacks are provided on the rotor and/or on the stator. The movement devices may influence radial positions of the respective magnetic device and thus set the radial air gap width. It is thereby possible to exert open-loop and/or closed-loop control over a power or torque of the electric machine without adjusting stator currents. Vibration or unbalance of the rotor may also be counteracted quickly and effectively during operation of the machine.

A passive magnetic bearing employs eddy currents in a copper core between neodymium annular magnets to support the copper core and an associated rotating shaft. The copper core has an annular flange that is coaxial with a hollow cylinder. The hollow cylinder supports a rotating shaft. An annular iron core is coaxial with and surrounds the annular flange. Annular neodymium magnets surround the upper and lower portions of the hollow cylinder. In some embodiments a touch-down bearing is made up of an upper and a lower bearing race that are spaced away from the upper surface and lower surface of the annular flange. The core rotates over the bearing race(s) until sufficient magnetic flux is generated to support the copper core and hence the shaft. Once spinning, a magnetic field is generated in the copper core.