A system and method that converts rotational movement of a crank shaft into electrical energy is provided. The crank shaft is caused to rotate using a series of electromagnets powered by a power source. The electromagnets are arranged to encircle and magnetically affect a central magnet coupled to the shaft. The system effectively amplifies the energy supplied from the power source and saves the resulting excess energy to an energy storage device.

A rotating body is shorter in radial direction than in axial direction. The inner circumferential surfaces of a first bearing and a second bearing are fixed at an outer circumferential surface of the shaft member. In the axial direction, the outer diameter of the shaft member is substantially the same from a part, of the shaft member, opposing the first bearing to a part, of the shaft member, opposing the second bearing, and the inner and outer diameters of the rotating body are substantially the same from an end part, of the rotating body, on the first bearing side to an end part, of the rotating body, on the second bearing side. In the axial direction, one of stators is disposed at a central part (C1) of the shaft member, one of magnets is disposed at a central part (C2) of the rotating body.

A multi-axis linear motor actuator has a circuit board having a size covering coil portions in linear shaft motors arranged in a row, and combined with the linear shaft motors to be adjacent thereto and parallel to its arrangement direction; and magnetic shielding plates, longer than the coil portions, arranged and fixed along an axial direction at positions corresponding to positions between adjacent coil portions. Hall sensors are installed in the circuit board in each region corresponding to each linear shaft motor at intervals in a moving direction of a shaft of each linear shaft motor. Each magnetic shielding plate has a wide portion with a width greater than a diameter of the coil portion at a part corresponding to the region where the Hall sensors are installed. The circuit board has first slits for inserting the wide portions. The Hall sensors are installed adjacent to the wide portion.

A composite motor having high-precision positioning, comprising: a housing (1), a rough positioning assembly, a hollow output shaft (2), a fine positioning assembly, a power switching apparatus and a controller (6). A stepper motor (3) in the rough positioning assembly is responsible for rough positioning of the composite motor, an annular travelling wave ultrasonic motor in the fine positioning assembly is responsible for tail end fine positioning of the composite motor, and the controller (6) implements power output switching between the annular travelling wave ultrasonic motor and the stepper motor (3). The composite motor effectively solves the problem that annular travelling wave ultrasonic motors which operate continuously for a long time have a short service life, and ensures high-precision positioning while also extending motor service life.

Disclosed is a device for reducing a user-sensed weight of a wireless vacuum cleaner including a suctioning pipe and a suction motor disposed on a top of the suctioning pipe, the device comprising: a case disposed adjacent to the suction motor and having a space defined therein, and a rotatable assembly received in the space, wherein the rotatable assembly receives therein a motor and a battery, wherein the rotatable assembly is configured to rotate clockwise or counter-clockwise when the motor is activated.

A compressor or pump stage is provided. The compressor or pump stage at least comprising a central shaft (8) and one rotor (3), where the axis of rotation of the rotor (3) is the central shaft (8) and where the rotor comprises a number, n, of rows of impellers (5) arranged at an outer perimeter of the rotor with an axial distance between neighbouring rows of impellers (5), where n={2, 3, 4 . . . }.

A compressor or pump stage is provided. The compressor or pump stage at least comprising a central shaft (8) and one rotor (3), where the axis of rotation of the rotor (3) is the central shaft (8) and where the rotor comprises a number, n, of rows of impellers (5) arranged at an outer perimeter of the rotor with an axial distance between neighbouring rows of impellers (5), where n={2, 3, 4 . . . }.

A fluid moving apparatus includes an electric motor having a rotor and a stator and a propeller. The rotor rotates relative to the stator on an axis to generate a rotational output. The rotational output is provided to the propeller to power the marine propulsion apparatus. The stator includes one or more coils configured to power rotation of the rotor. The one or more coils extend circumferentially around and can be coaxial on the axis. A portion of a housing of the motor extends into the aquatic environment to facilitate heat dissipation.

An electromagnetic transmission assembly. The electromagnetic transmission assembly includes a stator having a central axis and a plurality of selectively-energized electromagnetic poles. A first rotor assembly is rotatably supported for rotation about the central axis. The first rotor assembly including a first rotor shaft and a castellated rotor including a plurality of radially arranged ferromagnetic pole portions disposed in a housing. A second rotor assembly is rotatably supported for rotation about the central axis. The second rotor assembly includes a second rotor shaft and a permanent-magnet rotor. The first rotor assembly is at least partially magnetically coupled to the second rotor assembly when the plurality of electromagnetic poles are energized.

A linear motor unit includes at least one first linear motor in which an armature is disposed spaced from a shaft guide supporting section which is provided at a distal end of a frame, and a shaft guide is disposed on a proximal side of the shaft guide supporting section; and at least one second linear motor in which an armature is disposed in contact with the proximal side the shaft guide supporting section which is provided at the distal end of the frame, and the shaft guide is disposed on the distal side of the shaft guide supporting section, wherein the first linear motors and the second linear motors are alternatively arranged in a width direction of the frame with the respective shaft guides of the linear motors aligned with each other, the shaft guide is rotated by a rotary motor.