A brushless electric motor is disclosed. A group of permanent magnets are physically attached to a group of piezoelectric actuators which push them toward or pull them away from a second group of permanent magnets when the piezoelectric actuators are electrically activated. The second group of permanent magnets may also be pushed and pulled with a second group of piezoelectric actuators. Alternate configurations using electromagnets are also disclosed.

A novel configuration for the groups of electromagnets which maximizes efficiency in a piezoelectrically actuated motor is also disclosed.

An assembly can include a rotor that defines a rotor axis and that includes a number of permanent magnets; a stator that defines a stator axis, coaxially aligned with the rotor axis, and that includes a number of electropermanent magnets; and a controller that controls polarity of the electropermanent magnets to rotate the rotor about the rotor axis.

An assembly can include a rotor that defines a rotor axis and that includes a number of permanent magnets; a stator that defines a stator axis, coaxially aligned with the rotor axis, and that includes a number of electropermanent magnets; and a controller that controls polarity of the electropermanent magnets to rotate the rotor about the rotor axis.

Provided are an electric motor that enables to achieve downsizing while securing performance, and a dental device that includes the electric motor. A brushless slotless electric motor 10 includes: a stator 3 that includes a stator core 301 and a plurality of coils 31 to 33, the plurality of coils 31 to 33 being disposed at an inside of the stator core 301; and a rotor 2 that includes a shaft 21 and a magnet 22, the rotor 2 being rotated around the shaft 21 with respect to the stator 3. The plurality of coils 31 to 33 are adjacent to each other in a rotation direction of the rotor 2 so as not to lap mutually. Lf<Lc is satisfied where Lf is a length of the stator core 301 in an axial direction and Lc is a length of the coil in the axial direction.

A linear vibration motor is disclosed. The linear vibration motor includes a housing; a vibrating unit in the housing, the vibrating unit including a magnet; a plurality of elastic members suspending the vibrating unit elastically in the housing; a drive coil positioned opposed to the magnet for driving the vibrating unit to vibrate along a first direction; a Hall sensor fixed on the housing and facing the magnet for detecting displacement of the vibrating unit along a direction vertical to the first direction; and a braking coil arranged on the housing and surrounding the Hall sensor for reacting upon the vibrating unit in accordance with the displacement detected by the Hall sensor in order to adjust the displacement of the vibrating unit vertical to the first direction.

The present invention is provided with: an insulation holder formed of a thermoplastic resin material and having a first opening; a wire connection ring formed of a thermoplastic resin material and having a second opening; and a joining component inserted astride in the first opening and the second opening, the joining component being formed of a metal material having a higher melting point than those of the thermoplastic resin materials, the joining component having a higher stiffness than those of the insulation holder and the wire connection ring, wherein a welded part is formed by welding in at least a part of an area where each of the Insulation holder and the wire connection ring has contact with the joining component.

The present invention is provided with: an insulation holder formed of a thermoplastic resin material and having a first opening; a wire connection ring formed of a thermoplastic resin material and having a second opening; and a joining component inserted astride in the first opening and the second opening, the joining component being formed of a metal material having a higher melting point than those of the thermoplastic resin materials, the joining component having a higher stiffness than those of the insulation holder and the wire connection ring, wherein a welded part is formed by welding in at least a part of an area where each of the Insulation holder and the wire connection ring has contact with the joining component.

A three-dimensional magnet structure (6) made up of a plurality of individual magnets (4), the magnet structure (6) having a thickness that forms its smallest dimension, the magnet structure (6) incorporating at least one mesh (5a) exhibiting mesh cells each one delimiting a housing (5) for a respective individual magnet (4), each housing (5) having internal dimensions just large enough to allow an individual magnet (4) to be inserted into it, the mesh cells being made from a fibre-reinforced insulating material, characterized in that a space is left between the housing (5) and the individual magnet (4), which space is filled with a fibre-reinforced resin, the magnet structure (6) comprising a non-conducting composite layer coating the individual magnets (4) and the mesh structure (5a).

A three-dimensional magnet structure (6) made up of a plurality of individual magnets (4), the magnet structure (6) having a thickness that forms its smallest dimension, the magnet structure (6) incorporating at least one mesh (5a) exhibiting mesh cells each one delimiting a housing (5) for a respective individual magnet (4), each housing (5) having internal dimensions just large enough to allow an individual magnet (4) to be inserted into it, the mesh cells being made from a fibre-reinforced insulating material, characterized in that a space is left between the housing (5) and the individual magnet (4), which space is filled with a fibre-reinforced resin, the magnet structure (6) comprising a non-conducting composite layer coating the individual magnets (4) and the mesh structure (5a).

A motor includes a fixed shaft, a first rotor supported by the fixed shaft in a rotatable manner relative to the fixed shaft, a first stator fixed to the fixed shaft and applying rotation torque that rotates the first rotor toward one side in a circumferential direction of the fixed shaft, a second rotor provided at a position different from a position of the first rotor in an axial direction in a rotatable manner relative to the fixed shaft, and a second stator fixed to the fixed shaft and applying rotation torque that rotates the second rotor toward another side in a circumferential direction of the fixed shaft.