A rotor unit for a brushless electric motor, incudes an annular rotor core surrounding a central axis, a plurality of magnet arrangements that are arranged around the rotor core in a circumferential direction of the rotor and that each have a convex outer peripheral face, an inner contact face, two axial end faces and two side faces pointing in the circumferential direction, a magnet holder having a number of holding portions which are each arranged between two adjacent magnet arrangements and are moulded onto a ring portion of the magnet holder. The holding portions are configured T-shaped in a cross section along a plane running transversely to the central axis and each have a shank portion and a head portion. The shank portion lies on the side faces of the magnet arrangements in a contact region and the head portion lies on the peripheral faces of the magnet arrangements.

A BLDC motor server includes a stator configured in a hollow cylindrical shape and comprising a plurality of teeth around which a plurality of coils is wound to form an electromagnetic field, respectively; and a rotor configured in a cylindrical shape rotatable within the stator and comprising a plurality of permanent magnets, each having an arched section in which an outer circumference side is extended in both directions from a rotation center side, wherein the plurality of permanent magnets is disposed, so that facing outer surface portions of two permanent magnets neighboring each other are adjacent to each other, and wherein a width Wo of the outer circumference side of each permanent magnet is configured to be smaller than a width Wc of the rotation center side thereof. The BLDC motor may reduce a noise and a vibration as well as increasing an efficiency of the motor.

A cleaner includes a BLDC motor and a power unit. The BLDC motor includes a rotor and a stator provided with a DC coil and an AC coil in a separate manner. The power unit is configured to supply DC power and AC power to the DC coil and the AC coil, respectively.

A cleaner includes a BLDC motor and a power unit. The BLDC motor includes a rotor and a stator provided with a DC coil and an AC coil in a separate manner. The power unit is configured to supply DC power and AC power to the DC coil and the AC coil, respectively.

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.

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.

An electric motor (10) has a stator (20) having a number S of stator poles (21, 22, 23, 24, 25, 26); a rotor (40) having a rotor magnet (40′), which rotor magnet (40′) has a number R of rotor poles (41, 42, 43, 44, 45, 46), R being equal to S, and the rotor (40) or the stator (20), or both, exhibiting a magnetic asymmetry. The asymmetry facilitates startup. The electric motor has a single-phase winding arrangement (30) with first (11), second (12) and third (13) terminals. Current can be made to flow, selectively, from either the first or the second terminal, through certain coils, to the third terminal (13). There is an output stage (50), preferably an H-bridge. The W total coils comprise a plurality of subgroups (TG1, TG2) of coils. A method for current flow through an electric motor utilizes these sub-groups (TG1, TG2) for current flow.

An electric motor (10) has a stator (20) having a number S of stator poles (21, 22, 23, 24, 25, 26); a rotor (40) having a rotor magnet (40′), which rotor magnet (40′) has a number R of rotor poles (41, 42, 43, 44, 45, 46), R being equal to S, and the rotor (40) or the stator (20), or both, exhibiting a magnetic asymmetry. The asymmetry facilitates startup. The electric motor has a single-phase winding arrangement (30) with first (11), second (12) and third (13) terminals. Current can be made to flow, selectively, from either the first or the second terminal, through certain coils, to the third terminal (13). There is an output stage (50), preferably an H-bridge. The W total coils comprise a plurality of subgroups (TG1, TG2) of coils. A method for current flow through an electric motor utilizes these sub-groups (TG1, TG2) for current flow.

A motor includes a stationary structure, and a rotor rotatable about a central axis with respect to the stationary structure. The stationary structure includes a stator including a coil, a bracket that supports the stator, and a circuit board disposed between the stator and the bracket. The bracket includes a board support that holds the circuit board between the bracket and the stator in an axial direction. The board support includes a wiring through hole that penetrates the board support in the axial direction and through which a wire extending from the circuit board passes, a lid that partially covers the wiring through hole, and a guide bridge that is located inside the wiring through hole when viewed in the axial direction and holds the wire between the lid and the guide bridge.

A motor includes a stationary structure, and a rotor rotatable about a central axis with respect to the stationary structure. The stationary structure includes a stator including a coil, a bracket that supports the stator, and a circuit board disposed between the stator and the bracket. The bracket includes a board support that holds the circuit board between the bracket and the stator in an axial direction. The board support includes a wiring through hole that penetrates the board support in the axial direction and through which a wire extending from the circuit board passes, a lid that partially covers the wiring through hole, and a guide bridge that is located inside the wiring through hole when viewed in the axial direction and holds the wire between the lid and the guide bridge.