The disclosed device includes a single electric motor for linear and rotary movement with a stator. The stator includes a multi-phase coil arrangement with a plurality of coils or coil sets and a rotor. The rotor is movable in an axial direction of a rotational axis thereof and includes a plurality of poles respectively with at least one permanent magnet The device further includes a control unit operative to determine currents (I.sub.r, I.sub.s, I.sub.t) by calculation formulas and based on at least a number of coils or coil sets of the plurality of coils or coil sets, and an angle of rotation of said rotor and a parameter depending on an axial position of the rotor. Each current (I.sub.r, I.sub.s, I.sub.t) has a current component (I.sub.rΦ, I.sub.sΦ, I.sub.tΦ) for generating a torque and a current component (I.sub.rx, I.sub.sx, I.sub.tx) for generating an axial force, and to supply the determined currents in open loop to the number of coils or coil sets, so that the sum of the currents is zero. Further, at least one of the stator and the rotor, includes a back-iron.

The invention relates to a rotor unit for a brushless electric motor with 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, wherein 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, wherein 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, wherein the contact region of the shaft portion in the radial direction of the side faces has an extension of 30% to 70% of the radial extension of the side surfaces.

A stator to which a power supply lead wire for supplying electric power is connected, includes a stator core, a winding wound around the stator core, a winding terminal connected to the winding, a circuit board connecting the power supply lead wire and the winding terminal to each other and having a surface facing the stator core, a power supply terminal provided on the surface and connected to the power supply lead wire, and a wiring pattern provided on the surface and connecting the winding terminal and the power supply terminal to each other.

The invention relates to a rotor unit for a brushless electric motor with 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, wherein 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, wherein 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, wherein the head portion lies on the peripheral faces in a contact area, which contact area is separated by a distance from a transition between the shank portion and the head portion.

Handwheel systems, including control consoles incorporating handwheels of the inventive subject matter, are described in this application. Handwheels described in this application can be used to control remotely located motors, especially those configured to control camera movements. To make it easier for camera operators to control remotely located motors using handwheels, those handwheels can be incorporated into a control console. Control consoles of the inventive subject matter can include several dials, toggle buttons, a display, and a variety of different inputs and outputs.

Disclosed is a brushless DC vibration motor. An eccentric weight of a rotor is securely sandwiched between a back yoke and a permanent magnet, being heavier to provide an increased vibrational force. A bearing coupling portion with upper and lower stopping protrusions prevents detachment of a bearing. A bracket is formed with grooves, instead of through holes, to strongly support a cogging plate of which pieces are connected with each other to form a single body for easy-placement on the bracket. An optimized area of the cogging plate can suppress the rotor not to rise during starting of the motor, resulting in no frictional noise, and a high stopping speed and uniform horizontal level of the rotating rotor.

Disclosed is a brushless DC vibration motor. An eccentric weight of a rotor is securely sandwiched between a back yoke and a permanent magnet, being heavier to provide an increased vibrational force. A bearing coupling portion with upper and lower stopping protrusions prevents detachment of a bearing. A bracket is formed with grooves, instead of through holes, to strongly support a cogging plate of which pieces are connected with each other to form a single body for easy-placement on the bracket. An optimized area of the cogging plate can suppress the rotor not to rise during starting of the motor, resulting in no frictional noise, and a high stopping speed and uniform horizontal level of the rotating rotor.

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.

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.