A single phase stepping motor, particularly for clocks, with a rotor having several pole teeth and a stator, the latter being made of two stator parts connected with one another via a bridge part, the latter carrying the excitation winding, of which each stator part on its free end has an equal or smaller number (in comparison to the rotor pole number) of stator pole teeth as well as a passage opening for the rotor shaft, the stator pole teeth being directed towards the face sides of the rotor. Each rotor pole tooth comprises a main pole and an auxiliary pole extending in the direction of rotation formed on the main pole, and between the stator pole teeth, a permanent magnetic circuit is provided, by means of which circuit the rest position of the rotor is determined during the unexcited stator condition.
A 4-pole armature is accommodated with in a 4-pole permanent-magnet ring, either the ring or armature serving as the rotor. The core of the armature is cross-shaped, a set of two members of the core in straight orientation has windings applied on each member with opposite winding directions, and the cross-shaped core is provided at each winding of four core ends with separable back-up cores extending in the rotational direction of the armature or in the direction opposite to the rotational direction of the ring. A device for converting armature polarity is provided which alternates the direction of electric current for the armature every 90.degree. rotation of the rotor.
The invention relates to a monophase electromagnetic actuator which includes a rotor (1) with a cylindrical magnetized section (5) divided into two N poles transversely magnetized in alternate directions. The actuator also includes a stator structure consisting of a first magnetic circuit (2) and a second magnetic circuit (3), which are joined only by non-magnetic linking parts. Application: miniature actuators for precision and instrumentation work.
6897579 - Motor - Owned by Canon Kabushiki Kaisha (Tokyo,JP)
A motor includes a magnet formed into a hollow disc shape and having at least one flat surface circumferentially divided and alternately magnetized to opposite poles, a first coil having an inner peripheral surface opposing the outer peripheral surface of the magnet, a second coil having an outer peripheral surface opposing the inner peripheral surface of the magnet, first magnetic pole portions opposing one flat surface of the magnet, formed from a plurality of teeth extending in the radial direction of the magnet, and excited by the first coil, second magnetic pole portions formed on the opposite side to the first magnetic pole portions via the magnet at positions opposing the first magnetic pole portions, third magnetic pole portions opposing one flat surface of the magnet, formed from a plurality of teeth extending in the radial direction of the magnet, and excited by the second coil, and fourth magnetic pole portions formed on the opposite side to the third magnetic pole portions via the magnet at positions opposing the third magnetic pole portions.
