In an actuator having a stator assembly which defines a pair of stator pole faces, a permeable rotor assembly which is positioned to rotate relative to the stator assembly, and which defines a driving pole face separated from each of the stator pole faces by a flux permeable driving gap, the rotor assembly having an operational range of rotor angular positions over which drive flux passing across the driving gap drives the rotor assembly, the extent of the driving gap at one of the stator pole faces being reduced as the rotor assembly rotates toward the limit of the operational range, the improvement including a flux-permeable compensating gap between the driving pole face and each stator pole face which provides a secondary path for drive flux as the rotor assembly rotates toward the limit of the operational range, the compensating gap being less permeable than the driving gap.
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of copending U.S. patent application Ser. No. 402,432, filed July 28, 1982, and assigned to the same assignee as this application.
Ordinary alarm conditions are escalated into a critical alarm condition by first accumulating the ordinary alarm conditions. Upon each ordinary alarm condition, a number of previously accumulated alarm conditions are deleted in accordance with the elapsed time since the last alarm condition. When the number of accumulated alarm conditions (less those deleted) exceeds a threshold, a critical alarm condition is then generated.
The invention relates to a two-pole single-phase synchronous motor having a permanent-magnet rotor (11), a magnetic detent torque, which viewed over one revolution exhibits positive and negative values with resulting stable and unstable rest positions, the stable rest positions being offset in the positive direction relative to the average direction of the stator field (39) by the asymmetry angle (.gamma.), and a critical detent torque (M.sub.K1kr) being active in the parallel position of the stator field (9) and the rotor field (41), and a starting device provided with rotational backlash between a driving member connected to the rotor (11) and a load member, and with a directional blocking device (22).
A device for converting magnetic force to mechanical force including a member having an axis about which it is rotatable, the member having a peripheral edge portion formed of a material that is effected by the presence of a magnetic force adjacent thereto, at least one magnetic member positioned adjacent the peripheral portion of the rotatable member to produce a magnetic coupling force therebetween, the peripheral portion of the rotatable member having a shape such that the magnetic coupling between the magnetic member and the peripheral portion of the rotatable member varies continuously as the rotatable member rotates.
A skeleton type brushless motor comprises: a rotor in which a rotational shaft is pressed and fixed; a stator including a first stator core and a second stator core in which rotor receiving parts for receiving the rotor are formed, a coil winding unit coupled to the stator cores, and a coil wound on the coil winding unit; and the first and second stator cores are separated and faces each other centering around the rotational shaft of the rotor, whereby a leakage flux is reduced and maneuverability and efficiency are increased.
A stator core of the invention is structured such that the stator core is provided with an arm portion for pressure inserting a coil portion, and pole tooth portions arranged in a columnar space for inserting a rotor in an opposing manner. In the stator core, a stator core entire body having a front entire shape of the stator core and a pair of stator core divided bodies approximately divided into two pieces are connected in an overlapping manner. A pair of stator core divided bodies are arranged in both sided so as to be provided with a space portion therebetween and oppose the pole tooth portions to each other, and a portion in the vicinity of the space portion of the stator core entire body connects the stator core divided bodies in both sides as a connection portion and is integrally formed. In accordance with the stator core, it is possible to improve an assembling workability at a time of manufacturing without generating reduction of a generation torque.
