Shinko Electric Company, Ltd.

Shinko Denki Kabushiki Kaisha

Tetsuo Oishi

Mitsuji Karita

Tsutomu Shinya

Since the DC linear brushless motor is constructed based on a principle that an ordinary DC brushless motor is developed into a linear shape, it is inevitable that its stator should have a large number of permanent magnets arrayed linearly and the adjacent poles of which are separated by many gaps, in addition, that its armature core has a finite length at each end in the direction of the travel of the moving member. Both the gaps or boundaries between adjacent magnetic poles of the stator and the teeth slots as well as the both ends in the armature core result in synthesized detent thrusts, and these detent thrusts are not preferable for applying this type linear motor to OA devices or precise measuring device. Though it is possible to reduce the detent thrust due to the gaps or boundaries between poles in the stator and the parallel slots between the teeth of the armature core by arraying the permanent magnets in skewed manner with respect to the lengthwise axis of the stator, there has not been suitable and effective way to reduce or eliminate the detent thrust caused by the end effect of the armature core. In view of this, the linear DC brushless motor of this type has solved the problem by reducing the unit volume of the tooth or teeth at the axial ends of the armature core by either cutting out a part of the tooth or teeth, attaching a rightangled triangular pillar(s) or by slantly cutting the teeth at each end of an armature core in the direction of travel.

Linear DC brushless motor

A transporting apparatus using a linear motor comprises at least a primary unit and a secondary unit. The primary unit faces the secondary unit with a predetermined gap. The primary unit consists of a core and coils supplied with three-phase alternating currents so that the primary unit generates a progressive magnetic field. The secondary unit at least includes a core and permanent magnets. These permanent magnets are magnetized so that each section of the secondary unit is magnetized in a north pole and a south pole in turn along a longtitudinal direction thereof. Hence, the primary unit can be transported along the secondary unit by controlling the currents supplied to the primary unit.

Transporting apparatus

The present invention is related to a linear motor which is composed of mainly:

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Ise, Japan

Tetsuo Oishi