초록 ▼

The drive roller of this invention utilizes a brushless D.C. motor which has a stator or armature mounted on a fixed shaft which directly drives a permanent magnet rotor mounted inside a roller tube. A variable frequency drive supplies three-phase power to a Y-connected three phase winding which is

The drive roller of this invention utilizes a brushless D.C. motor which has a stator or armature mounted on a fixed shaft which directly drives a permanent magnet rotor mounted inside a roller tube. A variable frequency drive supplies three-phase power to a Y-connected three phase winding which is composed of three groups of two coils. Thus twelve electromagnets are formed which drive the permanent magnet rotor which has sixteen poles. The brushless D.C. motor is of a modular design and can be easily built in one inch length increments to supply one lb-in of torque for each one-inch increment. The variable frequency controller operates at a relatively low frequency of 15-75 Hz. Hall effect sensors are used to provide feedback on motor speed and position. The armature laminations making up the brushless D.C. motor core are also relatively thick because of the relatively low power necessary to drive the motor and the resultant relatively low eddy currents present in the motor core. For a motor with a 4.0 lb-in design torque and a rotor and stator length of four inches, the current draw will be approximately 0.8 amps consuming about 15 Watts of power.

대표청구항 ▼

[I claim:] [1.]a shaft rigidly mounted to a conveyor support:a stator having a core and plurality of windings on the core, the windings producing a plurality of magnetic poles when energized the stator being mounted about the shaft;a roller tube surrounding the shaft and the stator, the roller tube

[I claim:] [1.]a shaft rigidly mounted to a conveyor support:a stator having a core and plurality of windings on the core, the windings producing a plurality of magnetic poles when energized the stator being mounted about the shaft;a roller tube surrounding the shaft and the stator, the roller tube having an interior a first end and a second end, and an exterior surface having a diameter of about 1.9 inches;a first tube closure mounted to the roller tube first end, and a second tube closure mounted to the roller tube second end, the tube closures being rotatable mounted on the shaft to rotatable mount the roller tube on the shaft;a permanent magnet rotor having a plurality of poles which alternate North and South the rotor being fixedly mounted to the roller tube interior and overlying and coaxial with the stator, the rotor and the stator forming a brushless three-phase motor, with the rotor and the fixedly mounted roller tube being driven by changes in induced magnetic fields in the stator; anda variable frequency controller in power supplying connection to the windings of the stator for controlling the rotation speed of the rotor, wherein the permanent magnet rotor is constructed of a plurality of cylindrical segments, each segment constructed of ferromagnetic particles embedded in a flexible matrix, and wherein the plurality of poles is imposed on said cylindrical segment.