ELECTROMAGNETIC CLUTCH, ELECTROMAGNETIC CLUTCH CONTROL DEVICE, AND ELECTROMAGNETIC CLUTCH CONTROL METHOD

摘要

An electromagnetic clutch provided with an armature in which two or more non-magnetic sections of differing radii are provided and which is installed on a rotary shaft, a rotor in which three or more non-magnetic section of differing radii that do not overlap with the non-magnetic sections are provided on a friction plate that faces the armature, and which rotates with respect to the rotation shaft by external force, a stator equipped with an electromagnetic coil for fixing the armature to the rotor by applying magnetic flux, which is generated by passage of an electric current, on the friction plate, and a control device for the electromagnetic coil. The control device is provided with a magnetomotive force change circuit for increasing, with a command to start power supply to the electromagnetic coil, the magnetomotive force of the electromagnetic coil above the magnetomotive force of the electromagnetic clutch during normal operation and for returning the magnetomotive force of the electromagnetic coil to the magnetomotive force of the electromagnetic clutch during normal operation when the armature is fixed to the rotor.

主权项

1. An electromagnetic clutch comprising:
an armature that is attached to a rotary shaft; at least two non-magnetic portions that are disposed in the armature, the at least two non-magnetic portions having varying radii; a rotor that is rotated with respect to the rotary shaft by an external force; a friction plate that faces the armature and is included in the rotor; at least three non-magnetic portions that are disposed in the friction plate and do not overlap the at least two non-magnetic portions, the at least three non-magnetic portions having varying radii; a stator; an electromagnetic coil that is included in the stator, the electromagnetic coil generating, when a power is supplied to the electromagnetic coil, a magnetic flux that is applied to the friction plate and causing the armature to be magnetically attracted to and fixedly attached to the rotor; a control device that controls supplying power to the electromagnetic coil; and a magnetomotive force change unit that is included in the control device, wherein when a command to start supplying power to the electromagnetic coil is issued, the magnetomotive force change unit increases a magnetomotive force of the electromagnetic coil, and when the armature is magnetically attracted to and fixedly attached to the rotor, the magnetomotive force change unit returns the magnetomotive force of the electromagnetic coil to a normal operation magnetomotive force.