摘要:
A magnetic bearing device comprises a machine main body having position sensors for detecting the position of a rotary body and magnetic bearings for magnetically contactlessly supporting the rotary body, a controller for controlling the magnetic bearings based on the signals from the position sensors, a data processing computer installed at a location away from the controller, and modems for connecting the controller to the computer by communication lines.
摘要:
A magnetic spindle device for machine tools has a spindle contactlessly supportable by a plurality of controllable magnetic bearings for mounting thereon a tool element which is automatically changeable for a tool element of different kind. The spindle device comprises a device for measuring the weight of the tool element by measuring the exciting currents of the magnetic bearing, and a device for changing over the control characteristics of the magnetic bearings based on the measured weight of the tool element.
摘要:
A magnetic bearing apparatus comprises a pair of radial magnetic bearings arranged on both sides in the axial direction of an axial magnetic bearing. A pair of first touchdown bearings are arranged at both ends of a spindle. Annular slide bearings are mounted as second touchdown bearings for receiving the spindle on inner peripheral parts of electromagnets in the axial magnetic bearing. The radial internal clearance between the slide bearing and the spindle is larger than the radial internal clearance between the first touchdown bearings and the spindle and is smaller than the radial internal clearance between the radial magnetic bearings and the spindle. Even if a central part of the spindle is deflected at the time of emergency stop, both the first touchdown bearings and the slide bearings receive the spindle, so that the load on the first touchdown bearings can be reduced.
摘要:
In a control unit for magnetic bearing, a sampling frequency of a DSP 4 is varied according to a number of rotation of a rolling element 1. Thus, a frequency band to be damped by a notch filter 42 as a digital filter is varied in correspondence with a resonance frequency associated with a natural frequency and a rotational vibration frequency, thereby to damp a resonance signal contained in a control signal. The occurrence of resonance is thus prevented through digital control.
摘要:
In the magnetic bearing apparatus, there is provided a current sensor for detecting a current flowing in a motor. When the current increases over a reference value, a DSP enhances a support stiffness of the magnetic bearing, thereby securing a stable rotation of the rotor.
摘要:
A control magnetic bearing device comprises a plurality of control magnetic bearings for contactlessly supporting a rotor, an electric motor for rotating the rotor, a magnetic bearing drive circuit for driving the magnetic bearings, an inverter for driving the electric motor, a main control circuit for controlling the magnetic bearing drive circuit and the inverter, and a power source unit connected to an external power source for supplying electric power to the magnetic bearing drive circuit, the inverter and the main control unit. The main control unit has software-programmable digital processing means for controlling the inverter in accordance with an input voltage value from the power source unit.
摘要:
A machine tool comprises a spindle device carrying a tool element attached to the forward end of a rotor spindle drivingly rotatable as supported by a control-type magnetic bearing device, a working force calculating unit for calculating a working force acting on the tool element upon the tool element coming into contact with a workpiece based on exciting current of a magnetic bearing of the bearing device, and a discriminating unit for discerning whether the contact of the tool element with the workpiece is normal or abnormal based on variations in the working force.
摘要:
A control magnetic bearing device comprises a plurality of control magnetic bearings for contactlessly supporting a rotor, an electric motor for rotating the rotor, a magnetic bearing drive circuit for driving the magnetic bearings, an inverter for driving the electric motor, a main control circuit for controlling the magnetic bearing drive circuit and the inverter, and a power source unit connected to an external power source for supplying electric power to the magnetic bearing drive circuit, the inverter and the main control unit. The main control unit has software-programmable digital processing means for controlling the inverter in accordance with an input voltage value from the power source unit.
摘要:
A control magnetic bearing device comprises a plurality of control magnetic bearings for contactlessly supporting a rotor, an electric motor for rotating the rotor, a magnetic bearing drive circuit for driving the magnetic bearings, an inverter for driving the electric motor, a main control circuit for controlling the magnetic bearing drive circuit and the inverter, and a power source unit connected to an external power source for supplying electric power to the magnetic bearing drive circuit, the inverter and the main control unit. The main control unit has software-programmable digital processing means for controlling the inverter in accordance with an input voltage value from the power source unit.
摘要:
A magnetic bearing device comprising a magnetic bearing main body having at least electromagnets for magnetically levitating a rotary body and position sensors for detecting the position of the rotary body, and a controller connected to the main body by a cable for controlling the electromagnets based on output signals of the position sensors. The magnetic bearing main body is provided with memory means having stored therein characteristics of the rotary body and the electromagnets.