US 5,027,280 A · Machining apparatus having a main spindle supported by magnetic bearings

Abstract

A machining apparatus having a main spindle supported by magnetic bearings which controls machining conditions by controlling electric current values flowing in electromagnets according to predetermined conditions, thereby obtaining an optimum machining condition and thus improving accuracy and machining efficiency. The machining apparatus comprises a spindle having a tool at its one end, electromagnets for radially and axially supporting the spindle by magnetic force without contact to the spindle, position detecting means for detecting radial and axial positions of the spindle, control means responsive to outputs from the position detecting means for controlling current flowing in the electromagnets, current measuring means for measuring current values flowing in at least one of the electromagnets, and machining control means for controlling machining conditions by controlling current values at the electromagnets according to the measured current values.

Claims17

Dependent claims

A machining apparatus having a main spindle supported by magnetic bearings, comprising:

a spindle having means at one end thereof for holding a tool;
electromagnets for radially and axially supporting said spindle by magnetic forces without contacting said spindle;
position detecting means for detecting radial and axial position of said spindle;
control means responsive to outputs from said position detecting means for controlling currents flowing in said electromagnets;
current means for measuring current values in at least one of said electromagnets;
and
machining control means for controlling at least one controllable variable by controlling current values flowing in said electromagnets according to said measured current values.

4 more elements

An apparatus for performing a machining operation on a workpiece, comprising:

a rotary spindle having means for releasably holding a tool for performing a machining operation on a workpiece;
electromagnetic bearing means responsive to current flowing therein for producing magnetic forces effective to magnetically support the spindle in the radial and axial directions thereof during the machining operation;
position detecting means for detecting the radial and axial positions of the spindle and producing corresponding detection signals;
control means responsive to the detection signals for controlling the flow of current in the electromagnetic bearing means;
current measuring means for measuring the value of current flowing in the electromagnetic bearing means and producing a measurement signal corresponding to the measured current value;
and machining control means responsive to the measurement signal for controlling at least one controllable variable of the machining operation in accordance with the measured current value.

3 more elements

Dependencies are inferred from the claim text.

Machining apparatus having a main spindle supported by magnetic bearings

Life of this patent

Machining apparatus having a main spindle supported by magnetic bearings

Life of this patent

Abstract

Claims17