US 4,214,481 A · Method and device for applying a detectable reference mark on a body to be balanced

Abstract

An annular ferromagnetic portion, i.e., "track", of the body to be balanced is rotated adjacent a first electromagnet having a decaying magnetic field which renders that track magnetically homogeneous. Thereafter, a large electrical current of short duration from the discharge of a capacitor is passed through a second, marking electromagnet positioned adjacent that track to produce a high-intensity magnetic pulse. This magnetic pulse produces a very localized spot of permanent magnetization in the track which spot serves as the reference "mark". When the body is then rotated during its balancing operation, that mark will produce an electrical signal each time it passes a magnetic/electric transducer positioned adjacent the rotating track. When the periphery of the body to be balanced consists of a plurality of lands separated by axially aligned slots, the periphery is scanned (while the body is being rotated) and triggering of the discharge current from the capacitor through the marking electromagnet is determined by that scanning to the end that it occurs when one of the lands is immediately adjacent the marking electromagnet.

Claims21

Dependent claims

A method for balancing a body having an axis and a peripheral ferromagnetic portion thereabout and comprising the steps of:

(a) applying a detectable reference mark on the body,
(b) rotating the body about the axis at an unbalance measuring rotary speed,
(c) while the body is so rotating detecting the reference mark and generating therefrom a reference signal for measuring the unbalance position,
(d) while the body is so rotating measuring the unbalance of the body as to amount and unbalance position making use of the reference signal,
(e) thereafter detecting the reference mark and positioning the body relative to unbalance correcting apparatus in accordance with this detecting and with the unbalance position measured relative to the reference mark, and
(f) while the body is so positioned correcting the measured unbalance,
characterized in that the application of the reference mark comprises the steps of:
magnetic homogenizing said peripheral portion to define a rotating track of the body of substantially magnetic homogeneity;
and
thereafter generating a substantially instantaneous magnetic pulse of high intensity at a location immediately adjacent the rotating track for generating a locally limited permanent magnetization serving as said reference mark.

7 more elements

An apparatus comprising the combination of a device for applying a detectable reference mark on a body to be balanced and having an axis and a peripheral ferromagnetic portion thereabout, said mark being adapted to generate a reference signal employed for determining the unbalance position and employed for positioning the body during unbalance correction operation, and additional elements for detecting the magnitude and angular position of the unbalance of said body and for correcting said unbalance,

said device comprising:
means adjacent said body for substantially magnetically homogenizing said peripheral portion to define a rotating track of the body of
substantially magnetic homogeneity;
and
means for generating a substantially instantaneous magnetic pulse of high intensity at a location immediately adjacent the magnetically homogenized rotating track for generating a locally limited permanent magnetization serving as said reference mark;
and
said elements comprising:
drive means for rotating the body about the axis at an unbalance measuring rotary speed;
detector means adjacent the rotating body for detecting the reference mark and for producing a first detector signal;
signal processing means connected to said detector means for generating a reference signal from said detector signal;
unbalance measuring means coupled to the rotating body and including unbalance sensors for generating unbalance measuring signals and an unbalance signal processing circuit, to which the unbalance measuring signals and the reference signal are supplied, for generating output signals which represent the unbalance of the body as to amount and position;
and
unbalance correction means and a positioning device for positioning the body relative to the unbalance correction means such that the unbalances to be corrected are in the correct position for correction relative to the unbalance correction means, the positioning means, to which the output signals representing the position of the unbalance are applied from the unbalance measuring device, comprising a detector device for detecting the reference mark and for generating a second detector signal, and positioning the body in accordance with this second detector signal and the position of the unbalance measured relative to the reference mark.

10 more elements

said device comprising:
drive means for rotating said body about said axis at a first speed;
means adjacent said body for substantially magnetically homogenizing said peripheral portion to define a rotating track of the body of substantially magnetic homogeneity;
and
means for generating a substantially instantaneous magnetic pulse of high intensity at a location immediately adjacent the magnetically homogenized rotating track for generating
a locally limited permanent magnetization serving as said reference mark;
and
said elements comprising:
drive means for rotating the body about the axis at an unbalance measuring rotary speed which is greater than said first speed;
detector means adjacent the rotating body for detecting the reference mark and for producing a first detector signal;
unbalance measuring means coupled to the rotating body and including unbalance sensors for generating unbalance measuring signals;
unbalance correcting means;
and
means connecting said detector means, said unbalance measuring means and said unbalance correcting means for receiving said detector signal and said unbalance measuring signals and for providing signal to the unbalance correcting means representing the unbalance to be corrected and the location of that unbalance relative to said reference mark.

11 more elements

Dependencies are inferred from the claim text.

Method and device for applying a detectable reference mark on a body to be balanced

Life of this patent

Method and device for applying a detectable reference mark on a body to be balanced

Life of this patent

Abstract

Claims21