METHOD FOR CORRECTING PERMANENT CALIBRATION AND FORCE-MEASURING BALANCING MACHINE

• US 20130186170A1
• Filed: 12/21/2012
• Published: 07/25/2013
• Est. Priority Date: 01/23/2012
• Status: Active Grant

• Current Assignee: Schenck Rotec GmbH (Durr AG)
• Original Assignee: Schenck Rotec GmbH (Durr AG)
• Inventors: TRUKENMUELLER, Kai
• Granted Patent: US 9,057,650 B2
• Time in Patent Office: Days
• US Class Current: 73/1.14
• CPC Class Codes: G01L 5/0066 Calibration arrangements
• CPC Class Codes: G01M 1/02 Details of balancing machines or devices
• CPC Class Codes: G01M 1/08 Instruments for indicating directly the magnitude and phase of the imbalance
• CPC Class Codes: G01M 1/22 and converting vibrations due to imbalance into electric variables

Abstract

Using a force-measuring balancing machine (1), the empirically determined permanent calibration is corrected in that the resonant frequencies (m) of the rotor (2) to be balanced are calculated, in a translatory direction and (ω₂) in a rotational direction, from the mass (m_R) of a rotor (2) to be balanced, which is mounted in the balancing machine (1), the co-oscillating mass (M_s) of the bearing supports (3), the rigidity (c) of the bearing supports (3) and the spacing (L) of the rotor bearings, and a frequency response calculated from the resonant frequencies (ω₁, ω₂) and the frequency (Ω) of the rotor (2) is introduced to the permanent calibration.

Claims

1. Method for correcting the empirically determined permanent calibration of a force-measuring balancing machine, comprising the steps of

calculating the resonant frequencies of the rotor to be balanced, in a translatory direction corresponding to the measuring direction of sensing elements and in a rotational direction about an axis which is perpendicular to the measuring direction and to the rotational axis of the rotor, from the mass of a rotor to be balanced, which is mounted in the balancing machine, the co-oscillating mass of the bearing supports, the rigidity of the bearing supports and the spacing of the rotor bearings of the bearing supports, and

introducing to the permanent calibration a frequency response calculated from the resonant frequencies and the rotor frequency.

2. Method according to claim 1, wherein the permanent calibration is established in the form of a calibration matrix P and, using a correction matrix H, which describes the frequency response, according to the formula:

P_k<sup>−

1</sup>=Q<sup>−

1</sup>HQP<sup>−

1</sup>.

is offset with respect to the corrected permanent calibration matrix P_k, the matrix Q being

4. Force-measuring balancing machine comprising resilient bearing supports, to which are fitted sensing elements which detect the dynamic effect of a rotor on the bearing supports, comprising a frequency sensor which detects the frequency of the rotor, and comprising an evaluation device which, for the purpose of signal evaluation, has an electronic computer having been programmed by means of an empirically determined permanent calibration and a data memory containing the empirically determined machine parameters of rigidity and co-oscillating mass, wherein the electronic computer has a program for correcting the empirically determined permanent calibration according to the method according to any of the preceding claims.

3. Method according to claim wherein the correction matrix is calculated according to the following formula: