METHOD FOR DETERMINING BEARING PLAY OF EXHAUST-GAS-TURBOCHARGER FRICTION BEARINGS

• US 20120197579A1
• Filed: 10/01/2010
• Published: 08/02/2012
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: Walter, Norbert, Seiler, Andre
• Granted Patent: US 10,119,419 B2
• Time in Patent Office: Days
• US Class Current: 702/113
• CPC Class Codes: F01D 25/166 Sliding contact bearing gas bearings F01D25/22
• CPC Class Codes: F02C 6/12 Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure
• CPC Class Codes: F05D 2220/40 in turbochargers
• CPC Class Codes: F05D 2260/80 Diagnostics
• CPC Class Codes: F16C 17/246 related to wear, e.g. sensors for measuring wear
• CPC Class Codes: F16C 2360/24 Turbochargers
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis

Abstract

The invention relates to a method for determining bearing play of exhaust-gas-turbocharger friction bearings comprising the following method steps: accelerating the exhaust-gas turbocharger or the body group from standstill to a maximum rotational speed and at the same time registering the vibration acceleration by means of a sensor; determining the constant-tone frequency of the friction bearing at at least one rotational speed; plotting the determined constant-tone frequency in a diagram, in which bearing-play ranges determined experimentally in advance are assigned to constant-tone frequency ranges; and establishing whether or not the determined constant-tone frequency lies in a bearing-play target range.

Claims

1. A method for determining bearing play of exhaust-gas-turbocharger friction bearings comprising the following method steps:

accelerating the exhaust-gas turbocharger or the body group from standstill to a maximum rotational speed and at the same time registering the vibration acceleration by means of a sensor;

determining the constant-tone frequency of the friction bearing at at least one rotational speed of the turbocharger;

plotting the determined constant-tone frequency in a diagram, in which bearing-play ranges determined experimentally in advance are assigned to constant-tone frequency ranges; and

establishing whether or not the determined constant-tone frequency lies in a bearing-play target range.

2. The method as claimed in claim 1, wherein a frequency spectrum is determined for determining the constant-tone frequency at a rotational speed of the exhaust-gas turbocharger determined experimentally in advance that leads to a well measurable constant tone.

3. The method as claimed in claim 2, wherein respectively one frequency spectrum is determined at two experimentally determined rotational speeds of the exhaust-gas turbocharger.

4. The method as claimed in claim 2, wherein the frequency spectrum or the frequency spectra are determined using a Fourier transform.

5. The method as claimed in claim 2, wherein the frequency spectrum or the frequency spectra are evaluated on the basis of a predeterminable analysis frequency.

6. The method as claimed in claim 5, wherein the analysis frequency lies between 2 Hz and 4 Hz.

7. The method as claimed in claim 2, wherein the maxima within predetermined frequency ranges are determined in each frequency spectrum.

8. The method as claimed in claim 2, wherein the maxima are assigned to the inner or outer bearing play due to the frequency.

9. The method as claimed in claim 2, wherein the constant-tone frequency is determined during the production of the exhaust-gas turbocharger on an operational balancing bench.

10. The method as claimed in claim 9, wherein the oil temperature, the oil pressure, and/or the oil viscosity are taken into account as bearing-oil parameters.

11. The method as claimed in claim 1, wherein the sensor is attached to the turbocharger or the body group on the compressor-housing side.

12. The method as claimed in claim 1, wherein the maximum rotational speed constitutes one of the rotational speeds determined experimentally in advance.

13. The method as claimed in claim 1, wherein the bearing play constitutes the inner bearing play between bushing bore and shaft.

14. The method as claimed in claim 1, wherein the bearing play constitutes the outer bearing play between bushing outer diameter and bearing-housing bore.