Apparatus and method for measuring resonance in bearing device

• US 20040182159A1
• Filed: 12/19/2003
• Published: 09/23/2004
• Est. Priority Date: 12/19/2002
• Status: Active Grant

• Current Assignee: NSK Limited
• Original Assignee: NSK Limited
• Inventors: Yamada, Hitoshi
• Granted Patent: US 6,918,302 B2
• Time in Patent Office: Days
• US Class Current: 73/593
• CPC Class Codes: F16C 19/527 related to vibration and noise
• CPC Class Codes: F16C 19/54 Systems consisting of a plurality of bearings with rolling friction spindle bearings F16C35/08
• CPC Class Codes: F16C 2226/16 by wedge action, e.g. by tapered or conical parts
• CPC Class Codes: F16C 35/077 between housing and outer race ring
• CPC Class Codes: G01M 13/045 Acoustic or vibration analysis
• CPC Class Codes: G01N 2291/2696 Wheels, Gears, Bearings
• CPC Class Codes: G01N 29/12 by measuring frequency or resonance of acoustic waves measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00

Abstract

An additional mass member 22 for measuring resonance of a bearing device comprises an elastic ring 30 having an inner periphery 30a larger in diameter than the outer periphery of the outer ring 24 of the bearing device 25 and being contracted and expanded in the radial direction, and a fixed ring 31 having a large rigidity and fitted onto the elastic ring 30. The elastic ring 30 is fitted to the outer ring 20, and then the fixed ring 31 is fitted to the elastic ring 30 to push the elastic ring 30 in the radial direction, so as to contract the inner periphery 30a of the elastic ring 30, so that the additional mass member 22 is fixed to the bearing device 21, whereby the resonance frequency of the bearing device having a double row of bearings can be measured precisely and readily.

Claims

1. An apparatus of measuring resonance of a bearing device comprising a pair of bearings having an inner ring and outer ring with an outer periphery, and a shaft connected to the inner ring, the apparatus having an additional mass member to be fixed to the bearing device, a vibrator for applying input vibrations to the bearing device to which the additional mass member is fixed, and a vibration detector for detecting vibrations of the bearing device to measure the resonance frequency of the bearing device, the additional mass member having an inner periphery which is larger in diameter than the outer periphery of the outer ring and can be expanded and contracted in the radial direction, and the additional mass member comprising an elastic ring having an inner periphery and a radial rigidity and being fitted onto the outer rings and a fixed ring having a rigidity larger than the radial rigidity of the elastic ring and being fitted onto the elastic ring, so that the fitting of the fixed ring onto the elastic ring contracts the inner periphery of the elastic ring.

2. An apparatus of measuring resonance of a bearing device according to claim 1, wherein the elastic ring has an outer periphery which is formed in a taper shape, with the inner periphery of the elastic ring being formed in a straight shape, wherein at least one slit is formed in the axial direction of the elastic ring, and wherein the fixed ring has an inner periphery which is formed in a taper shape which is the same in taper to the taper shape of the outer periphery of the elastic ring.

3. An apparatus of measuring resonance of a bearing device according to one of claims 1 and 2, wherein the pair of bearings are spaced apart from each other by a distance, wherein the elastic ring has an axial length longer than the distance between the pair of bearings, and wherein the fixed ring has an axial length shorter than the distance between the pair of bearings.

4. An apparatus of measuring resonance of a bearing device according to one of claims 1 and 3, wherein the elastic ring has an outer periphery which is formed in a taper shape, with the inner periphery of the elastic ring being formed in a straight shape, wherein at least one slit is formed in the axial direction of the elastic ring, and wherein the fixed ring has an inner periphery which is formed in a stepped straight shape.

5. A method of measuring resonance of a bearing device comprising a pair of bearings having an inner ring and outer ring with an outer periphery, and a shaft connected to the inner ring, the method comprising the steps of providing an additional mass member comprising an elastic ring which has a radial rigidity and an inner periphery larger in diameter than the outer periphery of the outer rings and can be contracted and expanded in the radial direction, and a fixed ring which has rigidity larger than the radial rigidity of the elastic ring, fitting the elastic ring onto the outer rings, fitting the fixed ring onto the elastic ring, pressing the elastic ring in the radial direction to contract the inner periphery of the elastic ring to fix the additional mass member to the bearing device, setting the bearing device with the additional mass member attached thereto to the vibrator-detector system of a resonance measurement apparatus, applying input vibrations to the bearing device through the vibrator, and detecting vibrations of the bearing device with the vibration detector, thereby measuring a resonance frequency of the bearing device.