Specification for instrument precision rolling bearings (ball bearings)

1985 ◽  
Keyword(s):  
Ball Bearings ◽  
Rolling Bearings

scholarly journals STUDY OF EFFECT OF SOLID CONTAMINANTS IN THE LUBRICANT ON BALL BEARINGS VIBRATION

2012 ◽  
pp. 28-31
Author(s):  
ONKAR L. MAHAJAN ◽  
ABHAY A. UTPAT
Keyword(s):  
Experimental Tests ◽  
Solid Particles ◽  
Particle Sizes ◽  
Ball Bearings ◽  
Bearing Failure ◽  
Mean Square ◽  
Rolling Bearings ◽  
Vibration Signals ◽  
Deep Groove ◽  
Concentration Levels

In deep groove ball bearings contamination of lubricant grease by solid particles is one of the main reason for early bearing failure. To deal with such problem, it is fundamental not only the use of reliable techniques concerning detection of solid contamination but also the investigation of the effects of certain contaminant characteristics on bearing performance. Nowadays the techniques such as vibration measurements are being increasingly used for on-time monitoring of machinery performance. The present work investigates the effect of lubricant contamination by solid particles on the dynamic behavior of rolling bearings, in order to determine the trends in the amounts of vibration affected by contamination in the Grease and by the bearing wear itself. Experimental tests are performed with Deep-groove ball bearings. The Dolomite powder in three concentration levels and different particle sizes was used to contaminate the grease. Vibration signals were analyzed in terms of Root Mean Square (RMS) values and also in terms of defect frequencies.

Oil Pumping in High Speed and High Loaded Ball Bearings

2004 ◽  
Author(s):  
Michael Flouros
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Research Programme ◽  
Aircraft Engine ◽  
Ball Bearings ◽  
European Research ◽  
Rolling Bearings ◽  
Engine Design ◽  
Oil Flow ◽  
Total Oil

Trends in aircraft engine design cause increased mechanical stress requirements for rolling bearings. Consequently high amounts of heat are rejected which results in high oil scavenge temperatures. The direction of oil flow in the bearing can considerably affect the heat transported by the oil. An RB199 turbofan bearing and its associated chamber were modified to carry out the survey. The test bearing was a 124mm PCD ball bearing. The bearing has a split inner-ring employing under-race lubrication by two individual jets. The total oil flow could be devided to any ratio through the jets. This had an impact on the oil scavenge temperatures and the scavenge flows on both sides of the bearing. Significant reduction in the ‘heat to oil’ was achieved when oil was fed at certain proportions (ratio). This work is part of the European Research programme Brite Euram ATOS (Advanced Transmission and Oil Systems).

CALCULATION OF ADDITIONAL AXIAL FORCE OF ANGULAR-CONTACT BALL BEARINGS IN ROTOR SYSTEM

2016 ◽  
Vol 40 (4) ◽  
pp. 585-596
Author(s):  
Zhenhuan Ye ◽  
Zhansheng Liu ◽  
Liqin Wang
Keyword(s):  
Axial Force ◽  
Dynamic Properties ◽  
Descent Method ◽  
Rotor System ◽  
Ball Bearings ◽  
Rolling Bearings ◽  
System A ◽  
Calculation Results ◽  
Relationship Of ◽  
Raphson Method

Based on a loading-deformation relationship of bearing elements and the coordination of displacement between bearings in the rotor system, a model for calculating the additional axial force of angular-contact ball bearings in a single-rotor system is established. Nonlinear equations of this model are solved through the Rapid Descent method and Newton-Raphson method. The simulation results which are based on Gupta’s example verify that both the model and solving methods in this paper are reliable. A pair of 276927NK1W1(H) angular-contact ball bearings in symmetry in the single-rotor system is used as the example, calculation results of the additional axial force of bearings from the model in this paper and from the ISO method are compared and the influence of bearing geometry parameters and working conditions on the additional axial force is further studied. This model and its conclusions could provide the basic data and reference for analyzing the carrying ability and dynamic properties of rolling bearings.

scholarly journals Mathematical model of the impact assessment of roughness and waviness deviations of races surfaces of rolling bearings on the level of generated vibration

Mechanik ◽  
2019 ◽  
Vol 92 (1) ◽  
pp. 35-37
Author(s):  
Paweł Zmarzły
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Impact Assessment ◽  
Ball Bearings ◽  
Vibration Level ◽  
Rolling Bearings ◽  
Shape Deviations ◽  
Specific Frequency ◽  
The Impact ◽  
Dominant Influence

The article presents mathematical models allowing to describe the level of vibration generated by ball bearings 6304-2z type depending on the value of roughness and waviness deviations of inner and outer bearings races. This models will allow to estimate what type of shape deviations have dominant influence on the vibration level generated in specific frequency ranges.

Sign in / Sign up

Export Citation Format

Share Document