scholarly journals Study on the Thermal Distribution Characteristics of High-Speed and Light-Load Rolling Bearing Considering Skidding

2018 ◽  
Vol 8 (9) ◽  
pp. 1593 ◽  
Author(s):  
Junning Li ◽  
Jiafan Xue ◽  
Zhitao Ma
Keyword(s):  
Temperature Distribution ◽  
Power Loss ◽  
High Speed ◽  
Roller Bearing ◽  
Transient Temperature ◽  
Rolling Bearings ◽  
Slip Ratio ◽  
Friction Power ◽  
Thermal Distribution ◽  
Light Load

Skidding, which frequently occurs in high-speed rolling bearings, has a significant effect on the thermal distribution and service reliability of the bearings. An improved theoretical model of friction power loss distribution in high-speed and light-load rolling bearings (HSLLRBs) considering skidding is established, and the effects of various operating parameters on the friction power loss are investigated. The results show that the friction power loss of the inner ring and outer ring as well as the total friction power loss of the bearing increase as the slip ratio increases, but that the friction power loss of the cage guide surface and roller oil churning show a reverse trend. In addition, the increase in inner ring speed and kinematic viscosity leads to an increase in bearing friction power loss. The steady and transient temperature field distribution of HSLLRBs is obtained by the finite element method (FEM), and the results show that the inner ring raceway has the highest temperature, whereas the cage has the lowest. The temperature distribution test rig of a full-size roller bearing is constructed, and the influence mechanism of the slip ratio, rotation speed, load, lubrication, and surface topography on the bearing temperature distribution are obtained. The experimental results are consistent with the theoretical results, which also validates the theoretical method.

scholarly journals Experimental Study on the Skidding Damage of a Cylindrical Roller Bearing

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4075 ◽  
Author(s):  
Qing Zhang ◽  
Jun Luo ◽  
Xiang-yu Xie ◽  
Jin Xu ◽  
Zhen-huan Ye
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Failure Modes ◽  
Roller Bearing ◽  
Weight Ratio ◽  
Operating Conditions ◽  
Roller Bearings ◽  
Light Load ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

As large-scale rotating machines develop toward high rotating speed and high power–weight ratio, skidding damage has become one of the major initial failure modes of cylindrical roller bearings. Therefore, understanding the skidding damage law is an effective way to ensure the safety of machines supported by cylindrical roller bearings. To realize the skidding damage, a high-speed rolling bearing test rig that can simulate the actual operating conditions of aviation bearings was used in this paper, and the skidding damage dynamic behaviors of cylindrical roller bearings were investigated. In addition, to ensure the accuracy of the obtained skidding damage mechanism, the cylindrical roller bearing was carefully inspected by microscopic analysis when the skidding damage occurred. Out results show that instantaneous increases in friction torque, vibration acceleration, and temperature are clearly observed when the skidding damage occurs in the cylindrical roller bearing. Furthermore, under the conditions of inadequate lubrication and light load, the critical speed of skidding damage is rather low. The major wear mechanisms of skidding damage include oxidation wear, abrasive wear, and delamination wear. The white layers are found locally in the inner ring and rollers under the actions of friction heat and shear force.

Stack-Up Forces for Normal and Abnormal Operating Conditions in a Railroad Roller Bearing Assembly

1998 ◽  
Vol 120 (4) ◽  
pp. 707-713
Author(s):  
H. Wang ◽  
T. F. Conry ◽  
C. Cusano
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Operating Temperature ◽  
Roller Bearing ◽  
Operating Conditions ◽  
Transient Temperature ◽  
Surface Geometry ◽  
Tapered Roller Bearing ◽  
Transient Temperature Distribution ◽  
Abnormal Operating Conditions

Stack-up force distributions are obtained for normal and abnormal operating conditions in a class F (6 1/2 × 12) railroad tapered roller bearing-axle assembly for various friction coefficients, press-fits and cap screw preloads. Three conditions that affect the stack-up force distribution are considered: a steady-state normal-operating temperature distribution, a steady-state temperature distribution resulting from a stuck brake or a jammed outboard roller, and a transient temperature distribution due to multiple jammed outboard rollers. The steady-state normal or abnormal operating temperature have insignificant effects for nominal values of interference, friction and cap screw preload. However, the effect of the transient temperature due to multiple jammed outboard rollers on the stack-up system is detrimental due to localized high temperature gradients near the outboard cone area and a distortion of the original surface geometry of the cone.

Optimum Design of a Spiral Groove Bearing

1968 ◽  
Vol 183 (16) ◽  
pp. 147-151
Author(s):  
L. M. I. Fernlund ◽  
E. M. Kellström
Keyword(s):  
Temperature Distribution ◽  
Power Loss ◽  
Operating Conditions ◽  
Design Parameters ◽  
Computer Programme ◽  
Spiral Groove ◽  
Rolling Bearings ◽  
Flat Spiral ◽  
Bearing System ◽  
Spiral Groove Bearing

A new bearing system, consisting of a combination of a flat spiral groove bearing and rolling bearings, has been analysed in respect of temperature distribution under different operating conditions with the aid of a computer programme universally applicable to different design parameters. This programme, in combination with another for the optimization of a function which varies with certain auxiliary conditions, has also been used for the design of the spiral groove bearing in order to obtain maximum film thickness or minimum power loss.

Cage Instabilities in Cylindrical Roller Bearings

2004 ◽  
Vol 126 (4) ◽  
pp. 681-689 ◽  
Author(s):  
Niranjan Ghaisas ◽  
Carl R. Wassgren ◽  
Farshid Sadeghi
Keyword(s):  
High Speed ◽  
Roller Bearing ◽  
Degree Of Freedom ◽  
Stable Motion ◽  
Roller Bearings ◽  
Light Load ◽  
Cylindrical Roller Bearing ◽  
Six Degree Of Freedom ◽  
Cylindrical Roller ◽  
Inner Race

A six-degree-of-freedom model was developed and used to simulate the motion of all elements in a cylindrical roller bearing. Cage instability has been studied as a function of the roller-race and roller-cage pocket clearances for light-load and high-speed conditions. The effects of variation in inner race speed, misalignment, cage asymmetry, and varying size of one of the rollers have been investigated. In addition, three different roller profiles have been used to study their impact on cage dynamics. The results indicate that the cage exhibits stable motion for small values of roller-race and roller-cage pocket clearances. A rise in instability leads to discrete cage-race collisions with high force magnitudes. Race misalignment leads to a rise in instability for small roller-cage pocket clearances since skew control is provided by the sides of the cage pocket. One roller of larger size than the others causes inner race whirl and leads to stable cage motion for small roller-race clearances without any variation in roller-cage pocket clearance. Cage asymmetry and different roller profiles have a negligible impact on cage motion.

scholarly journals Study on the Thermal Performance and Temperature Distribution of Ball Bearings in the Traction Motor of a High-Speed EMU

2020 ◽  
Vol 10 (12) ◽  
pp. 4373
Author(s):  
Yu Wang ◽  
Junci Cao ◽  
Qingbin Tong ◽  
Guoping An ◽  
Ruifang Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Thermal Performance ◽  
High Speed ◽  
Convection Heat Transfer ◽  
Ball Bearings ◽  
Convection Heat ◽  
Rolling Bearings ◽  
Traction Motors

The transient thermal performance of rolling bearings affects the mechanical performance and system safety of traction motors. Most of the traditional empirical formulas used in temperature analysis have been simplified and cannot be completely applied to the calculation of heat generation and convection heat transfer coefficients. Based on the comparative analysis of finite element transient temperature and experimental data, this paper proposes a correction method of mathematical model and derives an accurate calculation formula for the heat generation and lubricant convection heat transfer coefficient of ball bearings applicable for the non-driving end in the traction motor of a high-speed EMU (Electric Multiple Unit). The accuracy of the results has been verified by durability experiment data. In addition, with changes in speed, radial load and other factors taken into account, we have analyzed the influence of these time-varying factors on ball bearing temperature, as well as the temperature distribution law of each component in a grease-lubricated bearing, in a bid to lay a foundation for follow-up research on the heat transfer laws of traction motors and rolling bearings.

Dynamic Simulation of Temperature Field in Hybrid Laser-GTAW Welding of Galvanized Steels in a Gap-Free Lap Joint Configuration

2009 ◽  
Author(s):  
Shanglu Yang ◽  
Fanrong Kong ◽  
Ehsan Forroozmehr ◽  
Radovan Kovacevic
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
High Speed ◽  
Numerical Results ◽  
Frame Rate ◽  
Welding Parameters ◽  
Transient Temperature ◽  
Lap Joint ◽  
Joint Configuration ◽  
Galvanized Steels

During hybrid laser-arc welding of galvanized dual phase steel 980 in a gap free lap joint configuration, the welding parameters have the significant influences on the weld quality, which is directly related to the temperature distribution of welds. In this paper, a 3D FEM model is used with the application of the double ellipsoidal moving heat source to simulate the transient temperature field and the dimensions of fusion zone and heat affected zone (HAZ) for hybrid laser-arc keyhole welding of galvanized steels in a gap-free lap joint configuration. Temperature-dependent thermophysical properties are used in the simulation. Effects of various welding parameters on the temperature distribution are studied. To validate the numerical results, a high-speed camera with the frame rate of 4000 fps is used to real-time capture the images of the molten pool. The numerical results show a good agreement with the experimental results.

Heat Generation of Bearing

2011 ◽  
Vol 480-481 ◽  
pp. 962-967 ◽  
Author(s):  
Yan Shuang Wang ◽  
Zhe Liu ◽  
Hai Feng Zhu
Keyword(s):  
Heat Generation ◽  
Power Loss ◽  
Integral Method ◽  
High Speed ◽  
Ball Bearing ◽  
High Reliability ◽  
Roller Bearing ◽  
Rolling Bearing ◽  
Heat Sources ◽  
Local Method

Heat generation of a bearing was studied based in this paper. Computational models of power loss were built. The total heat generation was gotten. Influences on total heating were analyzed at various inner ring rolling velocities and applied loads. The results show that bearing rolling velocity and axial load affect heat generation strongly. Meanwhile sliding friction, which exists between balls and the cage pocket, cages and the surface of outer ring, is the main factors of bearing heating. Bearings with shaft are mainly used in gyro motors of aviation, aerospace, marine navigational systems, which own a long life and high reliability. Heat generated by friction affects its performance, life and reliability, and consequently influences control precision and life of gyro motors. If the rate of heat dissipation is less than the rate of the heat generation, the system temperatures will raise, the hardness of bearing ring and rolling element steel decrease, and resulting in plastic deformations, lubricant deterioration occurs, ultimately, heat imbalance failure leads to breakage of bearing components and bearing seizure[1,2].So precise evaluating heat generation of bearings with shaft is important for design, manufacture and application of bearing. The heat generation of bearing comes from power loss of friction. The traditional methods contain the local method and integral method [3]. Palmgren who used the integral method based on experimental results advanced an empirical formula of total friction moment [4]. The calculation result is lower than the fact because ignoring infection of lubricant flux. Astringe and Smith improved the above formula .But it was just for roller bearing. Harris established a local method for the ball bearing and rolling bearing [5]. Pouly et al [6, 7] analyzed part power loss of the high speed rolling bearing based on local method. Compared with the integral method, the local method calculated heating of all heat sources. The results were more accurate. Liu Zhi-quan, Han Min-zheng et al computed the heat of high speed rolling and ball bearing by the local method [8, 9]. This paper studies heat generation mechanism of bearing with shaft from a gyro motor. Different heat sources from bearings are calculated by a self-made program. All factors which influence heat generation would be gotten by analyzing at different working conditions. It would offer a theoretical basis for optimal design and proper use of bearings with shaft.

scholarly journals Measurement of Windage Losses and Temperature Distribution for a High Speed Composite Rotor in a Stator Assembly at Low Air Pressures

2003 ◽  
Author(s):  
Jonathan Hahne ◽  
Mike Werst ◽  
Charles Penney ◽  
Hsing-Pang Liu ◽  
Jeremy O’Rarden ◽  
...  
Keyword(s):  
Experimental Data ◽  
Temperature Distribution ◽  
Thermal Effects ◽  
High Speed ◽  
Operating Conditions ◽  
Heat Distribution ◽  
Loss Analysis ◽  
Thermal Distribution ◽  
Specific Geometry ◽  
Proper Design

With the advancements in composite technology several innovative applications present themselves that involve high-speed composite rotors spinning in a stator assembly. As rotational speeds and rotor tip speeds increase, these rotors must operate in low air pressure environments to minimize windage losses and thermal effects of being at high speed for long durations. Accurately predicting this windage loss for a specific geometry and operating conditions is very important for a proper design. It is also very important to know the relative heat distribution that is seen by the rotor and stator from this windage loss. Analysis tools to date do not have a coupled link that calculates windage loss and a resultant thermal distribution to the rotor and stator surfaces. This paper presents the design and fabrication of a test setup to measure the total windage loss and temperature distribution from a high-speed composite rotor in a stator structure. Rotor speeds up to 40,000 rpm and rotor tip speeds up to 900 m/s with pressure ranges from 0.1 torr to 10 torr were operating parameters during the testing. The paper will also present experimental data obtained during the testing. Experimental data obtained during the testing will be used to evaluate new analysis methods for predicting the windage loss and thermal distribution in new high-speed rotor applications.

scholarly journals Lubrication of High-Speed, Large Bore Tapered-Roller Bearings

1978 ◽  
Vol 100 (1) ◽  
pp. 31-38 ◽  
Author(s):  
R. J. Parker ◽  
H. R. Signer
Keyword(s):  
Flow Rate ◽  
Power Loss ◽  
High Speed ◽  
Roller Bearing ◽  
Inlet Temperature ◽  
Shaft Speed ◽  
Roller Bearings ◽  
Lubricant Flow ◽  
Tapered Roller ◽  
Tapered Roller Bearings

The performance of 120.65-mm- (4.75-in.-) bore tapered-roller bearings was investigated at shaft speeds up to 15,000 rpm (1.81 × 106 DN). Temperature distribution and bearing heat generation were determined as a function of shaft speed, radial and thrust loads, lubricant flow rate, and lubricant inlet temperature. Lubricant was supplied either by jets or by a combination of holes through the cone directly to the cone-rib contact and jets at the roller small-end side. Cone-rib lubrication significantly improved high-speed tapered-roller bearing performance, yielding lower cone-face temperatures and lower power loss and allowing lower lubricant flow rates for a given speed condition. Bearing temperatures increased with increased shaft speed and decreased with increased lubricant flow rate. Bearing power loss increased with increased shaft speed and increased lubricant flow rate.

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