Influence of angular misalignment on the tribological performance of high-speed micro ball bearings considering full multibody interactions

2020 ◽  
pp. 135065012094829
Author(s):  
Chengwei Wen ◽  
Xianghui Meng ◽  
Bugao Lyu ◽  
Jiaming Gu ◽  
Lin Xiao
Keyword(s):  
Fatigue Life ◽  
Axial Load ◽  
Power Loss ◽  
High Speed ◽  
Influencing Factor ◽  
Total Power ◽  
Angular Misalignment ◽  
Absolute Value ◽  
Life Model ◽  
Comprehensive Comparison

To study the angular misalignment effects on the high-speed micro ball bearing which is applied to the dental handpiece, an improved five-degree-of-freedom quasi-dynamic model considering full multibody interactions is established in this paper. Then the modified fatigue life model presented by Jones is adopted to further evaluate the influence of angular misalignment on the reliability of the bearing. The results show that the angular misalignment significantly influences the contact load and contact angle distributions as well as the skidding behavior under both pure axial load and combined axial and radial loads. After comprehensive comparison, it is found that the impacts of angular misalignment on total power loss and bearing fatigue life are different under the two types of loads. Under pure axial load, the total power loss increases consistently and the bearing fatigue life decreases significantly when the absolute value of angular misalignment becomes larger. However, under combined axial and radial loads, the effects of angular misalignment are rather complicated and the direction of angular misalignment turns out to be a key influencing factor.

Reducing Gear Windage Losses From High Speed Gears

2000 ◽  
Author(s):  
Don D. Winfree
Keyword(s):  
Power Loss ◽  
High Speed ◽  
Total Power ◽  
Fort Worth ◽  
Trial And Error ◽  
Test Rig ◽  
Cost Overruns ◽  
Basic Set ◽  
Drive Trains ◽  
Reducing Gear

Abstract Windage losses in gearboxes account for a large portion of the total power loss in high-speed drive trains. Very little actual data has been collected specifically quantifying these losses. Traditional techniques to measure the effects of baffles in high speed gearing applications have been done by trial and error on very complex systems. This trial and error technique is used throughout the gearing industry to solve problems without isolating each individual gear windage effect. These solutions are usually sub-optimum. They cause time-consuming delays and cost overruns in many programs. This paper describes a gear baffle test rig that was built to quantify and minimize the gear windage losses in high-speed drive trains. These tests were conducted at the Lockheed Martin Aeronautics Company, Fort Worth Texas Facility. The intent of the gearbox baffle test rig was to isolate and measure the windage effects on a single high-speed bevel gear with various baffle configurations. Results of these tests were used to define a basic set of ground rules for designing baffles. Finally the set of ground rules was used to design an optimum baffle configuration.

Reducing Gear Windage Losses From High Speed Gears and Applying These Principles to Actual Running Hardware

2013 ◽  
Author(s):  
Don D. Winfree
Keyword(s):  
Complex Systems ◽  
Power Loss ◽  
High Speed ◽  
Total Power ◽  
Trial And Error ◽  
Test Rig ◽  
Cost Overruns ◽  
Basic Set ◽  
Drive Trains ◽  
Reducing Gear

Windage losses in gearboxes account for a large portion of the total power loss in high-speed drive trains. Very little actual data has been collected specifically quantifying these losses. Traditional techniques to measure the effects of baffles in high speed gearing applications have been done by trial and error on very complex systems. This trial and error technique is used throughout the gearing industry to solve problems without isolating each individual gear windage effect. These solutions are usually sub-optimum. They cause time-consuming delays and cost overruns in many programs. This paper describes two gear baffle test rigs that were built to quantify and minimize the gear windage losses in high-speed drive trains. The intent of the first gearbox baffle test rig was to isolate and measure the windage effects on a single high-speed bevel gear with various baffle configurations. The results of these tests were used to define a basic set of ground rules for designing baffles. This set of ground rules was then applied to another rig replicating the F-35 Liftfan gear box configuration. Immediate benefits were seen. Without this work Lockheed Martin’s X-35 STOVL aircraft would not have been able to operate.

scholarly journals Lubrication and Fatigue Life Evaluation of High-Speed Cylindrical Roller Bearing under Misalignment

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hongyu Duan ◽  
Jiawei Song ◽  
Zhijian Wang
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Roller Bearing ◽  
Coupled Model ◽  
Roller Bearings ◽  
Life Model ◽  
Fatigue Life Evaluation ◽  
Roller Profile ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

This paper developed a coupled model, incorporating the quasistatic model, fatigue life model, and mixed lubrication model, to investigate the effect of misalignment angle on high-speed cylindrical roller bearings. The model is verified by comparing with the published literature results. Then, a parametric analysis is carried out. The results show that as the misalignment increases, the load distribution is basically unchanged, but the fatigue life of the roller bearing decreases due to the variation of contact pressure, and the skewing moment of single roller contact pair increases. Furthermore, the optimal design of roller profile needs to consider the effect of lubrication in order to improve the fatigue life of roller bearings. In general, the optimal crown drop is too small according to the design from the slicing technique.

Analysis of Counter-Rotating Roller Bearing in Different Mounting Configurations

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Wenjun Gao ◽  
Daniel Nelias ◽  
Zhenxia Liu
Keyword(s):  
Thermal Behavior ◽  
Load Distribution ◽  
Power Loss ◽  
High Speed ◽  
Roller Bearing ◽  
Total Power ◽  
Kinetic Behavior ◽  
Uniform Load ◽  
Roller Ring ◽  
Differential Speed

Advanced engine configuration studies have shown large advantages for an engine with counter-rotating spools with intershaft counter-rotating roller bearings. Mounted on two counter-rotating differential-speed hollow rotors, the bearing internal kinetic behavior, dynamic behavior, and then thermal behavior change greatly, causing a severe challenge to engine designers using traditional analysis methods. A special quasi-dynamic model for counter-rotating roller bearing is proposed, considering rings deformation and windage effects, to analyze the bearing mechanical and thermal behavior in different mounting configurations. Roller sliding and bearing heat generation are calculated and compared with experimental data to verify the model capabilities. It shows that the configuration that connects the inner ring to the high-speed rotor has life cycle advantage with more uniform load distribution, smaller roller/ring clearance, and lower cage speed. This leads to less drag loss due to the rotation of the rollers and cage assembly. The decrease of the total power loss is a key element to minimize the quantity of oil required to lubricate the roller bearing.

Load Spectrum Compiling and Fatigue Life Estimation of the Automobile Wheel Hub

2020 ◽  
Vol 13 ◽  
Author(s):  
Xintian Liu ◽  
Yang Qu ◽  
Xiaobing Yang ◽  
Yongfeng Shen
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Two Dimensional ◽  
Load Spectrum ◽  
One Dimensional ◽  
Life Estimation ◽  
Load Spectra ◽  
Fatigue Life Estimation ◽  
Program Load Spectrum ◽  
Program Load

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.

Durability Analysis of the Reduction Gear for High Speed Train Considering Driving Histories

2012 ◽  
Vol 586 ◽  
pp. 269-273
Author(s):  
Chul Su Kim ◽  
Gil Hyun Kang
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Element Model ◽  
Rolling Stock ◽  
Reduction Gear ◽  
High Speed Train ◽  
Analysis Software ◽  
Tractive Effort ◽  
Durability Analysis ◽  
The Finite Element Model

To assure the safety of the power bogies for train, it is important to perform the durability analysis of reduction gear considering a variation of velocity and traction motor capability. In this study, two types of applied load histories were constructed from driving histories considering the tractive effort and the train running curves by using dynamic analysis software (MSC.ADAMS). Moreover, this study was performed by evaluating fatigue damage of the reduction gears for rolling stock using durability analysis software (MSC.FATIGUE). The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the gears. The results showed that the fatigue life of the reduction gear would decrease with an increasing numbers of stops at station.

scholarly journals On-CMOS Image Sensor Processing for Lane Detection

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3713
Author(s):  
Soyeon Lee ◽  
Bohyeok Jeong ◽  
Keunyeol Park ◽  
Minkyu Song ◽  
Soo Youn Kim
Keyword(s):  
Edge Detection ◽  
High Speed ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Image Resolution ◽  
Lane Detection ◽  
Frame Rate ◽  
Total Power ◽  
Detection Accuracy ◽  
Total Power Consumption

This paper presents a CMOS image sensor (CIS) with built-in lane detection computing circuits for automotive applications. We propose on-CIS processing with an edge detection mask used in the readout circuit of the conventional CIS structure for high-speed lane detection. Furthermore, the edge detection mask can detect the edges of slanting lanes to improve accuracy. A prototype of the proposed CIS was fabricated using a 110 nm CIS process. It has an image resolution of 160 (H) × 120 (V) and a frame rate of 113, and it occupies an area of 5900 μm × 5240 μm. A comparison of its lane detection accuracy with that of existing edge detection algorithms shows that it achieves an acceptable accuracy. Moreover, the total power consumption of the proposed CIS is 9.7 mW at pixel, analog, and digital supply voltages of 3.3, 3.3, and 1.5 V, respectively.

Testing and assessment of fatigue life prediction models for Indian PHWRs piping material under multi-axial load cycling

2016 ◽  
Vol 85 ◽  
pp. 98-113 ◽  
Author(s):  
Punit Arora ◽  
Suneel K. Gupta ◽  
V. Bhasin ◽  
R.K. Singh ◽  
S. Sivaprasad ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Axial Load ◽  
Life Prediction ◽  
Prediction Models ◽  
Fatigue Life Prediction ◽  
Load Cycling

The Study of Thermal Raising and Transmission Torque of High Speed Ball-Screw Lubricated by Different Greases

2015 ◽  
Vol 642 ◽  
pp. 212-216
Author(s):  
Yi Haung ◽  
Chin Chung Wei
Keyword(s):  
Contact Area ◽  
Axial Load ◽  
High Speed ◽  
Performance Test ◽  
Vertical Motion ◽  
High Viscosity ◽  
Ball Screw ◽  
Frictional Heat ◽  
Motion Platform ◽  
Base Oil

Ball screw is a high-precision and high performance linear drive of mechanical elements. The frictional heat of internal components what is very significant impact for platform transmission in high speed and the high axial load and causes the thermal expansion of element. In this research , the influence of different greases on ball screw is investigated in thermal rising of nut and driving torque in high speed and high axial load. A vertical motion platform was used for driving performance test. Thermal rising of nut of ball screw and the variance of transmission torque whose lubricated by high viscosity base oil grease is significant larger than the lower one. High viscosity grease is not easy to carry out the friction heat generated at ball and raceway contact area due to the bad flowing properties. It also has more serious wear occurred at contact area and high friction force, whose causes the large variance of transmission torque.

Sign in / Sign up

Export Citation Format

Share Document