Heat Transfer Across Ball Bearings in Vacuum

2005 ◽  
Author(s):  
Yoshimi R. Takeuchi ◽  
James T. Dickey ◽  
Steven M. Demsky ◽  
Matthew A. Eby
Keyword(s):  
Heat Transfer ◽  
Axial Load ◽  
High Speed ◽  
Thermal Conductance ◽  
Thermal Conditions ◽  
Test Results ◽  
Angular Contact Ball Bearing ◽  
Conductance Data ◽  
The Subject ◽  
Aerospace Corporation

Accurate spacecraft bearing temperature predictions often require both system and bearing level heat source and thermal conductance information. Bearing thermal conductance data is usually the most significant unknown in the development of the thermal model and little has been published in open literature on the subject. Consequently experiments have been conducted at The Aerospace Corporation to address this topic, with special attention given to applications such as high-speed momentum and flywheels. An experiment was designed to measure thermal conductance across a single bearing under both static and dynamic states. This paper will describe the test results for an angular-contact ball bearing under controlled inner race rotational speed, axial load, and thermal conditions. Tests were conducted on both dry and Nye Pennzane SHF2001 synthetic oil lubricated bearings. Test data showed that thermal conductance is sensitive to a complex interdependent set of variables including maximum run-in speed, axial load and temperature. A basic physical understanding of the heat transfer mechanism across a bearing was developed based on experimental results.

Thermal Conductance Measurement Techniques for High-Speed Bearings in Vacuum

2005 ◽  
Author(s):  
Steven M. Demsky ◽  
Yoshimi R. Takeuchi ◽  
James T. Dickey
Keyword(s):  
Experimental Method ◽  
Rotational Speed ◽  
Axial Load ◽  
High Speed ◽  
Thermal Environment ◽  
Measurement Techniques ◽  
Thermal Conductance ◽  
Conductance Measurement ◽  
Aerospace Corporation ◽  
Inner Race

An experimental method has been developed at The Aerospace Corporation to determine the thermal conductance of moving bearings in vacuum. The test involves the measurement of thermal conductance of a single bearing under controlled inner race rotational speed, axial load, and thermal environment. Applications of interest include high-speed momentum wheels and flywheels. This paper covers the experimental method developed for this purpose and the techniques used to establish measurement uncertainty.

Effects of Heat Generation in an Air Hydrostatic Journal Bearing

1970 ◽  
Vol 92 (4) ◽  
pp. 607-616
Author(s):  
R. E. Baker ◽  
K. G. Hornung
Keyword(s):  
Heat Transfer ◽  
Heat Generation ◽  
High Speed ◽  
Journal Bearing ◽  
Temperature Measurements ◽  
Heat Transfer Analysis ◽  
Hydrostatic Bearing ◽  
Thermal Deformations ◽  
The Subject ◽  
Viscosity Variation

A rather complete heat transfer analysis is carried out for a specific air hydrostatic bearing. The effects of viscosity variation and thermal deformations are included. The result is a prediction of film temperature of the bearing at high speed. Torque and temperature measurements are made on the subject bearing and show fair correlation with the theory.

Determination of Heat Repartition Parameters on High Speed Pin-on-Disc Tribometer by Inverse Heat Conduction Method

2012 ◽  
Vol 504-506 ◽  
pp. 1061-1066
Author(s):  
Damien Meresse ◽  
Michel Watremez ◽  
Souad Harmand ◽  
Laurent Dubar
Keyword(s):  
Heat Conduction ◽  
High Speed ◽  
Thermal Conductance ◽  
Thermal Conditions ◽  
Heat Fluxes ◽  
Temperature Fields ◽  
Inverse Heat Conduction ◽  
Pin On Disc ◽  
Steel Disc ◽  
Heat Transfers

The heat transfers are investigated between a phenolic pin sliding against a steel disc. Inverse heat conduction methods are used to identify the temperature fields and the heat fluxes at the contact surface for each part. Experimentals tests are performed on the High Speed Tribometer designed to reproduce mechanical and thermal conditions met in forming and braking applications at reduced scale. It allows to measure temperatures inside rotating part in seven locations with K-type thermocouples sensors connected to a telemetry system. Their positions have been chosen regarding a sensibility analysis performed in expected thermal conditions. The heat distribution on the disc surface, the heat repartition parameter α between the pin and the disc and the sliding thermal conductance hc are discussed regarding the friction conditions during the tribological tests performed. In this tribological system, the temperature and the pressure influences on hc are highlighted. The originality of this work is the possibility to calculate two dimensional transient heat fluxes for sliding speed until 15m.s-1 thanks to several thermocouple measurements.

Experimental Investigations of Radially Rotating Miniature High-Temperature Heat Pipes

2000 ◽  
Vol 123 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Jian Ling ◽  
Yiding Cao ◽  
Alex P. Lopez
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Pipe ◽  
High Speed ◽  
Thermal Conductance ◽  
Heat Pipes ◽  
Experimental Investigations ◽  
Temperature Heat ◽  
Heat Transfer Capacity ◽  
High Temperature Heat Pipe

A radially rotating miniature high-temperature heat pipe employs centrifugal force to return the condensate in the condenser section to the evaporator section. The heat pipe has a simple structure, very high effective thermal conductance and heat transfer capacity, and can work in hostile high-temperature environments. In this research, a high-speed rotating test apparatus and data acquisition system for radially rotating miniature high-temperature heat pipes are established. Extensive experimental tests on two heat pipes with different dimensions are performed, and various effects of influential parameters on the performance characteristics of the heat pipes are investigated. The ranges of the important parameters covered in the current experiments are: 470⩽ω2Za¯/g⩽1881; 47 W⩽Q⩽325W; di=1.5 and 2 mm; and 1.05×10−3m3/s⩽W⩽13.4×10−3m3/s. The experimental data prove that the radially rotating miniature high-temperature heat pipe has a high effective thermal conductance, which is 60–100 times higher than the thermal conductivity of copper, and a large heat transfer capacity that is more than 300 W. Therefore, the heat pipe appears to be feasible for cooling high-temperature gas turbine components.

scholarly journals EFFECT OF SEED FILLING AND RELEASING ANGLES ON THE PERFORMANCE OF COMPOUND VACUUM SEED METERING DEVICE

2021 ◽  
pp. 153-162
Author(s):  
Zeqi Liu ◽  
Zhang Meng ◽  
Jie Han ◽  
Yajun Zhuang ◽  
Xiang Yin ◽  
...  
Keyword(s):  
Negative Pressure ◽  
High Speed ◽  
Test Results ◽  
Camera System ◽  
Seed Filling ◽  
Evaluation Indexes ◽  
Air Chamber ◽  
The Subject ◽  
Seed Metering Device

In this paper, taking compound air-suction seed metering device as the subject, the effect rule of seed filling angle and seed releasing angle on the performance of seed filling and seed metering is studied. An indoor test was conducted with a JPS-12 metering test bench and a high-speed camera system. The starting and ending angles of the air chamber were changed by adjusting the regulating plate, that is, the angles of seed filling and seed releasing, and the filling and seed metering performance was taken as evaluation indexes. The test results show that: the seed filling angle has significant effect on the seed filling effect, and the miss fill index decreases with the increase of the quality of fill index. When the seed filling angle exceeds 50°, they will stabilize gradually ending at the multiple fill index of 0%. The negative pressure and operating speed are interactive and have a significant effect on filling performance. The seed releasing angle has significant effect on the metering performance. With the increase of the angle, the quality of feed index increases firstly and then decreases. The multiple index and miss index are opposite to the quality of feed index which is the max at the seed releasing angle of 39.5°. The negative pressure and forward speed are interactive and have a significant effect on metering performance. The quality of feed index under the same condition is lower than that of fill index.

Finite Element Analysis for Thermal Characteristics of High Speed Angular Contact Ball Bearing

2013 ◽  
Vol 397-400 ◽  
pp. 126-130
Author(s):  
Peng Wang ◽  
Chun Li Lei ◽  
Bao Cheng Zhou ◽  
Wei Ping Zhao
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
High Speed ◽  
Ball Bearing ◽  
Simulation Analysis ◽  
Cooling System ◽  
Thermal Characteristics ◽  
Element Model ◽  
Angular Contact Ball Bearing ◽  
Element Analysis

According to the high speed bearing failure problem caused by the high temperature, finite element model of high-speed hybrid ceramic angular contact ball bearing is established in this paper. Quantity of heat and heat transfer coefficient are calculated by using the heat transfer and thermodynamics theory, which are boundary condition for the temperature field simulation analysis of ball bearing. The temperature distribution of bearing is obtained when bearing speed is 12000rad/min. The results can provide a theoretical foundation for lubrication cooling system controlling temperature.

IMPROVE THE INTERETATION OF STUDY SUBJECTS PANCASILA AND CITIZENSHIP EDUCATION BY APPLYING KONSTEXTUAL LEARNING MODEL BERBASIS A TASK IN CLASS INFORMATICS XI SMK BINA ECLECTUS ACADEMIC YEAR 2015/2016

EDUKASI ◽  
2016 ◽  
Vol 13 (2) ◽  
Author(s):  
Hasanudin S. Usman
Keyword(s):  
Teaching And Learning ◽  
Learning Model ◽  
Positive Influence ◽  
Motivation To Learn ◽  
Test Results ◽  
Applied Learning ◽  
Know How ◽  
Design Activities ◽  
The Subject ◽  
Academic Year

The purpose of this research is to know how to incerease the students’ learning achievement that has been applied learning contextual task-based learning model and to know the influence of contextual learning in  the task-based teaching model to improve achievemen and motivation to learn the material pe civis lesson.   This research is an action research by theree rounds. Each round consists of four phases. Design activities are observation, and revesion. The subject of the research is XI grade students of Bina Informatika Ternate accademic year 2015/2016. Data obtained in the form of a formative test results, observation sheet teaching and learning activities. The results of the research showed that students’ achivement increased from round I to III that the round 1, (70.00 % ), (92,50 %)  3 cycles, conclusions of this research is the method of cooperatif learning can be a positive influence on students motivation and achievement in material udaya politics in Indonesia. It means that this model can be used as one of the alternative learning for Pkn.            Kata  kunci: PKn, cooperative learning method

Recent Patents on the Angular Contact Ball Bearing of High-Speed Motorized Spindle

2020 ◽  
Vol 13 ◽  
Author(s):  
Yudong Bao ◽  
Linkai Wu ◽  
Yanling Zhao ◽  
Chengyi Pan
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Rapid Development ◽  
Ceramic Materials ◽  
Development Trend ◽  
Numerical Control ◽  
Angular Contact Ball Bearing ◽  
Practical Applications ◽  
High Speed Cutting ◽  
Advantages And Disadvantages

Background:: Angular contact ball bearings are the most popular bearing type used in the high speed spindle for machining centers, The performance of the bearing directly affects the machining efficiency of the machine tool, Obtaining a higher value is the direction of its research and development. Objective:: By analyzing the research achievements and patents of electric spindle angular contact bearings, summarizing the development trend provides a reference for the development of electric spindle bearings. Methods:: Through the analysis of the relevant technology of the electric spindle angular contact ball bearing, the advantages and disadvantages of the angular contact ball bearing are introduced, and the research results are combined with the patent analysis. Results:: With the rapid development of high-speed cutting and numerical control technology and the needs of practical applications, the spindle requires higher and higher speeds for bearings. In order to meet the requirements of use, it is necessary to improve the bearing performance by optimizing the structure size and improving the lubrication conditions. Meanwhile, reasonable processing and assembly methods will also have a beneficial effect on bearing performance. Conclusion:: With the continuous deepening of bearing technology research and the use of new structures and ceramic materials has made the bearing's limit speed repeatedly reach new highs. The future development trend of high-speed bearings for electric spindles is environmental protection, intelligence, high speed, high precision and long life.

Temperature Rise Prediction of Oil-Air Lubricated Angular Contact Ball Bearings Using Artificial Neural Network

2019 ◽  
Vol 12 (3) ◽  
pp. 248-261
Author(s):  
Baomin Wang ◽  
Xiao Chang
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Temperature Rise ◽  
High Speed ◽  
Ball Bearing ◽  
Influence Factors ◽  
Ball Bearings ◽  
Ann Model ◽  
Angular Contact Ball Bearing ◽  
Artificial Neural

Background: Angular contact ball bearing is an important component of many high-speed rotating mechanical systems. Oil-air lubrication makes it possible for angular contact ball bearing to operate at high speed. So the lubrication state of angular contact ball bearing directly affects the performance of the mechanical systems. However, as bearing rotation speed increases, the temperature rise is still the dominant limiting factor for improving the performance and service life of angular contact ball bearings. Therefore, it is very necessary to predict the temperature rise of angular contact ball bearings lubricated with oil-air. Objective: The purpose of this study is to provide an overview of temperature calculation of bearing from many studies and patents, and propose a new prediction method for temperature rise of angular contact ball bearing. Methods: Based on the artificial neural network and genetic algorithm, a new prediction methodology for bearings temperature rise was proposed which capitalizes on the notion that the temperature rise of oil-air lubricated angular contact ball bearing is generally coupling. The influence factors of temperature rise in high-speed angular contact ball bearings were analyzed through grey relational analysis, and the key influence factors are determined. Combined with Genetic Algorithm (GA), the Artificial Neural Network (ANN) model based on these key influence factors was built up, two groups of experimental data were used to train and validate the ANN model. Results: Compared with the ANN model, the ANN-GA model has shorter training time, higher accuracy and better stability, the output of ANN-GA model shows a good agreement with the experimental data, above 92% of bearing temperature rise under varying conditions can be predicted using the ANNGA model. Conclusion: A new method was proposed to predict the temperature rise of oil-air lubricated angular contact ball bearings based on the artificial neural network and genetic algorithm. The results show that the prediction model has good accuracy, stability and robustness.

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