Minimization of Transient Temperature Fluctuations in High Speed Spindle Bearing

2014 ◽  
Vol 592-594 ◽  
pp. 1114-1118
Author(s):  
Venugopal Prabhu Raja ◽  
P. Pal Pandian ◽  
Devara Venkata Krishna ◽  
R. Sathiya Moorthy

The performance of a high speed spindle is mainly attributed to the thermal behavior of spindle bearings. Hence, it is very significant to simulate the thermal behavior of spindle bearings. Finite element analysis is carried out for a typical high speed spindle by considering bearing and motor heat generation under various loading conditions to investigate the transient temperature rise of the spindle assembly. The influence of different cooling arrangements on the thermal behaviour of spindle bearings is then investigated with the objective of minimization of transient temperature fluctuations.

2011 ◽  
Vol 52-54 ◽  
pp. 1206-1211 ◽  
Author(s):  
Huai Xing Wen ◽  
Mei Yan Wang

The thermal characteristics of the motorized spindle determines maching qualities and cutting capabilities, and is one of the important factors influencing the precision of the high speed NC machine tool. To improve the performance of the high speed machine tool, it is important to study the thermal characteristics of the motorized spindle. It had been studied in two ways: one is finite element analysis by Ansys software, in which the finite element analysis model was built. According to the actual working condition, the heat source and the heat transfer coefficient of every part are calculated. On this basis, the temperature field and temperature rises were gotten in Ansys software. The other way is temperature rises experiment on the motorized spindle test platform. The result was shown in the form of curve. These two ways shown the same result: the highest temperature rise appears in the area of electromotor, then followed by the rolling bearing .The result provides the necessary theory basis for optimizing the structure of the motorized spindle and establishes a basis for the research and application about the high speed spindle.


2013 ◽  
Vol 690-693 ◽  
pp. 3316-3320 ◽  
Author(s):  
Chi Liu ◽  
Yi Lun Liu ◽  
Li Yong Ma ◽  
Pin Yuan

Wire spinning, which is a deformation process of great complexity in laying head pipe, was simulated using MSC. Marc, a software for finite element analysis, with the aid of production data collected in a high-speed wire spinning production line. The stress condition and the temperature distribution of the laying head inner wall, under the condition of high speed dry sliding friction, were obtained. The effects of different feed speeds on the contact stress and the transient temperature of the easily-wear part were analyzed. The simulation result coincides with the actual wear condition in the laying head pipe, indicating the soundness of the finite element model and making a contribution to optimizing the special curve of the laying head pipe and the finished rolling speed.


2015 ◽  
Vol 764-765 ◽  
pp. 289-293
Author(s):  
Yi Chang Wu ◽  
Han Ting Hsu

This paper presents the magnetostatic field analysis of a coaxial magnetic gear device proposed by Atallah and Howe. The structural configuration and speed reduction ratio of this magnetic gear device are introduced. The 2-dimensional finite-element analysis (2-D FEA), conducted by applying commercial FEA software Ansoft/Maxwell, is performed to evaluate the magnetostatic field distribution, especially for the magnetic flux densities within the outer air-gap. Once the number of steel pole-pieces equals the sum of the pole-pair numbers of the high-speed rotor and the low-speed rotor, the coaxial magnetic gear device possesses higher magnetic flux densities, thereby generating greater transmitted torque.


Author(s):  
Oscar O. Rodriguez ◽  
Arturo A. Fuentes ◽  
Constantine Tarawneh ◽  
Robert E. Jones

Thermoplastic elastomers (TPE’s) are increasingly being used in rail service in load damping applications. They are superior to traditional elastomers primarily in their ease of fabrication. Like traditional elastomers they offer benefits including reduction in noise emissions and improved wear resistance in metal components that are in contact with such parts in the railcar suspension system. However, viscoelastic materials, such as the railroad bearing thermoplastic elastomer suspension element (or elastomeric pad), are known to develop self-heating (hysteresis) under cyclic loading, which can lead to undesirable consequences. Quantifying the hysteresis heating of the pad during operation is therefore essential to predict its dynamic response and structural integrity, as well as, to predict and understand the heat transfer paths from bearings into the truck assembly and other contacting components. This study investigates the internal heat generation in the suspension pad and its impact on the complete bearing assembly dynamics and thermal profile. Specifically, this paper presents an experimentally validated finite element thermal model of the elastomeric pad and its internal heat generation. The steady-state and transient-state temperature profiles produced by hysteresis heating of the elastomer pad are developed through a series of experiments and finite element analysis. The hysteresis heating is induced by the internal heat generation, which is a function of the loss modulus, strain, and frequency. Based on previous experimental studies, estimations of internally generated heat were obtained. The calculations show that the internal heat generation is impacted by temperature and frequency. At higher frequencies, the internally generated heat is significantly greater compared to lower frequencies, and at higher temperatures, the internally generated heat is significantly less compared to lower temperatures. However, during service operation, exposure of the suspension pad to higher loading frequencies above 10 Hz is less likely to occur. Therefore, internal heat generation values that have a significant impact on the suspension pad steady-state temperature are less likely to be reached. The commercial software package ALGOR 20.3TM is used to conduct the thermal finite element analysis. Different internal heating scenarios are simulated with the purpose of obtaining the bearing suspension element temperature distribution during normal and abnormal conditions. The results presented in this paper can be used in the future to acquire temperature distribution maps of complete bearing assemblies in service conditions and enable a refined model for the evolution of bearing temperature during operation.


Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.


1999 ◽  
Vol 36 (04) ◽  
pp. 203-210
Author(s):  
Steven P. McGee ◽  
Armin Troesch ◽  
Nickolas Vlahopoulos

In 1994 the International Maritime Organization adopted the Code of Safety for High-Speed Craft (HSC Code). After two years of use, several shortfalls were found, one being the damage length predictor, which is based on traditional steel, mono-hulled vessels. Other damage predictors were developed based on historical data, but they do not account for variables such as aluminum or fiberglass construction, transverse members, indenter geometry variation, or for the case where the vessel comes to rest on the grounding object. This paper proposes a damage prediction model based on material properties, structural layout, grounding object geometry, and vessel speed. The model incorporates four grounding mechanisms: plate cutting, plate tearing, crushing of plate behind transverse members, and transverse member failure. The method is used to determine the resistance energy, compared to the kinetic energy, of the vessel, to determine an effective damage length. Finite-element analysis was used to model the failure of both aluminum and steel transverse members with significant differences in the results. It was found that the transverse members provided the majority of the resistance energy in one grounding mechanism and negligible resistance energy in another.


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