scholarly journals Designed a Passive Grinding Test Machine to Simulate Passive Grinding Process

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1317
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao
Keyword(s):  
High Speed ◽  
Testing Machine ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Test Machine ◽  
High Speed Rail ◽  
Grinding Machines ◽  
Conventional Rail ◽  
And Function ◽  
Grinding System

Passive grinding is a high-speed rail grinding maintenance strategy, which is completely different from the conventional rail active grinding system. In contrast to active grinding, there is no power to drive the grinding wheel to rotate actively in passive grinding. The passive grinding process is realized only by the cooperation of grinding pressure, relative motion, and deflection angle. Grinding tests for passive grinding can help to improve the passive grinding process specifications and be used for the development of passive grinding wheels. However, most of the known grinding methods are active grinding, while the passive grinding machines and processes are rarely studied. Therefore, a passive grinding test machine was designed to simulate passive grinding in this study. This paper gives a detailed description and explanation of the structure and function of the passive grinding tester. Moreover, the characteristics of the grinding process and parameter settings of the testing machine were discussed based on the passive grinding principle. The design of a passive grinding test machine provides experimental equipment support for investigating passive grinding behavior and grinding process.

Study on Balance Precision of Ultra-High Speed CBN Grinding Wheel System

2008 ◽  
Vol 375-376 ◽  
pp. 614-618 ◽  
Author(s):  
Shi Chao Xiu ◽  
Jian Liu ◽  
Chang He Li ◽  
Guang Qi Cai
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Rigid Rotor ◽  
Machining Quality ◽  
Ultra High Speed ◽  
High Speed Grinding ◽  
Cbn Grinding Wheel ◽  
Grinding System

The balance precision of grinding wheel is a key technical parameter in ultra-high speed grinding process. The actual standard for the balance precision of rigid rotor is not fit for the thin ultra-high speed grinding system well. The unbalance factors affected on the ultra-high speed grinding wheel and its system were analyzed, and its effects on the machining quality in the process were also discussed. The theory and select principle of the balance precision for ultra-high speed grinding wheel system were studied. The test of dynamic performance was performed for the thin ultra-high speed CBN grinding wheel system whose structure was optimized. The groundwork to establish the standard of balance precision for thin ultra-high speed grinding system was offered.

Study on Edge Contact Area and Surface Integrity of Workpiece in Point Grinding Process

2009 ◽  
Vol 407-408 ◽  
pp. 577-581
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
High Speed ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Edge Contact ◽  
Cylindrical Grinding ◽  
Theoretic Foundations

During cylindrical grinding process, the geometric configuration and size of the edge contact area between the grinding wheel and workpiece have the heavy effects on the workpiece surface integrity. In consideration of the differences between the point grinding and the conventional high speed cylindrical grinding, the geometric and mathematic models of the edge contact area in point grinding were established. Based on the models, the numerical simulation for the edge contact area was performed. By means of the point grinding experiment, the effect mechanism of the edge contact area on the ground surface integrity was investigated. These will offer the applied theoretic foundations for optimizing the point grinding angles, depth of cut, wheel and workpiece speed, geometrical configuration and size of CBN wheel and some other grinding parameters in point grinding process.

scholarly journals Infrastructure costs and benefits of European high-speed rail

2021 ◽  
Vol 1 (2) ◽  
pp. 47-53
Author(s):  
Nedžad Branković ◽  
Aida Kalem
Keyword(s):  
High Speed ◽  
New Technologies ◽  
Operational Parameters ◽  
Negative Effects ◽  
Railway Network ◽  
High Speed Rail ◽  
Rail Network ◽  
High Speed Trains ◽  
Conventional Rail ◽  
Ecologically Sustainable

The development of new technologies has significantly influenced railways modernization and has caused the appearance of high-speed rail which represent a safe, comfortable and ecologically sustainable way of transportation. The high-speed rail present a big step in a relation to conventional railways, where the biggest difference is speed which even entails a change of other organizational and operational parameters, better utilization of trains, higher performance of manpower and better service to users.  That is visible in many cities around the world where high-speed trains are used by billions of users. In the EU there is no unique high-speed railway network, besides that in many EU member countries various operational models are applied. The future of the high-speed railways market depends on political, economical and technical factors and challenges as high infrastructure costs, various rates of return on investment and the negative effects of economic crises. The main objective of the paper is to analyze infrastucture costs of high-speed rail in Europe and benefits such us  time savings, higher reliability, comfort, safety, reducing pollution and the release of capacity in the conventional rail network, roads and airport infrastructure.

Study on Effect of Grinding Fluid Supply Parameters on Surface Integrity in Quick-Point Grinding for Green Manufacturing

2008 ◽  
Vol 53-54 ◽  
pp. 209-214 ◽  
Author(s):  
Shi Chao Xiu ◽  
Ya Dong Gong ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
High Speed ◽  
Point Contact ◽  
Green Manufacturing ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Fluid ◽  
Fluid Supply ◽  
High Speed Grinding ◽  
Grinding Power

In high and super-high speed grinding process, there is an airflow layer with high speed around the circle edge of the grinding wheel that hinders the grinding fluid into contact layer, namely, the air barrier effect. The speed of airflow layer is directly proportional to the square of the wheel speed. Quick-point grinding is a new type of high and super-high speed grinding process with a point contact zone and less grinding power. The edge effect of the air barrier is weakened because the thin CBN wheel is applied in the process. By the analysis of dynamic pressure and velocity distributions in the airflow layer around the wheel edge, the mathematic models of the flow and jet pressure of grinding fluid for effective supply in the process were established and the process of optimization calculation of the jet nozzle diameter for green manufacturing was also analyzed based on the thermodynamics and the technical character of quick-point grinding process. The quick-point grinding experiment for surface integrity influenced by grinding fluid supply parameters was performed.

scholarly journals Study on Contact Rolling Fatigue of Rails : 2nd Report, Analysis by High Speed Rail Testing Machine

1985 ◽  
Vol 28 (243) ◽  
pp. 1819-1824 ◽  
Author(s):  
Shin-ichi NISHIDA ◽  
Kazuo SUGINO ◽  
Chikayuki URASHIMA ◽  
Hiroki MASUMOTO
Keyword(s):  
High Speed ◽  
Testing Machine ◽  
High Speed Rail ◽  
Report Analysis

scholarly journals Understanding the urbanization impacts of high-speed rail in China

2021 ◽  
Vol 58 (2) ◽  
pp. 21-34
Author(s):  
Anthony Perl ◽  
Taotao Deng ◽  
Leandro Correa ◽  
Dandan Wang ◽  
Yulin Yan
Keyword(s):  
Urban Form ◽  
High Speed ◽  
Industrial Development ◽  
Vital Role ◽  
High Speed Rail ◽  
National Network ◽  
Rail Network ◽  
Form And Function ◽  
Negative Impacts ◽  
And Function

Advances in transport technology have been shown to play a vital role in urban development over millennia. From the engineering and pavement innovations of the Roman road network to the aerospace breakthroughs that enabled jet aircraft, cities have been reshaped by the mobility changes resulting from new designs for moving people and goods. This article explores the urbanization impacts of High-Speed Rail’s introduction in China, which has built the world’s largest High-Speed Rail network in record time. Since High-Speed Rail was launched in Japan in 1964, this technology has worked to reshape intercity travel as a revolutionary transportation alternative. High-Speed Rail has developed steadily across Japan, France, Germany, Italy, Switzerland during the 1970s and 1980s. It expanded to Russia, Spain, the United Kingdom, and Sweden in the 1990s. In the 21st century, China began developing High-Speed Rail on an unprecedented scale, and now has a national network that is longer than the totality of the rest of the world’s High-Speed Rail operations combined. China’s High-Speed Rail operation is exerting a transformative influence on urban form and function. This article synthesizes secondary research results to analyse the impacts of HSR on urbanization. These effects include population redistribution, urban spatial expansion and industrial development. We offer a typol-ogy that considers the urban effects of High-Speed Rail at three spatial levels: the station area, the urban jurisdiction, and the regional agglomeration. When organized through our typology, research findings demonstrate that High-Speed Rail influences urban population size, urban spatial layout and industrial development by changing the acces-sibility of cities. We highlight the processes by which High-Speed Rail ultimately affects the urbanization process for people, land use, and industrial development. However, High-Speed Rail’s impacts on urbanization are not always positive. While leveraging the development opportunity enabled by High-Speed Rail, governments around the world should also avoid potential negative impacts by drawing lessons from the experience of High-Speed Rail’s rapid de-ployment in China.

scholarly journals A Study on the Influence of Tire Speed and Pressure on Measurement Parameters Obtained from High-Speed Tire Uniformity Testing

Vehicles ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 559-573
Author(s):  
Meng Du ◽  
Pengfei Sun ◽  
Shuiting Zhou ◽  
Hongwu Huang ◽  
Jie Zhu
Keyword(s):  
High Speed ◽  
Tangential Force ◽  
Testing Machine ◽  
Lateral Force ◽  
Radial Force ◽  
Signal Acquisition ◽  
Test Machine ◽  
Tire Pressure ◽  
Force Fluctuation ◽  
Uniformity Test

In order to improve the test conditions of the tire uniformity test and the effect of the speed and tire pressure on the uniformity parameters, the uniformity test of the tire under different speeds and tire pressure was carried out by a high-speed uniformity test machine, and the experimental data were analyzed and fitted by the regression analysis method. This paper introduces the definition of uniformity and the uniformity parameters of automotive tires; the working principle of a high-speed uniformity testing machine is briefly described, a mathematical model of the uniformity testing machine is established, and the signal acquisition process of the tire uniformity parameters and the calculation method of the uniformity parameters are described. The test result indicates: As the speed increases, the radial force fluctuation, lateral force fluctuation, tangential force fluctuation, and turning torque fluctuation of the tire increase, and the positive torque fluctuation first increases and then decreases; with the increase of tire pressure, the radial force fluctuation and the tangential force fluctuation of the tire increase, and the lateral force fluctuation, the turning torque fluctuation, and the returning moment fluctuation are all reduced. Compared to the low speed uniformity test, the high speed uniformity test can better reflect the uniformity of the tire, reducing the speed of the vehicle can reduce the radial runout and lateral sway of the tire; increasing the tire pressure can reduce the left and right swing of the vehicle.

Study on contact rolling fatigue of rails (2nd report, A result by high speed rail testing machine)

1985 ◽  
Vol 51 (461) ◽  
pp. 296-301 ◽  
Author(s):  
Shin-ichi NISHIDA ◽  
Kazuo SUGlNO ◽  
Chikayuki URASHIMA ◽  
Hiroki MASUMOTO
Keyword(s):  
High Speed ◽  
Testing Machine ◽  
High Speed Rail

Modelling and experiment of gear hob tooth profile error for relief grinding

2021 ◽  
pp. 095440542110172
Author(s):  
Shuying Yang ◽  
Weifang Chen ◽  
Zhiqiang Wang ◽  
Yanfeng Zhou
Keyword(s):  
Prediction Model ◽  
High Speed ◽  
Tooth Profile ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Feed Speed ◽  
Machining Parameters ◽  
Profile Error ◽  
Mechanical Coupling ◽  
Axial Profile

Gear hob is an important tool that is most used in gear processing. Hob accuracy directly exerts an overwhelming influence on the quality of the processed gear. Generally, the hob tooth profile accuracy is mainly determined by relief grinding process. Studies on tooth profile errors of gear hobs caused by severe friction and cutting with the high-speed rotation of the wheel during the form grinding machining of hobs are limited. Thus, a theoretical model of the tooth profile error prediction under different machining parameters was established based on the analysis of coupling influence of high temperature and high strain rate on gear hobs in the relief grinding process. The model was completed on the basis of the dynamic explicit integral finite element method of thermo-mechanical coupling. Through the prediction model, the influence of the grinding depth ap, feed speed Vw and grinding speed Vs on the tooth profile error can be analysed. In addition, an algorithm for accurately calculate the grinding wheel axial profile by combining instantaneous envelope theory and hob normal tooth profile was proposed. The hob relief grinding experiments were carried out using the proposed grinding wheel profile algorithm. The relative error of the prediction obtained by comparing the calculation results of the prediction model with the experimental results is within 10%. Results prove the validity of the prediction model. This finding is greatly important for optimising the accuracy of hob relief grinding.

Theoretical and Experimental Aspects Concerning Elastic Behavior in the Grinding Technological System

2014 ◽  
Vol 1036 ◽  
pp. 292-297 ◽  
Author(s):  
Sergiu Mazuru ◽  
Maxim Casian
Keyword(s):  
Technological System ◽  
Elastic Behavior ◽  
Grinding Wheel ◽  
Work Piece ◽  
Grinding Process ◽  
Negative Effects ◽  
Gear Grinding ◽  
Processing Errors ◽  
Rotational Direction ◽  
Grinding System

In this paper will be treated the problem of strains and stresses within the connections and elements from the grinding technological system. These system deformations can lead to positive or negative effects. Main negative effects will be occurrence of processing errors on the part profile, but also the excessive tension from system elements. Cause of processing errors and the low safety due of the system rigidity must be sought in its joints between parts, stiffness of moving pieces, low number and reduced rigidity of parts used to assembling (bolts, cotter joints, pins). Elastic properties of the assembly are modeled by the inserted connections with specific characteristics. The elastic deformation of the work piece must be taken into account, besides the elastic behavior of the device which appears in manufacturing process. A very important aspect in the study of elastic behavior of the whole system is how the abrasive tool interacts with the work piece, namely the displacement of contact zone. Contact stresses lead to a deformation of the grinding wheel and the work piece, and as a result the work piece loses from precision of tooth profile. The rigidity of system can be characterized by two aspects, one static and one dynamic and we will describe both aspects using CAE simulations and classical mathematical models. It will be presented some results of numerical simulation of the stiffness of gear grinding system using finite element method (FEM). The elastic dynamic model was design using the forces of inertia and gravity that occurs during grinding process. Also by permanent pursuing of the technological forces variation during the grinding process will be sought the dynamic deformation of the system. The study its concentrated around the low stiffness of components inside the system, in order to find errors that may affect the precision on the horizontal, vertical and rotational direction of technological system elements. Since through this analysis it tried to find how the forces influence on the ETS stiffness, it will present numerical values of the system displacements and stress distribution. Knowing the direction, sense and numerical values of these errors can be made interpretation of the results, namely the removal of these consequences.

Sign in / Sign up

Export Citation Format

Share Document