Recent Patents for the Motorized Spindle Preload Mechanism

2021 ◽  
Vol 13 ◽  
Author(s):  
Ye Dai ◽  
Wan-Jian Wen ◽  
Li-Yu Xuan ◽  
Xiao-Yang Yu ◽  
Gang Wang
Keyword(s):  
Working Conditions ◽  
High Efficiency ◽  
Dynamic Performance ◽  
Machining Accuracy ◽  
Hydraulic Pressure ◽  
Motorized Spindle ◽  
Existing Problems ◽  
Advantages And Disadvantages ◽  
High Level ◽  
Structural Research

Background: The motorized spindle preload technology is one of the motorized spindle key technologies, and adjusting the preload according to the working conditions can effectively improve the dynamic performance of the motorized spindle and enhance the machining accuracy. Objectives: Review the preload mechanism development, introduce various preload mechanisms, and show research status in recent years. Then to explore and predict the future development of preload technology through the analysis of the overall preload mechanism. Methods: Search for different kinds of patents and literature about spindle preload structure in recent years. Through structural research and comparison with the traditional preload mechanism, to review the structure principle of various preload mechanisms at the present stage, then shown the advantages and disadvantages of each structure. Result: According to the patents and research of the preload mechanism in recent years, classification introduced the piezoelectric ceramic preload device, electromagnetic preload device, and hydraulic preload device, and so on. Introduce their advantages and existing problems in detail, then comprehensively compare the advantages and disadvantages of various mechanisms in control and mechanism. Finally, discuss the prospects and development directions of preload technology. Conclusion: With the further development of technology, high-precision products have higher requirements for machine tools, such as low latency, low heat generation, high efficiency, and long life. People use electromagnetic force, air pressure, hydraulic pressure, and other methods, to control the magnitude of the preload, maintain the performance of the motorized spindle at a high level. Compared with the traditional quantitative preload, their applicable working conditions are more extensive and accuracy is higher. However, various new preload methods still have certain shortcomings and need further improvement.

Multi-Axis Spiral Tool Path Generation for Aviation Blade Numerical Control Machining

2014 ◽  
Vol 496-500 ◽  
pp. 1535-1538
Author(s):  
Yan Cao ◽  
Zhi Jie Wang ◽  
Yu Bai
Keyword(s):  
Tool Path ◽  
High Efficiency ◽  
Contact Point ◽  
Numerical Control ◽  
Free Form ◽  
Machining Accuracy ◽  
Numerical Control Machining ◽  
Advantages And Disadvantages ◽  
Spiral Tool Path ◽  
Low Efficiency

Aiming at the low machining accuracy, low efficiency, cumbersome programming process, strong empirism and great programming difficulty of special shape blades, a new NC spiral milling method of high-quality and high-efficiency is put forward to process aviation blades. Three methods of constructing spiral tool path are studied, i.e., constructing the spiral using interpolation in parametric domain, constructing the spiral based on a driving surface and projection technology, and segmentally constructing the spiral by plane intersection. By comparison and analysis, their advantages and disadvantages are presented. According to the characteristics of spiral milling, the principles and algorithms of interference-free cutter location calculation for space free-form curved surface are introduced and the focus is put on cutter contact point calculation algorithms.

scholarly journals Measurement Research of Motorized Spindle Dynamic Stiffness under High Speed Rotating

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaopeng Wang ◽  
Yuzhu Guo ◽  
Tianning Chen
Keyword(s):  
High Speed ◽  
Production Efficiency ◽  
Dynamic Stiffness ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Machining Accuracy ◽  
Motorized Spindle ◽  
Response Curves ◽  
Tool Technology ◽  
High Speed Machine

High speed motorized spindle has become a key functional unit of high speed machine tools and effectively promotes the development of machine tool technology. The development of higher speed and more power puts forward the stricter requirement for the performance of motorized spindle, especially the dynamic performance which affects the machining accuracy, reliability, and production efficiency. To overcome the problems of ineffective loading and dynamic performance measurement of motorized spindle, a noncontact electromagnetic loading device is developed. The cutting load can be simulated by using electromagnetic force. A new method of measuring force by force sensors is presented, and the steady and transient loading force could be measured exactly. After the high speed machine spindle is tested, the frequency response curves of the spindle relative to machine table are collected at 0~12000 rpm; then the relationships between stiffness and speeds as well as between damping ratio and speeds are obtained. The result shows that not only the static and dynamic stiffness but also the damping ratio declined with the increase of speed.

Design and Analysis of a Sawing-Milling Compound Machining Center for Special-Shaped Stone Products

2014 ◽  
Vol 610 ◽  
pp. 123-128
Author(s):  
Do Hong Zhao ◽  
Jing Sun ◽  
Ke Zhang ◽  
Yu Hou Wu ◽  
Feng Lu
Keyword(s):  
High Efficiency ◽  
Dynamic Performance ◽  
Processing Technology ◽  
Machining Accuracy ◽  
Processing Capacity ◽  
Under Five ◽  
Machining Center ◽  
Simultaneous Control ◽  
Five Axis ◽  
Better Than

Nowadays, the equipment for processing special-shaped stone products is developing towards high efficiency, intelligent and multifunction. Based on the features of stone processing technology, a sawing-milling compound machining center with eight axes and double five-axis simultaneous control for special-shaped stone products was designed. The dynamic performance and processing capacity were tested. Research shows that the sawing and milling compound machining in the same horizontal slide saddle is practicable. This machine can realize both vertical and horizontal machining under five-axis simultaneous control, and its machining accuracy is better than the normal industrial standard.

scholarly journals Buck-Boost Single-Stage Microinverter for Building Integrated Photovoltaic Systems

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7854
Author(s):  
Derick Mathew ◽  
Mohamed Emad Farrag ◽  
Rani Chinnappa Naidu ◽  
Rajesh Kumar Muthu ◽  
A Sivaprakasam ◽  
...  
Keyword(s):  
Single Phase ◽  
High Efficiency ◽  
Harmonic Distortion ◽  
Experimental System ◽  
Optimal Number ◽  
Single Stage ◽  
Passive Components ◽  
Advantages And Disadvantages ◽  
Building Integrated Photovoltaic ◽  
High Level

Microinverters for Building Integrated Photovoltaic (BIPV) systems must have had a small number of components, be efficient, and be reliable. In this context, a single-phase Buck-Boost Single-stage Microinverter (BBSM) for grid-connected BIPV systems is presented. The concept of topology is extracted from the buck-boost converter. The leakage current in the system is kept under control. It uses an optimal number of active and passive components to function at a high-efficiency level. The suggested topology provides a high level of reliability due to the absence of shoot-through problems. To validate the findings, a simulation in combination with an experimental system for a 70 W system is developed with the design approach. The efficiency of the microinverter, total harmonic distortion of the grid current are measured as 96.4% and 4.09% respectively. Finally, a comparison study has indicated the advantages and disadvantages of the suggested inverter.

Influence of negative aff ectivity, social suppression and anxiety on motivation for health and a healthy lifestyle in coal industry workers

2020 ◽  
pp. 354-358
Author(s):  
I. P. Danilov ◽  
N. I. Vlakh ◽  
V. I. Gugushvili ◽  
N. Ya. Paneva ◽  
T. D. Logunova
Keyword(s):  
Working Conditions ◽  
Occupational Diseases ◽  
Healthy Lifestyle ◽  
Coal Industry ◽  
Type D ◽  
Situational Anxiety ◽  
Personal Anxiety ◽  
High Level ◽  
Level Of Motivation ◽  
Social Suppression

Introduction. A healthy lifestyle is one of the most eff ective methods of preserving health and preventing non-infectious diseases. The mechanisms and factors that infl uence the formation of motivation for health and a healthy lifestyle in employees engaged in harmful working conditions have not been suffi ciently studied. The study of these mechanisms will allow us to more eff ectively shape health-saving behavior.The aim of the study is to study negative aff ectivity, social suppression and anxiety in the formation of motivation to maintain health and a healthy lifestyle in coal industry workers.Materials and methods. A survey was conducted of 75 employees of mines and sections in the South of Kuzbass with an established diagnosis of occupational diseases, as well as 54 people who do not work in harmful working conditions (engineering and technical workers). Surveys were conducted using the method “Index of motivation to health and a healthy lifestyle”, the presence of personality type D was conducted using the DS14 questionnaire, the level of personal and situational anxiety was assessed using the Spielberger — Hanin questionnaire.Results. Th e level of motivation for health and a healthy lifestyle among patients with occupational diseases is signifi cantly lower than the level of motivation for the health of engineering and technical workers. Th e infl uence of negative reaction and social suppression on the level of motivation for health and a healthy lifestyle was not found. Th e level of situational anxiety also has no eff ect on health motivation. A higher level of personal anxiety among people with a high level of motivation for a healthy lifestyle was determined.Conclusions. Personal anxiety aff ects the level of motivation for health and a healthy lifestyle in people with occupational diseases. 

Assessment of professional risk of health of workers of the enterprise for repair of railway carriage

2020 ◽  
pp. 9-19
Author(s):  
O. Klepikov ◽  
A. Boreyko ◽  
G. Kurenkova
Keyword(s):  
Relative Risk ◽  
Working Conditions ◽  
Light Level ◽  
Occupational Risk ◽  
Rolling Stock ◽  
Joint Stock Company ◽  
Stock Company ◽  
Production Factors ◽  
Object Of Study ◽  
High Level

The aim of the study was to assess the professional risk of developing diseases in workers of the railway car repair enterprise. The Voronezh Car Repair Plant, a branch of Vagonremmash Joint-Stock Company, was chosen as the object of study. Methods: «The methodology for calculating individual occupational risk depending on the working conditions and the health status of the employee», developed by the Klin Institute for Protection and Working Conditions in conjunction with the Research Institute of Occupational Medicine (2013), the main professions; cohort study with the calculation of the relative risk of morbidity with temporary disability, the odds ratio, the etiological share of factors in the formation of morbidity (group size: 250 people, experimental group — workers of the main specialties, 95 people — comparison group). Results. According to the research results, the priority factors of occupational health risk include: chemical, noise, heating microclimate, low light level. For certain professions, the share of the contribution of priority factors to the risk profile (PV) reaches 40 %. The indicator of individual occupational risk is 0.12 to 0.26 units. The high level of professional risk (0.22 ÷ 0.26) is characterized by the working conditions of the mechanics for the repair of rolling stock, machine tools (woodworking), casters (metal), thermists, plastic casters. In professional groups with medium and high risk, the indicator of the relative risk of morbidity with temporary disability is higher than 1 (RR = 1.75 and 1.39, respectively), and the etiological share of production factors in the formation of diseases is from 27.95 (subgroup with secondary professional risk) up to 42.88 % (a subgroup with high professional risk), which indicates the professional condition of the disease. Discussion. In general, our data are consistent with the results of similar studies conducted earlier at the car building and car repair enterprises. In order to ensure hygienically safe working conditions and preserve the health of workers, it is necessary to reduce the level of exposure to production factors, including through the introduction of modern equipment and improvement of technological processes.

Trends in Diagnosis for Active Tuberculosis Using Nanomaterials

2019 ◽  
Vol 26 (11) ◽  
pp. 1946-1959 ◽  
Author(s):  
Le Minh Tu Phan ◽  
Lemma Teshome Tufa ◽  
Hwa-Jung Kim ◽  
Jaebeom Lee ◽  
Tae Jung Park
Keyword(s):  
Sensitivity And Specificity ◽  
High Efficiency ◽  
Point Of Care ◽  
High Sensitivity ◽  
Signs And Symptoms ◽  
Diagnostic Methods ◽  
Advantages And Disadvantages ◽  
Treatment And Prevention ◽  
Clinical Tools ◽  
Diagnostic Applications

Background:Tuberculosis (TB), one of the leading causes of death worldwide, is difficult to diagnose based only on signs and symptoms. Methods for TB detection are continuously being researched to design novel effective clinical tools for the diagnosis of TB.Objective:This article reviews the methods to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods based on nanomaterials.Methods:The current methods for TB diagnosis were reviewed by evaluating their advantages and disadvantages. Furthermore, the trends in TB detection using nanomaterials were discussed regarding their performance capacity for clinical diagnostic applications.Results:Current methods such as microscopy, culture, and tuberculin skin test are still being employed to diagnose TB, however, a highly sensitive point of care tool without false results is still needed. The utilization of nanomaterials to detect the specific TB biomarkers with high sensitivity and specificity can provide a possible strategy to rapidly diagnose TB. Although it is challenging for nanodiagnostic platforms to be assessed in clinical trials, active TB diagnosis using nanomaterials is highly expected to achieve clinical significance for regular application. In addition, aspects and future directions in developing the high-efficiency tools to diagnose active TB using advanced nanomaterials are expounded.Conclusion:This review suggests that nanomaterials have high potential as rapid, costeffective tools to enhance the diagnostic sensitivity and specificity for the accurate diagnosis, treatment, and prevention of TB. Hence, portable nanobiosensors can be alternative effective tests to be exploited globally after clinical trial execution.

scholarly journals A survey: which features are required for dynamic visual simultaneous localization and mapping?

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Zewen Xu ◽  
Zheng Rong ◽  
Yihong Wu
Keyword(s):  
Simultaneous Localization And Mapping ◽  
Dynamic Environments ◽  
Visual Features ◽  
Advantages And Disadvantages ◽  
Intelligent Robots ◽  
Localization And Mapping ◽  
High Level ◽  
Static World ◽  
Robotic Applications ◽  
Significant Attention

AbstractIn recent years, simultaneous localization and mapping in dynamic environments (dynamic SLAM) has attracted significant attention from both academia and industry. Some pioneering work on this technique has expanded the potential of robotic applications. Compared to standard SLAM under the static world assumption, dynamic SLAM divides features into static and dynamic categories and leverages each type of feature properly. Therefore, dynamic SLAM can provide more robust localization for intelligent robots that operate in complex dynamic environments. Additionally, to meet the demands of some high-level tasks, dynamic SLAM can be integrated with multiple object tracking. This article presents a survey on dynamic SLAM from the perspective of feature choices. A discussion of the advantages and disadvantages of different visual features is provided in this article.

scholarly journals Experimental Investigation and Comparison of the Thermal Performance of Additively and Conventionally Manufactured Heat Exchangers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 574
Author(s):  
Ana Vafadar ◽  
Ferdinando Guzzomi ◽  
Kevin Hayward
Keyword(s):  
Surface Roughness ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Experimental Studies ◽  
Manufacturing Method ◽  
Industrial Sectors

Air heat exchangers (HXs) are applicable in many industrial sectors because they offer a simple, reliable, and cost-effective cooling system. Additive manufacturing (AM) systems have significant potential in the construction of high-efficiency, lightweight HXs; however, HXs still mainly rely on conventional manufacturing (CM) systems such as milling, and brazing. This is due to the fact that little is known regarding the effects of AM on the performance of AM fabricated HXs. In this research, three air HXs comprising of a single fin fabricated from stainless steel 316 L using AM and CM methods—i.e., the HXs were fabricated by both direct metal printing and milling. To evaluate the fabricated HXs, microstructure images of the HXs were investigated, and the surface roughness of the samples was measured. Furthermore, an experimental test rig was designed and manufactured to conduct the experimental studies, and the thermal performance was investigated using four characteristics: heat transfer coefficient, Nusselt number, thermal fluid dynamic performance, and friction factor. The results showed that the manufacturing method has a considerable effect on the HX thermal performance. Furthermore, the surface roughness and distribution, and quantity of internal voids, which might be created during and after the printing process, affect the performance of HXs.

scholarly journals Distributed Simulation Platforms and Data Passing Tools for Natural Hazards Engineering: Reviews, Limitations, and Recommendations

2021 ◽  
Author(s):  
Lichao Xu ◽  
Szu-Yun Lin ◽  
Andrew W. Hlynka ◽  
Hao Lu ◽  
Vineet R. Kamat ◽  
...  
Keyword(s):  
Natural Hazards ◽  
Data Exchange ◽  
Distributed Simulation ◽  
Distributed Data ◽  
Interactive Simulation ◽  
Integrated Simulation ◽  
Domain Specific ◽  
Advantages And Disadvantages ◽  
High Level ◽  
Data Passing

AbstractThere has been a strong need for simulation environments that are capable of modeling deep interdependencies between complex systems encountered during natural hazards, such as the interactions and coupled effects between civil infrastructure systems response, human behavior, and social policies, for improved community resilience. Coupling such complex components with an integrated simulation requires continuous data exchange between different simulators simulating separate models during the entire simulation process. This can be implemented by means of distributed simulation platforms or data passing tools. In order to provide a systematic reference for simulation tool choice and facilitating the development of compatible distributed simulators for deep interdependent study in the context of natural hazards, this article focuses on generic tools suitable for integration of simulators from different fields but not the platforms that are mainly used in some specific fields. With this aim, the article provides a comprehensive review of the most commonly used generic distributed simulation platforms (Distributed Interactive Simulation (DIS), High Level Architecture (HLA), Test and Training Enabling Architecture (TENA), and Distributed Data Services (DDS)) and data passing tools (Robot Operation System (ROS) and Lightweight Communication and Marshalling (LCM)) and compares their advantages and disadvantages. Three specific limitations in existing platforms are identified from the perspective of natural hazard simulation. For mitigating the identified limitations, two platform design recommendations are provided, namely message exchange wrappers and hybrid communication, to help improve data passing capabilities in existing solutions and provide some guidance for the design of a new domain-specific distributed simulation framework.

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