scholarly journals Dynamic Modelling and Analysis of the Microsegment Gear

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yangshou Xiong ◽  
Kang Huang ◽  
Tao Wang ◽  
Qi Chen ◽  
Rui Xu
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Dynamic Modelling ◽  
Weight Ratio ◽  
Load Condition ◽  
Main Idea ◽  
Heavy Load ◽  
Rotating Speed ◽  
Involute Gear

The development of technology requires higher load capacity, rotating speed, power-weight ratio, lower vibration, and noise with respect to the gear transmission. The new type microsegment gear’s tooth profile curve is composed of many microsegments. Previous researches indicate that the microsegment gear has a good static performance, while the dynamic behavior of the microsegment gear has never been investigated. This paper will focus on the dynamic performance of the gear. The profile deviation between microsegment gear and involute gear is regarded as a displacement excitation in the proposed dynamic model. The numerical analysis for three cases is conducted and the results shows that, in low-speed and heavy-load, medium-speed and medium-load conditions, microsegment gear and involute gear both exhibit a good performance, while, in high-speed and heavy-load condition, microsegment gear has a better performance than that of involute gear. The influence of backlash on the dynamic performance is also studied. It is found that the variation of backlash does not change the type of motion, but the vibration amplitude and the stability of the motion are much affected. The main idea in this paper is supposed to provide a novel method for the precision grinding of the microsegment gear.

scholarly journals A Novel Stick-Slip Nanopositioning Stage Integrated with a Flexure Hinge-Based Friction Force Adjusting Structure

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 765
Author(s):  
Junhui Zhu ◽  
Peng Pan ◽  
Yong Wang ◽  
Sen Gu ◽  
Rongan Zhai ◽  
...  
Keyword(s):  
Friction Force ◽  
High Speed ◽  
Simulation Analysis ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Critical Role ◽  
Vertical Direction ◽  
Flexure Hinge ◽  
Stick Slip ◽  
Static Performance

The piezoelectrically-actuated stick-slip nanopositioning stage (PASSNS) has been applied extensively, and many designs of PASSNSs have been developed. The friction force between the stick-slip surfaces plays a critical role in successful movement of the stage, which influences the load capacity, dynamic performance, and positioning accuracy of the PASSNS. Toward solving the influence problems of friction force, this paper presents a novel stick-slip nanopositioning stage where the flexure hinge-based friction force adjusting unit was employed. Numerical analysis was conducted to estimate the static performance of the stage, a dynamic model was established, and simulation analysis was performed to study the dynamic performance of the stage. Further, a prototype was manufactured and a series of experiments were carried out to test the performance of the stage. The results show that the maximum forward and backward movement speeds of the stage are 1 and 0.7 mm/s, respectively, and the minimum forward and backward step displacements are approximately 11 and 12 nm, respectively. Compared to the step displacement under no working load, the forward and backward step displacements only increase by 6% and 8% with a working load of 20 g, respectively. And the load capacity of the PASSNS in the vertical direction is about 72 g. The experimental results confirm the feasibility of the proposed stage, and high accuracy, high speed, and good robustness to varying loads were achieved. These results demonstrate the great potential of the developed stage in many nanopositioning applications.

scholarly journals Influence of Temperature Effect on the Static and Dynamic Performance of Gas-Lubricated Microbearings

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 716
Author(s):  
Liangliang Li ◽  
Zhufeng Liu ◽  
Chongyu Wang ◽  
Yonghui Xie
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Operating Environment ◽  
Low Friction ◽  
Operating Stability ◽  
Comprehensive Performance ◽  
Different Temperatures ◽  
Dynamic Performances ◽  
The Difference

Gas-lubricated microbearings are widely applied in multiple fields due to their advantages of high-speed, low friction level and other features. The operating environment of microbearings is complex, and the difference of temperature has an important influence on their comprehensive performance. In this investigation, FEM (finite element method) is employed to investigate the static, dynamic and limit characteristics of microbearings lubricated by different kinds of gas at different temperatures. The results show that the rise of temperature leads to the decline of equivalent viscosity of gas, which weakens the load capacity of microbearings, and furthermore, affects the operating stability of microbearings. The dynamic performances of microbearings at different temperatures are very different, and the two dynamic limit characteristics are more sensitive to temperature when it changes.

Dynamics modeling and analysis of a four-wheel independent motor-drive virtual-track train

2020 ◽  
pp. 146441932096401
Author(s):  
Zhonghui Yin ◽  
Jiye Zhang ◽  
Haiying Lu ◽  
Weihua Zhang
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Spatial Dynamics ◽  
Dynamic Responses ◽  
Dynamics Modeling ◽  
Dynamics Model ◽  
Coupling Effects ◽  
Dynamic Interactions ◽  
Modeling And Analysis

Due to urbanisation and the economic challenges of traffic, it is urgently necessary to develop an environmentally friendly virtual-track train with suitable speed, high load capacity and low construction cost in China. To guide the design and evaluate this train’s dynamic behaviour, a spatial-dynamics model has been developed based on the dynamics theory and tyre-road interaction. The proposed dynamics model comprises mechanical vehicle systems, traction and braking characteristics and tyre-road dynamic interactions. The coupling effects amongst those systems of virtual track train are derived theoretically for the first time. The nonlinear characteristics of the tyre are modelled by the transit tyre-magic formula with consideration of road irregularities. Based on a designed PID controller and the comprehensive dynamics model, the dynamic performance of the system can be revealed considering motion coupling effects and complicated excitations, especially under traction and braking conditions. The dynamic responses of whole virtual track train can be obtained by numerical integration under different conditions. The vibration characteristics of such train are assessed under running at a constant speed and during the traction/braking process. The results show that the vibrations of the vehicle system are significantly influenced by road irregularities, especially at high speed ranges. The motions and vibrations of different components are intensive coupled, which should not to be neglected in the dynamics assessment of the virtual track train. Besides, the dynamics model can also be applied to dynamics-related assessment (fatigue, strength and some damage conditions, et al.) and parameter optimisation of the virtual-track train.

Nonlinear dynamic analysis of a microsegment gear system with a time-varying base circle

2020 ◽  
Vol 44 (2) ◽  
pp. 279-293
Author(s):  
Kang Huang ◽  
Fengwei Xu ◽  
Yangshou Xiong ◽  
Meng Sang ◽  
Yong Yi
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
High Speed ◽  
Operating Conditions ◽  
Gear System ◽  
Resonant Peak ◽  
Time Varying ◽  
Heavy Load ◽  
Involute Gear ◽  
Base Circle

A systematic dynamic analysis of a microsegment gear system with a time-varying base circle, time-varying mesh stiffness, and gear backlash is carried out in this paper. By discretizing the meshing process, a six degree-of-freedom nonlinear dynamic model of a microsegment gear pair is established. To study the dynamic response of the microsegment gear and involute gear under various operating conditions, the numerical integration method is adopted. The dynamic transmission error (DTE) of the two gears is analysed in terms of time history charts, phase diagrams, fast Fourier transformation spectra, and Poincaré maps. The effects of support damping and support stiffness on radial vibration are also investigated. Results reveal that, compared with the involute gear system, the microsegment gear system is more stable at the high-speed condition and has a smaller amplitude of DTE under medium-speed and heavy-load, high-speed, and heavy-load conditions. The support damping and support stiffness have great effects on the resonant peak in the radial direction of the microsegment gear. Both the proposed model and numerical results are expected to provide a useful source of reference for the dynamic design of the microsegment gear system.

A dynamic modeling approach for the winding spindle during start-up with a coupled flexible support system

2019 ◽  
Vol 90 (7-8) ◽  
pp. 757-775
Author(s):  
Yongxing Wang ◽  
Lijun Zhang ◽  
Xi Hou ◽  
Jiang Yan ◽  
Shujia Li ◽  
...  
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Dynamic Performance ◽  
Beam Theory ◽  
Filament Winding ◽  
Heavy Load ◽  
Frequency Dependent ◽  
Spindle System ◽  
Start Up ◽  
Deep Groove

A polyester filament winding spindle is the most complex winding rotor system, due to its high speed, heavy load, and frequency-dependent parameters; furthermore, the spindle's rotating speed constantly changes and it is continually crossing the critical speed points. This paper presents an approach to establish the finite element model of the winding spindle to predict its dynamic behavior characteristics during start-up. Firstly, three finite element models of the discrete single component were developed based on the Timoshenko beam theory. The bending, transverse shear effect, and gyroscopic moment were considered in these models. The flexible supporting system, which consists of a deep groove ball bearing and several rubber O-rings, is simplified by a nonlinear spring and damper. Its frequency-dependent dynamic supporting parameters are identified by experiment. Secondly, a fully dynamic model of the polyester winding spindle system, which consists of the cantilever supporting arm, shaft, and sleeve, as well as the flexible and rigid coupling elements, was established. Thirdly, the Newmark method was used to develop a program for solving the dynamic equations of the spindle system in MATLAB®. Based on the model of the spindle system and the computation program, the effects of the supporting stiffness, damping, and start-up time on the spindle's unbalanced response were investigated. The results indicate that the model of the spindle system presented in this paper is suitable for the prediction of the dynamic performance during its start-up.

Study on Dynamic Characteristic of 64m Railway Steel Truss Bridge on Expanding Heavy-Load Transport Condition

2011 ◽  
Vol 90-93 ◽  
pp. 1100-1105
Author(s):  
Zhi Jie Sun ◽  
Jun Min Shen ◽  
Jian Bin Zhao ◽  
Zhong Ming Su
Keyword(s):  
Dynamic Performance ◽  
Load Condition ◽  
Vertical Acceleration ◽  
Performance Parameters ◽  
Heavy Load ◽  
Double Line ◽  
Truss Bridges ◽  
Conventional Condition ◽  
Steel Truss ◽  
Steel Truss Bridges

Through theoretical calculation, systemic analysis of dynamic performance of the 64m single and double line railway steel truss bridges on the expanding condition and conventional condition. Contrast and analysis the main dynamic performance parameters of bridges on the two kinds of operating condition. In 64m steel truss bridges of Shuozhou-Huanghuagang Railway application practice proves that on expanding heavy-load condition, the main dynamic performance parameters of bridges are slightly larger than conventional condition, but the variation law of vertical acceleration of mid-span is different.

Application of Water-Lubricated Bearings in Motorized Centrifugal Air Compressor for Fuel Cell Automotives

2014 ◽  
Vol 670-671 ◽  
pp. 920-923 ◽  
Author(s):  
Ming Feng ◽  
Tian Ming Ren
Keyword(s):  
High Speed ◽  
Proton Exchange Membrane ◽  
High Efficiency ◽  
Load Capacity ◽  
Pressure Ratio ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Air Compressor ◽  
Rotating Speed ◽  
New Energy

Proton exchange membrane (PEM) fuel cells intended for new energy automotives require a high efficiency and reliability motorized compressor to supply pressurized air. This paper presents a study and development of a motorized centrifugal air compressor using water-lubricated bearings. Comparing the performance of water-lubricated bearing with gas-lubricated bearing, we found that under the same power consumption the load capacity of water-lubricated bearings are more suitable for high speed motorized compressor system. A prototype was built and tested to verify the possibility of the developed motorized centrifugal air compressor. The results show that the system can operate at a stable rotating speed up to 80,000 rpm. The flow rate of the pressurized air is 350Kg/h and pressure ratio is 1.52 at 60,000 rpm, with a global efficiency of approximately 80%.

scholarly journals The Mechanical Properties Analysis of Machine Tool Spindle After Remanufacturing Based on Uncertain Constraints

2015 ◽  
Vol 9 (1) ◽  
pp. 150-155 ◽  
Author(s):  
Ling Liu
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Beam Theory ◽  
Optimized Design ◽  
Cnc Machine ◽  
Element Analysis ◽  
Heavy Load ◽  
Spindle System ◽  
Machine Spindle ◽  
The Cost

In this paper, the CNC machine spindle after remanufacturing is researched as an object on uncertain constraints. At first, the equations of the machine spindle motion based on beam theory are established. This article uses Finite Element Analysis (FEA) function to analyze the remanufacturing of machine spindle system in the free mode and while static and the actual working conditions of multi-modal analysis of the spindle’s constraints state. By analysis it is known that the spindle vibrates and deforms at high speeds, and some assumptions are used to improve the unreasonable parameters, so that the spindle’s dynamic performance is more stable and reliable in the conditions of the high speed and heavy load operation. In addition, simplifying the cost and shortening the design cycle are the part of the analysis. The results provides an optimized design and a basis for precision control for the heavy-duty mechanical spindle system or machine spindle system.

Modeling and Analysis of Micro Hybrid Gas Spiral-Grooved Thrust Bearing for Microengine

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Xiao-Qing Zhang ◽  
Xiao-Li Wang ◽  
Ren Liu ◽  
Yu-Yan Zhang
Keyword(s):  
Thrust Bearing ◽  
Load Capacity ◽  
Perturbation Technique ◽  
Dynamic Performance ◽  
Mems Devices ◽  
Modeling And Analysis ◽  
Rotating Speed ◽  
Power Mems ◽  
Hybrid Bearing ◽  
Rarefaction Effects

The micro hybrid spiral-grooved thrust bearing is a promising candidate to support the rotating elements in power MEMS devices such as micro gas turbine engines. However, the realization of hybrid thrust bearings has encountered a number of technical challenges due to the very high rotating speed and DN number (the product of the inner diameter and the rotational speed of the bearing, mm · rpm) to achieve high power density, the super thin gas film between rotors and thrust pad, and the relative large fabrication uncertainties according to the imperfection of the fabrication technology. In this paper, the configuration of a micro hybrid spiral-grooved thrust bearing for power MEMS is designed, and the steady and dynamic characteristics of this kind of bearing are then analyzed comprehensively, with the consideration of both the rarefaction effects and the influence of potential microfabrication defects. The nonlinear equations of molecular gas-film lubrication describing the gas rarefaction effects in a micro hybrid bearing are discretized by the finite volume method and solved by the Newton–Raphson techniques. The small perturbation technique is employed to study the dynamic behavior of a micro hybrid bearing. The results show that the micro hybrid thrust bearing exhibits better steady-state and dynamic performance than the existing micro hydrodynamic and hydrostatic bearings and that the hybrid bearings are likelier to be stable than their hydrodynamic counterparts, especially when the frequency number is high. The load capacity of the micro hybrid bearing increases slightly with the number of orifices and gradually with the diameter ratio of the orifice. The microfabrication defects of clogged orifices could lessen the load capacity and the dynamic coefficients of the hybrid thrust bearing. The model developed in this paper can serve as a useful tool to provide insight into micro hybrid gas thrust bearing-rotor systems.

A high-speed rolling bearing test rig supported by sliding bearing

2020 ◽  
Vol 72 (7) ◽  
pp. 955-959
Author(s):  
Hui Li ◽  
Heng Liu ◽  
Shemiao Qi ◽  
Yi Liu
Keyword(s):  
Service Life ◽  
Peer Review ◽  
High Speed ◽  
Load Capacity ◽  
Rolling Bearing ◽  
Test Rig ◽  
Sliding Bearing ◽  
Content Type ◽  
Rotating Speed ◽  
Operating Stability

Purpose The purpose of this paper is to introduce a high-speed rolling bearing test rig supported by sliding bearing and its first experimental results. Design/methodology/approach Through analyzing the disadvantages of using rolling bearing as supporting bearing, the bottlenecks that need to be resolved urgently in the development of rolling bearing experimental technology, and the advantages of the sliding bearing, this study used the sliding bearing as the supporting bearing for the high-speed rolling bearing test rig for the purpose of prolonging the service life, increasing the load capacity and promoting the operating stability. Findings The experimental results show that the high-speed rolling bearing test rig supported by sliding bearing could stably rotate at 70,800 rpm without installing the test bearing; the temperature of the sliding bearing is increasing with the rotating speed and the maximum is less than 95°C. Moreover, the new test rig, installing an angular contact ball bearing as test bearing, could also stably rotate at 54,000 rpm with 2 kN axial load and 1 kN radial load; the temperature of the sliding bearing is increasing with the rotating speed and the maximum temperature is less than 97°C. Practical implications Rolling test rig has been established. Originality/value This paper proposes a high-speed rolling bearing test rig supported by sliding bearing, which greatly prolongs the service life, increases the load capacity and promotes the operating stability, moreover, reduces the risk of supporting bearing failure before the test bearing. This paper can also provide a new idea and reference for the design of similar bearing test rig. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0085/

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