The Experts below are selected from a list of 108 Experts worldwide ranked by ideXlab platform
Xiaolu Zhao - One of the best experts on this subject based on the ideXlab platform.
-
Design and control of a directly-driven bond head for thermosonic bonding
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2010Co-Authors: Fei-yue Wang, Xiaolu Zhao, Da Wei ZhangAbstract:AbstractThis article presents a high-acceleration rotary bond head to improve the efficiency and precision of thermosonic bonding. The bond head is direct driven by a rotary voice coil actuator, and Needle Roller Bearings are adopted as the rotary connection parts. Using the finite-element analysis and experiment tests, the dynamic characteristics of the bond head were investigated. The results indicate that the vibrations of the bond head have negative influences on the bonding process and the ultrasonic transducer system. They can reduce the efficiency of the ultrasonic energy transmission and even result in the bonder working abnormally. To avoid these vibration modes, high-frequency harmonic components of the driving signals were eliminated by adding a notch filter to the control system. Considering the remnant vibrations during high-frequency starts and stops, friction compensation and proportion integration differentiation (PID) feedback control with anti-windup correction were adopted. The controll...
-
Design and control of a directly-driven bond head for thermosonic bonding
2009Co-Authors: Xiaolu Zhao, D ZhangAbstract:Abstract: This articlepresents ahigh-acceleration rotarybondhead to improve theefficiencyand precision of thermosonic bonding. The bond head is direct driven by a rotary voice coil actuator, and Needle Roller Bearings are adopted as the rotary connection parts. Using the finite-element analysis and experiment tests, the dynamic characteristics of the bond head were investigated. The results indicate that the vibrations of the bond head have negative influences on the bonding process and the ultrasonic transducer system. They can reduce the efficiency of the ultrasonic energy transmission and even result in the bonder working abnormally. To avoid these vibration modes, high-frequency harmonic components of the driving signals were eliminated by adding a notch filter to the control system. Considering the remnant vibrations during high-frequency starts and stops, friction compensation andproportion integrationdifferentiation (PID) feedback controlwithanti-windupcorrectionwereadopted.ThecontRollerwasdesignedandco-simulated by using MATLAB and MSC.ADAMS software. The co-simulation and experiment results show that the bond head provides for good performances
D Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Design and control of a directly-driven bond head for thermosonic bonding
2009Co-Authors: Xiaolu Zhao, D ZhangAbstract:Abstract: This articlepresents ahigh-acceleration rotarybondhead to improve theefficiencyand precision of thermosonic bonding. The bond head is direct driven by a rotary voice coil actuator, and Needle Roller Bearings are adopted as the rotary connection parts. Using the finite-element analysis and experiment tests, the dynamic characteristics of the bond head were investigated. The results indicate that the vibrations of the bond head have negative influences on the bonding process and the ultrasonic transducer system. They can reduce the efficiency of the ultrasonic energy transmission and even result in the bonder working abnormally. To avoid these vibration modes, high-frequency harmonic components of the driving signals were eliminated by adding a notch filter to the control system. Considering the remnant vibrations during high-frequency starts and stops, friction compensation andproportion integrationdifferentiation (PID) feedback controlwithanti-windupcorrectionwereadopted.ThecontRollerwasdesignedandco-simulated by using MATLAB and MSC.ADAMS software. The co-simulation and experiment results show that the bond head provides for good performances
Da Wei Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Design and control of a directly-driven bond head for thermosonic bonding
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2010Co-Authors: Fei-yue Wang, Xiaolu Zhao, Da Wei ZhangAbstract:AbstractThis article presents a high-acceleration rotary bond head to improve the efficiency and precision of thermosonic bonding. The bond head is direct driven by a rotary voice coil actuator, and Needle Roller Bearings are adopted as the rotary connection parts. Using the finite-element analysis and experiment tests, the dynamic characteristics of the bond head were investigated. The results indicate that the vibrations of the bond head have negative influences on the bonding process and the ultrasonic transducer system. They can reduce the efficiency of the ultrasonic energy transmission and even result in the bonder working abnormally. To avoid these vibration modes, high-frequency harmonic components of the driving signals were eliminated by adding a notch filter to the control system. Considering the remnant vibrations during high-frequency starts and stops, friction compensation and proportion integration differentiation (PID) feedback control with anti-windup correction were adopted. The controll...
Fei-yue Wang - One of the best experts on this subject based on the ideXlab platform.
-
Design and control of a directly-driven bond head for thermosonic bonding
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2010Co-Authors: Fei-yue Wang, Xiaolu Zhao, Da Wei ZhangAbstract:AbstractThis article presents a high-acceleration rotary bond head to improve the efficiency and precision of thermosonic bonding. The bond head is direct driven by a rotary voice coil actuator, and Needle Roller Bearings are adopted as the rotary connection parts. Using the finite-element analysis and experiment tests, the dynamic characteristics of the bond head were investigated. The results indicate that the vibrations of the bond head have negative influences on the bonding process and the ultrasonic transducer system. They can reduce the efficiency of the ultrasonic energy transmission and even result in the bonder working abnormally. To avoid these vibration modes, high-frequency harmonic components of the driving signals were eliminated by adding a notch filter to the control system. Considering the remnant vibrations during high-frequency starts and stops, friction compensation and proportion integration differentiation (PID) feedback control with anti-windup correction were adopted. The controll...
Iqbal Shoaib - One of the best experts on this subject based on the ideXlab platform.
-
Energy Analysis of High-Dynamic Components: Model Development and Experimental Evaluation for Needle Roller Bearings and Wet Clutches
2014Co-Authors: Iqbal ShoaibAbstract:In recent years, there has been a growing concern regarding the increasing prices and requirements of energy around the globe. One of the largest and cost effective ways to tackle this issue is by improving the energy efficiency of components/systems. This leads to a reduced total cost of ownership of machines, lower fossil fuel dependency and reduced greenhouse gas emissions.In this thesis two critical high-dynamic components, namely Bearings and wet clutches are subjected to detailed energy analysis. Bearings are commonly used component in machines/systems, whereas the wet clutches find application in most of the transmission devices. In addition, these components are considered as significant contributors to the overall energy losses in machines/systems. In view of the critical nature of these two components with regard to energy losses, research is still ongoing to understand the loss mechanisms and to improve the energy efficiency of these components.The Needle Roller bearing lubricated with a solid-grease is popularly used in applications where there is a demand for high load-carrying capacity, low space requirements and where access to Bearings are difficult for maintenance purpose. Nevertheless an appropriate model for calculating the energy losses in Needle Roller Bearings lubricated with solid-grease does not exist. In case of the wet clutch, the mechanisms causing energy losses differ according to the state (engaged or disengaged) of the clutch. When a wet clutch undergoes engagement, the frictional effect (asperity contact torque) is mostly dominant and governs the energy losses. On the other hand, when the wet clutch is in disengaged condition, the viscous effect responsible for producing drag torque is considered as energy loss. The energetic behavior of wet clutches can be examined through modeling and dedicated experiments. For modeling wet clutch engagement cycles, the required characteristics/parameters of the friction model for capturing the dynamic friction phenomena along with the realization of variation in normal force as well as ATF (automatic transmission fluid) temperature observed in wet clutches are unknown. On the other hand, the existing models as well as the experimental data related to drag torque in disengaged wet clutches do not consider the real operating conditions such as variable ATF flow rate and rotational states of the disks for the higher clutch speed range.To overcome these short-comings, this thesis aims to study the energy losses in these two critical components through model development and experimental characterization. This work is helpful in building energy efficient machines/systems.The first contribution redefines the parameters of the Palmgren and SKF® models for predicting power losses in Needle Roller Bearings lubricated with solid-grease. The updated models are applicable for both constant and varying speed profiles under constant loading conditions. In addition, a generic methodology has been proposed in order to verify and update the state-of-the-art models for predicting the power losses of any bearing type with any lubrication condition.The second contribution proposes an extended Reset-Integrator friction model for investigating the energetic (power and energy flow) behavior of wet clutches. The adaptation includes the experimentally determined stribeck function, viscous effect and the delay in actuation pressure signal. The friction torque generated by the extended model is dependent on the relative velocity, normal load and the ATF temperature. The model is validated with experimental results in both the time and the frequency domain. The developed model can also be used to study wet clutch vibration characteristics. By further analyzing the sets of experimental results, it is confirmed that the amplitude of shudder vibration is independent of the amplitude of applied contact pressure fluctuation. The third contribution through experiments and modeling provides a global view on the performance and energetic behavior of wet clutches with degradation and different initial driving energy levels. For this purpose, experiments are performed using an advanced SAE#2 test setup designed and built by our industrial collaborator, Dana Spicer Off Highway, Belgium. The simulation model incorporates an existing adapted form of the GMS friction model (for studying effects of degradation) and the developed extended Reset-Integrator friction model (for studying effects of initial driving energy levels). On the basis of the obtained results, some important conclusions are drawn regarding the design aspects of wet clutches such as COF (coefficient of friction), engagement duration, engagement torque, power and energy.Experimental characterization of drag torque in disengaged wet clutches is carried out, constituting a fourth contribution. For this purpose, experiments are performed using an advanced SAE#2 test setup designed and built by our industrial collaborator, Dana Spicer Off Highway, Belgium considering real operating conditions of wet clutches. By analyzing the obtained experimental results, the relationship between the amount by which the parameters such as ATF flow rate, ATF temperature, disk size and disks rotational states are varied and the corresponding change in the drag torque is established. In addition, a general description of the qualitative behavior of the drag torque in function of clutch speed is proposed and the associated physical phenomena are explained.A mathematical model based on continuity and Navier-Stokes equations, considering laminar flow in the gap between the disks, is developed as the fifth contribution to estimate the drag torque in disengaged wet clutches. The model validation results suggest that the model is capable of predicting the drag torque under real clutch conditions of variable flow rate and disks rotation states for the higher clutch speedrange.status: publishe
-
Frictional power loss in solid-grease lubricated Needle Roller bearing
'Wiley', 2012Co-Authors: Iqbal Shoaib, Al-bender Farid, Croes Jan, Pluymers Bert, Desmet WimAbstract:The use of solid grease as a lubricant, in comparison with standard grease or oil, is a pre-requisite when Needle Roller Bearings undergo a high-speed oscillating motion and when access to the bearing is difficult for maintenance purposes. This paper examines the frictional power loss of a solid-grease-lubricated Needle Roller bearing. First set of measurement result reveals that the test bearing has higher frictional power loss as compared with other Bearings with conventional lubrications, due to the high viscosity of the solid grease. Furthermore, measurements are compared with the Palmgren and SKF models. For improving these models, the parameters of the models are updated on the basis of the measurement data. A second set of measurement result shows that the use of oil (kept at higher temperature) in addition to solid grease significantly reduces the frictional power loss. The reduction is due to the decrease in operational viscosity of the solid grease. Copyright © 2012 John Wiley & Sons, Ltd.status: publishe
