Force Reduction by Motion Design in Spring-Loaded Cam Mechanisms

1984 ◽  
Vol 106 (3) ◽  
pp. 278-284 ◽  
Author(s):  
R. C. Johnson
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Critical Force ◽  
Inertia Force ◽  
Motion Synthesis ◽  
Spring Force ◽  
Force Reduction ◽  
Motion Design

A strategy of motion synthesis is developed for reducing critical forces in relatively rigid high-speed spring-loaded cam mechanisms. A special motion is specifically presented to illustrate application of the developed strategy, for the dwell-rise-dwell displacement case. Critical force graphs are presented for a numerical industrial probelm in three examples, comparing the developed special motion with the commonly used cycloidal and modified trapezoidal motions. Maximum values of cam contact force, inertia force, and spring force are all appreciably reduced by the special motion.

Linear motor drive ultrahigh-speed injection moulding machine

2002 ◽  
Vol 216 (5) ◽  
pp. 773-781 ◽  
Author(s):  
Y-B Bang ◽  
S Ito
Keyword(s):  
Contact Force ◽  
Injection Moulding ◽  
High Speed ◽  
Linear Motor ◽  
Total Output ◽  
Inertia Force ◽  
Motor Drive ◽  
Direct Drive ◽  
Linear Motors ◽  
Moulding Machine

This paper presents a report on the development of a linear motor drive injection moulding machine for the attainment of ultrahigh-speed injection moulding. Until now it has been impossible to produce such a high speed with all-electric injection moulding machines, although the need for such ultrahigh-speed, electrically driven injection moulding machines has clearly existed. However, direct drive by linear motors may cause brief nozzle separation from the sprue bushing because of an inertia force as large as the total output thrust of the linear motors, and this momentary separation can cause molten plastic leakage. In this paper, two solutions are proposed for this inertia force problem. One is mechanical cancellation of the inertia force, the other is an increase in the nozzle contact force. Furthermore, a new nozzle contact mechanism is proposed that prevents the stationary platen bending caused by the nozzle contact force. Some experimental results on a manufactured all-electric, ultrahigh-speed injection moulding machine are presented.

scholarly journals Driving Torque Model and Accuracy Test of Multilink High-Speed Punch

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fuxing Li ◽  
Hao Liu ◽  
Menglei Li ◽  
Jun Guo ◽  
Xinjian Lu ◽  
...  
Keyword(s):  
High Speed ◽  
Calculation Model ◽  
Effective Control ◽  
Inertia Force ◽  
Conservation Of Energy ◽  
Accuracy Test ◽  
Operation Stability ◽  
Strategy Planning ◽  
The Stability ◽  
Driving Torque

Inertia force is an important factor for operation stability and stamping precision of high-speed punch; adjusting drive torque of high-speed punch can realize effective control of inertia force. In this paper, a kind of 600 KN multilink high-speed punch inertia force balancing mechanism was designed. The calculation model of ideal inertia force was proposed based on conservation of energy and numerical analysis method. In addition, the calculation model of ideal driving torque were analyzed, simplified, and corrected by using numerical calculation and simulation methods, which solved the problem of controlling inertia force from the perspective of driving torque and realized the stability strategy planning of high-speed multilink punch press. Finally, the proposed ideal driving torque calculation model was simulated and verified by ADAMAS and bottom-dead-point accuracy test was carried out.

Study of Electrostatic-Induced Jumping Droplets on Superhydrophobic Surfaces

2017 ◽  
Author(s):  
B. Traipattanakul ◽  
C. Y. Tso ◽  
Christopher Y. H. Chao
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Electrostatic Force ◽  
Droplet Radius ◽  
Inertia Force ◽  
Resistance Force ◽  
Average Charge ◽  
Electrical Voltage ◽  
Fluid Systems ◽  
Set Up

Condensation of water vapor is an important process utilized in energy/thermal/fluid systems. When droplets coalesce on the non-wetting surface, excess surface energy converts to kinetic energy leading to self-propelled jumping of merged droplets. This coalescing-jumping-droplet condensation can better enhance heat transfer compared to classical dropwise condensation and filmwise condensation. However, the resistance force can cause droplets to return to the surface. These returning droplets can either coalesce with neighboring droplets and jump again, or adhere to the surface. As time passes, these adhering droplets can become larger leading to progressive flooding on the surface, limiting heat transfer performance. However, an electric field is known to be one of the effective methods to prevent droplet return and to address the progressive flooding issue. Therefore, in this study, an experiment is set up to investigate the effects of applied electrical voltages between two parallel copper plates on the jumping height with respect to the droplet radius and to determine the average charge of coalescing-jumping-droplets. Moreover, the gravitational force, the drag force, the inertia force and the electrostatic force as a function of the droplet radius are also discussed. The gap width of 7.5 mm and the electrical voltages of 50 V, 100 V and 150 V are experimentally investigated. Droplet motions are captured with a high-speed camera and analyzed in sequential frames. The results of the study show that the applied electrical voltage between the two plates can reduce the resistance force due to the droplet’s inertia and can increase the effects of the electrostatic force. This results in greater jumping heights and the jumping phenomenon of some bigger-sized droplets. With the same droplet radius, the greater the applied electrical voltage, the higher the coalescing droplet can jump. This work can be utilized in several applications such as self-cleaning, thermal diodes, anti-icing and condensation heat transfer enhancement.

Development of Small-Sized Motor-Driven Gyroscopic Power Generator Works Under Low-Frequency Vibration

2019 ◽  
Author(s):  
Akio Toyoshima ◽  
Hiroshi Hosaka ◽  
Akira Yamashita
Keyword(s):  
High Speed ◽  
Low Frequency ◽  
Spindle Motor ◽  
Inertia Force ◽  
Power Generator ◽  
Power Generators ◽  
Mechanical Parts ◽  
Low Frequency Vibration ◽  
Generator Type ◽  
Design Freedom

Abstract In order to realize a small-sized energy harvester with high output, this study prototypes a small motor-driven gyroscopic power generator. Supplying energy to sensors and devices is the biggest problem for Internet of Things (IoT) systems. One solution is gyroscopic power generators, which are a type of vibrational generator that amplify the inertia force of weights by rotating them at high speed, and in doing so can obtain greater output than conventional generators that use simple vibration for the same mass weight. This paper reports on a motor-driven type gyroscopic generator in which the flywheel is spun with an embedded motor, and which is superior in applicability to random vibration generators. The generators of this type that have been studied thus far are very large and have been primarily used for wave power generation in the ocean. However, when the shape of this gyroscopic power generator type is miniaturized proportionally, the output per volume decreases in proportion to the fifth power of the dimension. This makes it difficult to maintain the power output while miniaturizing the generator size. In this research, the structure of the gyroscopic power generator is thoroughly refined and miniaturization is realized by making full use of the available space. By using a motor with high design freedom, the spindle motor and flywheel are unified. From this accomplishment, not only is the required space reduced, the number of mechanical parts and the friction loss are decreased as well. The prototype generator has a size of about 150 mm on its long side. When a swinging vibration of 50 degrees in amplitude and 2 Hz in frequency is applied, a net output of 0.104 W is obtained. This output power is sufficient to drive sensors and low power wide area (LPWA) radio circuits.

scholarly journals Design and Simulation of Electromagnetic Linear Actuators for Jet Dispensers

2020 ◽  
Vol 10 (5) ◽  
pp. 1653
Author(s):  
Minh-Sang Tran ◽  
Sheng-Jye Hwang
Keyword(s):  
Thrust Force ◽  
Inertia Force ◽  
Resistance Force ◽  
Driving Frequency ◽  
Excitation Current ◽  
Damping Force ◽  
Element Analysis ◽  
Spring Force ◽  
Return Spring ◽  
Linear Actuators

Three electromagnetic-based linear actuators, namely a solenoid actuator (SA), a moving coil actuator (MCA), and a moving magnet actuator (MMA), are proposed for driving the needle in a jet dispenser. The total resistance force acting on the needle during operation, including the damping force, the friction force, the inertia force, the compression spring force, and the backpressure, are measured by an experimental model. The thrust force required to overcome this resistance force is then predicted for each actuator using finite element analysis (FEA) simulations. Simple two-dimensional models of the SA, MCA, and MMA are constructed using the same coil dimensions in every case in order to facilitate an objective comparison between them. Simulations in ANSYS Maxwell software are then performed to adjust the specific dimensions of each actuator structure in such a way as to generate the thrust force required to drive the needle in the jet dispenser with the minimum excitation current possible. The simulation results show that for a maximum needle driving frequency of 250 Hz and a stroke length of 0.5 mm, the excitation current required to generate the necessary thrust force is equal to 1.8 A and 1.9 A for the MCA and MMA models, respectively, when a return spring is not used, and 2.2 A, 3.8 A, and 4.1 A for the SA, MCA, and MMA models, respectively, when a return spring is employed. It is additionally shown that the thrust force drop of the MCA and MMA models is far less than that of the SA model, about 0.7%, 1.8%, and 61% for three models, respectively. Three preliminary designs for jet dispensers incorporating the proposed actuators are also generated for reference purposes.

Fluid Drag Force Production and Motion Control of an Aquarobot Manipulator by Ejecting Air Bubbles

1990 ◽  
Vol 2 (5) ◽  
pp. 351-357
Author(s):  
Masakazu Ogasawara ◽  
◽  
Fumio Hara ◽  
Keyword(s):  
Drag Force ◽  
High Speed ◽  
Robot Manipulator ◽  
Force Production ◽  
Air Bubbles ◽  
Air Bubble ◽  
Fluid Forces ◽  
Fluid Drag ◽  
Force Reduction ◽  
Controlled Flow

The motion of a robot manipulator submerged in water is strongly affected by fluid forces, and it is an important technique to avoid their influence on the motion of an aquarobot manipulator to achieve high-speed, precise motion. This paper deals with extension of the technique of air bubble ejection from the manipulator surface, i.e., the mechanisms of reduction of drag force by air bubble ejection and its effects on the control of the aquarobot manipulator. Using a two-degree-of-freedom and two-joint manipulator, experiments were performed and the following major results were obtained: (1) There exists a particular pattern of air bubble ejection for reduction fluid drag force acting on the manipulator and it resulted in reduction of drag force by 25% compared to that for no air bubble ejection. (2) There exists a particular pattern of air bubble ejection that brought a 40% reduction of the control torque required for compensating the fluid drag force. (3) The major mechanisms for drag force reduction were found to be the controlled flow pattern around the manipulator formed by ejecting air bubbles. However, it is noted that these effects of air bubble ejection were dependent on the mode of manipulator motion.

A Study on Speed Elevation Possibility at the Connection between High Speed Lines and Conventional Lines with Korean High Speed Train

2006 ◽  
Vol 326-328 ◽  
pp. 635-638 ◽  
Author(s):  
Young Sam Ham ◽  
Jai Sung Hong
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Integrated System ◽  
Communication Line ◽  
Mass Transportation ◽  
Test Results ◽  
High Speed Train ◽  
Safety Standards ◽  
Derailment Coefficient ◽  
Train Speed

Railways are a mass transportation system with high safety and punctuality. These strengths have been well proved by tests and evaluations. Railways are an integrated system with cars, power, signal, communication, line structures and operation. Among many safety standards of these systems, contact force between wheels and lines can be chosen since a derailment coefficient evaluated by contract force is the most important fact that decides the safety of railways. Especially regarding express trains, since they run twice faster than conventional ones, the evaluation of a derailment coefficient is more important than any other criteria. Currently, Korean express trains between Seoul and Pusan use the same stations as conventional trains in Daejeon and Dong-Daegu; therefore, express trains run on conventional lines from express lines. This paper describes test results acquired by increasing the train speed where express lines and conventional lines are connected. Test results tell that it is safe with under 0.8 derailment coefficient and running time is reduced by 10~30 seconds in each section.

scholarly journals Active Control of Contact Force for a Pantograph-Catenary System

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jiqiang Wang
Keyword(s):  
Active Control ◽  
Contact Force ◽  
High Speed ◽  
Large Scale ◽  
Vibration Suppression ◽  
Numerical Study ◽  
Primary Objective ◽  
Geometric Framework ◽  
High Speed Trains ◽  
Catenary System

The performance of the high speed trains depends critically on the quality of the contact in the pantograph-catenary interaction. Maintaining a constant contact force needs taking special measures and one of the methods is to utilize active control to optimize the contact force. A number of active control methods have been proposed in the past decade. However, the primary objective of these methods has been to reduce the variation of the contact force in the pantograph-catenary system, ignoring the effects of locomotive vibrations on pantograph-catenary dynamics. Motivated by the problems in active control of vibration in large scale structures, the author has developed a geometric framework specifically targeting the remote vibration suppression problem based only on local control action. It is the intention of the paper to demonstrate its potential in the active control of the pantograph-catenary interaction, aiming to minimize the variation of the contact force while simultaneously suppressing the vibration disturbance from the train. A numerical study is provided through the application to a simplified pantograph-catenary model.

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