scholarly journals Self-weight Balance Design of Portal Crane Boom

2021 ◽  
Vol 267 ◽  
pp. 01056
Author(s):  
Yi Huang ◽  
Haixia Zeng ◽  
Yan Chen
Keyword(s):  
Energy Consumption ◽  
Center Of Gravity ◽  
Drive System ◽  
The Self ◽  
Maximum Height ◽  
Balance Design ◽  
Drive Mechanism ◽  
Balance System ◽  
Extra Energy ◽  
Portal Crane

During the luffing of the portal crane, the height changing of the center of gravity of the boom needs to consume extra energy, which not only wastes energy, but also makes the luffing drive system need to use a larger motor. This paper uses the lever-movable counterweight balance method to design the self-weight balance of the portal crane, and verifies that the designed jib self-weight balance system meets the requirements of the maximum height deviation, unbalanced torque and comprehensive unbalanced torque by evenly taking points. The power and unnecessary energy consumption of the luffing drive mechanism are reduced.

scholarly journals Decomposition approaches for parallel machine scheduling of step-deteriorating jobs to minimize total tardiness and energy consumption

2021 ◽  
Author(s):  
Xiao Wu ◽  
Peng Guo ◽  
Yi Wang ◽  
Yakun Wang
Keyword(s):  
Energy Consumption ◽  
Tabu Search ◽  
Processing Time ◽  
Deteriorating Jobs ◽  
Parallel Machine Scheduling ◽  
Parallel Machine ◽  
Total Tardiness ◽  
Master Problem ◽  
Starting Time ◽  
Extra Energy

AbstractIn this paper, an identical parallel machine scheduling problem with step-deteriorating jobs is considered to minimize the weighted sum of tardiness cost and extra energy consumption cost. In particular, the actual processing time of a job is assumed to be a step function of its starting time and its deteriorating threshold. When the starting time of a job is later than its deteriorating threshold, the job faces two choices: (1) maintaining its status in holding equipment and being processed with a base processing time and (2) consuming an extra penalty time to finish its processing. The two work patterns need different amounts of energy consumption. To implement energy-efficient scheduling, the selection of the pre-processing patterns must be carefully considered. In this paper, a mixed integer linear programming (MILP) model is proposed to minimize the total tardiness cost and the extra energy cost. Decomposition approaches based on logic-based Benders decomposition (LBBD) are developed by reformulating the studied problem into a master problem and some independent sub-problems. The master problem is relaxed by only making assignment decisions. The sub-problems are to find optimal schedules in the job-to-machine assignments given by the master problem. Moreover, MILP and heuristic based on Tabu search are used to solve the sub-problems. To evaluate the performance of our methods, three groups of test instances were generated inspired by both real-world applications and benchmarks from the literature. The computational results demonstrate that the proposed decomposition approaches can compute competitive schedules for medium- and large-size problems in terms of solution quality. In particular, the LBBD with Tabu search performs the best among the suggested four methods.

scholarly journals Use of mechanical resonance in impact machines

2018 ◽  
Vol 211 ◽  
pp. 17006
Author(s):  
Wieslaw Fiebig ◽  
Jakub Wrobel
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Demand ◽  
Drive System ◽  
Mechanical Resonance ◽  
Total Energy Consumption ◽  
At Resonance ◽  
Innovative Method ◽  
Drive Systems

An innovative method exploiting mechanical resonance in machines drive systems, especially useful in impact machines, has been developed. Accumulation of energy at resonance can be applied to the drive system in a similar way as flywheels in eccentric presses. Under resonance conditions, the total energy consumption of the oscillating mass is equal to the energy lost due the damping forces. Energy accumulated in the oscillator can be several times greater than the energy supplied continuously to the oscillator. The developed method can be used in many applications, especially in impacting machines. Finally, the energy demand of resonance punching press will be compared with the energy demand of eccentric press.

Factors Contributing to Maximum Height of Dives after Takeoff from the 3M Springboard

1988 ◽  
Vol 4 (3) ◽  
pp. 231-259 ◽  
Author(s):  
Ross H. Sanders ◽  
Barry D. Wilson
Keyword(s):  
Vertical Velocity ◽  
Kinetic Data ◽  
High Speed ◽  
Mechanical Energy ◽  
Center Of Gravity ◽  
Whole Body ◽  
Maximum Height ◽  
Body Angle ◽  
High Speed Cinematography ◽  
Hip Flexion

This study investigated factors contributing to the maximum height achieved by divers after takeoff from the 3m springboard. Twelve elite male divers and 12 elite female divers competing in the 1986 Australian National Championships were filmed using high-speed cinematography. Kinematic and kinetic data for the takeoff phase were derived from the digitized film. Variables analyzed included center of gravity (CG) displacement and velocity, the acceleration of the CG relative to the springboard, and the components of mechanical energy contributing to height achieved by the diver’s CG. Body orientation was described in terms of the angles at the hip, knee, and ankle, and whole body angle of lean. Comparison of timing differences among dive groups and divers was aided by normalizing the data with respect to time. It was found that the height achieved was highly dependent on the rotational requirements of the dive, with males achieving greater heights than females. Divers who achieve good height compared to other divers performing the same dive are characterized by a large vertical velocity at touchdown from the hurdle and a minimization of hip flexion (forward dives) and knee flextion (reverse dives) at takeoff.

The Design of the Drive System of the Crank Underdrive Quick Presses

2013 ◽  
Vol 584 ◽  
pp. 189-193
Author(s):  
Mao Hua Xiao ◽  
Fei Yang ◽  
Zun Mang Ke ◽  
Si Hong Zhu ◽  
Deng Song Xiao
Keyword(s):  
Optimization Design ◽  
Drive System ◽  
Transmission Mechanism ◽  
Reliable Operation ◽  
Preliminary Calculation ◽  
Drive Mechanism ◽  
Pressure Angle ◽  
Nominal Pressure ◽  
Punching Process ◽  
Crank Mechanism

Based on production needs, a main transmission mechanism of underdrive speed press was designed in this paper. The design of the main transmission mechanism is the improvements and alternative of sine institutions slider-crank mechanism made. Underdrive and dual slider mechanism were designed, in order to achieve the presses punching process. The nominal pressure angle and the nominal torque were calculated. A preliminary calculation and design of the crankshaft, bearings, slider of the main drive mechanism. Ensure reliable operation and to provide a basis for the optimization design.

scholarly journals Energy consumption in the life cycle of plumbing fixtures

2018 ◽  
Vol 19 (1) ◽  
pp. 70-78
Author(s):  
A. Kalbusch ◽  
E. Ghisi
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Total Energy ◽  
The Self ◽  
University Campus ◽  
Southern Brazil ◽  
Total Energy Consumption ◽  
Production Phase ◽  
Use Phase

Abstract The main objective of this paper is to propose a method for quantifying the energy consumption in the life cycle of different plumbing fixtures. The method can be used to estimate the energy consumption in the production, use and disposal phases of plumbing fixtures. This allows for the comparison between the performances of different plumbing fixtures and the identification of the share of each phase on the energy consumption over the life cycle. The method was applied in a case study in Southern Brazil to quantify the energy consumption in the life cycle of two types of taps installed on a university campus. The total energy consumption in the life cycle of ordinary and self-closing taps used in the study was respectively, 177.71 MJ and 164.11 MJ over 4 years. Production accounted for 33% of the energy consumption share of the ordinary tap, while the use phase accounted for 65% and the disposal phase for 2%. For the self-closing tap, the production phase accounted for 46% of the energy consumption share, the use phase for 52% and the disposal phase for 2%. Therefore, considering the energy consumption in the life cycle, self-closing taps should be preferred over ordinary taps.

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