Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in mining.However,substantial energy waste occurs during the ...Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in mining.However,substantial energy waste occurs during the descent of the hoisting system or the deceleration of the slewing platform.To reduce the energy loss,an innovative hydrau-lic-electric hybrid drive system is proposed,in which a hydraulic pump/motor connected with an accumulator is added to assist the electric motor to drive the hoisting system or slewing platform,recycling kinetic and potential energy.The utilization of the kinetic and potential energy reduces the energy loss and installed power of the min-ing shovel.Meanwhile,the reliability of the mining shovel pure electric drive system also can be increased.In this paper,the hydraulic-electric hybrid driving principle is introduced,a small-scale testbed is set up to verify the feasibil-ity of the system,and a co-simulation model of the proposed system is established to clarify the system operation and energy characteristics.The test and simulation results show that,by adopting the proposed system,compared with the traditional purely electric driving system,the peak power and energy consumption of the hoisting electric motor are reduced by 36.7%and 29.7%,respectively.Similarly,the slewing electric motor experiences a significant decrease in peak power by 86.9%and a reduction in energy consumption by 59.4%.The proposed system expands the application area of the hydraulic electric hybrid drive system and provides a reference for its application in over-sized and super heavy equipment.展开更多
The transmission mechanism of a jack is required to support the combat vehicle reliably within a very short time. So reliability research is very important because the mechanism completes motions required under the co...The transmission mechanism of a jack is required to support the combat vehicle reliably within a very short time. So reliability research is very important because the mechanism completes motions required under the conditions within limited time. If the transmission mechanism of the jack supports the rocket launcher steadily, it needs to go through several stages as follows ： unlocking, starting, operating, braking, stopping, fixing position and locking. The transmission mechanism of the jack is a complicated and single degree of freedom mechanical system; it can be considered an imaginary mechanical model that has an equivalent moment of inertia and equivalent torque. According to the characteristics of each supporting stages, dynamics equations of the mechanism are established. At the stages of starting and operating, a driving moment and resistance moment are dealt with for a Normal distribution. The design principles for movement reliability of completing action are established and the design principles for time reliability of completing action within a limited time are established. Finally, movement reliability of the transmission mechanism of the jack is 0. 9 852, according to our calculation. Reliability of time to complete action is 0. 9 943.展开更多
The three-bucket jacket foundation is a new type of foundation for offshore wind turbine that has the advantages of fast construction speed and suitability for deep water. The study of the hoisting and launching proce...The three-bucket jacket foundation is a new type of foundation for offshore wind turbine that has the advantages of fast construction speed and suitability for deep water. The study of the hoisting and launching process is of great significance to ensure construction safety in actual projects. In this paper, a new launching technology is proposed that is based on the foundation of the three-bucket jacket for offshore wind turbine. A complete time domain simulation of the launching process of three-bucket jacket foundation is carried out by a theoretical analysis combined with hydrodynamic software Moses. At the same time, the effects of different initial air storage and sea conditions on the motion response of the structure and the hoisting cable tension are studied. The results show that the motion response of the structure is the highest when it is lowered to 1.5 times the bucket height. The natural period of each degree of freedom of the structure increases with the increase of the lowering depth. The structural motion response and the hoisting cable tension vary greatly in the early phases of Stages Ⅰ and Ⅲ, smaller in Stage Ⅱ, and gradually stabilize in the middle and late phases of Stage Ⅲ.展开更多
It is illustrated that there exists an inflection circle on the linkage rigid body by the principle of relative motion. Confirmed methods of the inflection circle, curvature radius and curvature center of the point tr...It is illustrated that there exists an inflection circle on the linkage rigid body by the principle of relative motion. Confirmed methods of the inflection circle, curvature radius and curvature center of the point track on the linkage rigid body are given in the case of the different contact type of move instantaneous center line and static instantaneous center line. The regularity of distribution of curvature radius and curvature center of the point track is researched. The identification methods called determination parameters and auxiliary vertical line of the diameter and direction of the inflection circle in the four bar mechanism are pointed out. A design method of the crane hoisting mechanism is discussed in the end of this paper.展开更多
Helicopter rescue has become an important way of life and property relief in modern society.The structure and parameters of the helicopter hoist bracket influence the convenience,safety and reliability of the rescue o...Helicopter rescue has become an important way of life and property relief in modern society.The structure and parameters of the helicopter hoist bracket influence the convenience,safety and reliability of the rescue operation for the lifeguard and hoistman.Based on fatigue analysis theory and ANSYS workbench software,the fatigue life analysis of the hoist bracket is carried out.First,the structure of the hoist bracket is modeled according to the body standard of the hoistman and lifeguard.Then an approach is presented to obtain the S-N curve of the hoist bracket by modifying the S-N curve of the bracket material based on Goodman curve while considering the influences of the shape,size,surface state,loading conditions and the average stress.Further,based on the ANSYS workbench analysis,the life and safety nephogram of the bracket under the fluctuating cyclic load can be obtained.Finally,the designed bracket is analyzed with the proposed method.The cycles number of the bracket is greater than 107 under the extreme conditions of the pulsating cyclic load,which may be considered as the unlimited life and meets the requirement of the fatigue strength.展开更多
The effect of uncertainty and its evolution with time on the incline hoist reliability are investigated in this paper.The performance of incline hoist is changed over time and gradually degraded.The degradation will i...The effect of uncertainty and its evolution with time on the incline hoist reliability are investigated in this paper.The performance of incline hoist is changed over time and gradually degraded.The degradation will influence the safe usage and reliability of incline hoist.Degradation process can be described by stochastic process.The degradation process of incline hoist is modeled in geometric Brownian motions(GBM),and the drift rate and diffusion rate of this process can reflect the failure extent and fluctuation of the system.Evolution-based uncertainty analysis(EBUA)method is proposed to describe the dynamic reliability of the incline hoist,and the system of incline hoist can be designed with the specified reliability value at the given time.展开更多
This paper mainly introduces the scientific cutting and hoisting construction technology before the large spherical tank(hereinafter referred to as spherical tank)moving and loading,so as to better ensure the construc...This paper mainly introduces the scientific cutting and hoisting construction technology before the large spherical tank(hereinafter referred to as spherical tank)moving and loading,so as to better ensure the construction quality of field assembly and welding in the process of spherical tank moving and loading.展开更多
The torsional vibration analytical physical model of mine hoist gear transmission system is set up. The original parameter's calculation method of hoist transmission system are analyzed and discussed. The design ...The torsional vibration analytical physical model of mine hoist gear transmission system is set up. The original parameter's calculation method of hoist transmission system are analyzed and discussed. The design sensitivity of natural and dynamic behavior for hoist transmission system are analyzed, including the design sensitivity of natural frequency, the design sensitivity of mode shape and the design sensitivity of dynamic respondence. The torsional vibration dynamic behavior of mine hoist gear transmission system is studied.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.U1910211)National Key Research and Development Program of China(Grant No.2021YFB2011903).
文摘Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in mining.However,substantial energy waste occurs during the descent of the hoisting system or the deceleration of the slewing platform.To reduce the energy loss,an innovative hydrau-lic-electric hybrid drive system is proposed,in which a hydraulic pump/motor connected with an accumulator is added to assist the electric motor to drive the hoisting system or slewing platform,recycling kinetic and potential energy.The utilization of the kinetic and potential energy reduces the energy loss and installed power of the min-ing shovel.Meanwhile,the reliability of the mining shovel pure electric drive system also can be increased.In this paper,the hydraulic-electric hybrid driving principle is introduced,a small-scale testbed is set up to verify the feasibil-ity of the system,and a co-simulation model of the proposed system is established to clarify the system operation and energy characteristics.The test and simulation results show that,by adopting the proposed system,compared with the traditional purely electric driving system,the peak power and energy consumption of the hoisting electric motor are reduced by 36.7%and 29.7%,respectively.Similarly,the slewing electric motor experiences a significant decrease in peak power by 86.9%and a reduction in energy consumption by 59.4%.The proposed system expands the application area of the hydraulic electric hybrid drive system and provides a reference for its application in over-sized and super heavy equipment.
文摘The transmission mechanism of a jack is required to support the combat vehicle reliably within a very short time. So reliability research is very important because the mechanism completes motions required under the conditions within limited time. If the transmission mechanism of the jack supports the rocket launcher steadily, it needs to go through several stages as follows ： unlocking, starting, operating, braking, stopping, fixing position and locking. The transmission mechanism of the jack is a complicated and single degree of freedom mechanical system; it can be considered an imaginary mechanical model that has an equivalent moment of inertia and equivalent torque. According to the characteristics of each supporting stages, dynamics equations of the mechanism are established. At the stages of starting and operating, a driving moment and resistance moment are dealt with for a Normal distribution. The design principles for movement reliability of completing action are established and the design principles for time reliability of completing action within a limited time are established. Finally, movement reliability of the transmission mechanism of the jack is 0. 9 852, according to our calculation. Reliability of time to complete action is 0. 9 943.
基金financially supported by the National Natural Science Foundation of China (Grant No.52171274)。
文摘The three-bucket jacket foundation is a new type of foundation for offshore wind turbine that has the advantages of fast construction speed and suitability for deep water. The study of the hoisting and launching process is of great significance to ensure construction safety in actual projects. In this paper, a new launching technology is proposed that is based on the foundation of the three-bucket jacket for offshore wind turbine. A complete time domain simulation of the launching process of three-bucket jacket foundation is carried out by a theoretical analysis combined with hydrodynamic software Moses. At the same time, the effects of different initial air storage and sea conditions on the motion response of the structure and the hoisting cable tension are studied. The results show that the motion response of the structure is the highest when it is lowered to 1.5 times the bucket height. The natural period of each degree of freedom of the structure increases with the increase of the lowering depth. The structural motion response and the hoisting cable tension vary greatly in the early phases of Stages Ⅰ and Ⅲ, smaller in Stage Ⅱ, and gradually stabilize in the middle and late phases of Stage Ⅲ.
文摘It is illustrated that there exists an inflection circle on the linkage rigid body by the principle of relative motion. Confirmed methods of the inflection circle, curvature radius and curvature center of the point track on the linkage rigid body are given in the case of the different contact type of move instantaneous center line and static instantaneous center line. The regularity of distribution of curvature radius and curvature center of the point track is researched. The identification methods called determination parameters and auxiliary vertical line of the diameter and direction of the inflection circle in the four bar mechanism are pointed out. A design method of the crane hoisting mechanism is discussed in the end of this paper.
基金Research Fund for the Doctoral Program of Higher Education of China(No.20122125120013)Department of Transportation Technology of Construction Project,China(No.2013328225080)+1 种基金Scientific Research Fund of Liaoning Provincial Education Department,China(No.L2013206)the Fundamental Research Funds for the Central Universities,China(Nos.3132015087,3132014303)
文摘Helicopter rescue has become an important way of life and property relief in modern society.The structure and parameters of the helicopter hoist bracket influence the convenience,safety and reliability of the rescue operation for the lifeguard and hoistman.Based on fatigue analysis theory and ANSYS workbench software,the fatigue life analysis of the hoist bracket is carried out.First,the structure of the hoist bracket is modeled according to the body standard of the hoistman and lifeguard.Then an approach is presented to obtain the S-N curve of the hoist bracket by modifying the S-N curve of the bracket material based on Goodman curve while considering the influences of the shape,size,surface state,loading conditions and the average stress.Further,based on the ANSYS workbench analysis,the life and safety nephogram of the bracket under the fluctuating cyclic load can be obtained.Finally,the designed bracket is analyzed with the proposed method.The cycles number of the bracket is greater than 107 under the extreme conditions of the pulsating cyclic load,which may be considered as the unlimited life and meets the requirement of the fatigue strength.
基金National Natural Science Foundation of China(No.51075029)
文摘The effect of uncertainty and its evolution with time on the incline hoist reliability are investigated in this paper.The performance of incline hoist is changed over time and gradually degraded.The degradation will influence the safe usage and reliability of incline hoist.Degradation process can be described by stochastic process.The degradation process of incline hoist is modeled in geometric Brownian motions(GBM),and the drift rate and diffusion rate of this process can reflect the failure extent and fluctuation of the system.Evolution-based uncertainty analysis(EBUA)method is proposed to describe the dynamic reliability of the incline hoist,and the system of incline hoist can be designed with the specified reliability value at the given time.
文摘This paper mainly introduces the scientific cutting and hoisting construction technology before the large spherical tank(hereinafter referred to as spherical tank)moving and loading,so as to better ensure the construction quality of field assembly and welding in the process of spherical tank moving and loading.
文摘The torsional vibration analytical physical model of mine hoist gear transmission system is set up. The original parameter's calculation method of hoist transmission system are analyzed and discussed. The design sensitivity of natural and dynamic behavior for hoist transmission system are analyzed, including the design sensitivity of natural frequency, the design sensitivity of mode shape and the design sensitivity of dynamic respondence. The torsional vibration dynamic behavior of mine hoist gear transmission system is studied.
