Lifting Device Research Articles

Design and Experiment with a Double-Roller Sweet Potato Vine Harvester

The yield of sweet potato vines is large, making it a good source of food. However, it is difficult to harvest sweet potato vines due to creeping and intertwining. Therefore, according to the domestic sweet potato planting model, this paper designed a double roll sweet potato vine harvester which can complete the operations of vine picking, vine killing, conveying and header harvesting at one time. The machine adopts the process of front roll vine picking, rear roll vine killing and rod bar lifting. The key components of the vine picking device, vine killing device and lifting device were designed and calculated. A numerical simulation test of the vine harvesting process was carried out by using the discrete element numerical simulation method. It was determined that the length of the vine picking rod from the outside to the inside is 175 mm, 150 mm and 105 mm, respectively, and the inclination angle of the end is 160°. There are six vine killing knives on each vine killing knife plate. The inclination of the lifting device is 50°and the conveying speed is 3 m/s. Using the box Behnken experimental design method, taking the vine picking roller speed, vine killing roller speed and ground clearance as the experimental factors, and taking the sweet potato vine harvest rate, stubble height and potato injury rate as the evaluation indexes, a quadratic regression orthogonal test was carried out, the effects of various factors on the evaluation indexes were analyzed, and the experimental factors were optimized and verified. The experimental results showed that the optimal parameter combination is as follows: the rotation speed of vine picking roller should be 716 r/min, the rotation speed of vine killing roller should be 1960 r/min and the ground clearance should be 16 mm. With these parameters, the harvest rate of sweet potato vines is 93.1%, the stubble height is 29.5 mm and the potato injury rate is 0.174%. As such, the harvester meets the requirements for the mechanized harvesting of sweet potato vines and is of great significance as a light and simplified product for the sweet potato industry.

Effect of engine failure on aerodynamic characteristics of a light transport aircraft model

In-flight engine failure has always been a hazardous situation in case of a single-engine aircraft associated with losing altitude and making a landing within the available gliding range. In the event of a multi-engine aircraft, this situation improves markedly due to the potential flight continuation. The necessary conditions to continue a flight are available excess thrust, satisfactory aerodynamic performance, and a fixed-wing control. If the half of engine thrust is lost, which adversely affects a rate of climb, the most critical flight modes are the take-off and go-around procedures performed at low altitudes using the engine asymmetric thrust. Ensuring flight safety in these modes requires extensive experimental studies in wind tunnels to simulate the basic flight envelope with an inoperative engine. The aim of studies is the effect of a critical engine failure on the aerodynamiccharacteristics of an aircraft model as well as ensuring the required efficiency of the flight controls to dampen the yaw and roll moments that arise during an asymmetric thrust flight. The complexity of solving the problem is determined by the necessity of recovering from the substantial yaw, roll moments and by a significant decrease in the wing lifting efficiency along with an increase in a drag force which limits a climb rate and aircraft control. This article presents an analysis of the effect of critical engine failure on the aerodynamic characteristics of a light twin-engine transport aircraft model in the wing take-off and landing configurations. The aircraft aerodynamic configuration is made according to the classic pattern with the high-mounted tapered wing and deck-type empennage. The high lift devices comprise a double-slot hinged flap with a fixed deflector. The aircraft is equipped with a loading ramp with a relatively short flat rotatable part of the lower fuselage surface. Experimental studies of the longitudinal and lateral characteristics of the model with installed simulators of a power plant were carried out in TsAGI low-speed wind tunnel T-102. The analysis of engine failure effect on the model aerodynamics was executed in changing the load factor within the range B = 0.3…2. The capabilities to dampen the yaw and roll moments, using the primary flight controls (rudder and ailerons), were determined.

Understanding Work-Related Injury Risk Among Rural Rehabilitation Clinicians

Background: Rehabilitation clinicians have a high risk of occupational injury. Work-related musculoskeletal disorders (WMSDs) are one of the most frequent injuries for rehabilitation clinicians due to repeated heavy lifting and other forceful tasks. The primary objective of this study was to identify factors that caused or contributed to WMSDs for clinicians specifically working in rehabilitation settings (e.g., acute care, inpatient rehabilitation, long-term care, outpatient therapy). Methods: An, in person, proctored questionnaire was conducted of physical therapists (PTs), occupational therapists (OTs) and therapy assistants working at a rural community hospital. Information on general workload, work-related pain or discomfort, patient handling, and clinical experience were gathered using both a scripted interview questionnaire and a semi-scripted post-interview discussion. The questionnaire was analyzed using both descriptive and inferential statistical methods to determine the 1-year prevalence of WMSDs and factors associated with WMSDs and use of safe patient handling techniques. Results: Respondents (n=27) included 18 PTs, 6 OTs and 3 therapy assistants. On average, rehabilitation clinicians spent over eight hours per day delivering “hands-on” care to patients. During a typical workday, therapists spent more than 20% performing heavy lifting, physically fatiguing tasks, or were in a static or awkward posture. Bending or twisting, repetitive tasks, and kneeling or squatting were each performed 30% or more of a typical workday, especially bending or twisting (38%). More than half (63%) suffered musculoskeletal pain/discomfort during the past year. Inadequate lifting devices were reported to be available in the working environment. A negative association was observed between the availability of multiple lifting devices and WMSDS (p-values<0.05). Less than a third of clinicians (31.5%) reported complete confidence to use mechanical lifting devices during rehabilitation activities. Conclusion: Rehabilitation clinicians are at higher risk for WMSDs due to patient handling tasks. More ongoing training must be provided to ensure clinicians have confidence to use the technologies available for rehabilitation tasks. However, additional research is still needed to understand the causal factors of WMSDs related to patient handling, particularly for rural care settings that lack access to technology and adequate staffing.

Improvement of Employees’ Working Conditions When Processing Vegetables in Open Ground by the Designing Device for Lifting and Lowering Containers in the Storage

Introduction. Vegetable production is one of the branches of plant cultivation that is distinguished by the specifics of conducting technological processes, characterized by the structural variety of cultivation facilities and special working conditions. Injuries of employees are the serious problem in the workplace now. The body of a worker is exposed to a complex of unfavorable production factors: mineral fertilizers, pesticides and products of their metabolism: heating microclimate, high humidity, significant physical exertion. If agrotechnical techniques are followed, they cannot be a source of deterioration of health. Violation of sanitary and hygienic regulations and technological schemes for growing crops increases the risk of health problems and affects the ability to work.Problem Statement. The task for the study is to develop a simplified design to lower vegetables into storage, improve working conditions and safety of workers. Theoretical Part. Occupational safety improvement in agriculture is necessary, first of all, from the point of the preservation and purpose of the system as a mechanism for protecting the interests of workers, guaranteeing the preservation of their life, health, working capacity in the process of professional activity, as well as for the purpose of agricultural production efficiency. There is an urgent problem of safety when laying vegetables in containers. The main type of injury to workers is occurred during work for eliminating technical and technological failures. Conclusions. As a result of the research, market analysis and evaluation of the competitiveness of the development under consideration, the main distinguishing features of the proposed device from the existing ones are determined. This design can be recommended for further integration into the existing enterprise system, as well as for use in any agricultural enterprises.

Development and Fidelity Assessment of Potential Flow based Framework for Aerodynamic Modeling of High Lift Devices

High lift devices play a vital role in dictating the accelerated performance of an aircraft for different flight phases such as takeoff, landing, and aerobatic maneuvers. The aerodynamic design of high lift devices for any particular aircraft is an iterative process and is achieved through extensive aerodynamic Analysis of the aircraft for various flap configurations. Computational Fluid Dynamics (CFD) and Wind tunnel testing are highly effective techniques for performing the required Analysis, yet they have high computational costs and time. To overcome this shortcoming, a robust framework based on potential flow solver (PFS) and geometry parameterization is required without compromising the fidelity of the Analysis. This research aims to develop a highly robust aerodynamic analysis framework based on the Vortex Lattice Method (VLM) coupled with Polhamus Suction Analogy and parametric modeling of high lift devices. The fidelity of the framework is validated through experimental testing and is quantified by developing a fidelity assessment matrix. It is established that the computational cost of CFD has been reduced three times with only a 10% to 20% loss in accuracy when the developed framework is used. The developed PFS framework gives results from 80% to 90%. The framework results for a reference aircraft are thoroughly compared with CFD analyses. The framework provides values that agree with corresponding CFD analyses in a fraction of the time.

Graphic Method to Evaluate Power Requirements of a Hydraulic System Using Load-Holding Valves

It is very well known that the use of a load-holding valve (LHV) in a hydraulic system introduces additional energy consumption. This article presented a simplified graphical method for analyzing the power requirements of hydraulic systems equipped with load-holding valves for overrunning load control. The method helps to understand the performance of load-holding valves during actuator movement. In addition, it allows visualization of the influence on the overall system consumption of the main parameters (pilot ratio, set pressure) and others such as flow rate, back pressure, and load force. The method is attractive because, with only the pressures at the three ports and the valve relief function curve, it is sufficient to evaluate the energy consumption and to define the power ratio as an index indicating the percentage of energy that is to be used to open the LHV valve. The method was applied to real cases, in particular to two types of lifting mobile machines. It was validated following several outdoor tests on two mobile machines where experimental data were obtained. During tests, both machines were equipped with a set of seven different performance LHV valves. The described method could be beneficial for hydraulic machine manufacturers engaged in designing lifting devices when selecting a suitable valve for energy efficiency applications, especially now that the trend towards electrification is a reality.

Design and optimization of a transmission mechanism developed for distributed electric propulsion aircraft

In order to obtain better aerodynamic efficiency and take-off/landing capacity, it will be an excellent configuration for distributed electric propulsion (DEP) aircraft to install the blown flap in the propulsion wake. For this configuration, the coupling motion between the blown flap and the duct is hard to be achieved by the transmission mechanism of traditional distributed electric propulsion aircraft. This article describes the design and optimization of a transmission mechanism of a high lift device which composed of the distributed electric propulsion system and the blown flap. Firstly, the theoretical design rationale which is mainly based on the analytic hierarchy process and ant colony algorithm is introduced. Then, the kinematic simulation is conducted in details using closed loop vector equation. To further demonstrate the feasibility and reliability of the design approach, the functional test of a full-size transmission mechanism model is carried out. Kinematic simulation and ground test results show that the proposed mechanism can meet the requirements of the coupling motion between the duct and the blown flap, and the corresponding design scheme can be used to solve the design problem of such DEP aircraft transmission mechanism with the blown flap.

Comparison of Proportional and PWM Pneumatic Control in Terms of Positioning and Compressed Air Consumption

In this paper is shown a comparison of proportional pneumatic control and Pulse Width Modulation (PWM) pneumatic control in terms of positioning and compressed air consumption. All experimental tests were performed on a device for lifting and holding of the workpieces, which consists of one vertically mounted rodless cylinder with integrated vacuum gripper. In the case of the proportional pneumatic control, cylinder piston is always positioning in the correct position, but position losses are recurring during the time (in majority of cases, the position loss is 4 mm). As the control system constantly returns the cylinder piston to the desired position, that increases the compressed air consumption. In the case of the PWM pneumatic control, the position error is occurring (in majority of cases, the absolute value of the relative position error is less than 2%), but there is no position loss during the period of workpiece holding, i.e. there is no additional compressed air consumption. The compressed air consumption differential is approximately 18.6%. In addition, in case of Meter-out control in combination with previously defined types of control, the positioning is more accurate but the compressed air consumption slightly increases with decreasing the opening level of the one-way flow control valve.

Simulation Research on the Effect of Reynolds Number on the Aerodynamic Characteristics of High Lift Device

Based on the consideration of grid factors and turbulence model factors, the confluence boundary layer and aerodynamic characteristics of the NHLP-2D airfoil are studied. Compared with the experimental results, the grid distribution near the confluence boundary layer is important for calculating the width of the wake area. The calculation results of the structured and unstructured grids are basically the same when the surface grid distribution is the same. On the basis of the mesh refinement in the wake area, the aerodynamic characteristics calculated by the SA turbulence model and the distribution of the total pressure coefficient in the confluence boundary layer are in good agreement with the experimental results. The width of the confluence boundary layer and the wake strength decrease with the increase of Reynolds number, the lift coefficient increases with the increase of Reynolds number, but the drag and pitching moment have opposite pattern. The maximum lift of the airfoil increases as the Reynolds number increases. As the Reynolds number increases, the stall angle of attack of the airfoil gradually increases and then remains stable with the increase of the Reynolds number.

Ovarian suspension loop: an assembled device for ovarian lifting and immobilization during laparoscopic cystectomy

The mobility and smooth surface of the ovaries can pose a challenge during laparoscopic cystectomy, with difficulties in manipulation and visualization. We describe assembling a device for ovarian lifting and immobilization that utilizes a nylon suture and a “scalp vein set” to create a loop. The loop can be passed into the pelvic cavity and then slid beneath the ovary, elevating and stabilizing it during surgery without the need to puncture the ovarian tissue or grabbing and damage the utero-ovarian infundibulopelvic ligaments. This device is inexpensive, and its components are easily accessible. This assembled device prevents repetitive falling of the ovary into the pelvic cavity, facilitates laparoscopic ovarian cystectomy, and saves operative time.

Design and Fabrication of Motorized Hydraulic Jack System

Abstract: A jack is a mechanical lifting device used to apply great forces or lift heavy loads. A mechanical jack employs a screw thread for lifting heavy equipment. A hydraulic jack uses hydraulic power. In the case of tyre puncture or replacing wheels lift the car is more important part. This time we use traditional ways to lift the tyre. In that case a physically handicapped person, older person aged person not lifts the tyre easily. They require more time and also require more force to lift the tyre. In that way to help those who are physically challenged, aged person this project automatic hydraulic jack system is more useful. So, we tried to grab the opportunity. Here we use a wiper motor to drive the hydraulic jack loading subsequently and automatically. Keywords: Hydraulic jack, Mechanical jack, Motor, Battery, Switch

Determination of the Coefficient of Friction in a Pulley Groove by the Indirect Method

In lifting systems used for the vertical transport of bulk materials and individual items or persons, so-called frictional force transmission between a steel cable and pulley is used. Due to the sufficient contact pressure between the pulley groove and the surface of the steel cable, the steel cable moves as a result of fibre friction. In general, it is possible to define fibre (also called belt) friction as the resistance that is imposed on a flexible steel cable sliding over the rounded surface of a pulley. The frictional transmission of the tractive force is considered safe if there is no slippage of the cable in the pulley groove. In the event of insufficient cable pressure against the pulley groove or insufficient friction, the transport process fails, and the lifting device is unable to perform its function. The purpose of the article and of the created measuring devices is to obtain by experimental measurements the most accurate true value possible of the coefficient of friction acting on the contact surface of the cable with the pulley groove. The values of the friction coefficients obtained by indirect measurements on laboratory equipment when the tractive force is transferred by friction differ in many cases and do not coincide with the values calculated using theoretical relationships. The aim of the paper is to present a method of measurement and to identify the magnitude of the forces acting on both sides of a cable belted in the V-groove of a cable drum. From the results obtained from the experimental measurements, to express the value of the random variable is based on the knowledge of the known values obtained from the measurements for their use in a failure analysis. This paper presents results that can be applied in the field of online monitoring of this type of lifting equipment for failure analysis, prediction and evaluation of their operational indicators.

Control method of three-wheel intelligent tracking logistics car based on OpenMV4

The author designs an intelligent lifting transport device based on STM32 microcontroller. The lifting device is designed with STM32F407ZGT6 as the control core, and the hardware consists of OpenMV4 recognition, gray tracking, motor drive and other modules. It can carry out automatic, gray tracking, OpenMV4 recognition, intelligent material grasping and other functions, and can follow the track black line on the set plane track, and complete the preset operation. The experimental results are good.

A Novel Modular Biomimetic Live Working Robot for Power Distribution Line

Live working on power distribution lines is an effective way to improve the reliability of power supply. The aerial lift device with an insulated boom is often used as a platform to carry out live working, which is difficult to carry out in mountainous areas, paddy fields, and other complex environments. At the same time, power distribution live working requires highly skilled operators, and a lot of personal security measures, which is not conducive to the application in some developing countries. We imagine that the solution of the above problem is to use a robot to climb up the pole and complete the live working instead of the operator. In this article we report a low-cost modular biomimetic robot. The structure of the robot is designed to meet the requirements of live working, and the motion mechanism of the robot climbing poles and performing live work is analyzed. The feasibility of the technology is verified through simulation, experiments, and tests.

PLC-based Lifting Device for Shore Power Cable

Due to the different sizes and heights of ships docked at the port and the rise and fall of water at the harbor, there are many problems in providing electricity to ships berthing at the port [1]. The shore power cable lifting device is adaptable to the cable connection under different environments, mainly consisting of a multi-stage telescopic hydraulic arm [2], a cable drum, a luffing mechanism, and a slewing mechanism. In the process of cable lifting, the cooperative control of multiple working mechanisms is related to the cable connection precision, as well as the safety. Compared with the traditional control of the circuit, PLC control can ensure higher accuracy and safety, and improve the automation level and convenience of shore power connection.

Occupational injuries and patient lift usage among physical rehabilitation therapists

Physical therapists (PTs) and physical therapist assistants (PTAs) are at high risk for work-related musculoskeletal pain and discomfort. Determine the prevalence and exposure risk factors for work-related injuries (WRIs) among rehabilitation PTs and PTAs. A cross-sectional research survey was conducted among 170 PTs and 67 PTAs at 51 free-standing rehabilitation hospitals and rehabilitation units embedded in general hospitals in the Midwestern states of Iowa, Kansas, Missouri and Nebraska. The prevalence of WRIs and significant risk factors for developing WRIs were determined for PTs and PTAs. The 1-year prevalence of WRIs among PTs and PTAs working in physical rehabilitation was 29.5%. Multifaceted causes were identified including frequently bending/twisting, over-exerting force during patient handling activities, inadequate lifting devices, and lack of ongoing training for mechanical lifting device usage. Equipment usage barriers point to a critical need for technology creation, research, and education to advance worker safety while simultaneously enhancing patient outcomes.

A Novel Electro-Hydraulic Compound Driving System With Potential Energy Regeneration Capability for Lifting Device

In order to realize the high energy efficiency and high performance motion control of the lifting device of construction machinery, this paper proposes an electro-hydraulic compound driving system that can regenerate the potential energy. In this new system, the high-power density combination of hydraulic cylinder with accumulator is used to balance the self-weight of the lifting device and recycle the gravitational potential energy directly. The green electro-mechanical actuator with high energy efficiency and control performance is used to control the motion of the lifting device. In addition, control valves are added to dynamically adjust the pressure of the two chambers of the hydraulic cylinder and increase the stiffness of the hydraulic system, which can restrain the impact of acceleration and deceleration of large inertia lifting device and rapid charging and discharging of accumulator on electro-mechanical actuator. Finally, a typical construction machinery excavator is structurally modified to build a test platform. The test results show that, under the same working conditions, the proposed electro-hydraulic compound driving system can further reduce energy consumption by 31% and reduce peak power by 15% than that of the high energy efficiency three-chamber hydraulic cylinder driving system with potential energy regeneration. The boom runs smoothly, and the velocity overshoot and fluctuation time are significantly reduced, realizing high performance driving of the lifting device with low energy consumption. The research results also have broad application prospects in missile erection devices, cranes, presses, and other equipment.

Дослідження параметрів пристроїв підйому стосів картонних заготовок у поліграфічному обладнанні

Дослідження параметрів пристроїв підйому стосів картонних заготовок у поліграфічному обладнанні

Research of Comprehensive Operation Vehicle for Apple Picking

Aiming at the defects of low mechanization, single function, poor integration of machinery, agronomy and high damage rate in apple picking process, a comprehensive operation equipment for apple picking was developed. Around the standardized apple cultivation mode with dwarf and dense planting, intensive and efficient, the research of multi-link mechanized operation technology method based on the integration of agricultural machinery and agronomy is carried out. The structure of apple picking comprehensive operation equipment is designed, including the orchard traffic system, chassis support device, operation platform, platform lifting device, apple collection device, apple conveying system, automatic sorting, bagging device and fruit box rotation platform, which solves the key technical problems of mechanization, such as adaptability of trafficability, extension of operation space and low loss of fruit delivery and fruit collection and placement. The damage of apples is reduced by adopting flexible collection, conveying device and the quality of apples is improved by adopting apple collection, automatic sorting and packing system to realize the second sorting and packing of apples. The design of the device can realize the integrated service of apple from picking to sealing and selling, eliminating the intermediate labour-intensive and time-consuming links, the production efficiency of apples is improved and the production cost is reduced. It laid a foundation for the realization of the whole mechanization of apple production.

A Structural Design of COVID-19 Patient Lifting Device Using Crane and Hydraulic Mechanism

COVID-19 has brought the mankind into the worst condition. The health care workers as the forefront player during this pandemic are psychology and physically exhausted. In 2021, the infected patient is decreasing in some countries, yet increasing in others. Therefore, this study is aimed to design and analyze a patient lifting device in order to help the health workers in handling paralyzed and bone traumatic patients in effective way. This lifting device is designed to be operated by only one person and contactless with the patient. Thus, the healthcare worker can work on safety procedure of COVID-19. The structural design of the device is using the concept of crane and hydraulic mechanism that can handle a maximum weight of 2,000 N. Every mechanical part that is considered critical becomes the focus in the strength analysis. The analysis is done by theoretical approach under static and dynamic loading. As the results, the static and fatigue analyses show that the most critical part of the lifting device is at the fork structure with safety factor of 1.04. This indicates the design is in safety condition and could have an infinite service life cycle.