Push Rods Research Articles

Customizable Push Rod for Forsus Appliance

Introduction Among fixed orthodontic appliances, Forsus fatigue-resistant device (FRD) is a popular choice for treating Class II malocclusion in permanent dentition due to its patient-friendly design. FRD utilizes nickel titanium coil springs to deliver precise and adjustable forces for clinical applications. Material and method A 16 gauge stainless steel wire is used for the fabrication of push rods. Results The fabricated push rods work with efficacy in advancing the mandible in forward position. Conclusion In cases of push rod size mismatch our innovative design overcomes these limitations, ensuring optimal fit and performance.

Design and Simulation of Exoskeleton Robot

Based on the research of lower limb exoskeleton robots and extensive literature review, combined with human anatomy and kinematics, a four-degree-of-freedom lower limb exoskeleton robot was designed, and its three-dimensional model was established using UG software. In the design of the exoskeleton robot, it is required to have a simple structure, zero sensitivity in response speed, and be easy to realize automatic control. The exoskeleton robot designed in this paper uses electric push rods as the driving elements, and the dimensions of each part of the robot are obtained from the national standard human body size table; based on the analysis of the human gait cycle, and using cubic polynomial interpolation to plan the spatial posture of each joint; Adams was used to simulate the movement of the exoskeleton robot, and the motion curves of each joint were obtained.

Enhancing UAV elevator actuator model using multibody dynamics simulation

This paper proposes an improved actuator system model for UAV elevators using multibody dynamics simulation. The multibody dynamics simulation employs the Simscape Multibody, module in MATLAB coupled with Simulink to model the servo and hinge moment calculation. The actuator system comprises an electrical servo and mechanical components, including arms, push rods, horns, and the elevator. The electrical servo is modeled using a PID controller and a simplified motor model. The multibody dynamics simulation is employed to capture the dynamics of the mechanical components, coupled with the electrical servo through torque delivery to the mechanical components. The simulation is applied to the elevator of a medium altitude long endurance (MALE) UAV with a Maximum Take Off Weight of 1300 Kg. Generating these quantities provide a benefit in capturing the operational envelope of the servo to be compared to its limitations. Given the features of this simulation, it is proposed to extend the research by integrating this method with flight dynamics simulation.

A Diagnostic Machine Learning Algorithm for Air Brakes in Commercial Vehicles⁎

To safely introduce any level of autonomy to trucks, the health of their brake systems needs to be monitored continuously. Out-of-adjustment push rods and leakages in the air brake system are two major reasons for increased braking distances in trucks, and result in safety violations. Air leakages can occur due to small cracks or loose/improperly ft couplings which do not affect the overall braking capacity but contribute greatly to increasing the braking lag and reducing the maximum braking torque at the wheels. Similarly, an increased stroke of push rod leads to a larger delay in brake response and a smaller value of the brake torque at the wheels. Currently, the condition of an air brake system is inspected manually by measuring the push rod offset, checking the couplings and hoses of the system for air leakages. These inspections are highly labor intensive, subjective, time consuming and do not accurately quantify how adversely the braking system is affected. Having an on-board diagnostic device that can monitor the health of air brakes would be crucial in the prevention of road accidents, especially when considering any level of automation and comply with FMSCA safety requirements. The focus of this paper is to aid the development of such a diagnostic system that facilitates enforcement and pre-trip inspections and continuous on-board monitoring of trucks through the development of a model for its multi-chamber braking system; this model can be used to estimate the severity of leakage and the push rod stroke using real time brake pressure transients. A machine learning algorithm for estimating the air leakage in the air brake system and its experimental corroboration is presented in this paper.

Modeling and driving function optimization of tree climbing robot

To ensure the tree-climbing robot can complete the up-tree or down-tree process, its arms need to adjust the displacement of the push rod in real-time according to the diameter size of the tree trunk so that the tire can smoothly bypass the smaller tree pile. However, the irregular shape of the trunk surface makes the inflatable tire vibrate during rolling, which will reversely affect the performance of the push rod. Based on this, the three-dimensional model of the tree-climbing robot is established by Solid Works software, and the kinematics simulation model of the tree-climbing robot is established by Automatic Dynamic Analysis of Mechanical Systems (ADAMS). The kinematics simulation analysis is carried out. According to the tire displacement curve of the tree-climbing robot, the optimal solution of the push rod driving function is solved. Under the condition of ensuring the trajectory of the spiral rise is unchanged, the mean square deviation of the distance between the two arms of the tree-climbing robot is the smallest, and the push rod is the least affected by the reverse effect of the tire. The simulation results show that under the condition of the optimal solution, the frequency distribution and amplitude of the four springs are basically the same. The force of the four springs is uniform, and the reverse influence of the tires on the two push rods is minimized, which is conducive to the improvement of the stability of the tree climbing robot.

Magnetic and dynamic analysis of a new type of wall-climbing robot

Wall-climbing robots are a promising enabling technology for a wide range of high-altitude operations in industrial production, including cleaning, descaling and spraying of large ships, inspection, flaw detection and maintenance of thermal power boilers, etc. This is due to their high work efficiency and high safety when compared with traditional manual operations. However, existing wall-climbing robots still remain some challenges that limit their development. Here, we propose a new type of wall-climbing robot capable of achieving floating obstacle-climbing by using springs and linear bearings and realizing magnetic adjustment by using electric push rods. We develop a theoretical model to analyze statics and dynamics of the wall-climbing robot, and then use Ansoft and Adams to analyze the process of obstacle crossing, magnetic attraction force, driving force and speed change. The simulation results demonstrate that the proposed wall-climbing robot can achieve the effect for floating to overcome obstacle crossing and adjustable magnetic force.

Sensitivity Optimisation of a Main Marine Diesel Engine Electronic Speed Governor

Electronic speed governors have become widespread on marine diesel engines. In comparison with hydromechanical ones, they have an additional setting parameter – input signal sensitivity. This parameter allows changing the response of governors to high-frequency disturbances. In camshaft diesel engines, such disturbances are generated when the cams run over fuels pump push rods, while in ME (MAN Energy Solutions) or RT-flex (Wärtsilä) engines they result from the use of inductive sensors with a serrated tape on the diesel shaft for speed measurement. If the engine is used as a main engine on vessels, the governor’s sensitivity additionally allows governors to vary the response to propeller shaft resistance moment fluctuations in sea waves conditions. In practice the value of sensitivity of electronic speed governors of main marine engines is selected intuitively. As a result, the adjustment of governors doesn’t provide satisfactory stability of speed modes at the change of sea conditions. The study aims to develop a methodology for adjusting the sensitivity of main engines electronic speed governors with considering the stochasticity of the load on the diesel engine in sea waves state. The study was carried out using the systems of automatic speed control model, which is based on the assumption of relatively small deviations of diesel engine shaft rotation speed and load parameters at sea waves conditions. Considering the character and magnitude of change of load on diesel engine at sea waves conditions depend on many variables of external conditions (waves levels, course of a vessel in relation to wind-wave conditions, wind gusts, vessel’s loading condition, given speed of a vessel), any set value of sensitivity of electronic speed governors appears to be optimum only for a particular case of vessel movement in sea waves state. The scientific novelty is defined by the fact that recommendations on the choice of governor sensitivity are determined with considering stochasticity of propeller shaft resistance moment fluctuations at sea waves conditions, that increased accuracy, and validity of recommendations. The practical significance of the research consist in the increase of stability of speed modes of the main engine with electronic speed governor at various sea waves conditions

Wheel Deflection Control of Agricultural Vehicles with Four-Wheel Independent Omnidirectional Steering

Due to the harsh working environment of wheeled agricultural vehicles in the field, it is difficult to ensure that all wheels make contact with the ground at the same time, which is easy to unequally distribute the yaw moments of each independent wheel. The commonly used vehicle lateral control methods are mostly controlled by coordinating the individual torque between different wheels. Obviously, this control method is not suitable for agricultural four-wheeled vehicles. The goal of this study was to provide a wheel steering angle control method that uses electric push rods as actuators that can cope with this problem. The design of a four-wheel steering controller generally adopts the linear PID control method, but the research object of this paper is difficult to establish an accurate and linear mathematical model due to the complex working environment. Therefore, fuzzy adjustment is added on the basis of PID control, which can meet the requirements of model difficulty and control accuracy at the same time. In order to verify the feasibility and rationality of the designed wheel steering mechanism, the model dynamics simulation based on ADAMS software and the response analysis of the electric linear actuator thrust were completed. Based on the kinematics model of the controlled object, the rotation angle of the actuator motor is used as the control target, the lateral deviation e and deviation variation ec are taken as input variables and the parameters KP, KI and KD are taken as output variables, thereby establishing a fuzzy PID controller. Then, this controller is constructed in the Matlab/ Simulink simulation environment to analyze the lateral deviation and response stability during the process of vehicle path tracking. From the verification results of the linear path walking test under the fuzzy PID control method, the maximum lateral deviation of vehicle chassis is 2.7 cm when the driving speed is set as 1 m/s, and the deviation adjustment stable time of the system is 0.15 s. It can be seen that the proposed steering control strategy has good response performance and effectively increases the steering stability.

Establishing the value of the deflection of the soil-piercing working body with an asymmetric tip when correcting the airway of movement

Trenchless laying of engineering communications is actively used in all countries of the world. Among the existing methods of formation of wells for the implementation of these technologies, the most popular is the method of ground penetration. The main disadvantage of this method is the poor accuracy of movement of the piercing head in the array. This requires constant adjustments to the trajectory of its movement. This process can be controlled by using a head with an asymmetrical tip and acting on it with translational and rotational motion. The transmission of these movements from the power unit by means of type-setting push rods. Therefore, it is important to choose a trajectory such that the deflection of the bar will be within the permissible stress range. If the bend goes beyond these limits, the rod may break and the puncture process will be interrupted. The conducted studies have established the regularities of the process of puncturing the soil with a head with an asymmetric tip in the form of an inclined flat surface. It has been established that the greatest deviation of the head from the action of the transverse component of the soil resistance force, which occurs when moving such a working body in the soil, will occur at an angle of inclination of the front surface of 25º, and the smallest deviation will occur at an angle of 55º. In addition, it was found that in heavy clay, deflection will occur almost 3 times worse than in a soup and 1.4 times worse than in a loam. It has been experimentally confirmed that at a distance of 10 m the puncture with a head with an inclined forehead surface in sandy loam was 40 mm, and in clay 20 mm. At an angle of inclination of 70º, a constant core of soil compaction is formed and the process of controlling the movement of the head stops.

Conceptual Design and Finite Element Fatigue Life Analysis of a Poppet Valve Spring Compressor

In the overhauling of the internal combustion engine, a lot of tools are used and among them is the poppet valve spring compressor. In Ghana, auto mechanics at the “way-side” garages make use of improvised tools, such as pipes, pliers, and push rods, for compressing valve springs. However, there are some challenges associated with the usage of these tools which include misplacement of cotters, injuries, and sometimes valve bends. In this work, a review of some of the existing designs of the improvised tools was considered. Also, a survey was conducted to seek the opinion of users (auto technicians and/or mechanics) of the tools. A design was made for spring compression by incorporating a magnet with a pull force of 679.78 N to take care of the removal of cotters during valve assembly dismantling. In this research, an efficient and user-friendly poppet valve spring compression tool with a total mass of 0.88 kg was designed. Finite element analysis (FEA) was performed on the upper and lower parts of the tool to examine its response due to the loads that act on it during operation. It was discovered from the analysis that the upper frame of the valve spring compressor experienced the highest von Mises stress of 59.77 MPa at the neck region, whilst the corresponding fatigue analysis showed a maximum fatigue life of 8.355 × 109 cycles.

Research on Design Method of High Speed and High Dynamic Pressure Separation Structure

The inter-stage separation scheme has always been the focus and difficulty of low-altitude high-speed aircraft design. The separation reliability of low altitude high-speed aircraft is required to be higher. Experts and scholars have carried out design research on different forms of separation schemes. In this paper, two typical kind of inter-stage separation schemes are introduced. For aircraft A, a point cold separation scheme is adopted, which is connected by four explosive bolts, and two piston push rods provide separation impulse. For aircraft B, exhaust ports are opened on both sides of the rear of the transition section. The tail section is equipped with four “X” full-motion rudders for flight control. In addition, two horizontal stabilizers were added to improve stability. Based on the comparison and analysis of different inter-stage separation schemes for The separation reliability of low altitude high-speed aircraft is required to be higher. Experts and scholars have carried out design research on different forms of separation schemes. two different types of aircraft A and aircraft B, a new high reliability interstage separation scheme is proposed, the feasibility of the scheme is verified by simulation analysis, and the design of the stage separation structure under high dynamic pressure and high speed with compact layout is realized.

Experimental investigation on the mechanical behavior of hybrid bonded (rivet/adhesive) tubular lap joint (composite to metal) under pure torsion

The hybrid joints being used in the design of mechanical structures because of their significant advantages. The tubular lap joints are used widely in aerospace, naval, and transport industries such as rudder and elevator rods, driving shafts, pull push rods, anti-roll bar and stabilizer bar in cars, trucks and trains. The torsional behavior of mechanical, adhesively bonded, and hybrid tubular lap joints for aluminum to aluminum, and composite to aluminum subjected to pure torsion have been investigated experimentally. The effect of outer tube material and thickness, the joint’s type, and cured and post-cured temperature (room temperature and 40 °C), have been investigated experimentally. A fixture and a torsional set-up device have been designed and manufactured to apply the required torque to the joint. The outcomes from composite to aluminum joints confirm that the hybrid joint has 39.5% and 276.6% higher torque capacity than the mechanical joint and adhesively bonded joint, respectively. Furthermore, the cured and post-cured process at 40 °C, increased the maximum torque to failure, 37.6% and 57.1% for adhesively bonded and hybrid (rivet/bonded) joint, respectively. It has been observed that by upgrading the mechanical joint and adhesively bonded joint to the hybrid (rivet/bonded) joint, increasing the amount of joint’s strength and torque capacity in comparison with the increase in the weight of the structure is affordable.

Dynamic and Static Characteristics of Double Push Rods Electromechanical Converter

Due to the influence of material characteristics and winding power, single output electromagnet has limited ability to improve the dynamic characteristic of electro-hydraulic valve. Therefore, an electromechanical converter with double push rods is proposed in this paper, which can simultaneously output two electromagnetic forces, can push or pull the valve core and sleeve according to the current direction and realize rapid operation of load. According to the electromagnetic principle and the magnetic circuit analysis method, the mathematical model and equivalent circuit of the electromechanical converter with double push rods are established. Through the finite element simulation model of the electromechanical converter with double push rods with the same magnetization directions, the changing rules of its magnetic field distribution and force–displacement behaviors are studied and analyzed. According to the analysis results, the electromagnetic mechanical parameters and mechanical structure of the electromechanical converter with double push rods are determined, and the prototype is made. The test platform for the push-pull characteristics of the electromechanical converter with double push rods is built, and its static and dynamic characteristics are tested and analyzed. The results show that the thrust and pull output characteristics of the internal and external push rods are basically consistent with the simulation output, and proportional to the current density of the coil; the push-pull hysteresis of internal and external push rods output force is less than 5%; and the dynamic time response characteristics of the displacement and force are obtained. The hysteresis effect of output force is improved effectively through the H bridge drive control circuit modulated by PWM. Compared with the displacement response of a single-winding electromagnet with a similar volume, it can effectively improve the dynamic displacement response. Follow-up work will further optimize the structure of the electromechanical converter and test the corresponding pilot valve. The research results provide a new theory for improving the output characteristics of electro-hydraulic pilot valve and have an extremely high engineering application value and broad application prospect.

A Direct-Push Crosshole (DPCH) Test Method for the In Situ Evaluation of High-Resolution P- and S-Wave Velocities

The direct-push crosshole (DPCH) test is a new, invasive, near-surface seismic testing method. DPCH combines the desirable characteristics of borehole-based crosshole seismic testing with the relative inexpensiveness and speed of direct-push testing methods like cone penetration testing (CPT). At each measurement depth (typically every 20–50 cm), compression (P) and shear (S) waves are generated simultaneously using hammer taps on one of the CPT push rods (a pushable, in-ground seismic source can also be used). These P- and S-waves are propagated between two instrumented seismic cones (i.e., a source and receiver cone). The instrumented cones contain a sensor package with three orthogonally oriented geophones to measure the seismic waveforms and a MEMS accelerometer to track the deviation/position of each cone as it is advanced into the ground. DPCH testing enables high-resolution profiles of P- and S-wave velocity to be measured over the top 20–30 meters of the subsurface for use in geotechnical engineering analyses. It also allows for testing across/through ground improvement elements like stone columns. The DPCH instrumentation, testing methodology, and data reduction techniques are explained in detail in this article, and results from several sites are discussed.

Numerical Modeling and Investigation on Aerodynamic Noise Characteristics of Pantographs in High-Speed Trains

Pantographs are important devices on high-speed trains. When a train runs at a high speed, concave and convex parts of the train cause serious airflow disturbances and result in flow separation, eddy shedding, and breakdown. A strong fluctuation pressure field will be caused and transformed into aerodynamic noises. When high-speed trains reach 300 km/h, aerodynamic noises become the main noise source. Aerodynamic noises of pantographs occupy a large proportion in far-field aerodynamic noises of the whole train. Therefore, the problem of aerodynamic noises for pantographs is outstanding among many aerodynamics problems. This paper applies Detached Eddy Simulation (DES) to conducting numerical simulations of flow fields around pantographs of high-speed trains which run in the open air. Time-domain characteristics, frequency-domain characteristics, and unsteady flow fields of aerodynamic noises for pantographs are obtained. The acoustic boundary element method is used to study noise radiation characteristics of pantographs. Results indicate that eddies with different rotation directions and different scales are in regions such as pantograph heads, hinge joints, bottom frames, and insulators, while larger eddies are on pantograph heads and bottom frames. These eddies affect fluctuation pressures of pantographs to form aerodynamic noise sources. Slide plates, pantograph heads, balance rods, insulators, bottom frames, and push rods are the main aerodynamic noise source of pantographs. Radiated energies of pantographs are mainly in mid-frequency and high-frequency bands. In high-frequency bands, the far-field aerodynamic noise of pantographs is mainly contributed by the pantograph head. Single-frequency noises are in the far-field aerodynamic noise of pantographs, where main frequencies are 293 Hz, 586 Hz, 880 Hz, and 1173 Hz. The farther the observed point is from the noise source, the faster the sound pressure attenuation will be. When the distance of two adjacent observed points is increased by double, the attenuation amplitude of sound pressure levels for pantographs is around 6.6 dB.

Design Manufacturing and Cost Estimation of Camshaft Used In Two Wheeler

The camshaft and its associated parts control the opening and closing of the two valves. The associated parts are push rods, rocker arms, valve springs and tappets. This shaft also provides the drive to the ignition system. The camshaft is driven by the crankshaft through timing gears. Cams are made as integral parts of the camshaft and are designed in such a way to open the valves at the correct timing and to keep them open for the necessary duration. In this project, a camshaft is designed for a two wheeler engine by using theoretical calculations. Cam profile is designed by using the calculations. A 3D model of the Camshaft is created using modeling software Pro/Engineer. For manufacturing cam shaft following manufacturing method are used by Machining, Casting and Forging. From above processes we selected casting processes because it’s used for bulk production. For the manufacture of Camshaft Core and Cavity is to be extracted from the model using manufacturing module in Pro/Engineer. Total Mould base is to be designed for the camshaft which is ready to go for production. CNC Program is to be generated for both core and cavity using roughing and finishing processes. This is also done in manufacturing module in Pro/Engineer. Total cost required for the manufacturing of die is estimated. From this project we will learn a manufacturing method for camshaft. Pro/ENGINEER is the standard in 3D product design, featuring industry-leading productivity tools that promote best practices in design.

Easy and effective technique of preventing incisor flaring during Forsus treatment

Lower incisor flaring is often encountered during Forsus treatment. To prevent this, consolidating the entire mandibular arch by ligature wire and cinching back the mandibular archwire has been recommended. However, lower incisor flaring might still occur due to ligature breakage from friction of the push rods and also cinching back the mandibular archwire might not be possible in few cases due to anatomic limitations. The following article describes an innovative technique to prevent any chances of lower incisor flaring during Forsus treatment in cases where cinching the archwire is not possible due to anatomic limitations. This method is simple, inexpensive, less time consuming and comfortable for the patient.

Research on Airbags Overturning Device due to the PID Closed-Loop Control Technology

Based on S7-200 PLC, pressure sensors and amplifiers, this paper uses PID instruction to establish the closed-loop pressure control system of the required thrust in turning airbags. So in the automatic overturning airbags, it is capable to real-time control the push rods running status.

Using slow-release permanganate candles to remove TCE from a low permeable aquifer at a former landfill

Past disposal of industrial solvents into unregulated landfills is a significant source of groundwater contamination. In 2009, we began investigating a former unregulated landfill with known trichloroethene (TCE) contamination. Our objective was to pinpoint the location of the plume and treat the TCE using in situ chemical oxidation (ISCO). We accomplished this by using electrical resistivity imaging (ERI) to survey the landfill and map the subsurface lithology. We then used the ERI survey maps to guide direct push groundwater sampling. A TCE plume (100–600μgL−1) was identified in a low permeable silty-clay aquifer (Kh=0.5md−1) that was within 6m of ground surface. To treat the TCE, we manufactured slow-release potassium permanganate candles (SRPCs) that were 91.4cm long and either 5.1cm or 7.6cm in dia. For comparison, we inserted equal masses of SRPCs (7.6-cm versus 5.1-cm dia) into the low permeable aquifer in staggered rows that intersected the TCE plume. The 5.1-cm dia candles were inserted using direct push rods while the 7.6-cm SRPCs were placed in 10 permanent wells. Pneumatic circulators that emitted small air bubbles were placed below the 7.6-cm SRPCs in the second year. Results 15months after installation showed significant TCE reductions in the 7.6-cm candle treatment zone (67–85%) and between 10% and 66% decrease in wells impacted by the direct push candles. These results support using slow-release permanganate candles as a means of treating chlorinated solvents in low permeable aquifers.

마그네틱 파우더 브레이크를 이용한 소형 진자형 충격시험기 개발

A miniature pendular type impact testing machine was designed and developed, adopting a magnetic powder brake in order to investigate tensile and shear behavior of a small solder ball at high speed. In this testing system, the potential energy of the pendulum is transferred into the impact energy during its drop. Then, the impact energy is transmitted through the striker which is connected to the push rods to push the specimen for tensile loading. The tensile behavior of lead-free solder ball in diameter of 760 <TEX>${\mu}m$</TEX> was successfully investigated in a speed range of 0.15 m/s~1.25 m/s using this designed device. The maximum tensile strength of the solder joint decreases with the loading speed in the testing condition. The maximum tensile strength of the joint was 56 MPa in the low speed region.