Quick-return Mechanism Research Articles

Effect of process parameters on the rheological properties of banana (Musa acuminata) fiber and optimization using response surface methodology

The labor-intensive, time-consuming, and uneconomical nature of manually extracting banana (Musa acuminata) fibers from pseudo-stem sheaths has prompted the exploration of automation as a solution. This study focuses on automating the feeding process of banana pseudostem sheaths using a quick return mechanism, which is more effective than other approaches. A comprehensive study was conducted to assess the impact of key process parameters, namely the decorticator (480–540 rpm), roller speed (50–80 rpm), and clearance between rollers (2–4 mm), on the mechanical properties of the extracted banana fiber. The Response Surface Methodology (RSM) was employed for the experimental design and analysis of data, and the mechanical properties under investigation included the tensile strength, Young's modulus, and strain percentage of the banana fiber. The results revealed that the decorticator speed, roller speed, and clearance between rollers are significantly influenced by their mechanical properties. Herein, the optimal process parameter values are identified as follows: a decorticator speed of 510 rpm, roller speed of 65 rpm, and clearance of 3 mm between rollers. The mechanical characterization of the optimized banana fiber exhibited impressive properties, with an ultimate tensile strength of 679.48 MPa, Young's modulus of 25.47 GPa, and strain of 3 %. This study demonstrates that automation coupled with systematic parameter optimization can enhance the mechanical attributes of banana fibers. This research not only addresses the challenges of manual extraction, but also advances the understanding of how process parameters affect banana fiber quality, thereby facilitating the utilization of this natural fiber in various industrial applications.

Revisiting the degree of quick-return of the linkage considering programmable input for contemporary mechanical systems

Starting from the programmable motion performance of modern actuation technology, this study elucidates that the degree of quick-return in a mechanical system is no longer entirely dependent on mechanism design. A theoretical framework is proposed for analyzing and synthesizing the degree of quick-return in contemporary mechanical systems based on time efficiency. This study adopts a functional perspective, first extending the traditional definition describing the degree of quick-return mechanism to encompass broader mechanical systems. Subsequently, we present a general formula for calculating the time-ratio and travel velocity-ratio coefficients under contemporary technological conditions, supported by a detailed mathematical derivation. Finally, a corresponding procedure is established for analyzing and synthesizing the degree of quick-return in a mechanical system, fostering improved collaboration between managers and designers. Case studies demonstrate that designers can achieve the desired degree of quick-return in mechanical systems and robots by leveraging time efficiency. The theoretical framework introduced in this paper is versatile and can benefit various industries, notably the field of robotics. This broadens the applicability of the degree of quick-return concept, marking a significant advancement in enhancing the time efficiency of mechanical systems.

Analisis Kinematika pada Quick Return Mechanism dengan Menggunakan Metode Bilangan Kompleks

Kinematics analysis includes analysis of position, velocity and acceleration of the rods of a mechanism. The complex number method is a kinematic analytical way to express position, velocity and acceleration vectors in the form of complex numbers. The first step that needs to be done is to determine the position vector of the point to be analyzed, then determine the velocity and acceleration vectors by differentiating with time. After that is done, then the algorithm can be made. The mechanism used for this study is the quick return mechanism. The assumed data for this analysis is the angular velocity of rod 2 is 19.0986 rpm and the acceleration of rod 2 is 0 rad/s2. The results of the position analysis show that if rod 2 rotates one full rotation (360o), then rod 4 rotates about 1/6 circle (232.72o - 294.12o) and the slider moves along the X axis (406.939 - 504.111). The maximum speed behind the slider is 121.45 mm/s while the maximum speed forward for the slider is 101.09 mm/s. A large change in velocity (acceleration) is needed when bar 4 and the slider change direction (from CW to CCW or vice versa), this is indicated by a decrease and increase at the beginning and end of the graphic with significant acceleration

A Computer Simulation of a Modified Oldham Coupling

In this research, an Oldham coupling is used, and it has been modified to obtain new features. The modification is made on the intermediate part of the Oldham coupling and hence a kinematic model is approached, and two new applications are found. The proposed mechanism can be used as a function generator for some specific functions such as cardioid for the ratio, crank/shift=1, and the second finding as a sort of quick return mechanism. The results of the mathematical model show a good agreement with those of the cad model simulation and the related literature.

Finite element analysis of crank and slotted lever quick return mechanism for shaper machine application

Quick Return Mechanism (QRM) is a mechanical assembly to form a reciprocating motion that is so designed to reduce the ideal time required for a reappearance stroke. It translates rotational motion into countering motion, but dissimilar to the crank and slider, the onward reciprocating gesture is at a slower proportion than the return stroke. This paper mainly focuses on finite element examination of the QRM for shaper application. The 3D model of the QRM was modeled in SOLIDWORK 17, and finite element analysis was performed in ANSYS 18. There are three different lengths of connecting rod (link 2) compared to each other. By increasing the crank length, the cutter speed will be increased (i.e., velocity is directly related to crank length). Ram velocity varies from zero at the beginning, maximum at the middle of the stroke, and zero at the end. In the numerical analysis when the crank length decreases the total deformation decreases and vice versa for cutting speed.

Optimizing the Modified Whitworth Quick Return Mechanism Using Taguchi and ANOVA Methods

The cutting time ratio is one of the most important parameters pointing out the effectiveness of the Whitworth quick return mechanism. The study supplemented a novel modification to a traditional Whitworth quick return mechanism to improve the cutting time ratio. The alteration was performed by consolidating a set of links to the conventional mechanism. This supplemental encompasses a crank, a ground, a sliding pivot, and a slotted link. A mathematical model was derived for the modified Whitworth quick return mechanism. This mathematical model was used for simulation to check the enhancement of cutting time ratio due to the new additional links. It was shown that the increase in the value of cutting time ratio exceeds eight times that of the original mechanism. Taguchi and Analysis of Variance (ANOVA) methods were utilized to verify the effectiveness and weight of each additional link on the enhancement of cutting time ratio. The outcomes manifested that the added links and their joining to the ground are more influential than the original links.

Dynamic Analyses of Whitworth Quick Return Mechanism

Herein, we present a dynamic analysis on a Whitworth quick return mechanism, which was proposed as a class project to engage Mechanical Engineering students in the Machine Dynamics course. The objectives of the project are to teach (1) kinematic analysis on planar linkage mechanism using complex numbers and (2) kinetic analyses using distributed and lumped mass models. The analytical models were implemented using an engineering math software – Mathcad, and the results were validated by a multibody dynamics simulation software – Inventor. Loop closure equations were first built and solved to find link positions, and then velocities and accelerations were confirmed with numerical differentiation in Mathcad. Based on the solved kinematic quantities, a kinetic analysis was carried out using distributed and lumped mass models as well as in Inventor. The reactions and torques at the input link of the distributed mass model were found identical to those derived from Inventor. It was found the maximum reactions at pin joints were 11% to 100% different between the distributed mass model and the simplified lumped mass model. However, the shaking forces found in both models were nearly identical, and the peak values of the shaking moments were comparable. It is confirmed the lumped mass model can serve as a quick method to find the magnitude of the shaking forces and moments without solving simultaneous equation systems.

Finite Element Analysis of Crack and Slotted Lever Quick Return Mechanism for Shaper Application

Finite Element Analysis of Crack and Slotted Lever Quick Return Mechanism for Shaper Application

Design, simulation, and analysis using 316 stainless-steel alloy based automatic protection guard for bike

An automatic protection guard for bikes reduces the impact to the side panels, engine, and the rider's leg when the bike collides with the ground, which follows the reverse quick return mechanism. Include a tilt sensor to monitor the bike's lean angle to activate the system and a wave spring inside the hollow bars to absorb the impact. A tilt sensor will be installed and will set a lean angle to the system. When the bike crosses the calibrated lean angle, the system activates and releases the bars from the system installed onto the bike frame and will take the first contact with the ground surface. To match real-life situations, the time taken for the protection guards to move from initial position to extreme position has been calculated using solid Works motion analysis with an average time taken is 0.14 s, and to find the total deformation different loads and different spring constants have been applied using Ansys software the average deformation is 12 mm. The system helps the rider to ride the bike in a safe mode. The total design system is dynamic and varies with the bike segment but follows the same mechanism.

Optimal sliding mode control for cutting tasks of quick-return mechanisms

A solution of the constant cutting velocity problem of quick-return mechanisms is the main concern of this paper. An optimal sliding mode control in the task space is used to achieve uniform and accurate cuts throughout the workpiece. The switching hyperplane is designed to minimize the position error of the slider-dynamics in an infinite horizon.A Jacobian compensator is used to exploit the mechanical advantage and ensure controllability. The velocity profile is constructed in terms of the mechanism and workpiece geometric properties. Stability of the closed-loop dynamics is verified with the Lyapunov stability theory. Experiments are carried out in a quick-return mechanism prototype to validate the proposal.

Improving The Efficiency of Stationary Concrete Pumps Using Whitworth Quick Return Mechanism

The objective of this paper is to study the working of concrete pumps and to establish an alternative mechanism that would enhance their efficiency. A concrete pump is a machine used for transferring semi-solid, ready-mix concrete by pumping. As observed from the analysis of their functioning, it was evident that the transition of energy from mechanical to hydraulic, and back to mechanical during the process was accompanied with significant energy loss, which comprehensively reduced the efficiency of the concrete pump. A great proportion of this energy was lost through heat dissipation. Reducing the number of energy conversions posed to be a promising concept, for which the usage of hydraulic system in the current setup was to be withdrawn. The Whitworth Quick Return mechanism sufficed as a suitable alternative for the required purpose. It was observed from the mathematical analysis of the new mechanism that the theoretical flow rate increased from 45m3/h to 73m3/h, indicating a higher volume of concrete being pumped at the same input energy supply.

Different Dynamic Formulations for a Mechanism using Bond Graph

For modeling dynamics of mechanisms, various classical formulations are available in the literature. The equations of dynamics given by various classical formulations can also be derived from the bond graph. The bond graph is a convenient graphical representation for modeling dynamics of physical systems in multi-energy domains.In this paper, various alternative causality assignment procedures in the bond graph are used to derive different classical formulations such as the Lagrange’s equations of the first kind (with multipliers), Lagrange’s formulation of the second kind, and Hamiltonian formulations. An example of the quick return mechanism has been modeled using the bond graph technique, and various alternative causality assignment procedures are applied to derive the various formulations. Simulation coding has been done using MATLAB and results have been analyzed and discussed. The purpose of this paper is to show how the various formulations can be obtained from bond graph using various alternative causality assignment procedures.

Design and Fabrication of Pneumatic Can Crushing Machine

This paper is based on the design and fabricate of a pneumatic can crusher that will reduce to the smallest possible amount of the volume of aluminum cans by 70%. The can crusher is made up of various parts containing parts such as a lever, base frame, can bin, piston cylinder arrangement, chain sprocket mechanism and bearing. The inspiration behind this design came from the wastages in eateries, canteens of big companies where people gather and consume a lot of canned beverages. Thus, it makes sense that there should be an easy way to dispose of used cans properly during large social gatherings. The Can Crushing machine works with the help of pneumatic single acting cylinder. The machine is portable in size, and as such is easily transportable. Most companies find it difficult to dispose of their used cans in hotels and canteens and to create enough storage space that is required. This paper deals with the operations, the design and structural analysis of can crusher. A Can crusher is a device to reduce large material object into a smaller volume. The crusher reduces the size or change the form of waste materials so that they can be disposed off or recycled easily. The Can crushing machine is designed to crush aluminum waste cans by 80%. reduction in volume. It is used primarily to ease transportation of aluminum waste for recycling purposes. The machine is designed to smash an empty can of diameter 65mm and height 120mm to height of between 25mm to 30mm. It uses compressed air for its operations with the following component parts: pneumatic cylinder, solenoid valve, control unit and hoses. The cans are fed into the hopper and the cans travel in an orderly manner through the chute into the crushing chamber. The air compressor through the pneumatic cylinder supplies the required crushing force. The crushed cans drop through the created space into the collection tray below the crushing chamber Keywords: Belt Pulley, Cans Components, crushing machine, Quick return mechanism

Recent development in the field of shaper machine

Shaperis a type of machine tool that uses linear relative motion between the workpiece and a single-point cutting tool to machine a linear toolpath. Its cut is analogous to that of a lathe. It can cut curves, angles and many other shapes. It is a popular machine in a workshop because its movement is very simple although it can produce a variety of work. A shaper is used to machine a single job by using a single point cutting tool and hence it cannot be used for high production rates. A single point cutting tool is rigidly held in the tool holder, which is mounted on the ram. The work piece is rigidly held in a vice or clamped directly on the table. The table may be supported at the outer end. The ram reciprocates and thus cutting tool held in tool holder moves forwards and backwards over the work piece. In a standard shaper, cutting of material takes place during the forward stroke of the ram the backward stroke remains idle. This is obtained by "Quick Return Mechanism". The depth of the cut is adjusted by moving the tool downwards towards the workpiece. The feed motion is given to the workpiece and follows the "Pawl and Ratchet mechanism".

A linear guide-based actuation concept for a novel morphing aileron

ABSTRACTThis paper deals with the actuation system design of a full-scale morphing aileron for regional aircraft. The aileron is allowed to smoothly change its geometrical configuration and perform the in-flight transition from a baseline shape to a set of optimal morphed ones pre-defined on the basis of aerodynamic requirements. The design of such innovative aileron is aimed not only at substituting the conventional aileron installed on a real aircraft but also to provide additional functionality. The aileron is free to rotate around its main hinge axis and it is also allowed to smoothly modify camber with two independent actuation systems. In such manner it can be used also during cruise with a symmetric deflection between the two half wings in order to reduce drag in off design condition. To accomplish variable aileron shape, a rigid-body mechanism was designed. The proposed aileron architecture is characterised by segmented adaptive ribs rigidly linked each other with spanwise reinforcements such as spars and stringers in a multi-box arrangement. Each rib is split into two movable plates connected by means of rotational hinges in a finger-like mechanism. The mechanism is driven by a load-bearing actuator by means of a kinematic chain opportunely tied based on the structural requirements in terms of shape to be matched and load to be withstood. The proposed device is an innovative arrangement of the quick-return mechanism composed of a beam leverage, commercial linear guides and a crank. The actuator shaft is directly inserted in the crank, which transmits the rotation to the linear guide that slide along a rail moving upward or downward the beam thus resulting in a camber variation. The entire aileron is moved by three leverages internally contained and distributed along the first two bays while the most external ribs are considered passive and their movement slaved. Two actuation layouts are analytically and numerically studied, the analytical theory is presented and validated by means of a multi-body simulation. Moreover, a linear static analysis was carried out under the hypothesis of glued contact between linear guides components simulating a jamming condition. This assumption has been formulated because it represents the most severe condition that envelop all the operative loads to which the actuation system is subjected. The analyses conducted are preliminarily aimed to verify that no failure occur under the imposed loads. In this first design loop, the vertical static force acting on the linear carriage exceeded allowable value and then a new configuration with double-sided linear guides was then investigated.

Design and Development of Manual Operated Sugarcane Bud Chipping Machine

Sugarcane is a primary crop in many parts of India. The seed or bud of the sugarcane is a part of the plant itself. Due to complicated and expensive tools, separating bud from plant is a difficult process. Use of plant for its raw materials and products leads to loss of buds whereas planting buds with the plant leads to loss of plant products. Current machines used for sugarcane bud cutting require skill and training but are also unsafe. The risk of injury is also high. Thus, there is a need for development of bud chipping machine which satisfies the above criterion. Research was done by conducting literature survey, patent search and market survey. Different concepts were generated, developed and analysed. A foot operated machine which requires less effort than hand operating machine was adopted. Whitworth quick return mechanism is used because it gives constant velocity throughout the cutting stroke and return stroke is quicker than cutting stroke thus increasing productivity and reducing idle time. Designing and modelling of machine is carried out by considering aspects of design and human ergonomics. Hence, simple and effective machine is designed which can be used to cut sugarcane buds without much effort, reduced loss of plant product, reduced muscular problems and can be safely operated.

Enhancing the Efficiency of Reciprocating Compressors by Incorporating with Quick Return Mechanism

Enhancing the Efficiency of Reciprocating Compressors by Incorporating with Quick Return Mechanism

Influence of Pelvis Width and Leg Length on the Wear Behavior of UHMWPE Hip Cup

Total hip joint replacement considered one of the success sections of the modern medicine, but still the wear of total hip prostheses is a significant clinical problem and this problem might be increasingly complex with adding the influence of pelvis width and leg length during the preclinical testing. This study aims to analyze the effect of the leg length (femur and tibia) and the pelvis width on the wear behavior of ultra-high molecular weight polyethylene (UHMWPE) hip cup. The experiments have been carried out on a total leg joint’s simulator (TLJS), which was particularly designed for this purpose according to ISO 14242-1 standard. The TLJS consists of three units: leg components (femur, tibia, and foot), quick-return mechanism, and cam mechanism were used to reproduce the flexion–extension and external–internal movement, respectively, and upper body was used to stimulate the pelvis construction and applied load. The wear behavior of the tested cups (in weight loss form) was evaluated under dry lubricating conditions, and then the wear mechanism of worm cups was examined by using scanning electron microscopy. The results showed that the length of the femur, tibia, and pelvis width have a positive effect on the wear rate of the tested cups due to flexion and pelvic moment which is resulted by the ground reaction force and pelvic rotation force.

Determination of the acceleration and instantaneous center of the accelerations by 1/ω2

This paper explores the straight movement and a method conditionally marked 1/ω2 in which acceleration vectors multiplied by the reciprocal value of the square of the angular velocity. That is, at the quick-return mechanism and piston mechanism with oscillating cylinder allow schematic and simplified construction plan acceleration compared to the classical procedure. In addition, this paper presents a new method of determining the instantaneous center of the accelerations in the intersection of the two circles described from the centers of the acceleration vectors multiplied by the reciprocal value of the square of the angular velocity. Also for the first time, this paper presents a method of determining the instantaneous center of the accelerations in the intersection of the two circles that passes through the initial point of the two vectors of acceleration and their intersection point, and the circle passing through the endpoints of these two vectors and their intersection point.

Design of a hand water pump using a quick-return crank mechanism

The detailed design procedure for a quick-return mechanism hand water pump is presented. The system designed is basically a modification to reciprocating lift pumps also known as India mark III. The modified pump is operated by the up and down reciprocating movement of the handle. The major problems associated with the India mark III pump were the high level of fatigue of the operator, and low pump capacity. These problems motivated the design and fabrication of a manually operated hand pump that employs a quick-return mechanism and a gear drive in the power train to ease the operation and at the same time increase the pump’s capacity. Results obtained show that the quick-return mechanism has a capacity of 15.2 litres/min which will require an effort of 102.7 N, whereas the conventional lever lift mechanism has a capacity of 10.65 litres/min and requires an effort of 127 N.