Clutch System Research Articles

Influence of hinged device parameters on negative resonance oscillations during the operation of machine-tractor unit in transport mode

Annotation Purpose. Reducing the influence of resonance phenomena on the structural elements of a tractor of the KIY 14102 type when driving with an attached implement in transport mode. Methods. To solve this problem means of graph-analytical constructions, analytical geometry, oscillation theory and theoretical mechanics were used. Results. On the basis of the graphic-analytical analysis of the kinematic diagram of the tractor attachment of the KIY 14102 type, it was found that the position of the instantaneous center of its rotation significantly depends on the change in the angle between the tractor frame and the levers, which are united by the CA-1 automatic connection device. The frequency range of forced oscillations of the tractor frame, which occur when driving in a certain speed range, can coincide with the relative natural frequency of the tractors, which leads to resonance phenomena. Resonant longitudinal-angular vibrations of the tractor frame reduce the normal reactions of the steered wheels with the supporting surface, which worsens controllability. Changing the frequency of the natural resonance of the elements connecting the tractor with the implement can be done by changing the kinematic stiffness of the mounted system. Conclusions 1. The kinematic diagram of the hinged device of tractors significantly affects the dependence of the position of the instantaneous center of rotation of the hinged device relative to the mass of the implement that is aggregated. 2. The existing parameters of the mounted systems of tractors of the KIY 14102 type can lead to the occurrence of resonance phenomena when driving in transport mode on unpaved field roads, which negatively affects the controllability of the MTA. 3. Reducing the resonant frequency of natural vibrations of the attachment system with the tool, by reducing the kinematic stiffness, improves the dynamics of the interaction of the elements of the machine-tractor unit with each other and with the supporting surface. Keywords: machine-tractor unit, clutch system, tests, dynamic loads, strain gauge measurements, air pressure in tires.

Optimization of Belleville Spring by Inspecting Parameter Impacts

Clutch disc transmits the torque by frictional forces from the engine to transmission. For this purpose, clutch disc includes some components such a Belleville spring to provide vibration dampening. Belleville springs are used in order to perform hysteresis function of disc assembly by creating frictional torque into clutch system. Hysteresis function of disc is needed to absorb oscillations and prevent noise issues. Belleville spring geometrical shape is critically important and it defines load characteristic. A load of Belleville spring mainly depends on dimensions of inner diameter, outer diameter, thickness, angle, and slot dimensions. This study investigates the single and multi-objective optimization methodology in the automotive clutch system design. This novel methodology presents the design development approach to powertrain system components.

Effect of Passenger Car Oil Usage in a Motorcycle Engine

The aim of this research is to investigate the usage of passenger car engine oil into a motorcycle engine by determining the after effect of the lubricant to the engine. The difference between engine oil of passenger car and motorcycle is the friction modifier that is in the formulation of cars engine lubricant. A motorcycle engine has a wet clutch system in the crank case, such engine oil with a friction modifier will decrease the clutch capacity of the system. In this study, three types of methodology tests have been conducted such as endurance test which combined with the fuel efficiency test at the same time, drag test and Ferrography tests that were conducted to determine the amount of contamination in both types of engine oil. The results showed that using a passenger car lubricant on motorcycle engine did not affect the engine compartment and parts. The numbers of metal wear in the used oil of both types of cars and motorcycle were slightly different.

Numerical Simulation and Topological optimization of the dry clutch pressure plate

The common dry clutch pressure plate was prone to produce high temperature and axial thermal deformation due to the frictional heat generated during engagement. The overheated and overdeformed pressure plate decreases the torque transmission capacity of the clutch system and causes some kind of clutch malfunction including clutch slip and fracture. In this paper, the clutch pressure plate was firstly optimized by the topological optimization. Inspired by the topological optimized result, an improved design of the pressure plate was brought out, where the specific radial cooling channels and axial cooling holes were introduced in the new improved design in order to improve heat transfer and reduce the mass and thermal deformation as well. The performance of the new improved design is simulated and further optimized by the FE method. It is indicated that the mass of the optimum pressure plate was greatly reduced from the original design, with a mass reduction of 3.1 kg. The axial thermal deformation is also significantly decreased from the original pressure plate, decreasing from the original 0.35mm to the present 0.28mm while keeping the maximum temperature of pressure plate unchanged. These comparisons show that thermal-mechanical performance of the new pressure plate is improved effectively.

Fundamental study on the optimal path of centrifugal pendulum vibration absorbers in automatic transmissions

In recent years, high-power and low-cylinder engines have seen increasingly widespread use. These engines produce a strong torsional vibration due to engine combustion. Furthermore, automatic transmissions necessitate the use of a lock-up clutch system that directly links the engine and gear train when the engine rotational speed is low. Using a torsional spring called a lock-up damper in the torque converter is not sufficient to absorb the torsional vibration. Therefore, the centrifugal pendulum vibration absorber (CPVA) has been developed to suppress the torsional vibration. The natural frequency of a CPVA is proportional to the engine rotational speed, and it is expected to suppress the torsional vibration over a wide range of speeds. However, the natural frequency of the CPVA varies because of the nonlinearity when the vibration amplitude of the CPVA is large. In this study, the optimal path of the CPVA to suppress the torsional vibration of the engine was investigated.

Integrated Thermal and Dynamic Analysis of Dry Automotive Clutch Linings

Optimum operation of clutch systems is dictated by their dynamic as well as thermal performance. Both of these aspects are closely related to the interfacial frictional characteristics of the clutch lining material, which also affects the noise, vibration and harshness response of the entire vehicular powertrain system. Severe operating conditions such as interfacial clutch slip and increased contact pressures occur during clutch engagement, leading to generation of contact heat, and higher clutch system temperature. Therefore, any undesired oscillatory responses, generated during clutch engagement, such as take-up judder phenomenon can exacerbate generated heat due to stick-slip motion. The paper presents an integrated thermal, and 9-DOF dynamic model of a rear wheel drive light truck powertrain system. The model also includes experimentally measured clutch lining frictional variations with interfacial slip speed, non-linear contact pressure profile and generated surface flash temperature. It is shown that severe torsional oscillations known as take-up judder lead to an increased overall clutch temperature. It also shows that ageing of clutch lining material alters its dynamic and thermal performance.

A Radial Clutch Needle for Facile and Safe Tissue Compartment Access.

Efficient and safe access to targeted therapeutic sites is a universal challenge in minimally invasive medical intervention. Percutaneous and transluminal needle insertion is often performed blindly and requires significant user skill and experience to avoid complications associated with the damage of underlying tissues or organs. Here, we report on the advancement of a safer needle with a radial mechanical clutch, which is designed to prevent overshoot injuries through the automatic stopping of the needle once a target cavity is reached. The stylet-mounted clutch system is inexpensive to manufacture and compatible with standard hypodermic or endoscopic needles, and therefore can be adapted to achieve safe access in a myriad of minimally invasive procedures, including targeted drug delivery, at-home and in-hospital intravenous access, laparoscopic and endo- and trans-luminal interventions. Here, we demonstrate the clutch needle design optimization and illustrate its potential for rapid and safe minimally invasive cannulation.

Thermal Compensation Control Strategy in Automated Dry Clutch Engagement Dynamics and Launch Manoeuvre

Repeated engagements in dry clutch systems could yield remarkable increase of clutch disk temperature. In dry clutch based transmissions like Automated Manual Transmissions and Dual Clutch Transmissions the overheating leads to poor control of gearshift quality due to unpredictable and fast change of frictional characteristic. Even permanent damage of clutch facings may occur. Under this light, this paper focusing on thermal effects to improve control performances and prevent uncomfortable engagements. To this aim, detailed analyses of dry clutch architecture have been carried out to understand the main phenomena which affect the clutch torque transmissibility. Moreover, a lumped thermal model has been developed to predict both the disk surface and cushion spring temperature in real-time environment. To validate the proposed thermal model, a non-linear least squares method has been used by comparing simulations with finite element results. A control strategy based on model predictive control and thermal compensation effects has been proposed to simulate vehicle launch manoeuvres in flat and up-hill road conditions with low and high initial clutch temperature as well. Finally, the proposed control approach has been compared with classic PI control strategy to prove its effectiveness.

PENERAPAN MODEL PEMBELAJARAN OPEN ENDED PROBLEM UNTUK MENINGKATKAN HASIL BELAJAR SISTEM KOPLING GANDA

This study aims to determine; (1) teacher activities after applying the open ended problems learning model in class XI TBSM SMKN 1 Kurun, (2) student activities after applying the open ended problems learning model in class XI TBSM SMKN 1 Kurun, (3) student responses after applying the open ended problems learning model on the double clutch system lesson, and (4) learning outcomes of class XI TBSM SMKN 1 Kurun, after following the open ended problems learning model on the double clutch system lesson. This research is descriptive quantitative, this research took the subject of class students XI TBSM SMKN 1 Kurun chosen as the subject of research. The instrument used is a test of cognitive learning outcomes, student activity sheet, teacher activity sheet, and student response questionnaires. As well as student learning outcomes related to cognitive, affective and psychomotor aspects. The results of data analysis showed that overall student activity was carried out well. The completeness of the classically tested cognitive learning outcomes of students in 13 people (92,85%) and 1 student has not yet finished (2,94%), so classically the results of student learning using open ended problems models are said to be successful

TP–Based model transformation and gain-scheduling control of electromagnetic actuated clutch systems

"This paper suggests two combinations of Tensor Product (TP)–based model transformation and gain-scheduling control leading to two efficient control system structures that are applied to the position control of nonlinear electromagnetic actuated clutch systems. One of the two combinations is included in a cascade control system structure that consists of a TP–based controller in the inner control loop and a gainscheduling–based controller in the outer control loop. The proposed control system structures were tested on the nonlinear process model and validated by simulation results. A comparative analysis is given."

Finite Element Simulation of Thermal Behavior of Dry Friction Clutch System during the Slipping Period

Finite Element Simulation of Thermal Behavior of Dry Friction Clutch System during the Slipping Period

Robust output feedback controller with high-gain observer for automatic clutch

Abstract Precise and stable position control is critical in automatic clutch system, which is a challenging issue because of its nonlinear characteristics, uncertainties of parameters and disturbances, and lack of all-state sensors. Therefore, a novel robust output feedback control method is proposed in this paper to deal with the nonlinearities, uncertainties and modeling errors. First, an electromechanical dry clutch actuator system is formulated by theoretical analysis combined with experimental data. Then, a robust controller is designed, including the recursive control law calculation and a high-gain observer based on output feedback to estimate the unmeasured states. Next, simulations are carried out to verify the effectiveness of proposed method. Finally, experiments are conducted on a hybrid electric powertrain bench and the results show that the proposed method has a satisfactory performance.

습식 클러치 설계를 위한 실험 변수에 따른 드래그 토크 특성 평가

As environmental and energy issues increase, energy efficiency is of great significance in the automobile industries. Drag torque of a wet clutch in an automatic transmission system is one of the causes of energy loss. In this work, the drag torque characteristics of a wet clutch as a function of rotational speed was experimentally investigated with respect to the test parameters such as automatic transmission fluid (ATF) temperature and flow rate, clearance between friction disk and separator, and the number of disks in the test system, using two different friction materials. Drag torque was found to decrease with increasing ATF temperature as a result of the decrease in viscosity. Also, drag torque decreased as the clearance between friction disk and separator increased. In addition, the drag torque increased along with the delay in the generation of maximum drag torque as the ATF flow rate increased. Furthermore, it was observed that drag torque increased with the increase in the number of disks in the test system. The drag torque characteristics as a function of rotational speed may be dependent on the friction materials. The results obtained from this work may aid in the design of wet clutch system to enhance performance.

Design Optimization of A Rotating Flywheel Under High Centrifugal Forces using Response Surface Method

Flywheel is a mechanical device specifically designed to efficiently store rotational energy. Flywheels resist changes in rotational speed by their moment of inertia. In automotive clutch system, flywheel rotates at high speed under the influence of rotational force which may result in severe crack. In this study, finite element analysis was used to predict equivalent stress of the flywheel at different rotational speed. Taking 8000 rpm as the maximum rotational speed, the layout of the flywheel was then modified. This is done not only to reduce the maximum equivalent stress, but also reduce the mass of the flywheel. The comparison between the original layout of the flywheel and the modified one is shown in this work.

Experimental and numerical assessment of the seismic response of steel structures with clutched inerters

Supplemental rotational inertia devices provide an efficient means of suppressing ground-induced vibrations over a large range of structural periods. The beneficial effects of the inerter can be further enhanced by coupling it with a clutch system that prevents it from driving the structural response and ensures that its supplemental rotational inertia is only employed to resist the motion. In this paper, we examine the behaviour of single-degree-of-freedom and multi-degree-of-freedom structures equipped with twin inerter-clutch devices subjected to strong ground-motion. The influence of the clutch stiffness, gears play, viscous damping and dry friction, on the non-linear dynamics of the system are explored first, by analysing the stable periodic solutions of a structure with inerters under harmonic-sweeps. We demonstrate that, for the range of parameters typically expected in earthquake engineering practice, the influence of dry-friction and clutch damping are limited, although the clutch stiffness and gear play may need to be accounted for when large inertances or defective clutches are considered. Based on these findings, we propose a simplified numerical modelling strategy suitable for implementation in conventional Finite Element simulations. Small scale experiments on bare elastic structures as well as structures equipped with 3D-printed inerter and inerter-clutch twins are presented and employed for concept demonstration and for the validation of the numerical model proposed. Finally, a series of studies on detailed numerical models of multi-storey steel frames under idealized and real pulse-like ground-motions are used to demonstrate the vibration absorbing capabilities brought about by the twin inerter-clutch system and to highlight practical aspects related to their structural implementation.

An Output Regulator With Rejection of Time-Varying Disturbance: Experimental Validation on Clutch Slip Control

Time-varying disturbances may severely deteriorate control performance. For instance, the time-varying vehicle mass and the clutch friction coefficient may make automated manual transmission vehicle fail to startup on a slope. A quadratic output regulator is proposed in this brief to deal with time-varying disturbances, and the unmeasurable disturbances are estimated by a disturbance observer. To derive the control law, a novel form of multiplier function $\lambda $ is introduced, and the control law is represented as a feedback form of the system states, the disturbances and their derivatives. The system is guaranteed to be input-to-state stable, which will significantly relax the dependence of the controller on modeling accuracy. Eventually, the proposed control law is validated on clutch slip control. Although the performance of clutch slip control is susceptible to the uncertainties in dry clutch system and the disturbances from external environment, the simulation and experimental results demonstrate that the control law is robust enough and has strong ability in rejecting time-varying disturbances, and the vehicle can be launched successfully with high performance through clutch slip control under various working scenarios.

Diagnostic of Failure in Transmission System of Agriculture Tractors Using Predictive Maintenance Based Software

The expansion of services and technological equipment applied to the agribusiness sector grows year after year, e.g., tractors and agricultural machinery, which use systems shipped with sophisticated software that collaborate to aid, and optimize activities in the field. Maintenance of agricultural machinery, including tractors, is routine in the life of any farmer, especially the preventive and corrective maintenance. In this paper, the objective was to evaluate an alternative for the use of diagnostic software in the prediction of failures that may occur in the tractor clutch system. In this study, the PicoScope6 software was used to identify the failures in this system, and then, using the predictive maintenance phase, was compared with classic maintenance methods, allowed for estimating the necessary repair time. Results showed that software identified more precisely the mechanical components that presented failures. From the identification of failure components, a list of repairs and exchanges was estimated, and, when compared to the list of components generated by inspection without diagnostic software, the repair time was reduced by 88%, and the cost of repair in up to 93%. The availability of the equipment also increased as a result of the shorter repair time, thus maximizing the machine time in the field.

Micromechanical model of dry friction hybrid polymer composite clutch facings

Modelling the complex coupled thermomechanical and tribological contact of a dry friction clutch system between cast iron flywheel and scatter-wound hybrid composite clutch facing requires a thought through investigation of the friction material properties and behaviour. Challenges of the creation of a mechanical stiffness matrix for such a complex material are described in this paper along with simplification ideas and solutions.

Adaptive torque tracking control during slip engagement of a dry clutch in vehicle powertrain

Dry clutches have been gaining its popularity for use in the transmission systems of small and medium-sized vehicles as well as the engine clutch systems of parallel hybrid vehicles. With this trend, the ability to appropriately control the amount of torque transferred through the dry clutch becomes important. This paper addresses a feedforward control method of clutch torque during slip engagement of a dry clutch utilizing a clutch friction model. In many studies, the clutch friction coefficient is considered as the only uncertain parameter in the clutch friction model. However, the clutch touch point can also serve as a major source of uncertainty in the clutch friction model. Thus, this paper proposes a simultaneous adaptation method to estimate the clutch friction coefficient and the clutch touch point in real time and a feedforward control method of clutch torque during slip engagement of a dry clutch based on the proposed adaptation algorithm. This control approach is applied to the slip engagement control of a dry engine clutch in a parallel hybrid vehicle and its effect is experimentally verified using a production vehicle.

Kinematic model of multiple trailers on a tractor system for production logistics applications

Abstract This paper demonstrates kinematic analysis of multiple trailers on a tractor system for production logistics. The analysis concerned three different steering systems of the trailers: virtual clutch and drawbar system, conventional clutch and drawbar system, double Ackermann steering system. Designed kinematic models contain various variants of paths: turning at a constant value of the steering angle, changing the steering angle as a result of an approaching collision. Each of these variants also included driving in a straight line after a 90° turn. The validation of the developed kinematic model was done by using a real logistic train, which path was registered via aerial drone. For each of the developed kinematic models, a visualization of drive through the 90° turn was created.