Gear Position Research Articles

Correlation of Planetary Bearing Outer Ring Creep and Gear Load Distribution in a Full-Size Wind Turbine

In this work, bearing outer ring creep in the planetary gear of a gear wind turbine gearbox is investigated. So far, gear creep has only been investigated experimentally on very small bearings under simplified load conditions. This paper presents experimental measurement results from a full-size 2.75 MW wind turbine. The test were performed on a system test bench capable of applying loads in all six degrees of freedom at the rotor hub. The objectives of this investigation are to provoke and measure bearing outer ring creep and to identify correlations to the gear load distributions acting on the planetary gear. After a motivation, a literature overview on bearing ring creep is given. Influences on and occurrences of ring creep are described and the two mechanisms roller-induced creep and gear creep explained. Then, the test setup and the evaluated experiments are presented. The influence of torque, rotational speed and additional non-torque loads on gear load distribution and bearing outer ring creep is shown, discussed and put in relation to findings from literature. Key findings are that outer ring creep speed increases with global rotational speed and torque. Also, gear creep – acting in the opposite direction of roller-induced creep – was found at the generator-sided bearing ring for loads below 40% nominal torque. The planet gear load distributions with sun and ring gear were highly uneven and opposed to each other at low torques while leveling out at high torques due to the load-dependent deformations of sun gear, planet carrier and ring gear. The average gear load distribution over all ring gear positions showed to be influenced only by torque and to be independent of non-torque loads. In accordance, even extreme non-torque loads were found to not influence the creep behavior of the two planetary bearing outer rings.

Rancang Bangun Alat Pemeriksa Run Out Roda Gigi menurut Standar ISO 1328

Power Train Otomotif (P3TO) Polman Bandung saat ini dilakukan pengembangan berupa gearbox utility vehicle. Salah satu parameter yang menjadi acuan pada kualitas produk roda gigi yaitu run-out. Berdasarkan standar ISO 1328:1976, Run Out of Gear adalah metode pemeriksaan penyimpangan kesalahan putar RCE (radial composite error) pada sepasang roda gigi. Rancang BangunAlat pemeriksa run out ini dibuat dengan prinsip kerja roda gigi diputar motor stepper dan pembacaan run-out digunakan sensor LVDT (linear variable differential transformator) melalui program software interface mikrokontroler Arduino. Sehingga dihasilkan data aktual nilai pengukuran run out sepasang roda gigi dalam bentuk grafik file (.csv) dan (.txt). Pada alat pemeriksa run out ini dilakukan pemeriksaan RCE terhadap sepasang roda gigi Otomotif ISO grade 8 (modul 2, Z=34, toleransi RCE = 0.09 mm ) . Berdasarkan Hasil pengukuran didapatkan RCE sebesar 0.10 mm. Hasil analisa penyimpangan RCE tersebut diakibatkan akumulasi penyimpangan toleransi ketegak-lurusan dan kesejajaran sumbu serta dimensi geometri profil roda gigi saat proses pembuatan produk roda gigi.

Design and application of air to fuel ratio controller for LPG fueled vehicles at typical down-way

This article presents an investigation of air–fuel ratio (AFR) controllers applied to liquefied petroleum gas (LPG) fuelled vehicles with second-generation LPG kits. When a vehicle is running on a down-way, fuel consumption tends to be rich because of the increased vacuum in the intake manifold. Therefore, an AFR controller was developed that can work based on a vehicle’s tilt sensor combined with an oxygen sensor. AFR controllers are employed to regulate injectors to form leaner mixtures. We tested the performance of AFR controller at a typical down-way of 10°, 15°, and 20°. As a result, the AFR controller was able to increase AFR value from an average of 14.5 (without controller) to 15.5–16.2, depending on the gear position and down-way angle. Furthermore, a greater of road slope was observed to have produced greater AFR. This AFR controller is very promising to be applied to vehicles operating in mountainous areas.

DESIGN AND EVALUATION OF A CONTROLLER TO ACHIEVE OPTIMUM SEEDING RATE WITH SPECIFIC SPATIAL MANAGEMENT IN AGRICULTURAL MACHINERY

Abstract. Achieving optimal seeding rates in different areas of the field is very important for maximizing crop yield. Nowadays, spatial management of croplands as a modern technology has been recommended in precision agriculture systems. Agricultural inputs such as seed, fertilizers, herbicides, etc., should be optimized with field conditions in different areas. For example, fertilizing and moisture should being compatible. Due to changes in these two factors, optimum seeding rates might being different in a field; areas with higher fertility or higher soil moisture have the higher seed rates. An applicable method to reach the ability of variable seeding rates in agricultural machines is to add controllers to the conventional fixed seeding rate seed drills. In the spatial management technology for seeding in a variable rate, first, the map of required seed for seeding practice is prepared for each particle of the field and then loaded in the machine at GIS format. The controller controls the seed rate continuously using the GIS map and the spatial position of the machine at field is provided by positioning systems. The aim of this study was to select the best closed-loop variable rate control system for Hassia seed drill shifting from a fixed rate to variable rate. To this end, Assessment of the performance of a control system that mounted on the seed dill and vary the rotational speed of the seed metering drive shaft performed. The control system was included a 250-watt DC engine, gearbox with constant gear ratio, two encoders (first for sensing the seed drill speed and second for sensing the rotational speed of the engine), position receiver and navigation, DC engine controller, and a portable computer for collecting data. The response time for transmitting seeding rate by the controller was determined from low to high 4/7 seconds and from high to low 2/5 seconds.

Effect of residual shaft bow on the dynamic analysis of a double-stage geared rotor-bearing system with translational motion due to shaft deformation

In this study, the dynamic responses of a double-stage geared rotor-bearing system with translational motion due to the effects of rotating shaft deformation were examined, which was lacking in past research. Residual shaft bow has been neglected in most geared rotor-bearing system models. In this study, the dynamic response of a double-stage geared rotor-bearing system whose gear set underwent translational motion was examined when the shaft was deformed (residual shaft bow). The proposed model considers contact ratio and pressure angle of gear pair as time-dependent variables, whereas in other models, they are constants. A finite element model of a double-stage geared rotor-bearing system with residual shaft bow was developed, and equations of motion were obtained by applying the Lagrange’s equation. System equations of motion are solved by Runge–Kutta numerical method. The dynamic response was investigated, including lateral response, contact ratio and pressure angle of gear pair with different residual shaft bow magnitudes and gear positions. The results show that residual shaft bow raises the amplitudes of lateral displacement, contact ratio and phase angle of gear pairs in the system. This study demonstrated that the residual shaft bow effect is too considerable to ignore when it becomes sufficiently large.

Locating Faulty Planet Gears Using External Vibration Measurements

In this study, a mesh phasing-based approach is developed to locate the positions of faulty planet gears using external vibration measurements. Previous studies have illustrated how this can be achieved using internal vibration measurements recorded from a sensor placed on the planet carrier. It was shown in these studies that the timing of identifiable fault symptoms in the vibration signal relative to the phase of the gear-mesh component depends on which of the planet gears carries a fault. A signal processing technique is then developed to locate the position of a spalled gear using internal vibration measurements. However, internally mounted sensors are not commonly used in planetary gearboxes and it is much more convenient to mount sensors externally, for example on the gearbox casing. Therefore, this study extends the concept of using mesh phasing relationships to locate faulty planet gears, this time using external vibration measurements. The updated procedure is validated using experimental data collected from a test-rig running under a range of operating conditions. The results show that the updated procedure is able to identify the locations of faulty planet gears so long as an absolute phase reference (for example from a tachometer) of the planet carrier is available.

Simulation and Life Prediction of Gear Meshing Process of Gearbox of A Crawler Vehicle

A crawler vehicle gearbox was easy to invalidation, stress change of the gear tooth meshing process was difficult to accurately measure, and the life prediction was not accurate. this paper established a finite element model of gear meshing, the analysis of the gear teeth began to come into contact with the complete separation of highly nonlinear dynamic process, and the simulation results of test, and established the life prediction model by nCode Designife software, and estimated the gear fatigue failure position and life. Compared with the actual results verified the feasibility of dynamic analysis method of gear meshing, for gear strength check, the reference for the optimization design and fatigue life prediction.

A Computationally Efficient and Hierarchical Control Strategy for Velocity Optimization of On-Road Vehicles

Velocity profile optimization of on-road vehicles is one of the main eco-driving techniques, which has great potential to extend the capability of powertrain and automatic longitudinal control by minimizing the energy consumption. Due to the multi factors affecting the driving trajectory and longer prediction horizon comparing with other traditional control, the calculation of a velocity profile optimization often requires a large number of computations. In this paper, a hierarchical control (HC) strategy of velocity optimization is proposed to reduce computation burden with little accuracy loss. In the HC strategy, a specific driving task is divided into several operation of modes as acceleration (A), constant speed (C), deceleration (D), and braking (B). The shift timing of the driving modes are optimized by formulating a nonlinear programming problem in a master controller. Then, engine torque, gear position, and brake force are optimized in each driving mode. Results indicate that the computation time of velocity profile optimization using the proposed HC strategy is reduced by 90% of the ones using the basic centralized optimal controller while the resulting velocities are similar. It is also shown that an improvement of 30% in fuel economy is achieved compared with the real-life human-driven velocity profiles.

Optimization of drivability control functions with two-stage rate limiters

Load changes in automotive drivelines may cause uncomfortable vibrations. A suitable motor torque control is able to remedy this problem. Often, a two degrees of freedom structure is used in these drivability control functions. In this structure, the desired motor torque is pre-filtered by a multi-stage rate limiter. However, those functions are still parametrized experimentally by laborious test drives or on the test-bench. This paper addresses the model-based optimal parametrization of these rate limiters in automotive drivability functions. For this, a recently published gear specific model is identified and validated for another gear position. In addition, a linear transfer function of multi-stage rate limiters is approximated by the transient input describing function method. The characteristics of this transfer function are used to reduce the number of design variables for the multi-objective optimization of a two-stage rate limiter for drivability control.

Identification of firefly algorithm-based fluctuation coefficient of the exciting torque for vehicle driveline

The unbalanced excitation force and torque generated by an engine that resonate with the natural frequency of drivetrain often causes vibration and noise problems in vehicles. This study aims to comprehensively employ theoretical modelling and experimental identification methods to obtain the fluctuation coefficients of engine excitation torque when a car is in different gear positions. The inherent characteristics of the system are studied on the basis of the four-degree-of-freedom driveline lumped mass model and the longitudinal dynamics model of vehicle. The correctness of the model is verified by torsional vibration test. The second order's engine torque fluctuation coefficients are identified by firefly algorithm according to the curves of flywheel speed in different gears under the acceleration condition of the whole open throttle. The torque obtained by parameter identification is applied to the model, and the torsional vibration response of the system is analysed. The influence of the key parameters on the torsional vibration response of the system is investigated. The study concludes that proper reduction of clutch stiffness can increase clutch damping and half-axle rigidity, which can help improve the torsional vibration performance of the system. This study can provide reference for vehicle drivetrain modelling and torsional vibration control.

Use of mesh phasing to locate faulty planet gears

Abstract It is a challenge to determine by vibration analysis which planet gear carries a fault due to the complex layout of planetary gearboxes. In this study, we explain for the first time the possibility of using mesh phasing for distinguishing between faults on different planet gears. It has been found that, due to mesh phasing relationships, the vibration signals recorded on a planetary gearbox test rig exhibit different characteristics depending on the position of the faulty gear. These tests used localised seeded spalls giving impulsive signals, and it was found that due to the sequential mesh phasing arrangement, the timing of the fault-related impulse responses, as measured relative to the phase of the gearmesh component, depends on which planet is faulty. These timing differences can also give rise to different levels of asymmetry in the signal. This paper proposes a phase-based approach to differentiate and locate the faulty planet gear position using vibration response signals, and an indicator is developed for this purpose. With the assistance of absolute phase information, acquired through a tachometer on the planet carrier, the phase indicator is able to locate the position of the faulty gear. The approach has been applied to recorded experimental signals and it is found that the method can diagnose the position of the faulty gear effectively.

Determination on Damage Mechanism of the Planet Gear of Heavy Vehicle Final Drive

The works focus on the investigation of damage mechanism of fractured in the form of spalling of the planet gears from the final drive assembly of 160-ton heavy vehicles. The objective of this work is to clearly understand the mechanism of damage. The work is the first stage of the on-going research on the remaining life estimation of such gears. The understanding of the damage mechanism is critical in order to provide accurate estimate of the gear’s remaining life with observed initial damage. The analysis was performed based on the metallurgy laboratory works, including visual observation, macro-micro fractography by optical stereo and optical microscope and micro-vickers hardness test. From visual observation it was observed pitting that form lining defect at common position, which is at gear flank position. From spalling sample it was observed ratchet mark at the boundary between macro pitting and the edge of fractured parts. Further observation on the cross-section of the samples by optical microscope confirm that initial micro pitting occur without spalling of the case hardened surface. Spalling occur when pitting achieve certain critical size, and occur at multiple initiation site of crack propagation. From the present research it was concluded that pitting was resulted due to repeated contact fatigue. In addition, development of micro to macro pitting as well as spalling occur at certain direction towards the top of the gear teeth.

Dynamical load sharing behaviors of heavy load planetary gear system with multi-floating components

To investigate the dynamical load sharing behaviors of multi-floating components in the heavy load planetary gear system, a multi-floating planetary gear system that includes a floating central component and a quasi-floating planet flexible supporting pin is employed. Then a 21 degree of freedom lumped parameters dynamical model of this system is presented to study the dynamical load sharing behaviors. Some influencing factors, such as supporting stiffness, positions error of sun or carrier, and external input load are analyzed on the dynamical load sharing of the planetary gear system with multi-floating components. The results demonstrate that the load sharing condition of the system is best when both the sun gear and planet gears are multi-floating at the same time. When the planet gear position errors remain constant, reducing the flexible pin stiffness of planet gear or increasing external input load can effectively improve the load sharing. These conclusions are verified by the relevant experiments.

Thermomechanical coupled contact analysis of alternating meshing gear teeth surfaces for marine power rear transmission system considering thermal expansion deformation

Marine power rear transmission system is a constant power system under specific working condition, which relies on alternating meshing gears to transfer the movement and torque. It is difficult to accurately determine the actual thermal stress and thermal deformation for time-varying distribution using the traditional methods. Elastic structural mechanics modeling and method details of thermal expansion deformation are presented and analyzed. Both the actual reflection thermoelastic contact condition for meshing gears and the coupling effect results of the practical loading process of marine power rear transmission system carried out on alternating meshing gear surfaces are also detailed. In this article, the changes in gear meshing angles of several key meshing positions are presented. The 16 meshing positions of contact stresses and loaded deformation approach are analytically evaluated in terms of the rotation range of driving spur gear (35°) and driving helical gear (36°). The purpose of this study is to confirm the significant stress concentration areas of gear meshing in and meshing out and to obtain that the deformation amounts of gear meshing impact positions within selected zones. The aim of this article is to reach gear deformation on the basis of theoretical conception.

Loaded tooth contact analysis of intersected beveloid and cylindrical involute gear pair with small shaft angle

A working pitch cone based geometry design approach for the intersected beveloid and cylindrical involute gear pair with small shaft angle was proposed. The cutter and geometry design parameters can be determined by the proposed method. Also, a quasi-static loaded mesh model was developed to calculate the contact characteristics. Then the influences of torque load, helix angle and misalignments on the mesh behaviors were investigated. Results show that the contact type is point contact both for light and heavy load situations. The increase of load tends to increase the root stress, transmission error and mesh stiffness obviously. However, the variations of the peak-peak value of transmission error and mean value of the mesh stiffness are greater under light load level compared with heavier load level. The increase of the helix angle obviously tends to increase the contact area, which is desirable. It also decreases the peak-peak value of transmission error and increases the mean mesh stiffness due to more area coming into contact. The shaft angle error tends to shift the position of the contact pattern and the peak value of the root stress along the tooth width direction slightly. Overall, the contact characteristics are not sensitive to the shaft angle error and gear axial position error.

Improving applied roughness measurement of involute helical gears

With improving gear design and manufacturing technology, improvement in metrology is necessary to provide reliable feedback to the designer and manufacturer. A recommended gear roughness measurement method is applied to a micropitting contact fatigue test gear. The development of wear and micropitting is reliably characterised at the sub-micron roughness level. Changes to the features of the localised surface texture are revealed and are related to key gear meshing positions. The application of the recommended methodology is shown to provide informative feedback to the gear designer in reference to the fundamental gear coordinate system, which is used in gear performance simulations such as tooth contact analysis.

SafeDrive: Online Driving Anomaly Detection From Large-Scale Vehicle Data

Identifying driving anomalies is of great significance for improving driving safety. The development of the Internet-of-Vehicle (IoV) technology has made it feasible to acquire big data from multiple vehicle sensors, and such big data play a fundamental role in identifying driving anomalies. Existing approaches are mainly based on either rules or supervised learning. However, such approaches often require labeled data, which are typically not available in big data scenarios. In addition, because driving behaviors differ under vehicle statuses (e.g., speed and gear position), to precisely model driving behaviors needs to fuse multiple sources of sensor data. To address these issues, in this paper, we propose SafeDrive , an online and status-aware approach, which does not require labeled data. From a historical dataset, SafeDrive statistically offline derives a state graph (SG) as a behavior model. Then, SafeDrive splits the online data stream into segments and compares each segment with the SG. SafeDrive identifies a segment that significantly deviates from the SG as an anomaly. We evaluate SafeDrive on a cloud-based IoV platform with over 29 000 real connected vehicles. The evaluation results demonstrate that SafeDrive is capable of identifying a variety of driving anomalies effectively from a large-scale vehicle data stream with an overall accuracy of 93%; such identified driving anomalies can be used to timely alert drivers to correct their driving behaviors.

Designing of Robot Gamelan Music using ATmega 16 Microcontroller

This paper presents a robot concept which is the robot can play the instrumental Gamelan music. Gamelan is a percussive instrument. Instrumental Gamelan music keys are consist of 2 octaves in 15 tones. Robot Gamelan music is using proportional-derivative (PD) control system. PD control of the robot is by controlling DC gear motor position to desired Gamelan key position. Robot Gamelan music using ATmega 16 microcontroller as a controller. Feedback of PD control is using magnetic rotary encoder (MRE) sensor. PD control is using the constant. The constant functions of PD control are determining the pulse width modulation (PWM) toward DC gear motor velocity in order to reposition a gamelan key position and pushing down the errors.

Integrated vehicle and powertrain optimization for passenger vehicles with vehicle-infrastructure communication

This research proposes an optimal controller to improve fuel efficiency for a vehicle equipped with automatic transmission traveling on rolling terrain without the presence of a close preceding vehicle. Vehicle acceleration and transmission gear position are optimized simultaneously to achieve a better fuel efficiency. This research leverages the emerging Connected Vehicle technology and utilizes present and future information—such as real-time dynamic speed limit, vehicle speed, location and road topography—as optimization input. The optimal control is obtained using the Relaxed Pontryagin’s Minimum Principle. The benefit of the proposed optimal controller is significant compared to the regular cruise control and other eco-drive systems. It varies with the hill length, grade, and the number of available gear positions. It ranges from an increased fuel saving of 18–28% for vehicles with four-speed transmission and 25–45% for vehicles with six-speed transmission. The computational time for the optimization is 1.0–2.1s for the four-speed vehicle and 1.8–3.9s for the six-speed vehicle, given a 50s optimization time horizon and 0.1s time step. The proposed controller can potentially be used in real-time.

The Analysis of Exhaust Gas Characterization in Reducing CO and HC Gas Pollution on the EFI Engine of Daihatsu Luxio 1500 CC

Air pollution from highways, particularly in an urban area which density and mobility are already on the verge of solid boundaries, resulting in environmental and human health problems. This is due to the lack of standardization of testing exhaust gas by the governmental body. Accurate results from the test and technology standardization on exhaust system which is one important component for gas pollutant elimination from the vehicle. In the present work, we examined the role of some modified exhausts on the level of pollutant exhaust, i.e. CO, HC, NOx gas. Experimental design for controlled variable is the speed, torque of the wheel, and gear position. Several modifications of exhaust gas were tested were tested, i.e. Standard, 3-way catalytic converter, racing and 2-ways catalytic converter. The data is gained through dynamometer and exhaust gas Analyzer as a speedometer gauges, torque wheels, and levels of exhaust gas that comes out of the tailpipe. Statistical analysis of the results uses one-way ANOVA. The result showed that the order in reducing exhaust gas CO and HC are: (1) two-way exhaust gas and 3 Way Catalytic Converter exhaust gas, (2) standard and (3) modified exhausts. 3 Way catalytic converter was the best to eliminate NOx than other three exhaust gas system