Output Shaft Speed Research Articles

Modelling width of the spectral component of a gas-turbine engine gearbox output shaft speed

Gearbox is the most stressed component in an aircraft gas-turbine engine. This implies the need for finding ways to monitor its technical condition. Practice shows that the most efficient method is vibration-based diagnostics. However, this method requires the use of sophisticated measurement systems and highly skilled personnel. This paper shows that errors of gear coupling manufacture and assembly, characteristics of machine operating mode, design factors, frequency modulation of the carrier of the engine rotor speed in the stationary mode of its operation, and wear of teeth flanks determine the width of the spectral component of the gearbox output shaft speed. Using the results obtained from the developed model of the width of gear tooth spectral component, ratios for width of the spectral component of the signal of the “standard” tachometric speed sensor of the gearbox output shaft speed and the corresponding spectral component of its vibration were obtained. Models for repaired and newly manufactured gearboxes and gearboxes with tooth flank wear were proposed. This allowed the development of a number of new diagnostic indicators of a defect. Several examples of the use of these new diagnostic indicators are given for the gearbox of one of turbo-prop engines. The results obtained provide an opportunity to assess the gearbox technical condition in operation.

Analysis of circumferential oil film thickness for piston ring in twin-rotor piston engine under differential velocity motion of combined annular cylinder

In this paper, a novel type of twin-rotor piston engine (TRPE) is proposed, and the circumferential oil film thickness for the piston ring in TRPE is analysed. Different from the integrated cylinder of a typical engine, the combined annular cylinder (CAC) of TRPE has unique structural composition and differential velocity motion characteristic, making the tribological performance more complicated. The main purpose of this paper is to reveal and explain the special tribological performance of TRPE, which has never been studied. Firstly, the special structural composition of CAC is introduced and the relative velocity between the piston ring and CAC wall at different circumferential positions of the piston ring is analysed. Then, based on the Greenwood-Trip asperity contact theory, radial and axial quasi-static equilibrium equations of the piston ring are both derived. The circumferential oil film thickness is calculated by solving the equilibrium equations and the two-dimensional average Reynolds equation within a cycle. Results indicate that there are significant differences in circumferential oil film thickness of the piston ring due to the special structure and motion of CAC, and the differences become greater as the output shaft speed increases. A long-time engine reverse towing experiment shows an obvious uneven wear phenomenon of the piston ring and CAC wall, which well validates the simulation results of the circumferential oil film thickness. The research work can be used as the basis of equal-wear design for the piston ring in TRPE with the help of surface texture technology, thereby greatly reducing the wear loss.

Gearshift Control in Engagement Process of Dual-Motor Coaxial Propulsion System for Electric Bus

Considering single-motor drive system cannot meet the requirements of high-performance electric buses for Beijing Winter Olympics, a dual-motor coaxial propulsion system based on single planet gear set is developed. At the same time, a shift control method based on hierarchical linear quadratic regulator (HLQR) algorithm is designed to improve the poor shift quality caused by the rapid change of output shaft speed in the shift process. In this method, the upper controller adopts robust tracking linear quadratic regulator algorithm to control the speed change rate of the output shaft in the process of gear shifting, so as to reduce the load of gear shifting actuator in the process of gear shifting; the lower controller adopts disturbance suppression linear quadratic regulator algorithm to control the shifting force and improve the adaptability of the system to disturbance conditions Through simulation analysis, the performances of hierarchical linear quadratic regulator algorithm, optimal control algorithm based on variational method and PI algorithm in the process of gear shifting were comparatively analyzed. Simulation results showed that the hierarchical linear quadratic regulator algorithm exhibited a better performance in gear control than the other two algorithms. In addition, a large number of bench test results also proved that compared with PI algorithm, hierarchical linear quadratic regulator algorithm reduced vehicle impact by 19.17% and reduced the shift force by 32.48% in the sacrifice of shift time by 5.03%.

Experimental study on vibration and noise of the ROEWE electric vehicle

In order to control the vibration and noise of the ROEWE electric vehicle, it is necessary to carry out the experimental study on the vibration and noise of the electric motor. Firstly, two acoustic sensors are arranged on both sides of the road to measure the pass-by noise of the electric vehicle and to analyze the influence of motor noise on the passing noise. Then, several acoustic sensors are arranged in the vehicle to measure the noise signal in the vehicle, and to analyze the characteristics of interior noise. At the same time, one acoustic sensor and three vibration acceleration sensors are arranged in the vehicle power cabin to measure the vibration signal, and measure the signals of the upper and lower vibration acceleration sensors of the powertrain mount, and analyze the vibration and noise characteristics of the motor and the vibration isolation rate of the powertrain mount. The experimental results show that the vibration of the ROEWE motor has obvious order characteristics, which is mainly composed of order components of order 8, order 16, order 24, order 40, order 48 and order 72 based on the motor output shaft speed and frequency converter switching frequency components concentrating on 10000Hz and 20000Hz. Therefore, to reduce vehicle vibration and noise from the perspective of optimizing motor vibration, the impact of cogging torque on motor vibration should be mainly considered.

Investigation on planetary gearbox fault mechanism under variable speed conditions based on rigid-flexible coupling dynamics model

Dynamic behaviors of wind turbine planetary gears are greatly affected by the transfer paths and variable conditions. However, previous studies have mainly considered single transfer path and stationary operating conditions. To overcome this problem, a rigid-flexible coupling dynamics model of wind turbine planetary gearbox under different transfer paths and variable conditions is established. By simulating the modal-based rigid-flexible coupling dynamics model, the gearbox output shaft speed as well as the box vibration response in the stationary condition are obtained well, which can be characterized by its frequency features. By conducting order envelope analysis on the simulated acceleration signals in the variable speed condition, the feature order in the sun gear fault state is obtained on the simulated acceleration signal. The planetary gearbox dynamics tests results are in good agreement with the simulation results. The experiment results verify the correctness of the established rigid-flexible coupling dynamics model. This modeling method provides a new idea for multi-path modeling of wind turbine gearboxes and the study of fault mechanism under variable speed conditions.

MODEL OF AN ADJUSTABLE ELECTROMAGNETIC GEARBOX WITH A THREE-PHASE STATOR WINDING IN THE STATE SPACE

A magnetic gearbox with a three-phase stator winding, powered by a static frequency converter with a sinusoidal current, which is in phase or in antiphase with the EMF of the idling winding, will have in this mode the maximum values ​​of the electromagnetic moments of the shafts proportional to the stator current. Such a gearbox will have no “overturning” of the rotors as long as the frequency converter is able to increase its current with increasing load.
 
 The electromagnetic moments of the rotors of the magnetic gear are a consequence of the presence of the electromagnetic moment of the stator. The electromagnetic moments of the rotors are rigidly related to the electromagnetic moment of the stator through constant coefficients.
 
 A mathematical model of an adjustable magnetic gearbox with a three-phase stator winding and the results of modeling a dynamic system are presented. Offers the structure of the output shaft speed stabilization system, such as a wind turbine. The introduction of the main research results is illustrated.

An experimentally validated control strategy to optimize power generation quality for waste heat recovery system

Roots-type engine is suitable for small power generation system fuelled by waste heat. The disorderly fluctuations of the waste heat source upstream of the power generation process and changes in external environmental factors cause the working parameters of the device to change, which makes the speed of roots engine unstable, and the output power quality of the system is not good. For this problem, this paper starts from the control structure and control strategy to improve the adjustment speed and anti-interference ability of the control system. In this contribution, the model transformation of the dynamic work unit of waste heat power generation device from engineering to theoretical model is performed, the temperature of working gas and the speed of output shaft of roots engine are determined as control objects, and the internal mode control strategy is introduced to optimize the controller of the system. Simulation results are in good agreement with the measurements, which verify that the optimized control system can effectively improve the following ability and anti-interference of the system, and shorten the response time.

Design and Fabrication of a Turbine having NACA 2415 Blades and Feasibility Study of its Application in Cooling Tower

In modern world, energy is a blessing, but its production is a problem with many human and economic ramifications. Comparing with others, solar and wind energies are much popular but have their own problems, primarily cost. Some of experiments are at MIT’s Media Laboratory are happening with cheap alternative energy sources. Wind energy is more efficient according to research, than solar energy. Mathematically it is proven, with the help of a 3 square meter turbine where velocity of wind is 36 km per hour and with 30% of total efficiency about 300 watt can be obtained. The main contents of this project and thesis include the design, construction and calculating the performance of aerofoil shaped turbine blade. To construct the aero foil shaped turbine three blades and a wood-hub are used. A shaft is fitted with hub with 5 cm diameter; a metallic gear is there for supporting the other end. In addition, gearing system is there to make the speed of output shaft are more high. A24 volt generator is also connected to the output shaft. The primary output was 6 watt & can apply this output power in various purposes like to run energy saving lamp, to charge mobile battery & other charge storage battery. A model has been used for simulation since the site of the actual turbine was not feasible for collecting effective data. The model was tested at different wind speeds and rpm of the rotor with respect to the amount of electricity produced.

Optimal Speed Regulation Control of the Hybrid Dual Clutch Transmission Shift Process

This paper presents a gear shift method for the dual clutch transmission (DCT) with integrated electric motor in pure electric drive mode. In contrast to clutch-to-clutch shift in conventional DCT, a good gear shifting process relies on the coordinated control of the motor and synchronizer in electric drive mode of the hybrid DCT. To shorten the torque interruption time and reduce the wear of the synchronizer during engagement, the key point is to adjust the oncoming gear speed to the output shaft speed rapidly. This study provides a speed regulation control framework based on model predictive control (MPC) and disturbance observer (DO), where the MPC controller is designed to achieve a good tracking performance and the DO is to eliminate effects from exogenous disturbances. Simulation and experimental results demonstrate that the proposed approach can attain a rapid and robust gear shifting performance.

Testing of Gear Transmission Units with Continual Variation of Transmission Ratio for WT-application

A new design of gear transmission unit with continual variation of gear transmission ratio, for application in wind turbines (WT), has been developed. By variation of transmission ratio the speed of output shaft is 1500 rpm, constant independently of the wind speed. The article contains the presentation of a testing rig and the testing procedure of this design. The testing rig is based on back-to-back connection and power circulation and the testing procedure on simulation of the WT service conditions. The objective of testing process is identification of gearbox operating features and behavior, gearbox reliability and durability.

Mode transition coordinated control for a compound power-split hybrid car

With a compound power-split transmission directly connected to the engine in hybrid cars, dramatic fluctuations in engine output torque result in noticeable jerks when the car is in mode transition from electric drive mode to hybrid drive mode. This study designed a mode transition coordinated control strategy, and verified that strategy’s effectiveness with both simulations and experiments. Firstly, the mode transition process was analyzed, and ride comfort issues during the mode transition process were demonstrated. Secondly, engine ripple torque was modeled using the measured cylinder pumping pressure when the engine was not in operation. The complete dynamic plant model of the power-split hybrid car was deduced, and its effectiveness was validated by a comparison of experimental and simulation results. Thirdly, a coordinated control strategy was designed to determine the desired engine torque, motor torque, and the moment of fuel injection. Active damping control with two degrees of freedom, based on reference output shaft speed estimation, was designed to mitigate driveline speed oscillations. Carrier torque estimation based on transmission kinematics and dynamics was used to suppress torque disturbance during engine cranking. The simulation and experimental results indicate that the proposed strategy effectively suppressed vehicle jerks and improved ride comfort during mode transition.

Kinematic synthesis of a novel type of the series of transmissions with independently controllable output speed

A power-split-type transmission with independently controllable output speed (ICTs) was recently proposed. It is capable of converting a variable or constant input shaft speed into a controllable output shaft speed independent of the input speed — without ordinary speed control system. However, this transmission has no practical significance, because of the huge control motor power and uncontrollable speed of one output shaft. The novel type of the hybrid ICT is proposed in this paper that consists of three differential gear trains and two ordinary gear drives, with input shaft of arbitrary speed and three more external shafts with mutually controllable speeds. The kinematic synthesis of the series of the proposed type of ICTs is carried out. The numerical example, assigned to a vehicle, is demonstrated where a continuous variation of required vehicle speeds at arbitrary riding conditions is achieved without using a speed control system. For the optimal speed of driving engine, i.e. for minimum fuel consumption at any vehicle speed, the engine speed control system is provided, with control motor that runs at speed forcing engine to run at optimal speed.

Development and friction estimation of the Half-Toroidal Continuously Variable Transmission: A wind generator application

This paper presents the modeling and the computer simulation of a continuously variable transmission (CVT), applicable to a (2kWatt power) wind turbine, as well as the evaluation of the suggested mechanism. Transmission in conventional wind turbines offers a constant ratio, as a result the rotational speed of the generator's shaft varies depending on the wind speed, so the generator usually operates at lower rpm than registered, leading to low power output. In contrast, wind turbines equipped with a CVT system offer a wider range of the power generator's shaft speed.The proposed mechanism is expected to provide a constant output shaft speed for any wind speed, maximizing the power produced. Furthermore, it is expected that the system will be able to collect more energy than conventional wind turbines and wind turbines equipped with CVT do, starting from a lower wind speed. This paper describes the operating principle of the proposed mechanism, followed by the mechanical designs of the individual components. Dynamical and Frictional Analysis of the proposed mechanism and its components are presented. The modeling of the CVT was performed using CATIA, and simulation carried out using the MSC Adams 2013 student edition.

Sensors Installation Guide to Monitor Automatic Transmission Performance

This paper aims to answer a key question during the design and development of a new product i.e. how many and where should one install the sensors to ensure effective health monitoring. In this paper, a sensor installation guideline for a 4R automatic transmission is presented. The guideline helps to visualize different possible combinations of sensors and their locations such that all malfunctions are monitored. The guideline is an outcome of structural analysis conducted on a kinematic model of the transmission. Faults in sensors, clutches and band brakes have been considered. The list of sensors include speed sensors to monitor shaft speeds and pressure sensors that can sense if the clutches/brakes are engaged or disengaged. It is concluded that turbine speed sensor, output shaft speed sensor and a pressure sensor can help to isolate all possible faults in the transmission under consideration.

Design and Implementation of the AMT Data Acquisition System Structure and Function

Based on electro-hydraulic control automatic transmission, in order to meet the shifting actuator control effect high response speed, high control accuracy requirements and real-time, accurate acquisition transmission work state. According to the proportional pressure solenoid valve, proportional flow valve response curve and rated operating parameters, designed the hardware control circuit. For the acquisition of automatic transmission shift the implementing agencies cylinder pressure, hydraulic oil temperature and transmission input, output shaft speed, designed the hardware circuit, according to the nominal operating parameters for each sensor. Acquisition speed and accuracy requirements for the quality of the output signal of the respective sensors and control system, designed for each of the output signal of the signal processing and analysis circuit. The bench test the experimental results show that the data acquisition system designed in this paper can meet the requirements of the control system for real-time and accuracy.

Data Acquisition System Design and Data Analysis on Automatic Transmission

An efficient data acquisition system for electronic automatic transmission test, which makes use of American NI’s data acquisition card, is designed based on Virtual Instrument. The data can be collected by the data acquisition system include automatic transmission oil pressure, solenoid duty, as well as engine speed ，turbine speed ，output shaft speed and throttle degree，and so on. The key problems of the system design are measurement method of automatic transmission solenoid duty, signal conditioning circuit design and multi-signal acquisition synchronization. Test platform is North-Benz dump truck 2627K (Its power-train assembly is replaced), of which transmission and engine use respectively HD4070PR electronic automatic transmission and BF6M1015CP electronic diesel engine. The automatic transmission shift control strategy and oil pressure characteristics of clutch or brake etc can be analyzed through test data acquisition.

2106 自動調圧カムを搭載したトラクションドライブ式2K-H型CVTの変速比に与える負荷トルクの影響(トラクションドライブ・機械要素,一般講演)

Traction drive CVT is a transmission changing the speed of output shaft continuously and smoothly. However, the speed ratio of the CVT is affected by the load torque - the increase of load torque generally makes the speed ratio lower. In this paper, effect of the load torque on the speed ratio of 2K-H type CVT equipping loading cam was investigated by the experiment focusing on the slip at contact zone in the unit. The experiment showed that the speed ratio drastically decreased when the load torque was quite small around zero, and that the change in speed ratio became moderate when the load torque became higher though the trend depended on the initial speed ratio. In addition, it was found that the slope of traction curve and traction coefficient at contact zone affected the speed ratio of the CVT.

Design Overview of a Three Kilowatt Recuperated Ceramic Turboshaft Engine

A three kilowatt turboshaft engine with a ceramic recuperator and turbine has been designed for small unmanned air vehicle (UAV) propulsion and portable power generation. Compared with internal combustion (IC) engines, gas turbines offer superior reliability, engine life, noise and vibration characteristics, and compatibility with military fuels. However, the efficiency of miniature gas turbines must be improved substantially, without severely compromising weight and cost, if they are to compete effectively with small IC engines for long-endurance UAV propulsion. This paper presents a design overview and supporting analytical results for an engine that could meet this goal. The system architecture was chosen to accommodate the limitations of mature, cost-effective ceramic materials: silicon nitride for the turbine rotors and toughened mullite for the heat exchanger and turbine stators. An engine with a cycle pressure ratio below 2:1, a multistage turbine, and a highly effective recuperator is shown to have numerous advantages in this context. A key benefit is a very low water vapor-induced surface recession rate for silicon nitride, due to an extremely low partial pressure of water in the combustion products. Others include reduced sensitivity to internal flaws, creep, and foreign object damage; an output shaft speed low enough for grease-lubricated bearings; and the potential viability of a novel premixed heat-recirculating combustor.

The improvement of hydraulic diesel railcar performance. 1st Report, Trial manufacture and test of high performance hydraric transmission and it's control device.

Diesel railcars in Japan have played a big role in transportation on mountainous lines. However, it can hardly be said that the efficiency of the current transmission is high enough when running up rising gradients. The authors built a new transmission based on an original design conception, aimed at simple construction and high efficiency. It is equipped with a pneumatically operated claw clutch. The clutch is electronically controlled to synchronize its output shaft speed with that of the imput shaft before the clutch is engaged. Built into a diesel railcar, the transmission was tested on a test stand and later in a car run on the line in the yard of RTRI, JR. The test result was satisfactory.