Transmission Shaft Research Articles

Influence of torsional stiffness on load sharing coefficient of a power split drive system

A dynamic model of power split transmission system with face gear and cylindrical gear is established. The factors including time-varying mesh stiffness, torsional stiffness, supporting stiffness, and clearance are considered in the model. The influence of the torsional stiffness of compound gear shaft on the load sharing coefficient is analyzed. The results show that the influence of the torsional stiffness of the compound gear shaft is obvious. Because the torsional stiffness of the output gear components is larger and the torsional stiffness of the input gear is smaller, so the input stage's deformation coordination ability is strong. Therefore, with the increase of the torsional stiffness of the compound gear shaft, the load sharing coefficient of the power input stages is improved, but the load sharing coefficient of the split torque stages and power confluence stages is worse. Hence, the torsional stiffness ratio of the transmission shaft should be rationally allocated under the condition that the torsional stiffness of the compound shaft is small.

Crown Gear Reducer with Seesaw Motion of Transmission Shaft

Crown Gear Reducer with Seesaw Motion of Transmission Shaft

A Study of a CCD Camera for Vibration Measurement

Vibration may occur in rotating equipment, for example on the transmission shaft of the gear. If the motor rotation is high enough, the load and torque could also be large enough. So that it can cause the shaft to vibrate and this vibration can damage the shaft. Therefore, the magnitude of vibration of the shaft need to be measured in order to monitor that the magnitude of the vibration is not high enough to damage the shaft. Usually for measuring the magnitude of this vibration is used a vibration meter. The weakness of the vibration meter is that the method of the measurement is by touching the measured object. So this measuring instrument is easily damaged by the vibration. An alternative to measure the vibration of a shaft is by applying an image processing method. Image processing is a method that performs processing of images digitally. The measurement of vibration by image processing method is tested on a vibrating shaft. The image of the vibrating shaft is captured by a CCD camera and then processed by a Matlab program to extract the value of vibration amplitude. From the tests performed, the measurement of vibration using the image processing method, the measurement can be done without touching the vibrating shaft. The obtained values of amplitude are deviate about 5.73% in average from the theoretical values. This method and tools can be used to measure the rotating shaft vibration amplitude provided the measurement instrument is calibrated prior being used by considering the value of deviation.

Investigation of Shape Effect of Transmission Shaft for Heat Treatment Distortion

Investigation of Shape Effect of Transmission Shaft for Heat Treatment Distortion

Preliminary Design of a Power Transmission Shaft under Fatigue Loading Using ASME Code

Power transmission shafting is a vital element of all rotating machinery. A complete shaft design involves many iterative phases and fundamental to this is the determination of preliminary dimensions of the shaft. This paper presents a comprehensive fatigue analysis approach of determining the initial dimensions of a power transmission shaft under fatigue loading based on American Society of Mechanical Engineers (ASME) Standard B106.1M:1985. A countershaft running at a constant speed is designed using this approach. Stress analysis at potential critical locations are conducted to determine the shaft sizes. The sizes from these locations are then used to estimate the sizes at low stress locations. Adjacent sizes are blended using the largest size. To help visualize, a CAD model of the preliminary designed countershaft is provided.

Study on Forced Torsional Vibration of CFRP Drive-Line System with Internal Damping

The use of CFRP transmission shaft has positive effect on the weight and flexural vibration reduction of drive-line system. However, the application of CFRP transmission shaft will greatly reduce the torsional stiffness of the drive-line, and may cause strong transient torsional vibration. Which will seriously affect the performance of CFRP drive-line. In this study, the forced torsional vibration of the CFRP drive-line system is carried out using the lumped parameter model. In addition, the effect of rotary inertia, internal damping, coupling due to the composite laminate, and excitation torque are incorporated in the modified transfer matrix model (TMM). Then, the modified TMM is used to predict the torsional frequency and forced torsional vibration of a CFRP drive-line with three-segment drive shafts. The results of modified TMM shown that the rotational speed difference of the CFRP transmission shaft segment is much larger than metal transmission shaft segment under excitation torque. And compared the results from finite element simulation, modified TMM and torsional vibration experiment respectively, and it has shown that the modified TMM can accurately predict forced torsional vibration behaviors of the CFRP drive-line system.

Health monitoring system for transmission shafts based on adaptive parameter identification

Abstract A health monitoring system for a transmission shaft is proposed. The solution is based on the real-time identification of the physical characteristics of the transmission shaft i.e. stiffness and damping coefficients, by using a physical oriented model and linear recursive identification. The efficacy of the suggested condition monitoring system is demonstrated on a prototype transient engine testing facility equipped with a transmission shaft capable of varying its physical properties. Simulation studies reveal that coupling shaft faults can be detected and isolated using the proposed condition monitoring system. Besides, the performance of various recursive identification algorithms is addressed. The results of this work recommend that the health status of engine dynamometer shafts can be monitored using a simple lumped-parameter shaft model and a linear recursive identification algorithm which makes the concept practically viable.

New radial turbine dynamic modelling in a low-temperature adiabatic compressed air energy storage system discharging process

It is challenging to gain insight of a Compressed Air Energy Storage (CAES) system dynamic behaviour under various operation conditions due to its complexity with mixed mechanical, thermal, chemical and electrical processes in one. Although a number of studies are reported on CAES steady state and dynamic modelling to reveal its characteristics, few studies have been reported in whole CAES system dynamic modelling involving a radial turbine. This paper explores a new method to analyse the transient performance of the radial turbine while it is integrated with whole low temperature Adiabatic-CAES system. The proposed modelling method approximates the average air flow within single stator/rotor stage. By applying the principle of energy and torque balance on the transmission shaft, the dynamic speed-torque characteristics of the turbine is obtained with a “quasi dynamic iterative searching” process. The model is then integrated to a simulation platform, which is created to synchronise the wide range of time scale dynamic responses including heat transfer, mechanical and electrical energy conversion processes. As every component of the low temperature adiabatic CAES system is built on its fundamental physical and engineering principles, the model is capable of revealing the system transient characteristics. Based on the model, various simulation studies are conducted and the results are compared with the operation data from the literature. It provides a valuable tool for preliminary design of a radial turbine to test its suitability in full and partial load operation conditions, and analyse its transient behaviours.

Evaluation of losses in transmission of machinery for development of mineral deposits in conditions of variable load

The influence of individual elements of machines transmissions on the operation of the whole system is shown. The approach of determining the resource of operation of systems elements based on the energy theory is presented. The formulas for determining the total energy resource of the reducer are given. The influence of individual elements of the system on each other is indicated. The principle of researching the system by the method of equivalent circuits is substantiated. The weakest places of transmission (gears, bearing supports and shafts) are determined. A mathematical model of a mechanical transmission was developed. To test the adequacy of the mathematical model, the stand for obtaining experimental data was designed. The description of the stand and the principle of its operation are given. Experimental data are presented. A comparative analysis of modeling and experimental data is carried out and the adequacy of the developed mathematical model is proved. The principle of determining the resource of the system as a whole for the element with the minimal resource of work is suggested.

Distortion Mechanisms During Carburizing and Quenching in a Transmission Shaft

Distortion control during industrial carburizing and quenching operation of precision transmission components is of utmost importance due to their direct impact on performance, such as efficiency, noise and vibrations. The importance of controlling various heat treatment process parameters for mitigating distortion is well accepted, but their specific influence on mechanisms is less understood. In the present work, an integrated finite element-based model is used to simulate gas carburizing and quenching operation on a typical transmission shaft. Investigation is carried out on the effect of raw materials, carburizing and quenching process parameters to predict, analyze and minimize distortion. The effect of phase transformation and generation of thermal strain during heating and cooling stage of heat treatment is investigated, and the mechanisms of bending, diameter and length distortion of a shaft are analyzed. The displacive nature of transformation of bainite at higher temperature with its inherent large shear component of deformation was identified to be responsible for bending distortion in a shaft. Bainitic transformation, martensitic transformation and thermal strains developed during quenching cause volume expansion which leads to diameter expansion and lesser length shrinkage. Finally, bending distortion of a shaft and bore distortion of a gear are contrasted, both in terms of mechanisms and distortion control strategies.

Development of block loading spectrum for car powertrain rig test correlated with customers’ usage

To establish the loading spectrum for rig test of a car powertrain, non-contact torque telemeter is adopted to measure the testing data, including target vehicle transmission shaft torque, rotation speed, and engine rotation speed, under the typical cases of customers’ actual usage. Then, the Process Builder module in Tecware is used to establish the gear split batch-processing model and process the customer data into target rotating rainflow counting cyclic matrix and eliminate the small cyclic loads which have relatively smaller influence on the fatigue life. Next, based on the road percentage and data collected in actual customer survey, the total cumulative damage of 90% customer is calculated according to the Weibull distribution equation, and powertrain damage calculation model for fatigue cumulative damage and its probability distribution function is examined by Kolmogorov–Smirnov. Finally, the customer data are compressed into block loading spectrum which can be identified by the rig test based on the fatigue damage equivalent principle, thus achieving the powertrain rig assembly testing life equivalent to the customers’ usage life. The car powertrain rig test can replace the full-vehicle road test, which efficiently lowers the testing cost and shortens the testing period.

Определение динамических нагрузок в трансмиссии гусеничной лесозаготовительной машины при преодолении препятствий

The theoretical analysis of dynamic phenomena in transmission tracked forest machine is much more difficult in the absence of experimental data on the effects of the input characteristic of the machine. The most characteristic species in the transmission effects that arise under real operating conditions allow to evaluate the results of experimental studies, they also provide an opportunity to assess the quality of theoretical studies. To determine the loading of the transmission in the experiment involves the measurement of a number of kinematic and power parameters characterizing the speed and stress state of the transmission. In the course of the research used a special measuring equipment made in Germany includes the high-speed digital telemetry system for strain "TEL1-PCM-HS" company KMT. This article describes how to determine the dynamic load transmission elements tracked forest machine LZ-5 in overcoming individual barriers in experimental studies (tests). The paper presents a program of pilot studies tracked forest machine. Presented curves change the time settings on the final drives and cardan shaft, depending on the speed of the engine and drive sprockets in overcoming obstacles GLZM with different gears. histograms were constructed on the distribution of the torque transmission shafts for various modes of overcoming obstacles in order to analyze the influence of operational factors on the magnitude of dynamic loads. The article presents the distribution curve of the moments on the driven shaft final drive to overcome obstacles tracked forest machine with a pack assortments in the volume of 12m3. It was noted that there are no less than 20 times the dynamic point values, which exceed the estimated time for the overcoming of obstacles. From the studies that the transmission level of at least dynamic forces having height obstacles.

Analysis on grease lubrication properties of the tripod sliding universal coupling in automotive transmission shaft

PurposeThis paper aims to investigate the grease isothermal lubrication properties of the tripod sliding universal coupling (TSUC) in automotive transmission shaft and study its impact on a variety of factors to improve its grease lubrication properties.Design/methodology/approachBased on the simplified geometrical model, the research of grease lubrication properties of the TSUC was analyzed, and compared with oil lubrication in same parameters. Then the effects of effective radius, frequency (vehicle speed) and amplitude (angle between intermediate shaft and input shaft) on grease isothermal lubrication properties are theoretically investigated by using multigrid methods.FindingsThe results indicate that the grease isothermal elastohydrodynamic lubrication (EHL) film thickness shape and pressure distribution shape of the TSUC are similar to the oil lubrication, but the film thickness of grease lubrication is less than that of oil lubrication. Higher effective radius results in a wider pressure distribution, a lower center pressure and a thicker lubricating film. Higher frequency (vehicle speed) results in a remarkable second pressure peak and a thicker lubricating film. The effects of amplitude (angle between intermediate shaft and input shaft) and frequency have similar tendencies.Originality/valueThe numerical analysis research on grease lubrication properties of the TSUC is significant because the automotive transmission shaft is widely used. And it provides a new direction in designing TSUCs.

Innovative design and motion mechanism analysis for a multi-moving state autonomous underwater vehicles

In order to achieve the functional requirements of multi-moving state, a new autonomous underwater vehicle (AUV) provided with the functions such as the submarine vectorial thrust, landing on the sea bottom, wheel driving on the ground and crawling on the ground was designed. Then five new theories and methods were proposed about the motion mechanism of the AUV such as vectorial thruster technology, design of a new wheel propeller, kinematics and dynamics, navigation control and the ambient flow field in complex sea conditions, which can all conquer conventional technique shortages and predict the multi-moving state performance under wave disturbance. The theoretical research can realize the results such as a vectorial transmission shaft with the characteristics of spatial deflexion and continual circumgyratetion, parameterized design of the new wheel propeller with preferable open-water performance and intensity characteristics satisfying multi-moving state requirements, motion computation and kinetic analysis of AUV’s arbitrary postures under wave disturbance, a second-order sliding mode controller with double-loop structure based on dynamic boundary layer that ensures AUV’s trajectory high-precision tracking performance under wave disturbance, fast and exact prediction of the ambient flow field characteristics and the interaction mechanism between AUV hull and wheel propellers. The elaborate data obtained from the theoretical research can provide an important theoretical guidance and technical support for the manufacture of experimental prototype.

Mathematical modelling of real transmission shafts and mechanical connections with clearances

Mathematical modelling of real transmission shafts and mechanical connections with clearances

Mathematical modelling of real transmission shafts and mechanical connections with clearances

Mathematical modelling of real transmission shafts and mechanical connections with clearances

A Dynamic Model for Simulation of Hot Radial Forging Process

A comprehensive dynamic process model has been developed to investigate features of the inherently transient hot radial forging process, taking account of complex process kinematics, thermo-elastoplastic material behaviour and microstructural evolution. As an input to this model, a fully systematic thermomechanical testing matrix was carried out on a Gleeble 3800 including temperature (20-1100°C), strain (up to a true strain of 1) and strain rates (from 0.1 to >50 s-1). The proposed model can accurately capture vibration characteristics due to the high frequency short strokes during radial forging, which have been found to have a strong effect on material flow, forging load. Numerical analyses were performed to investigate the effect of different axial spring stiffnesses on forging load, strain distribution in the workpiece, and maximum axial feeding rate. It has been found that forging load increases significantly with increasing stiffness of the axial spring. The axial spring stiffness was also found to have a strong effect on determination of axial feeding rate and reduction ratio of workpiece by limiting the axial vibration amplitude of workpiece under the maximum compression of spring coil to avoid hard stop of workpiece in the axial direction during forging. It has been found that the spring stiffness does not have a strong effect on the strain distribution in the work piece. For practical application, the proposed model is applied to simulate the manufacturing process of a hollow transmission shaft using a GFM SKK10/R machine. Simulation results based on a 3 dimensional framework provide a detailed insight of material flow, residual stress and grain size evolution during the multiple pass radial forging process and the results are compared with available experimental measurements. The results provide valuable insights for process design.

State of the art of different industrial approaches for face grinding applications

Face grinding is a critical process in manufacturing applied in several kinds of workpieces from automotive, aerospace or energy generation sectors. Motor and transmission shafts of hardened steel, Ni and Ti alloys or carbide coatings are some representative workpieces where this operation is applied. In order to carry out face grinding applications many different techniques and strategies can be applied. Apart from the significate lack of detailed kinematic analysis of this particular application there exist uncertainty about the definition of the associated most convenient technique. The objective of this work is to realize a classification and description of all the different strategies applied in face grinding applications, analysing their basic kinematics, showing the required technological approaches and the flexibility that each strategy offers. This is a starting point for a deeper research work that will be carried out in order to advance in the definition of optimal strategy and technological approach for maximum productivity in each case.

Simple mathematical models of transmission shafts and gear trains. Electrical and mechanical circuits

Simple mathematical models of transmission shafts and gear trains. Electrical and mechanical circuits

ENGLISH

3 ABSTRACT: In modern wind turbines, the energy conversion process uses the basic aerodynamic force of lift to produce a net positive torque on a rotating shaft, resulting first in the production of mechanical power and then its conversion to electricity in a generator. Wind turbines, unlike most other turbines, can produce power only in response to the wind that is available at the time. The output of a wind turbine is thus inherently fluctuating with the wind and can't be directly dispatched for a purpose. Apart from this, the output depends on individual components like rotor dimension, transmission shaft, gear box and alternator. Since the wind turbine is relatively large, expensive, and Wind Energy Conversion System (WECS) is complex, it is not convenient to do research on actual wind farm. Therefore, WECS model development for steady and dynamic state analysis and design has been research issue in recent years. This paper presents a new block-based approach for WECS dynamic modeling. The blocks (modules) developed by Aalborg University - Denmark, RISO national laboratory based on Kaimal Spectra have been customized, updated and integrated into MATLAB/SIMULINK platform and then utilized to simulate performance of 5kW WECS. In addition to the developed block sets, in this paper, a proportional-integral controller is designed to control the turbine pitch and integrated with the simulation models. The simulation result demonstrates that the model output is in agreement with what is expected. The system has advantages like: research cost reduction, ease in application and control, flexibility and completeness for analysis in MATLAB/SIMULINK environment. The system can be used for assessment of power quality and design of wind turbine system for grid connection.