Intermediate Shaft Research Articles

A Parameter Investigation Into the Thompson Constant-Velocity Coupling

The Thompson coupling is a relatively recent design of constant-velocity coupling, that is, principally based on the double Cardan mechanism. An extra mechanism comprising a spherical pantograph serves to align the intermediate shaft of this coupling and so maintains the constant velocity of the double Cardan mechanism, in a modular fashion. This technical note serves to introduce basic closed form expressions for the coupling’s geometry—which may then be used to derive linkage accelerations and dynamic forces. The expressions are derived using standard identities in spherical geometry. The resulting dynamic model then informs a basic conceptual design optimization, which object is intended to reduce induced driveline vibrations, when the coupling is articulated at nonzero angles of torque transmission.

Optimal Maintenance Interval for Wind Turbine Gearbox

A maintenance interval optimization model for wind turbine gearbox considering the maximization component profit per unit time was presented in this paper. First, the principle and configuration of gearbox were introduced, and the failure characteristic is analyzed as well as the failure rate distribution of components in gearbox. Then, the concept of component income coefficient λ and element utilizing rate per unit time U(t) were given. λ describes the proportion that component takes up the total income of wind turbine electric power sale，and U(t) represents the average income per unit time to wind turbine electric power sale during 0~t. Based on above two concepts the model of optimizing maintenance interval was proposed. Last, the paper used the proposed method to evaluate wind turbine gearbox maintenance interval in an actual wind farm. The simulating results indicates that the component profits per unit time for gears, intermediate speed shaft bearings and high speed shaft bearings increases by 16.88%, 30.26% and 32.59% respectively.

Research of Advancing Mechanism with Three Circular Arc Equidistant Profile Connection of Drill

Study the existing advancing mechanism of drill, analyze the disadvantage of the flat key and the spline, and the feature of the three circular arc equidistant profile connection. Taking the common chain advancing mechanism as basis, using three circular arc equidistant curve to make sprocket bore and intermediate shaft external cylindrical fit constitute the three circular arc equidistant profile keyless connection. Then introduce the advancing mechanism with three circular arc equidistant profile connection of drill. Applying Solidworks2010, we created the three-dimensional modeling of the mechanism, which lay the foundation for the further research and application. The new type advancing mechanism has many advantages, such as automatic-centering accurately, convenient in assembling and disassembling, eliminating the stress concentration, simplicity of the fit section，transferring bigger torque, suitable for heavy-loaded rock drill machine.

Multistage Compressor and Turbine Modeling for the Prediction of the Maximum Turbine Speed Resulting From Shaft Breakage

A mathematical model for the prediction of the maximum speed of a high pressure turbine following a shaft failure event was developed. The model predicts the high pressure compressor and ducting system pre- and poststall behaviors such as rotating stall and surge after the shaft breakage. The corresponding time-dependent high pressure turbine inlet conditions are used to calculate the turbine maximum speed, taking into account friction and blade and vane tip clearance variations as a result of the rearward movement of the turbine and destruction of the turbine blading. The compressor and ducting system is modeled by a one-dimensional, stage-by-stage approach. The approach uses a finite-difference numerical technique to solve the nonlinear system of equations for continuity, momentum, and energy including source terms for the compressible flow through inlet ducting, compressor, and combustor. The compressor blade forces and shaft work are provided by a set of quasisteady state stage characteristics being valid for prestall and poststall operations. The maximum turbine speed is calculated from a thermodynamic turbine stand-alone model, derived from a performance synthesis program. Friction and blade and vane tip clearance variations are determined iteratively from graphical data depending on the axial rearward movement of the turbine. The compressor and ducting system model was validated in prestall and poststall operation modes with measured high pressure compressor data of a modern two-shaft engine. The turbine model was validated with measured intermediate pressure shaft failure data of a three-shaft engine. The shaft failure model was applied on a modern two-shaft engine. The model was used to carry out a sensitivity study to demonstrate the impact of control system reactions on the resulting maximum high pressure turbine speed following a shaft failure event.

A new approach to the kinematic analysis of universal joints

Abstract This work is the continuation of a study which is concerned with the kinematics of an universal joint and its use in shaft connections. In the present work, case studies are carried out by numerical implementation of the kinematic formulas illustrated in a previous paper in which two different systems for transmission of rotational motions are kinematically analysed. The first of these systems consists of two shafts (an input and an output shaft) connected via an universal joint, while the other comprises three shafts (an input, an intermediate, and an output shaft) and two universal joints connecting them. Furthermore, it is investigated how the angles between shaft axes, the arm lengths of the cross pieces, the angles between cross arms, and the angle between yoke planes of the intermediate shaft affect the characteristics of output motion. For both systems, the relationships between rotation angles of shafts are derivated by applying the rigidity condition on the cross arms. The case studies show that the arm lengths of cross pieces have no effect on the angular relations, independently of the angles between arms. However, in a coplanar system of the second type, either parallel or crossed assembled, it is concluded that an input rotation cannot be transmitted onto the output shaft without losing its kinematic features as far as the angles between the cross arms in each joint deviate from 90°, and also the angle between the yoke planes from 0°, respectively. The interference of the working planes of the joint is not included in the study.

Digital Design System Characteristic Evaluation in the Sense of Dissipative Structure and Time-space Information Different

The dissipative structure characteristic of product digital design system is analyzed. It is proposed that in this kind of system,there universally exists time-space information difference closely related with the system orderliness,and which can be used to measure the characteristic of system evolution,thereby becoming an important order parameter in the evaluation of product digital design system. Based on information entropy theory,the quantitative calculation method for time-space information difference is given,and on this basis,a discrimination model of digital design system orderliness is established. The product modeling principle and software architecture technology of digital design system of product can be changed by using a new software platform which supports "a model with four bodies" product information model. The feasibility of using discriminate model of digital design system order to research evolution direction of digital design system is verified through completing example of same product like automotive transmission intermediate shaft and making comparative analysis of time-space information difference of digital design system of product.

Secondary Torque in Automotive Drive Shaft Ball Joints: Influence of Geometry and Friction

Automotive drive shafts are made of two constant velocity joints coupled by an intermediate shaft. In general, the joint close to the gearbox is a plunging tripod joint, the movement of which serves suspension. The joint close to the wheel is a fixed ball type joint, which allows the steering movement. The article is devoted to secondary torque generated by the ball joint during torque transmission. This study is based on an ADAMS model in rigid bodies with local deformation at contact (Hertz theory) and on industrial test bench measurements. After geometrical representation of ball joint kinematics and before the secondary torque calculation, the ADAMS model is validated through the calculation of internal efforts, which are compared with the models and measurements already presented in the literature. Concerning the secondary torque study, measurements with an industrial test bench at the NTN TE Test Department and the ADAMS model show that the R6 component of the secondary torque (orthogonal to the joint plane) is found to be negligible with respect to the transmitted torque (<2 N m for 300 N m input torque). The results of the ADAMS model also show that the steering component of the secondary torque (in the joint plane and orthogonal to the wheel axis) does not only depend on the joint angle but also on the friction and sign of the transmitted power.

스트레인 게이지를 이용한 선박용 추진 축계의 베어링 반력 측정에 관한 연구

Bearing damages by shaft misalignment have frequently been happened in marine ships. Specially, after stern tube bearing damage and failure for large crude oil carriers have been reported several times. However, the bearing reaction of the after stern tube bearing cannot be measured by jack-up test due to the hull structure condition. Therefore, when the jack-up test is used for the bearing reaction measurements, the bearing reaction for the after stern tube bearing obtained from the theoretical calculation method have to be used. In this paper, the shaft alignment on the large oil crude carrier is theoretically calculated and the differences between the calculated and actual installed bearing reaction values are compared. The bearing reactions for forward stern tube bearing and intermediate bearing are calculated by the simple formula using the strain gauge bending moments obtained from the measurements. Their reliability is confirmed by comparing the bearing reactions from jack-up test and the bearing reaction for after stern tube bearing is calculated by the same test. Also, the bearing reactions on the after stern tube bearing, forward stern tube bearing and intermediate shaft bearing under all operating conditions are calculated by using the bending moments obtained from the measurements and it is confirmed that the differences of the bearing reaction for all operating conditions are caused from hull deflection. The results of this study should prove useful for the future projects of the alignment calculation including the hull deflection effectiveness.

Modelling and measuring the axial force generated by tripod joint of automotive drive-shaft

The present paper deals with measurements and models of axial force produced by a tripod joint of an automotive drive-shaft. An automotive drive-shaft consists of a plunging tripod joint close to the gearbox and a fixed ball joint close to the wheel. Both joints are connected by an intermediate shaft.

Robert Hooke's ‘universal joint’ and its application to sundials and the sundial-clock

Robert Hooke is commonly thought of as the inventor of ‘Hooke's joint’ or the ‘universal joint’. However, it is shown that this flexible coupling (based on a four-armed cross pivoted between semicircular yokes attached to two shafts) was in fact known long before Hooke's time but was always assumed to give an output exactly matching that of the input shaft. Hooke carefully measured the relative displacements of the two axes, and found that if one were inclined to the other, uniform rotation of the input produced a varying rate of rotation of the output. He also recognized that this variable rate exactly corresponded to the movement of the shadow of a gnomon across the face of a sundial, as generated by the projection of the uniform motion of the Sun around an inclined polar axis. He therefore proposed that a ‘mechanical sundial’ might be made by coupling a 24-hour clock movement (with its hour shaft at the appropriate inclination) to a pointer via a universal joint. This proposal has been investigated both practically and mathematically, and shown to be valid. Hooke's studies of the universal joint caused it to be identified with his name, and it has ultimately proved far more important as a rotary coupling than as a sundial analogue. More complex versions subsequently designed by Hooke included provision for two basic couplings to be linked by an intermediate shaft. With appropriate setting of phase and shaft angles this ‘double Hooke's joint’ could annul the variable output velocity characteristic of the single universal. It has proved invaluable for modern automotive transmissions.

Safety in quick construction of a long water conveyance channel by shield tunneling method

The new Ishioka Tunnel project (in the second work section) involves the construction of a water conveyance tunnel with an inner diameter of 3.5 m by the slurry shield tunneling method. The project has two characteristics, long-distance excavation and quick construction. The tunnel has a length of 5,000 m without any intermediate shafts. This is one of Japan’s leading long-distance tunnelling projects. Construction including design is carried out quickly over a period of 36 months. Permanent excavation was started in late April 2004. A highest rate of monthly shield advance of 500.85 m was recorded. Construction was carried out rapidly at an average rate of monthly shield advance of 338 m, higher than 320 m as planned. The shield reached the reception shaft approximately two months earlier than scheduled. This paper provides an outline of construction and describes the major techniques applied. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. “Reprinted with permission from Elsevier”.

Tunnel engineering in the Iron Age: geoarchaeology of the Siloam Tunnel, Jerusalem

The Siloam Tunnel (ST) is the best-identified biblical structure that can be entered today. We use geological, structural, and chemical features of ST and its internal deposits to show that it is an authentic engineering project, without any pre-existing natural conduit that could have guided its excavators. Radiometrically and historically dated to ∼700 BCE, ST pinpoints the technological advance in leveling techniques that was essential for the construction of such a long tunnel without intermediate shafts. A combination of geological and archaeological evidence demonstrates that the circuitous route of ST and the final meeting of the two excavating teams are associated with continuous modifications of the plan to allow acoustic communication between hewers and the surface teams. Hydraulic plaster was applied throughout the tunnel in order to seal voids of dissolution and tectonic origin. Organic material accidentally entrapped in the plaster was carbon 14 dated, and speleothems were dated by U–Th, both corroborating the historic and epigraphic evidence ascribing the engineering advance in tunneling techniques to the Judahite King Hezekiah.

The Young Gametophyte of Lycopodiella lateralis and the Role of the Intermediate Shaft in Development of Lycopodiella Gametophytes

Abstract Spores of Lycopodiella lateralis germinate rapidly in illuminated cultures as is typical for most Lycopodiella spores. The young gametophyte develops into a solid, green, spherical primary tubercle. Mature gametophyte development occurs at the top of the primary tubercle by the formation of a crown with photosynthetic lobes. An intermediate shaft reported for other Lycopodiella gametophytes fails to form. Comparisons were made between intermediate shafts of Lycopodiella gametophytes growing in nature and in culture. In well illuminated conditions the intermediate shaft does not form as it does on poorly illuminated gametophytes. If the gametophyte development starts partially covered by soil, long intermediate shafts can be produced. The intermediate shaft raises the top of the young gametophyte to the top of the soil where a sexually-mature gametophyte develops and sexual reproduction can take place. The intermediate shaft provides the possibility for a young gametophyte in unsuitable illuminati...

Marmaray project: Tunnels and stations in BC contract

Abstract Istanbul is one of the most famous historical cities in the world. However, the project alignment selected as the best of a range of alignments cannot avoid passing beneath the historical and cultural heritages of Istanbul as well as under ancient and densely inhabited areas of the city. This paper will explain some of the challenges related to the bored tunnels. Historical buildings are vulnerable. Yet many existing residential and office buildings are old and constructed on minimal foundations. As a consequence, it is vital that any drawdown of groundwater and any ground settlements have to be minimized. In addition, the connection between the immersed and bored tunnels will be made directly and totally underground, without the usual intermediate shafts and beneath the deep waters of the Bosphorus Strait. This operation needs the utmost control of the tunnel excavation face to ensure its stability and to minimize water ingress. Based on such considerations, tunnel excavation by tunnel boring machine (TBM) using a slurry shield and having the ability to operate under high pore pressures was recommended as the method of excavation for the main running tunnels. The paper will explain how the design team from Avrasyaconsult – the Employer’s Representative – arrived at the final minimum, specific and functional requirements of the bored tunneling works which are to be carried out using the ‘FIDIC EPC/Turnkey Project’ conditions.

Excavation of Japan’s largest shield tunnels in the heart of Tokyo Metropolitan area - the Nishi-Shinjuku Tunnel

The Metropolitan Expressway is the main transportation route in the Tokyo Metropolitan area in Japan, with an average 1.15 million vehicles and an estimated two million users per day. In order to further improve the expressway network, an additional 46 km Central Ring was planned and constructed. Part of the Central Ring is the Shinjuku Line, which is approximately 11 km long and almost entire length was constructed below ground in bored tunnel. The Nishi Shinjuku Tunnel, forming a section of the Shinjuku Line, comprises of identical twin tunnels with outside diameter of the tunnel segment is 13.0 m. Each of the tunnels was designed to cater for traffic in one direction; each with two traffic lanes and about 600 m in length. Excavation of the tunnels was carried out by a pressurised slurry shield machine with an outside diameter of 13.23 m. The excavation operation commenced from a common launching cum receiving shaft, proceeded under an existing road for about 600 m until it reached an intermediate vertical shaft. The shield machine turned 180 degrees within the vertical shaft and headed back to the common launching cum receiving shaft, completed the twin tunnels with a total length of about 1200 m. Due to the location of construction site in the middle of the city, there was limited working space on the ground level. As such most of the temporary facilities including slurry treatment plant, slurry conveying equipment, sand screening device, back grouting equipment, etc. were installed inside the common launching/receiving shaft. The intermediate vertical shaft for rotation of the shield machine is located in gravel and sand formations with high water permeability and high pore water pressure. In order to protect the wall of vertical shaft from collapsing during arrival and re-launching of the shield machine, as well as to prevent water seepage, ground treatment work was conducted by the Freezing Method. The freezing Method was selected because of its outstanding performance in sealing off underground water and ability to create a high strength ground protection. In addition, swelling effect resulting from freezing process was relatively small in gravel and sandy soil layers and therefore impact on the surrounding ground formation was limited and/or negligible. Although there were quite a number of projects involving turning of shield machines with outer diameters of less than 7 m (weight below 350 ton) previously, there was no precedence for turning of large shield machine of this scale with a weight of 3000 ton. Therefore, various type of turning methods were thoroughly reviewed and a turning method using ball-bearings (each of the steel balls was /90 mm in size) with the assistance of two numbers of 400 ton · 2100 mm hydraulic jack, which is low cost and safe to execute, was selected. The whole turning operation took four days to complete, two days for the 180 degrees turn and another two days for lateral movements before and after the rotation. Excavation of the tunnels started in September 2000 and was successfully completed as scheduled in February 2002. (A). Reprinted with permission from Elsevier. For the covering abstract see ITRD E124500.

선박 추진축 선미 베어링 압력 분포 해석

Since the scale of vessels is growing up recently, some troubles between the shaft and after bush bearing are frequently reported. Generally, mean pressure on bush bearing is used as a design criterion. However, in some case of the long bearing such as after bush bearing of the propulsion shaft, it might be liable to be locally under high pressure. As for the main engine bearings and the intermediate shaft bearing, it is reasonable to take the mean pressure as a design criterion. But, in case of after bush bearing, it is not sufficient because of the possibility of high pressure caused by local contact. In this study, Hertzian contact condition was applied to evaluation of the local pressure for after bush bearing. To reduce the local maximum pressure, the height of the after bush bearing was controlled. It was found that local maximum pressure could be reduced effectively by taking a partial slope on the white metal of the aft bush bearing.

Radiometric dating of the Siloam Tunnel, Jerusalem.

The historical credibility of texts from the Bible is often debated when compared with Iron Age archaeological finds (refs. 1, 2 and references therein). Modern scientific methods may, in principle, be used to independently date structures that seem to be mentioned in the biblical text, to evaluate its historical authenticity. In reality, however, this approach is extremely difficult because of poor archaeological preservation, uncertainty in identification, scarcity of datable materials, and restricted scientific access into well-identified worship sites. Because of these problems, no well-identified Biblical structure has been radiometrically dated until now. Here we report radiocarbon and U-Th dating of the Siloam Tunnel, proving its Iron Age II date; we conclude that the Biblical text presents an accurate historic record of the Siloam Tunnel's construction. Being one of the longest ancient water tunnels lacking intermediate shafts, dating the Siloam Tunnel is a key to determining where and when this technological breakthrough took place. Siloam Tunnel dating also refutes a claim that the tunnel was constructed in the second century bc.

Joint tripode fixe d'une transmission automobile. Modèle de chocs et essais industriels

An automotive transmission is made of a fixed tripod joint close to the wheel and a plunging tripod joint close to the engine linked together by an intermediate shaft. The fixed tripod joint is excited by the shudder vibrations generated by the longitudinal movement of the intermediate shaft. The axial stop at the fixed joint level is obtained by a star clamp of large stiffness fixing the joint on the shaft and a spring under a stop whose stiffness and position permit the joint optimisation considering vibrations. The proposed mechanical model built with a mass spring system is used to predict shocks between the star clamp and the tripod, star clamp and stop and stop and tulip. The velocity restitution coefficient after shock steel on steel of 0.9 was used and the six state equations were numerically integrated using a Runge and Kutta algorithm. This model was used to show the star clamp-tripod separation and determined the relevant positions of deformation gauges on an instrumented transmission for the measurement of internal efforts.

Procedure for Optimum Design of a Two-Stage Spur Gear System

In this paper, an optimum design of a two-stage spur gear system is performed. The optimization is based on a multicriterion technique consisting of a Min-Max method combined with a direct search technique. The optimum design includes the minimization of seven objective functions. They are the volume of gears, the center distance and five dynamic factors in the input shaft, first-teeth meshing, intermediate shaft, second meshing and the output shaft. The dynamic factors are estimated using a dynamic model of twelve degrees of freedom. The objective functions are governed by eleven design variables, chosen to be the number of teeth and face width of the pinion of each stage, stiffness of the input, intermediate, and output shafts and the inertia of the four gears of the mechanism. The developed optimum design is found to give compact-gear system with quiet running (minimum dynamic factors) compared with the classical design. The angle between the power transmitting directions is found to have an important role on the objective functions and the optimum design. A value of 180° for this angle is found to be the optimal for all functions.

Dynamic Response Analysis of Rotor-Bearing Systems With Cracked Shaft

A general dynamic model for a large-scale rotor-bearing system with a cracked shaft is introduced. A finite shaft element with a crack is developed using a consistent finite element approach. The model accommodates shafts with tapered portions, multiple disks and anisotropic bearings. The formulation is applicable to rotor-bearing systems with different practical design configurations including intermediate bearings, shaft overhang, and stepped shaft assemblies. A reduced order form of equations of motion is obtained by invoking the actual non-planar (complex) modal transformations. The time-response due to different excitations are calculated, and comparisons are presented to establish the validity and efficiency of the reduced order model. It is hoped that the developed computational scheme offers an efficient and essential core module in establishing other specialized crack detection schemes for rotor-bearing systems.