Perencanaan Ulang Propeller Shaft pada Mobil Toyota Kijang Super 1500cc Tahun 1990

Mobil merupakan salah satu jenis kendaraan pribadi yang biasa digunakan dalam kehidupan sehari-hari. Kendaraan dapat berjalan/bergerak karena ada sistem yang memindahkan tenaga/momen/putaran dari mesin ke roda. Jenis dan merk tersebut juga banyak, salah satunya yaitu Kijang Super 1500cc dari Toyota. Mobil jenis ini memiliki komponen penting di antaranya body (bodi), machine (mesin), suspension (suspensi), electrical (kelistrikan), wheel (roda), chasis (rangka). Rangka merupakan salah suatu bagian penting dalam kendaraan. Komponen rangka sendiri terdiri dari flange yoke, propeller shaft, universal joint, sleeve yoke. Dari perhitungan diatas kita tahu bahwa: Tegangan aksial yang terjadi pada universal joint berdasarkan momen puntir yang transmisikan dari mesin sebesar 0,61 Mpa. Untuk menentukan kode bearing berdasarkan tabel 14/2 yang berbantuk konstruksi bantalan jarum sebesar 617 dan berdasarkan 14/1 yang sesuai dengan universal joint (bantalan jarum) dengan penyebutan lubang 01 mempunyai diameter dalam 12 dan diameter luar 21 jadi kode bearing yang didapat adalah NU 4901 E.MA.C2. Umur bearing yang dihitung berdasarkan tegangan aksial pada universal joint dengan putaran bearing sejumlah 372,4 jutaan putaran dapat bertahan sampai 1939,58 jam. Material bahan propeller shaft dan universal joint merupakan baja karbon rendah AISI 1045 dan AISI 4620 yang di rancang berdasarkan safety of factor sebesar 2 yang artinya material bahan aman.

SHAFT LOADS ON AZIMUTH PROPULSORS IN OBLIQUE FLOW AND WAVES

A range of model experiments have been carried out in calm water and waves for an oil spill vessel model with twin tractor azimuth thrusters at different heading angles and advance coefficients in the large towing tank at the Marine Technology Centre in Trondheim, Norway. Propeller shaft bending loads have been measured using a shaft dynamometer capable of measuring all shaft side force and bending moment components as well as propeller torque and thrust. The results include the loads on the propeller shaft with and without the presence of a ship hull model at the same heading angles and advance velocities in order to study the wake influence from the ship hull on the hydrodynamic loads. Results show that the ship hull wake has a much stronger effect on the propeller loads when the propeller is azimuthed outward from the ship hull centreline than inward. Measurements from the experiments in waves are also presented for the same thruster model in a straight-line course for both the head and following sea states under different wave conditions. Larger bending loads are found in head sea conditions compared with the following sea conditions. Generally it is found that the shaft bending loads and lateral forces are quite large, which is important to consider in the mechanical design layout and for dimensioning of components.

Estimating efficiency of forecasting technical conditions of ship propulsion systems

The article considers an approach to assessing the effectiveness of the most common methods of predicting the technical conditions and failure with reference to the ship shafting. There have been analyzed the main factors in operation of the ship shaft line, which cause the change in its technical state. It has been found that a special feature of some loads acting on the propeller shaft is their stochastic or changing nature over time, which hampers predicting the technical state of the shafting and its units. The features of stochastic and extrapolation forecasting methods have been analyzed. The possibility of using statistical methods in conditions of mass standard production of shafting units with a relatively short regulated service life is estimated. An extrapolation method is proposed for predicting the maximum permissible clearance of stern tube bearings. The case of accumulating samples of measuring results of the propeller shaft sagging in the given time intervals is considered, the approximating functions are constructed. The criteria for the reliability of the results of extrapolation methods for predicting the wear of stern tube bearings are determined. There have been developed the proposals for adapting the causal method as an alternative to the extrapolation method. A schematic diagram of a system for the ship shafting failure predicting has been developed using the registration and analysis of vibration parameters, which serves as the basis for constructing a regression model of damage accumulation. The proposed forecasting system allows studying the actual operating conditions of the shafting, defining the actual external loads and the regularities of their occurrence, measuring deformations and stresses, and determining quantitative indicators of the reliability of the shafting during normal operation and special operating modes, for example, with vibration resonance. The theoretical basis of the algorithm for calculating and registering loads affecting the service life of shafts is proposed.

Studuing and developing methods of propeller shaft technical diagnostics

The propeller shafts are the structural components that require increased attention. The results of studying the damage of propeller shafts are presented in accordance with the safety requirements (a case of the river vessels). It is shown that residual stresses greatly impact the reliability and operability of the shafts becoming a damaging factor. The residual stresses occur due to surfacing the propeller shaft by ST35 steel with SV-08A welding wire. There is considered the possibility of determining the magnitude of residual stresses by the acoustic method in the surfacing. To estimate stresses the phenomenon of acoustoelasticity was used: the dependence of the elastic waves propagation velocity on the magnitude of the acting stresses. The process of determining the acoustoelasticity coefficients was carried out using standard samples (in accordance with GOST1497). Samples modeling surfacing were manufactured and tested. Metallographic studies were carried out to assess the influence of the material composition of the propeller shaft on the structure and strength properties of the propeller shafts. The influence of the structure on the amount of residual stresses was evaluated. It has been inferred from the tests results that the speed of elastic waves depends on the residual stresses. The results of the work can be used in production conditions for the control of products made of 35 steel with surfacing. In conclusion, the proposed method can be used to determine the residual stresses directly on the propeller shafts in operation conditions during the appropriate maintenance of ships.

Structural analysis and optimization of an automotive propeller shaft

It is a trend to implement weight reduction in parts in recent years when developing a new car. This trend is because weight reduction is essential to respond to tightening environmental regulations. In other words, parts manufacturers of body, chassis, and power train systems have made considerable efforts to reduce weight from the proto design stage. This study performed structural analysis and optimization for weight reduction of a propeller shaft for a passenger car. The natural frequency and the durability of the developing propeller shaft were examined through finite element analyses and tests. Then, optimization was accomplished by focusing on the weight reduction of the tubes made of given steel material. In this process, the metamodel-based optimization technique, kriging interpolation, was applied, and the weight was reduced by 5.3% based on the propeller shaft and 14.1% based on the tube. ANSYS Workbench was used for structural analysis, an in-house program was used to build the kriging model, and MATLAB was used for optimization.

Analysis of damage and failure of ship propulsion shafts

The paper highlights the problem of a ship shaft line failure, which entails significant economic losses, because most vessels of the Russian fleet are equipped with a shaft line. A large number of domestic and foreign works are devoted to studying the causes of damage and failures of ship shafting. The complexity of collecting, systematizing and analyzing statistical data on breakdowns and damages of shafting lies in the fact that the data refer to different periods of time, different periods of operation and types of ships, and are also contained in various sources. There has been considered the approach to systematization of modern statistical data on damages and failures of ship shafting elements collected on the basis of defect-technological lists of the Astrakhan shipyards and from other sources. Information on breakdowns of ships, their elements and ship shaft lines within 2010 - 2019 provided by the Russian River Register of Shipping is given. The analysis of accidents on ships of the class of the Russian Maritime Register of Shipping. The places of occurrence and the nature of the propeller shaft cracks have been established, which makes it possible to assess the nature and magnitude of the destructive loads, as well as the real safety margins. The general classification of the location of the propeller shaft cracks in the order of the frequency of their occurrence is given. There have been shown the results of the analysis of defect-technological lists, which make it possible to establish the causes of ship shafting failures, which led to emergency repair, and the most common defects identified during the scheduled dock repair of ships. The influence of the diameter of propeller shafts on the nature and size of defects, as well as the frequency of their manifestation, is estimated. Based on the results of the analysis, certain measures have been proposed to reduce the number of accidents in shafting of projected vessels, and the most promising directions for improving the already developed structures of shafting in operation are outlined. The results of the analysis are in addition to the ongoing research and development work to improve the reliability of ship power systems.