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The purpose of this paper is to carry out research on friction and wear behavior of pin-bushing with magnetorheological fluids (MRFs).

The oscillation friction characteristics of MRFs with a magnetic field are evaluated by a pin-bushing friction wear tester. The housing is adjusted to apply the magnetic field to MRFs. Experiments are carried out with and without a magnetic field, and the coefficient of friction and temperature on the contact interface are measured. The surfaces of the pin and bushing are also examined by a surface profilometer and an optical microscope before and after tests. The experiment results show a lower coefficient of friction is observed when a magnetic field is applied.

The temperature is lowest when grease is used. The case when a magnetic field is present shows the higher temperature. The coefficient of friction is higher than grease lubrication when an MRF is applied. The coefficient of friction of the pin-bushing is lowest with grease and highest when a magnetic field is present. The friction coefficient of grease and MRFs decreases as the load increases and remains stable after 3 kN is added. The roughness, surface profile and morphology of the pin show the best results when grease is used as compared with MRFs.

The tribology characteristic of pin-bushing with MRFs shows more deficiency than that with grease. Nevertheless, it is necessary to carry out the research on the friction and wear characteristics of a pin-bushing with MRFs, as it is expected to increase the load-carrying capacity when an MRF is applied to the pin-bush system. Better friction and wear characteristics could be achieved by enhancing the property of MRFs.

Reducing wear of undercarriage track propulsion systems used in heavy construction equipment decreases the maintenance costs and increases the equipment's life. Therefore, understanding key factors that affect the wear rate is critical. This study is an attempt to predict undercarriage wear.

This research analyzes a sample of track-type dozers in the eastern half of North Carolina (NC), USA. Sand percentage in the soil, precipitation level, temperature, machine model, machine weight, elevation above sea level and work type code are considered as factors influencing the wear rate. Data are comprised of 353 machines. Machine model and work code data are categorical. Sand percentage, elevation, machine weight, average temperature and average precipitation are continuous. ANOVA is used to test the hypothesis.

The study found that only sand percentage has a significant impact on the wear rate. Consequently, a regression model is developed.

The regression model can be used to predict undercarriage wear and bushing life in soils with different sand percentages. This is demonstrated using a hypothetical scenario for a construction company.

This work is useful in managing maintenance intervals of undercarriage tracks and in bidding construction jobs while predicting machine operating expense for each specific job site soil makeup.

This paper seeks to present some new designs of sliding bearings lubricated with magnetic fluids (ferrofluids) and the possibility of using them in modern bearing technology, in new computer and audiovisual equipment among others.

The paper presents new designs of journal, thrust and journal‐thrust sliding bearings lubricated and sealed with magnetic fluids such as: magnetic fluid bearing bushing made of magnetizable material, pivot bearings with porous sleeve impregnated with ferrofluid, self‐aligning bearings, hydrodynamic ferrofluid bearings with spiral and herringbone grooves structure are presented. Moreover, examples are shown of applications in modern bearing technology.

The paper provides information about new designs of magnetic fluid sliding bearings assemblies and gives the main advantages of these bearings over conventional ball bearings, such as extremely low non‐repetitive run‐out (high‐accuracy of rotation), good damping and quietness of operation, maintenance free service and high reliability.

This paper offers some new designs of compact, low friction and self‐contained magnetic fluid sliding bearings and points up their practical applications.

The purpose of this paper is to propose a new approach for designing different parts of a high voltage bushing. It also aims to consider technical and economical criteria for the optimum solution of the design problem.

A novel method for finding the optimal contours of different elements of high voltage bushings, including ceramic insulator, electrode, and flange angle is presented. The rational Bézier curves are used for defining the surface of the insulators and conductors of the equipment. Then, these curves are optimally adjusted to obtain an appropriate techno‐economical solution. The utilized optimization method is the improved bacterial foraging algorithm (BFA) with variable step sizes. In the design procedure, two‐dimensional finite element method (2D FEM) is used to calculate the performance parameters in each step of the design procedure. In order to evaluate the performance of the proposed algorithm, optimal design of different elements of a 110 kV bushing using BFA and genetic algorithm is presented, compared, and discussed as well.

The results of this research show that the technical design criteria and economical costs are satisfied by the proposed method. It is concluded that the rational Bézier curves can be implemented for other similar applications and optimal design of other equipment in the electrical engineering field combined with heuristic optimization techniques.

Bezier curves are used for the first time for bushing design purpose. Two heuristic techniques are also implemented in order to facilitate the comparison and avoid local solutions.

The purpose of this paper is to study the influence of friction on static and dynamic characteristics, as well as the strength and lifetime of a flexible three-axes computer numerical control (CNC) machine tool.

The machine tool is first modeled by using finite element method to analyze static structure with frictionless surface-to-surface contact type. Because the machine tool structure is becoming more and more sophisticated over time, the significant influence of contact conditions between structural elements on the dynamic characteristics of the whole structure must be considered. To examine the dynamic effects caused by inertia forces and displacement of moving bodies on contact stress, the coefficient of friction between two contact bodies is added to perform dynamic simulation and compare the results with the static analysis results.

Distribution of stress and contact forces in solid-flexible contact is also studied by using the fundamental dynamic characteristics of a bushing joint.

Finally, the influence of dynamic structure, cutting conditions and material properties on the strength and lifetime of the CNC machine tool is discussed by using fatigue analysis. Consequently, this research can be used for efficient simulation of structural dynamics, lifetime assessment and interactions of the real CNC machine with the machine tool structure in a virtual environment.

The robot is proving itself to be a reliable and effective automation tool and users are finding them relatively easy to install. But the main problems surround the peripherals and the integration into the production system. This process can be eased by thoroughly studying potential applications as GE have proved.

The paper aims to analyze the evolution of the lubrication regime by studying the variation of friction coefficient with the rotational speed of the shaft and the impact of the applied load in the starting phase of a cylindrical journal bearing. The paper also aims to ensure that the oil layer is large enough for the rough edges of the outer layer of the bushing and the shaft cannot come into contact. The bearing is made of steel backing material and babbitted (88 per cent tin) on its inner surface.

A numerical analysis is performed taking into account the thermal effect to better predict the operating performance of a hydrodynamic plain cylindrical journal bearing during the start-up and observe the variation of the heat production in bushing inner surface. The flow is modeled based on the Reynolds equation and discretized using the finite volume method.

The evolutions of the start-up speeds of the bearing have remarkable influence on friction torque; average temperature and dissipated power increased with increasing speed and increasing load, but the maximum pressure and the eccentricity decreased with the increase of the start-up speed. The friction coefficient, minimum film thickness and attitude angle increase with elevation of start-up speed.

For the start-up speed of 750, 1,000 and 1,800 rpm and an applied load of 1,000 N, the regime of lubrication of the bearing passes the hydrodynamic regime to the mixed regime; therefore, during start-up and under heavy loads, the bearing must move very quickly at these speeds to avoid contact of the inner surface of the bearing and the shaft.

REPLACEMENT of sand‐cast bronze bushings by continuous‐cast bronze has recently solved a difficult operational problem in large diesel engines manufactured by Enterprise Engine and Machinery Company, of San Francisco, California. The company designs and constructs diesel engines for industrial and marine use.

The purpose of this study is to suppress the temperature rise of high voltage wall bushing metal plate.

First, the authors built a model of a traditional metal plate and got the magnetic field intensity distribution by FEA tools. Optimized according to the magnetic field intensity distribution, the authors slot the traditional metal plate and embed permanent magnets in the slot. Finally, the authors got the temperature distribution diagrams of the above three cases at different current levels by FEA tools.

Slotted metal plate is beneficial to suppress magnetic induction intensity, but the improvement of the magnetic induction intensity uniformity is not obvious. The method of embedding a permanent magnet in a slotted metal plate can optimize the magnitude and uniformity of the magnetic induction intensity in the metal plate. The larger the current passing through the metal plate, the better the temperature suppression effect of the slotted metal plate and the slotted metal plate embedded in the permanent magnet.

The effect of structural factors, slotting plate and setting permanent magnets on slots on the temperature of supporting plate is studied. The paper proposes two methods, slotting metal panels and embedding permanent magnet metal panels, to solve the problems of eddy current loss and high calorific value of the panel, which is of great significance to the safety of the grid equipment.