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The purpose of this paper is to describe a simulation and experimental research concerning the effect of recess depth on the lubrication performance of a hydrostatic thrust bearing by constant rate flow.

The computational fluid dynamics and finite volume method have been used to compute the lubrication characteristics of an annular recess hydrostatic thrust bearing with different recess depths. The performances are oil recess pressure, oil recess temperature and oil film velocity. The recess depth has been optimized. A test rig is established for testing the pressure field of the structure of hydrostatic thrust bearing after recess depth optimization, and experimental results show that experimental data are basically identical with the simulation results, which demonstrates the validity of the proposed numerical simulation method.

The results demonstrate that the oil film temperature decreases and the oil film pressure first increases and then decreases with an increase in the recess depth, but oil film velocity is constant. To sum up comprehensive lubrication performance, the recess depth of 3.5 mm is its optimal value for the annular recess hydrostatic thrust bearing.

The computed results indicate that to get an improved performance from a constant flow hydrostatic thrust bearing, a proper selection of the recess depth is essential.

This paper aims to describe a theoretical and experimental research concerning influence of recess shape on comprehensive lubrication performance of high speed and heavy load hydrostatic thrust bearing with a constant flow.

The lubrication performance of a hydrostatic thrust bearing with different recess shape under the working conditions of high speed and heavy load has been simulated by using computational fluid dynamics and finite volume method.

It is found that the comprehensive lubrication performance of a hydrostatic thrust bearing with circular recess is optimal. The results demonstrate that recess shape has a great influence on the lubrication performance of the hydrostatic thrust bearing.

The simulation results indicate that to get an improved performance from a hydrostatic thrust bearing with constant flow, a proper selection of the recess shape is essential.

This paper aims to combine the grooves with an annular air thrust bearing with multi-hole restrictors and discusses the influence of the groove parameters on the bearing performance.

Four models of aerostatic bearings with grooves of different geometries are established. The pressure distribution, load-carrying capacity (LCC), stiffness and flow characteristics of the flow field in the bearing clearances are obtained by computational fluid dynamics simulation.

The numerical and simulation results show that air bearing with grooved restrictors can slow down the pressure drop at the air inlet and increase the LCC and stiffness of the bearing. The gas flow in the aerostatic bearing is also studied, and the air vortex in the recess is analyzed.

This research optimizes the structure of the annular air thrust bearing, analyzes the gas vortex in the recess, improves the LCC and stiffness of the bearing and provides a reference for the bearing in the selection of groove parameters.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2023-0006/

The purpose of this paper is to maximize the load-carrying capacity (LCC) of a rotating ring, a numerical model optimizing both the surface and bottom shape of its surface textures is proposed.

The Reynolds equation is used to evaluate the film pressure and LCC obtained by integrating the film pressure is set as the objective function. Around the center of the computational domain, radial lines with an equal angle between adjacent ones are produced and the surface contour of textures is obtained by connecting the endpoints using a spline curve. The bottom profile is then obtained by connecting the endpoints of two vertical lines at the circumferential ends of textures. Lengths of these lines are set as design variables and genetic algorithm is used to solve optimization models.

Results show that optimum textures have an “apple-like” surface contour and a “wedge-like” bottom profile, which are both expressed by smooth spline curves. Optimum wedge-bottom textures generate higher LCC than optimum flat-bottom textures. Moreover, the optimum textures have the highest LCC compared with optimum grooves proposed previously, which validates the practical value of the current optimization model.

This work presents a comprehensive optimization method of texture geometry, which provides a new idea of the design of surface textures.

This study aims to investigate the effects of irregular groove textures on the friction and wear performance of sliding contact surfaces. These textures possess multiple depths and asymmetrical features. To optimize the irregular groove texture structure of the sliding contact surface, an adaptive genetic algorithm was used for research and optimization purposes.

Using adaptive genetic algorithm as an optimization tool, numerical simulations were conducted on surface textures by establishing a dimensionless form of the Reynolds equation and setting appropriate boundary conditions. An adaptive genetic algorithm program in MATLAB was established. Genetic iterative methods were used to calculate the optimal texture structure. Genetic individuals were selected through fitness comparison. The depth of the groove texture is gradually adjusted through genetic crossover, mutation, and mutation operations. The optimal groove structure was ultimately obtained by comparing the bearing capacity and pressure of different generations of micro-convex bodies.

After about 100 generations of iteration, the distribution of grooved textures became relatively stable, and after about 320 generations, the depth and distribution of groove textures reached their optimal structure. At this stage, irregular texture structures can support more loads by forming oil films. Compared with regular textures, the friction coefficient of irregular textures decreased by nearly 47.01%, while the carrying capacity of lubricating oil films increased by 54.57%. The research results show that irregular texture structures have better lubrication characteristics and can effectively improve the friction performance of component surfaces.

Surface textures can enhance the friction and lubrication performance of metal surfaces, improving the mechanical performance and lifespan of components. However, surface texture processing is challenging, as it often requires multiple experimental comparisons to determine the optimal texture structure, resulting in high trial-and-error costs. By using an adaptive genetic algorithm as an optimization tool, the optimal surface groove structure can be obtained through simulation and modeling, effectively saving costs in the process.

The purpose of this paper is to analyze journal thrust bearings geometries, used in household refrigerators, using a modified version of the Reynolds equation which includes the inertial terms.

The Reynolds equation was solved through the finite volume method, thus providing the pressure field in the lubricant film and, consequently, the load and the power used by the bearing. Such parameters depend on bearing geometry, which was optimized through the method of Lagrange multipliers, to support a given load and use the lowest power possible. The optimized geometries included the Rayleigh pad with 4, 8 and 16 steps, and a milled geometry with 4 steps.

For the Rayleigh pad, the number of steps was varied and a decrease in the power consumed with the increase in the number of steps was observed. The milled pad performance was better than that Rayleigh pad with 4 steps and comparable to the pad with 8 steps.

The manufacture of pads, with a high number of steps, is complicated and, then, a milled pad with 4 steps was proposed in this paper. The use of milled pads is a technological innovation worthy of a more thorough investigation, considering its facility of manufacture when compared to the Rayleigh pad.

In this paper, computer‐aided design optimization approach for hydrostatic bearings is presented. The optimization problem is formulated in multicriteria strategy. The power loss and the temperature rise of oil are considered as performance measures for optimal hydrostatic bearing design. Optimization results indicate the effectiveness of the proposed combined approach which has advantages over the single criteria optimization. Sample results are presented to verify the proposed approach.

The purpose of this paper is to analyze and optimize the roller burnishing process parameters using the design of experiments and grey relational analysis (GRA).

In this experimental work, the carbide burnishing tool has been selected for the machining of AISI-1040 high carbon steel to get better product quality and satisfactory machining characteristics. The material surface condition while machining, burnishing tool speed, feed rate, depth of penetration and No. of passes have been selected as process constraints to conduct experimental trials.

The surface roughness (SR) and surface hardness were considered as output responses. The experimental outcomes optimized by multi-parametric optimization showed considerable improvement in the process. The roller speed and number of passes are the most significant parameters for surface hardness, whereas the surface condition and roller penetration depth have the most significance on SR.

The GRA method shows the 0.03376 improvement in grey relational grade between the experimental values and the predicted values.

The experimental outcomes optimized by multi-parametric optimization showed the considerable improvement in the process and will facilitate steel industries to enhance and improve productivity while burnishing high carbon steel (AISI-1040).

This research represents valid work, and the authors have no conflict of interests.

The purpose of this paper is to study the influences of recess configurations on the performances of high-speed hybrid journal bearing. Hybrid journal bearing earns increasing attention in high-speed machine tool spindle owing to its intrinsic outstanding performances of low temperature rise and high stability.

To investigate the coupled effects of temperature, turbulence and the interaction between lubricant and journal/bearing bush, a thermal fluid-structure interaction approach is presented and validated by the experimental results.

Ladder-type recess has excellent tribological characteristics in decreasing temperature rise, improving stability and inhibiting cavitation, which are all beneficial to improve the performances of high-speed spindle system.

This work can be a valuable guide for the future high-speed hybrid journal bearing design.

The purpose of this paper is to improve static/dynamic characteristics of active-controlled hydrostatic journal bearing by using fractional order control techniques and optimizing algorithms.

Active lubrication has ability to overcome the unpredictable harsh environmental conditions which often lead to failure of capillary controlled traditional hydrostatic journal bearing. The research develops a mathematical model for a servo feedback-controlled hydrostatic journal bearing and dynamics of model is analyzed with different control techniques. The fractional-order PID control system is tuned by using particle swarm optimization and Nelder mead optimization techniques with the help of using multi-objective performance criteria.

The results of the current research are compared with previously published theoretical and experimental results. The proposed servo-controlled active bearing system is studied under a number of different dynamic situations and constraints of variable spindle speed, external load, temperature changes (viscosity) and variable bearing clearance (oil film thickness). The simulation results show that the proposed system has better performance in terms of controllability, faster response, stability, high stiffness and strong resistance.

This paper develops an accurate mathematical model for servo-controlled hydrostatic bearing with fractional order controller. The results are in excellent agreement with previously published literature.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0272