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The purpose of this study is to design a closed hydrostatic guideway has the ability to resist large-side load, pitch moments and yaw moments, has good stiffness and damping characteristics, and provides certain beneficial guidance for the design of large-span closed hydrostatic guideway on the basis of providing a large vertical load bearing capacity.

The Reynolds’ equation and flow continuity equation are solved simultaneously by the finite difference method, and the perturbation method and the finite disturbance method is used for calculating the dynamic characteristics. The static and dynamic characteristics, including recess pressure, flow of lubricating oil, carrying capacity, pitch moment, yaw moment, dynamic stiffness and damping, are comprehensively analyzed.

The designed closed hydrostatic guideway has the ability to resist large lateral load, pitch moment and yaw moment and has good stiffness and damping characteristics, on the basis of being able to provide large vertical carrying capacity, which can meet the application requirements of heavy two-plate injection molding machine (TPIMM).

This paper researches static and dynamic characteristics of a large-span six-slider closed hydrostatic guideway used in heavy TPIMM, emphatically considering pitch moment and yaw moment. Some useful guidance is given for the design of large-span closed hydrostatic guideway.

The purpose of this study is to investigate the coupling effects of the velocity slip, rarefaction effect and effective viscosity of the gas film on the performance of the aerostatic guideway in micro-scale and improve the analysis precision of the static performance of aerostatic guideway.

The corresponding model of the gas film flow with consideration of the velocity slip, rarefaction effect and effective viscosity of the gas film in micro-scale is proposed. By solving the corresponding model, the bearing capacity and the stiffness of the aerostatic guideway are obtained through the pressure distributions of the air cavity. Through comparing the bearing capacity and the stiffness in different situations, the couple effects of the three factors are analyzed. Finally, the experimental results about the stiffness are obtained and the contrast between the simulation stiffness and the tested stiffness is achieved.

Through comparing the coupling effects of the micro scale factors under different conditions on the performance of the aerostatic guideway, it was found that when comparing the effects of a single factor, the effect of the first-order slip is the largest. When two factors are randomly combined, velocity slip and viscosity of the gas film is the largest, but these coupling effects are less than the effect of considering three factors simultaneously.

It is essential to consider the first-order velocity slip, the flow factor Q and the effective viscosity when analyzing the static performance of the aerostatic guideway in micro-scale. This makes studying the performance of the aerostatic guideway in micro-scale feasible and improves the machine’s accuracy.

The purpose of this paper is to study the mechanical properties of aerostatic guideway taking the structural deformation into account, and further improve the calculation method of guideway.

A theoretical model of fluid-structure interaction for the numerical simulation was established and mechanical properties of the aerostatic guideway with porous restrictors were solved based on computational fluid dynamics. The deformation law of the guideway with different materials and gas-film thicknesses was revealed, and its static and dynamic characteristic curves were obtained.

The results indicate that ceramics as the material of guideways exhibit good applicability due to the small deformation, the quick dynamic response and the relatively light weight. The rational initial gas-film of guideway is recommended.

The present work can provide ideas for the design and optimization of aerostatic guideways.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0288

This paper aims to better understand the dynamic characteristics of an aerostatic slider caused by a gas film, and the impact of a gas film slip on the load capacity, stiffness and dynamic stiffness of the guideway is studied.

In theory, the Navier velocity slip model is introduced for fluid continuous flow equation to calculate the flow state in the micro-state; in experimental techniques, the stiffness experiment of the guideway by digital inductance meter is performed under different loadings, which are used to inspect the simulation results.

The maximum value of bearing stiffness in the condition of considering that the gas slip is larger than that of not considering the gas slip, and the gas film clearance of maximum bearing stiffness in the condition of considering the gas slip is less than that of not considering the gas slip. This is verified by the measurement of the stiffness of the guideway.

This paper mostly studies the influence of the gas slip effects on the performance of the aerostatic guideway, which will make a certain contribution to the guideway stability and the machining precision of the machine tool.

This study aims to investigate the efficacy of micro dimple in inhibiting stick-slip phenomenon on the sliding guideway.

In this study, micro-dimples were fabricated by laser on surfaces of steel disk and guideway. The disks and guideways were respectively performed pin-on-disk tribological tests and working condition experiments to study differences in lubrication condition and friction stability between textured and untextured surfaces.

Micro-dimples help reduce critical sliding speed that allows contact surfaces to enter in hydrodynamic lubrication regime. This increases hydrodynamic lubrication range and narrows speed range where stick-slip phenomenon can occur, enhancing sliding guideway’s adaptability for broader working conditions. Furthermore, friction stability on the textured surface improved, lowering the occurrence possibility of stick-slip phenomenon. Finally, difference between static and kinetic frictions on the textured surface is lower relative to the untextured surface, which decreases the critical velocity when the stick-slip phenomenon occurs.

The results indicate that laser-textured micro-dimples are significantly conducive to inhibit stick-slip phenomenon, thus providing smoother movement for the guideway and eventually increasing precision of the machine.

The purpose of this paper is to establish a simplified model of the closed hydrostatic guideway for the rapid analysis of static and dynamic characteristics. Further, the influence of compressibility and dynamic frequency are taken into consideration in the new dynamic model.

The new model is based on the second kind of Lagrange equation. In this model, the closed hydrostatic guideway is supported by 12 pads, and each oil pad is equivalent to a nonlinear spring-damper system. The equivalent spring coefficient and damper coefficient of the oil pad are extracted by the three different equivalent methods. Finally, the validation experiments of step load response and dynamic stiffness are conducted on a hydrostatic guideway.

For solving the step response, the linear spring-damper model and the nonlinear spring-damper Model 1 are better than the nonlinear spring-damper Model 2. The accuracy of the three methods are very high for static stiffness calculation. For the calculation of dynamic stiffness, the nonlinear spring-damper Model 2 is better than the nonlinear spring-damper Model 1. The linear spring-damper model has low precision for dynamic stiffness calculation, especially at high frequency. The accuracy of the new model is validated by experiments.

The equivalent method of nonlinear spring-damper system has higher accuracy. Different equivalent methods should be adopted for different load types. The computational speeds of the new dynamic model with the three methods are much better than finite element method (about ten times).

The purpose of this paper is to introduce a new method to carry out the design optimization of the tool head system in the heavy‐duty machine tool where closed hydrostatic guideways with multiple pockets are employed.

A more accurate method of pressure calculation for closed hydrostatic guideways is introduced. Then, a multidisciplinary design optimization (MDO) model is formulated for design of a tool head system, which minimizes the highest pocket pressure under some constraints from machining accuracy and vibration resistance requirements as well as constraints from ballscrew design specifications. Finally, a metamodel‐based design space alternation (DSA) strategy is proposed to solve the optimization problem.

The results show that the maximum pocket pressure in a tool head system can be reduced over 47 percent with a proper design while all the constraints are satisfied. As a consequence, the tool head system can safely work under the maximum output pressure of oil supply system.

This paper introduces a more accurate method of pressure calculation for multi‐pocket closed hydrostatic guideways, develops a metamodel‐based MDO model for the tool head system, and proposes a DSA strategy to solve the MDO problem.

An aircraft wing comprises one or more sections each foldablc about a fore‐and‐aft substantially horizontal axis and a power‐operated linearly moving member which works in a guideway and is connected through a link to a foldablc wing section such that with the foldablc section folded the link is substantially at right angles to the movable part so that, aided by the friction of that part with respect to its guide‐way, it prevents self‐return movement of the foldablc wing section. The folding wing section 1 is pivotally attached to the fixed wing stub 6 by brackets 2, 3, the bracket 2 being extended to form a member 7 having pivoted thereto one end of a link 8 the other end of which is pivoted to a rectangular slide 9 located in a straight open‐top guideway 10 carried by the wing section 6. The piston rod 12 of a hydraulic jack 11 is connected to the slide 9. An extension 13 of the wing section 1 is apertured at 13 so positioned with respect to a pair of apertured lugs 14 formed on a bracket 4 secured to the wing section 6 that a preferably power‐operated pin may be inserted therebetween to lock the folded wing in its spread position. When the wing section is folded the link 8 is positioned substantially at right angles to the guideway 10, the axis about which folding takes place being triangulated with respect to the axes of the pins passing through the ends of the link 8 so that return movement of the wing caused by wind gusts is prevented. An additional lock may be provided to hold one or both wings in a partial or fully folded position by providing a plurality of holes in the guideway 10 into any one ofwhich holes a pin may be inserted to prevent return movement of the slide 9. Specifications 635,260 and 635,261 are referred to.

The purpose of this paper is to introduce a robotic boring system for intersection holes in aircraft assembly. The system is designed to improve the boring quality and position accuracy of the intersection holes.

To improve the boring quality of intersection holes, a robot posture optimization model is established. The target of the model is to maximize the robot stiffness and the variate is location of the robot on the guideway. The model is solved by the iterative IKP algorithm based on the Jacobian matrix. To improve the position accuracy of intersection holes, a robot positioning accuracy compensation method is introduced. In the method, a laser tracker is used to measure the actual position and orientation of the boring bar. Combined with the desired position and orientation, the error can be obtained and compensated.

In practical case of the robotic boring system, the robot stiffness is effectively improved and the surface roughness of intersection holes achieves a grade of Ra0.8. Besides, the robot end achieves a position accuracy of 0.05 mm and an orientation accuracy of 0.05°.

The robotic boring system has been applied successfully in one of the aircraft assembly projects in northwest China.

The robotic boring system can be applied for machining intersection holes in an aircraft assembly. With the robot posture optimization method and accuracy compensation method, the boring quality and position accuracy of the intersection holes can be guaranteed.

The purpose of this paper is to validate dynamic analytic force modeling techniques with experimental results. The performance of previously presented 2-D and 3-D eddy current models will be assessed when the steady-state models are coupled to a dynamic mechanical model.

The previously presented 2-D analytic model was formulated in terms of the magnetic vector potential in conductive region and magnetic scalar potential in non-conductive region whereas the 3-D model was formulated in terms of the magnetic vector potential in both the conductive and non-conductive regions.

This paper experimentally confirms that incorporating the heave velocity term is important for accurately predicting the forces under dynamic mechanical motion while using a steady-state eddy current solution. A close agreement between the experimental and the dynamic analytic-based eddy current solution was achieved.

The force results presented from the previously developed 3-D analytic model assume that the width of the guideway is larger than that of the magnetic source and the magnetic source is placed at the center of the guideway along the z-axis.

The rotational and translational motion of a permanent magnet rotor above a conductive plate create lift and thrust force that are suitable for magnetic levitated (maglev) transportation. The previously developed 2-D and 3-D analytic models are fundamental to such maglev research as the models can quickly compute the electromagnetic forces acting on the maglev vehicle. This paper is of immense importance as the paper experimentally validates the analytic models.

The quasi-static analytic eddy current force models that are validated in this paper are different to analogous models developed by prior authors in that the heave velocity as well as the translational velocity of a magnetic source is incorporated into the eddy current force equation.