In this study, we propose a computational fluid dynamics (CFD)-based method to study the lubrication and temperature characteristics of an intermediate gearbox with splash lubrication. A volume (VOF) multiphase model was used track interface between oil air. multiple reference frame (MRF) adopted accurately simulate movement gears, bearings, surrounding flow field. The thermal-fluid coupling then established. Combined experimental results, verified that lubricating below limit requirement...

The fourth-moment method can accurately perform a reliability analysis when it is challenging to determine the distribution of random variable due limited available samples. This only utilizes first four moments and constructs index. However, cannot be applied in engineering cases where state function expressed explicitly, as becomes difficult establish correlation between function. Simplifying forcefully may result significant prediction errors. To address this limitation, study proposes an...

Meshing stiffness is a crucial parameter that affects gear transmission characteristics. Accurately calculating the meshing of gears and comprehensively analyzing influence various factors on it are essential for providing reference guidance design selection. In this paper, finite element method employed to calculate helical gears. Subsequently, axial modification introduced estimate after shape modification. Finally, parameters analyzed using numerical examples, selection principle based derived.

Reliability-based robust design methods have been widely used in the field of product design; however, they are difficult to apply fatigue reliability process rolling bearings due problems determining accumulated damage caused by internal cyclic time-varying load distribution and computational cost reliability. Therefore, a reliability-based method for bearing failure is proposed, which derives formula under spectrum significantly reduces compared with existing methods. First, state response...

Based on computational fluid dynamics, a two-phase flow model was established to calculate the churning power loss of spiral bevel gears under splash lubrication. The error between simulation results and experiment is only 7.04%. Taking certain helicopter as an example, intermediate gearbox ∼2.6051 kW, accounting for ∼1.93% input power. Besides, motion mechanisms free flow, ejection splashing gear were investigated. influences rotational speed oil immersion depth analysed. should be in range...

Purpose Under-race lubrication can increase the amount of lubricating oil entering a bearing and greatly improve cooling effects. The oil-air two-phase flow heat transfer characteristics inside ball with under-race play key role in performance. purpose this paper is to study these two characteristics, then provide guidance for dissipation lubrication. Design/methodology/approach In paper, simplified three-dimension model established; coupled level set volume fluid method used track flow,...

Under-race lubrication can increase the amount of lubricating oil entering a bearing and greatly improve cooling effects. The oil-air two-phase flow characteristics inside ball with under-race play key role in performance. motions subassemblies are complicated. Ball spin affects volume fraction. In this paper, coupled level set fluid (CLSVOF) method is used to track lubrication. influence various factors on fraction investigated, particularly rotating speeds, inlet velocity size supply...

Purpose This paper aims to propose a numerical method calculate the convective heat transfer coefficient of spiral bevel gears under condition splash lubrication and reveal temperature characteristics between oil-air two-phase flow. Design/methodology/approach Based on computational fluid dynamics, multiple reference frames (MRF) was used simulate rotational motions their surrounding fluid. The were studied by combining MRF with volume multiphase flow model. Findings can be improved...

In this study, two-row tapered roller bearings (TBR) with different rib structures were tested under the condition of loss lubrication. It was found that double-row TBR outer ring structure worked normally after 40 min test, but inner The bearing side has failed. order to explain phenomenon, computational fluid dynamics (CFD) numerical simulation models two structural established, and flow characteristics oil in cavity conditions full lubrication studied by method discrete inlet volume....

Loss of lubrication (LOL) is a severe problem in transmission systems wherein the temperature increases continuously until failure. The and flow-field distributions during this process are complicated. These heat generation system LOL have not been adequately studied. In study, we used computational fluid dynamics to establish an oil–gas, two-phase flow model for asymmetric bearings calculated oil volume fraction on bearing surface. A dynamic calculation method was proposed based kinematic...

Ball bearings operating at low speeds and under heavy loads are susceptible to wear failure, leading significant economic losses. The existing reliability-based robust design optimization method of the fourth-moment has high accuracy does not need determine random distribution input variables, but it is possible apply ball bearing due complexity state function that cannot be characterized as an explicit form. To address this issue, paper proposes a novel for wear. Firstly, surrogate model...

Gear transmission systems are widely used in various fields. The occurrence of gear cracks, tooth pitting, and other faults will lead to the dynamic characteristics deterioration system. In order calculate meshing stiffness faulty pairs more effectively precisely, this article improves loaded contact analysis (LTCA) method by analyzing influence different fault types on deformation, including bending-shearing deformation which combines accuracy finite element (FEM) rapidity analytical (AM)....