Gear transmission rattle: Assessment of meshing forces under hydrodynamic lubrication

Abstract

Noname manuscript No.(will be inserted by the editor) GEAR TRANSMISSION RATTLE: ASSESSMENT OF MESHING FORCES UNDER HYDRODYNAMIC LUBRICATIONA. Fernandez-Del-Rincon · A. Diez-Ibarbia · S. TheodossiadesReceived: date / Accepted: date Abstract The dynamic behavior of gear transmissions poses several challenges from the standpoint of design and requires the availability of more advanced models capable of simulating a wide range of operating conditions. In this paper, several formulations to represent efforts related to the lubricant in gear transmissions subjected to reduced torque levels has been assessed. Under these conditions, the lubrication regime is hydrodynamic and the dynamic behavior of the meshing contacts can happen in different scenarios depending on both the lubricant properties and operating conditions. Such problems are cumbersome in gear transmissions in which acoustic performance is a determining design factor, such as in car applications. In this regard, gear rattle is one of the subjects of concern by powertrain designers. In spite of several authors have approached this phenomena, the most recent interest is focused on the role played by the lubricant. The variety of fundamentals and aims of the developed models in this respect requires a better understanding of the effect taken into account by the different formulations in the accurate modeling of hydrodynamic lubrication in gears subjected to low torques. This is the reason why, in this work, several alternatives currently available in the literature to address the formulation of efforts in hydrodynamic regime was collected and presented. Such formulations were implemented in a transmission model previously developed by the authors which was used to simulate different operating conditions in order to assess the results obtained with each one of the considered formulations.

Gear rattle dynamics under non-stationary conditions: The lubricant role

“…Within this framework, the lubricant role is still to be understood, specifically under non-stationary conditions, since only few studies deal with this issue [1,6,7,26,27,28], being this the main goal of the present work, as well as the novelty with respect to the preliminary hydrodynamic force analysis under gear rattle conditions performed in [11]. In this regard, in previous analysis of the authors [11], six hydrodynamic formulations found in literature [29,30,31,32], which consider both squeeze and entraining fluid effects to model the fluid contact in HDL conditions, were implemented in the model developed by the authors [9,12,13] to simulate gear rattle under stationary conditions. Specifically, several mean input velocities were considered in that analysis, obtaining the dynamic response under several torque cases, concluding that, when constant input speed was considered, the wedge term overcomes the squeeze term effect on the dynamic response.…”

“…In order to avoid repetitions with the aforementioned analysis [10,11], only a summary of the lubrication concepts and the dynamic model is described in sections 2 and 3, highlighting the required information for this specific study. Then, the tests set-up and results are discussed in sections 4 and 5 whilst the conclusions are exposed in section 6.…”

Effect of micro-textures on lubrication characteristics of spur gears under 3D line-contact EHL model

“…Spur gear has been extensively implemented in vehicles, ships, aviation and other fields with its advantages of accurate and stable transmission and high efficiency (Dai et al, 2021;Liu et al, 2020;Mo et al, 2019Mo et al, , 2020a. The state of the tooth surface is one of the key factors that determine lubrication characteristics, load capacity and service life of the gear (Fernandez-Del-Rincon et al, 2019;Lorenz et al, 2021;Simon, 2019;Wang and Zhu, 2021). Generally, gear tooth surface roughness is of the same order of magnitude as the minimum film thickness.…”

Classifying, Predicting, and Reducing Strategies of the Mesh Excitations of Gear Whine Noise: A Survey

“…According to the literature reviewed, there are two kinds of noise emitted from the automotive gearbox, namely, gear rattle noise and gear whine noise. Gear rattle noise is generally caused by fluctuations in the engine torque and speed [1][2][3][4], which usually lead to contact loss and impacts between lightly loaded mating gears. Gear rattle noise also has a close relationship with lubricant conditions [5][6][7].…”