Intermittent gear rattle due to interactions between forcing and manufacturing errors

Abstract

The interaction between eccentricity and an external forcing fluctuation in gear rattle response is investigated experimentally. The experimental rig consists of a 1:1 ratio steel spur gear pair, the input gear being controlled in displacement and the output gear being under no load. Gear transmission errors recorded using high accuracy encoders are presented. Large variations in backlash oscillation amplitude are observed as the relative phase of the input forcing and the sinusoidal static transmission error due to eccentricity is varied. A simplified mathematical model incorporating eccentricity is developed. It is compared with experimental findings for three different gear eccentricity alignments by way of plots relating backlash oscillation amplitude to forcing amplitude and phase relative to eccentricity sinusoid. It is shown that eccentricity does not fully account for the experimentally observed large variations in amplitude. Through analysis of the experimental data, it is suggested that further tooth profiling errors may explain the discrepancies.

Non-Newtonian mixed thermo-elastohydrodynamics of hypoid gear pairs

“…The viscosity used in equations (16) to (20) is the average viscosity in the direction of film thickness, updated by the pressure and temperature iteratively. It is obtained from equation (6). It is noteworthy that effective viscosity is given by equations (16) to (20) if its local value reaches the limiting shear stress.…”

“…The viscosity is the average viscosity in the direction of film thickness, updated by the pressure and temperature using equation (6). It should be noted that viscosity assumes its effective value as the local viscosity promotes limiting shear stress.…”

“…1 Therefore, the drive for fuel-efficient lightweight powertrains has resulted in some major NVH concerns, for instance driveline clonk [1][2][3][4] and transmission rattle. 1,[5][6][7] With the lightweight concept remaining the over-riding objective and increased power a desired customer attribute, the excess energy leading to impulsive action needs to be somehow palliated. Under these circumstances, friction remains an important energy sink, which in turn would adversely affect the system efficiency.…”

A Dynamic Model for Gears

“…A study showing the interaction between the external forcing and the eccentricity deriving from the experimentally fluctuation in gear rattle response with a rig consists of a 1:1 ratio steel spur gear pair and the input gear is being controlled in displacement with the output gear being under no load, is presented by Ottewill et al (2009).…”

Modelling of Elastic Gearboxes Using a Generalized Gear Contact Model

“…Rigid models or simple elastic systems with only rotational degrees of freedom [7,3] 2. Coupled torsional and transversional elastic models [9,1,8,5] 3.…”