A model for evaluating the meshing characteristics and vibration characteristics of asymmetric spur gears with tooth modifications

Abstract Tooth surface wear is one of the most common faults of gearboxes which increases the fatigue load on the gearbox and endangers its stable output characteristics and service life. Gear meshing characteristics vary significantly with the wear location and severity. Thus, the wear fault model considering tooth profile deviation, friction and time varying mesh stiffness (TVMS) was established in order to quantitatively study the vibration characteristics of tooth fatigue wear (TFW). Tooth profile modification and friction coefficient coupling were applied to characterize TFW, and the maximum wear depth was introduced to characterize TFW severity. The gear-pair simulation models under multiple wear severities were established and imported to a single-stage parallel gearbox whose dynamic differential equation was established under multiple torque conditions. The dynamic simulation results showed good agreement with the experimental data, which validated the method’s effectiveness. The vibration characteristics under different wear severities and simulation conditions were then obtained and compared.

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PERFORMANCE INDICATORS OF CONCHOIDAL STRAIGHT SPUR GEARS WITH INCREASED LOADING CAPACITY. THE THEORY

Bulletin of the National Technical University «KhPI» Series Engineering and CAD ◽

10.20998/2079-0775.2021.2.12 ◽

2021 ◽

pp. 85-93

Author(s):

Pavlo Tkach ◽

Pavlo Nosko ◽

Oleksandr Bashta ◽

Grygorii Boiko ◽

Olha Herasymova

Keyword(s):

Performance Indicators ◽

Experimental Tests ◽

Maximum Load ◽

Spur Gears ◽

Surface Strength ◽

Actual Problem ◽

Reference Profile ◽

Meshing Characteristics ◽

Machine Drives ◽

Gear Drives

The article is devoted to the actual problem of increasing the performance indicators of machine gear drives. To solve this problem, in the article proposed to use a conchoidal engagement made with a shifting of the reference profile and special contact conditions. A feature of the proposed engagement is that it is less sensitive to manufacturing and assembly errors compared to conventional conchoidal engagement. As a result of theoretical studies, the performance indicators of such an engagement were determined. This made it possible to determine the level of load during further experimental tests of new gears. Contact strength and meshing losses were selected as performance indicators subject to further experimental verification. The ratios of these indicators, calculated for conchoidal spur gears with convex-convex contact, made with a shifting of the reference profile, with similar involute ones, are theoretically determined. Comparative analysis of performance indicators was carried out for gears of involute and conchoidal engagement with the same parameters and shifting of the reference profile. It was found that for experimental conchoidal drives with shifting, the maximum load is 1.2 times higher than that of a similar involute drive with shifting, and the loss in engagement is 21% less. A rational area of application of the new gearing is machine drives for high power transmissions. Keywords: spur gears, conchoidal gearing, profile shift, convex-convex contact, meshing characteristics, teeth surface strength, gearing power loss

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The Nonlinear Vibration Characteristics of Gear Swing System of Overload Swing Angle Milling Head

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.364.138 ◽

2013 ◽

Vol 364 ◽

pp. 138-143

Author(s):

Wen Tong Yang ◽

Shen Teng Yang ◽

Tie Neng Guo ◽

Zhi Feng Liu ◽

Li Gang Cai

Keyword(s):

Nonlinear Vibration ◽

Vibration Characteristics ◽

Cnc Machine Tools ◽

Spur Gears ◽

Analysis Method ◽

Cnc Machine ◽

Nonlinear Dynamic Model ◽

Nonlinear Characteristics ◽

Swing Angle ◽

Multi Level

The overloaded swing angle milling head is an important part of the CNC machine tools; the swing system is the drive components of overloaded swing angle milling head for feed movement, mainly by gears for cutting the feed motion. In this paper, a multi-degree-of-freedom nonlinear dynamic model with multi-level multi-backlash spur gears was established, by using of numerical analysis method to solve the analysis of gears wing nonlinear vibration characteristics of the system, the results show that the gaps between the gears have a rich nonlinear characteristics of the vibration of the system.

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Characterisation of the Humming-Type Noise and Vibration of the Automotive HVAC System

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.16.2.2019.12.0499 ◽

2019 ◽

Vol 16 (2) ◽

pp. 6634-6648

Author(s):

A. Z. A. Mazlan ◽

M. H. A. Satar ◽

M. H. Hamdan ◽

M. S. Md. Isa ◽

S. Man ◽

...

Keyword(s):

Vibration Characteristics ◽

Operating Conditions ◽

Hvac System ◽

Frequency Range ◽

Noise And Vibration ◽

Power Steering ◽

Pump Compressor

The automotive heating and ventilating air condition (HVAC) system, when vibrating, can generate various types of noises such as humming, hissing, clicking and air-rushes. These noises can be characterised to determine their root causes. In this study, the humming-type noise is taken into consideration whereby the noise and vibration characteristics are measured from various HVAC components such as power steering pump, compressor and air conditional pipe. Four types of measurement sensors were used in this study - tachometer for rpm tracking; accelerometer for the vibration microphone for the noise; and sound camera for the visualization measurement. Two types of operating conditions were taken into consideration - they were “idle” (850 rpm) and “running” (850-1400 rpm) conditions. A constant blower speed was applied for both conditions. The result shows that the humming noises can be determined at the frequency range of 300-350 Hz and 150-250 Hz for both idle and running conditions, respectively. The vibration of the power steering pump shows the worst acceleration of 1.8 m/s2 at the frequency range of 150-250 Hz, compared to the compressor and air conditional pipe. This result was validated with the 3D colour order and sound camera analyses, in which the humming noise colour mapping shows dominance in this frequency range.

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