Auto Gear Teeth Burnishing Machine Using Servo Control

A typical vehicle transmission is comprised of between five and six gear sets and a series of gear trains that allows a driver to control how much power is delivered to the vehicle without changing how fast the engine runs. This transmission makes noise such as burrs, nicks, high points and heat treat scales are the leading causes of noise in power transmission. There are many different causes of gear noise, all of them theoretically preventable. Unfortunately, the prevention methods can be costly, both in equipment and manpower. If the design of the gear and its application are appropriate, in theory all that is necessary is to have a tight control on the process of producing the finished gear. In reality, there are many variables that can cause a process, no matter how well-controlled, to deteriorate, and thus cause errors, some of which will cause a gear to produce unwanted noise when put to use. The effective way to eliminate this noise the process known as "Gear Burnishing". The proposed system uses gear shaving cutter as a master for burnishing or deburring operation of gear teeth with servo mechanism (includes servo motor and servo drivers), Programmable logic controller (PLC), Human machine interface (HMI) to remove gear inaccuracies and so as to reduce or eliminate transmission noise and provide more life and reliability to transmissions in vehicles resulted into noise free vehicles.

A study on the development and application of program for planetary gear design considering planetary gear noise and efficiency

In general, gear mechanical loss is associated with the friction of the lubricating contact surface of the gear and bearing that transmit the power, and a no-load spin loss which is load independent occurs due to gear rotation and the interaction of the bearing component with the lubricating element. In order to minimize planetary gear loss, it is desirable to design by checking the efficiency at the concept design stage. However, a design technique that considers the noise and efficiency of a planetary gear set simultaneously has not been achieved so far. In this paper, a program called 'pRMC with EHL' to check together the efficiency and noise that affected by gear specifications has been developed. By using developed program, planetary gear sets specifications have been designed. And through the experimental evaluation, automatic transmission efficiency could be reduced by 0.3% in combination fuel consumption mode and the planetary gear vibration could be also reduced by 10 dB than former design. Through this designing verification and input parameter correlation, a new planetary gear set designing process has been come up with successfully at the concept design stage.

Operating Performance of External Non-Involute Spur˝and Helical Gears: A Review

In practical use, most gears have an involute shape of tooth flanks. However, external involute gears have some drawbacks, such as unfavourable kinematic conditions at the beginning and end of meshing, a limited minimum number of teeth, and the highly loaded convex-convex (i.e., non-conformal) contact. Researchers have developed and analysed various non-involute forms of tooth flanks, but they have not been widely accepted. The main reasons are higher manufacturing costs and sensitivity to manufacturing and assembly errors. Analyses of non-involute forms of teeth are mostly theoretical (analytical and numerical), while there is a lack of experimental confirmations of theoretical assumptions. This paper reviews external non-involute shapes, their operating characteristics and possibilities of use compared to involute gears. Established criteria, such as Hertzian pressure, oil film thickness, bending stress at the root of the tooth, contact temperature, and gear noise, were used for assessment. The results of analytical studies and experimental research on S-gears are presented in more detail. S-gears have a higher surface durability and a lower heat load when compared to involute gears. The usability of non-involute gears is increasing with the development of new technologies and materials. However, the advantages of non-involute shapes are not so significant that they could easily displace involute gears, which are cheaper to manufacture.

Noise Reduction in Spur Gear Systems

This article lists some tips for reducing gear case noise. With this aim, a static analysis was carried out in order to describe how stresses resulting from meshing gears affect the acoustic emissions. Different parameters were taken into account, such as the friction, material, and lubrication, in order to validate ideas from the literature and to make several comparisons. Furthermore, a coupled Eulerian–Lagrangian (CEL) analysis was performed, which was an innovative way of evaluating the sound pressure level of the aforementioned gears. Different parameters were considered again, such as the friction, lubrication, material, and rotational speed, in order to make different research comparisons. The analytical results agreed with those in the literature, both for the static analysis and CEL analysis—for example, it was shown that changing the material from steel to ductile iron improved the gear noise, while increasing the rotational speed or the friction increased the acoustic emissions. Regarding the CEL analysis, air was considered a perfect gas, but its viscosity or another state equation could have also been taken into account. Therefore, the above allowed us to state that research into these scientific fields will bring about reliable results.

The influence of yaw on the unsteady surface pressures over a two-wheeled landing-gear model

Landing-gear noise is an increasing issue for transport aircraft. A key determinant of the phenomenon is the surface pressure field. Previous studies have described this field when the oncoming flow is perfectly aligned with the gear. In practice, there may be a cross-flow component; here its influence is investigated experimentally for a generic, two-wheel, landing-gear model. It is found that yaw angles as small as 5° cause significant changes in both overall flow topology and unsteady surface pressures. Most notably, on the outboard face of the leeward wheel, large-scale separation replaces predominantly attached flow behind a leading-edge separation bubble. The effect on unsteady surface pressures includes marked shifts in the content at frequencies in the audible range, implying that yaw is an important parameter for landing-gear noise, and that purely unyawed studies may not be fully representative of the problem.