The System Modification of Transmission on The RCWS Prototype UGV Robot (Unmanned Ground Vehicle)

An automotive transmission system is a system that has the function for conversion torsion and the rapidity (rotation) from the torsion machine and it has a different rapidity to keep on to the last activator. This conversion changes the high rotation speed becomes lower, but it has more energy conversely. The highest torsion in certain machines generally occurs in a half from the limit from the machine rotation which allowed, while the vehicle needs the highest torsion start from it could be moved. The purpose of this study is to modify the accuracy and the exact transmission, so that the activator transmission which uses a pulley system (part of the automobile chassis) and belt will have a gentle rotation by activator use motor stepper with more energy in it. This machine works by having a battery to supply electricity to the motor stepper, then it is controlled by azimuth and elevation moving control so that transmission of weapon bipod will move with elevation-100 s/d 600 degrees. Azimuth moving control will be pressed so it will move the motor stepper and make the weapon move to 360 degrees. The result of the rotation of the motor will move gently and the comparison between use motor DC gearbox which not really soft at the rotation itself.

Study on cracks and process improvement for case hardened gear shaft straightening

Gear shaft is one of the key components for transmitting torque and speed in automotive transmission. Deflections will inevitably occur after heat treatment. It is necessary to ensure the straightness of the parts by straightening. During straightening process, cracks often appear and result in scrapped parts. This paper focuses on the situation of high straightening crack rate of internal input shaft in one dual-clutch automotive transmission, makes an in-depth analyses the pressure straightening process theory, crack generation mechanism, working process and crack detection system. After studying on the case hardened gear shaft material properties, elastoplastic process theoretical basis, crack characteristic and finite element simulation, etc., This paper has systematically improved straightening crack performance and proposes three crack rate improvement methods by using finite element analysis to find out optimal punch point which can reduce the maximum stress value; increasing the punch increments and adopt vector straightening to improve the straightening procedure; reducing the gas quenching pressure in the heat treatment process to improve the mechanical properties of the parts, etc. Finally, the scrap rate of straightening crack was reduced from 1.95% to 0.14%.

Optimization on Nonlinear Dynamics of Gear Rattle in Automotive Transmission System

Recently, gear rattle noise is gradually becoming a nonignorable issue involving comfortableness in automotive transmission for a car. Generally, the rattle noise is influenced by nonlinear dynamic of multiple pairs of idler gears in the multistage gear transmission system. Optimization methods based on nonlinear rattle dynamic analysis are worthy of further study to control the noise. In this research, an equivalent rattle dynamic model of the idler gear is proposed, and the nonlinear rattle dynamic responses are solved based on the integral method. The effect laws of key factors on nonlinear dynamic performance are investigated by using a bifurcation diagram, spectrum map, and Poincaré map. Finally, the gear backlash, equivalent mass, and rotational speed are optimized based on Kriging surrogate model (KSM) and differential evolution (DE) algorithm by taking the minimization of the maximum rattle noise as the optimal object. It can be concluded that the rattle dynamics of the idler gear show rich nonlinear characteristics as the parameters change. The proposed method can not only reduce the sound pressure level of rattle noise but also provide a viable path and reference value for the low-noise design of the gear transmission system.