In this study, the deformation of a large industrial door subjected to wind load was investigated through computational fluid dynamic and structural analyses. The model for the structural analysis was simplified by considering the PVC curtain and wind bar in the shape of the actual door. The pressure distribution acting on the front of the door was obtained from computational fluid dynamic analysis and the deformation of the door was obtained from structural analysis. According to the results, the pressure distribution was not uniform on the front of the door and varied depending on the location. The distribution of the deflection in the wind bar was obtained and it was found that the position of the maximum deformation occurred slightly above the center of the door. Finally, the deformation of the door could be predicted by analyzing the deflections of the wind bar subjected to different wind speeds through regression analysis.

The differential gear distributes the power from the transmission shaft to both wheel axles and automatically ensures rotational difference to maintain the speed difference between the two axles. However, when the vehicle travels on a slippery road surface, a slip in the wheel induces improper transmission of the driving force. Therefore, the limited slip differential limits the function of the differential gear by transmitting the driving force to the normal wheel without the slip. The hydraulic differential limiting device is based on the principle that the fluid between the inner and the outer rotors is compressed by the rotation of the trochoidal gear, and the compressed fluid moves to the cylinder to generate sufficient pressure in the side pinion gear to limit the differential. In this study, the pressure is predicted by variation in viscosity and rotational speed through flow analysis.

Gerotor oil pumps are widely used for the lubrication oil of an engine and the hydraulic source of an automatic transmission. Recently, improvements for the purposes of fuel efficiency and noise reduction have come to the forefront of the automobile industry, and it has become necessary to study the design of gerotors and ports. In this study, an expanded cardioid curve was developed, and an equation for a tooth profile with an expanded cardioid lobe shape has been suggested to reduce pump noise. The design was created using an automatic program; the program generated inner and outer rotor profiles and calculated performance parameters. Also, in order to decrease irregularity, CFD analyses were performed according to groove shapes in the exhaust port. Results showed the noise of the improved oil pump (the suggested gerotor [expanded cardioid] + the proposed port) was 5.44% lower than the existing oil pump (the existing gerotor [2-ellipse] + basic port).

In this paper, we studied a new vacuum caterpillar drive system that can be used for solar panel cleaning robots. The conventional vacuum caterpillar structure has an issue, in that the vacuum hose becomes twisted. As a result, we designed a new vacuum caterpillar structure with no vacuum hose kinks. Also, we verified that no issues concerning flow analysis exist with this new system. We found that this system with the proposed vacuum caterpillar structure has an appropriate performance as a solar panel cleaning robot for practical use.