Key Engineering Materials Vol. 693

Abstract: The aerodynamic noise of a cross flow fan with uneven blade spacing in room air-conditioner was simulated by computational aerodynamic acoustics (CAA) method. It is detailed to analyze the vorticity distribution of the flow field and the power spectral density of measured points’ pressure fluctuations, and the results demonstrate the non-uniform impeller used in this paper can significantly improve internal flow characteristics. Thus the broadband noise got reduced.

Abstract: Because of the existing delivery machine’s fixed structure, its storage space is unable to adjust flexibly according to the size and quantity of express deliveries, the storage variable delivery machine is designed. The delivery machine structure comprises a display screen, an electromagnetic door for administrator, a fetching port, a panel’s storage container, a storage variable storing container, a storage variable storing modules, a variable storage fetching module and a manipulator module. The storage variable storing container, storage variable storing modules and variable storage fetching module are used to adjust the size and number of storage space. The storage variable delivery machine has the advantages of simple structure and has a wide market prospect.

Abstract: This paper presents a theoretical investigation into the response of the coupled system which consists of a regular or irregular enclosure with different excitation, including noise reduction level and panel vibration energy level. The results show that the noise reduction level curves appear changes in medium and high frequency region when the enclosure change from regular rectangular to irregular trapezoidal, but there is small variation in panel vibration energy. Compared with the incident plane wave perpendicular to the flexible wall, more panel modes are excited by the oblique plane wave, and it means that more noise go through the flexible wall into the enclosure.

Abstract: The reason of lacking of a suitable front-end actuator when excavators moving massive objects, a new type of hydraulic engineering gripper was designed. Its design theory was showed. The use of SimulationXpress in the Solidworks to optimize the design, made the structure of cured rod more reasonable.

Abstract: In this paper, a new type of explosive rotary quick-off tools device is designed. This new type of explosion rotary quick-off tools test device is composed of foundation, explosion chamber, piston body, pressure plate, locking wedge and customized tools, which has many advantages such as simple structure, convenient operation and high rigidity. The calculation results of the acceleration of tool-falling, plate strength, physical strength of combustion show that the device is expected to obtain complete chip root samples at 150m/min speed conditions, which can meet the requirements of researching metal cutting deformation process at high-speed cutting condition.

Abstract: In-wheel drive electric vehicles have the incomparable advantage over conventional electric vehicles, and the efficiency of the gear box is an important factor which affects the transmission efficiency of the electric vehicles. This paper focuses on a kind of gear boxes of the in-wheel drive system, in the premise of ensure the structure is stable and reliable, optimizes the related parameters with the goal of maximizing the efficiency of the gear box by using MATLAB optimizing toolbox. Comparing the optimization results with the efficiency before optimized,the influence of related parameters is studied. The results have practical significance to the selection of gear box parameters.

Abstract: In the engine cylinder head,the cooling water holes around the combustion chamber are tiny and deep,so it is necessary to clean them at fixed point.The paper designs a new type of CNC tool nozzle structure that mainly include the tool holder and nozzle body,on the primary side of the nozzle,there are six blowholes which distribute with a certain angle,and they can clean the cooling water holes at fixed point.The new type of tools nozzle can enhance the cleaning effect,improve the optimal moving path,accelerate the production tempo and save the energy consumption.

Abstract: In the constant-temperature indoor environment, the static principles of rubber materials for vibration damping in vehicles and the load and application scope of the experiments are studied in this paper. Basic experiments are carried out for common rubber materials in vehicle system by using advanced experimental equipment.

Abstract: LC-DCP (limited contact—dynamic compression plate) is the preferred plate in internal fixation. A new LC-DCP fixed with the femur was designed. Its strength was investigated with finite element method during stair climbing. Also, stress shielding and strength of femur fixed with TC4 (Ti6Al4V) compression plate was analyzed for different load mode during stair climbing. Simulated results demonstrated that compression plate’s design was reasonable, and it was not obvious to eliminate femoral stress shielding through adding preload on the screws. Also the analytical methods of stress shielding for femur fracture, established in the work, can be widely applied to stress shielding analysis of other bone fracture.

Abstract: Space deployable mechanisms have been widely employed in aeronautic industry, and the dynamic performance of the space deployable mechanisms become increasingly important. In this paper, the model of space deployable mechanism with double clearances is established by the multi-body program ADAMS. The deployable mechanism with ideal joint, single clearance joint and double clearance joints are simulated to investigate the effects of double clearance on the dynamic performance of the deployable mechanism. The results reveal that the coupler of double joint clearance has significant influence on dynamic performance of deployable mechanism. The results of simulation could help to predict the joint vibration in space deployable mechanisms.