Design Of Key Parts Research Articles

Residual Stress of a TC17 Titanium Alloy after Belt Grinding and Its Impact on the Fatigue Life.

Titanium alloy materials are widely used in the design of key parts, such as aeroengine blades and integral blades. The surface residual stress has a great influence on the fatigue life of the parts mentioned above. Presently, abrasive belt grinding can form residual stress on the surface. However, the formation mechanism has not yet been revealed, providing the impetus for the present study. First of all, the surface residual stress is characterized based on Bragg’s law. The influence of contact force, reciprocating frequency, and feed speed on the residual stress of a titanium alloy abrasive belt grinding is obtained using an experimental method. The residual stress model is simulated by the tensile force on the surface of the model, and the fatigue life of the bar under a sinusoidal tensile load is analyzed by simulating the fatigue test of the titanium alloy bar. Finally, fatigue testing and fracture analysis are carried out. The experimental results show that with the increase of the grinding contact force, increase of the reciprocating frequency, and decrease of the feed speed, the residual compressive stress on the surface of the parts increases and the fatigue life is higher at the same working stress level. It also shows that the residual compressive stress produced by abrasive belt grinding is in the range of 120–300 MPa. The fatigue simulation curve’s inflection point appears at the level of 550 MPa. The error between the simulation data and the experimental data is less than 10%, which shows the accuracy of the simulation experiment. The fracture morphology at room temperature is a ductile fracture with fine equiaxed dimples.

Design of Key Parts of a Pneumatic Conveying System Used in a New Small Trenchless Drilling Robot

Through research on Pneumatic Conveying technology and the principle of Laval Jet, we completed the design of key parts of a mud dust conveying system used a new small trenchless drilling robot in municipal road construction.

Development of a Multifunctional Abrasion and Friction Test Bench with High Ambient Pressure for Seawater Hydraulics

Seawater hydraulic pump, of which the performances and service life are highly dependent on the structural design and material selection of the friction pairs and sliding bearing, are the power componentof the seawater hydraulic systems. Based on the previous studies, a seawater abrasion and friction test bench with high ambient pressure (≧20MPa) is to be developed for deep-sea (≧2000m) application environments. The technical requirements are presented and comparison analyses have been made between two testing schemes: rotating cylinder-blockscheme and rotating swash-plate scheme. Details are presented on the designs of the three key friction pairs and sliding bearing of the rotating cylinder-block bench. This research provides a test bench for the design of key parts in deep-sea water hydraulic pump/motor and the studies of the related theories (such as the friction and wear theory, lubrication and bearing mechanism).

Three-Dimensional Design and Analysis of Multi-Spindle Drilling Device

Design and analysis of multi-spindle transmission device helps to improve design quality and efficiency of aggregated machine tools and other automatic mechanical devices. This paper analyzed principles and structures of two multi-spindle transmission mechanisms adopted extensively in mechanical area. A three-dimensional prototype of the multi-spindle drilling device designed for machining six holes simultaneously was built with Pro/Engineer software. The device adopted multi-spindle reciprocating transmission mechanism. The application of the software involved creating simplified model used for motion analysis, performing kinematic analysis of the mechanism, establishing measures of main parameters and executing optimal design of key parts.

The Dynamic Research on Flexible Impeller of the Large Wind Generators

According to designed parameters, the rigid model of the large wind generators has been built in UG software, the impeller is selected to be researched object, modal neutral files of key parts are attained by the analysis in ANSYS software. The analysis model of multi-flexible bodies of the impeller is built in ADAMS software. With analyzing, predigesting, loading of wind loads and analyzing of dynamic simulation of impeller model, a lot of dynamic parameters of flexible impeller are obtained, which are truer and exacter. These provide certain basis of the loads for designing, analyzing, optimizing the design of key parts of large wind generators in future. The new thought is explored, which are about dynamic research of multi-flexible bodies of large wind Generators. Further more; the high-performance large wind generators are designed.