The surface integrity of titanium part is poor after milling; it is unable to meet the accuracy requirements for use. To solve this problem, the ultrasonic vibration-assisted magnetic abrasive finishing was proposed to be used for the surface finishing treatment. The finishing experimental result shows that the efficiency of ultrasonic magnetic abrasive finishing is 40 % higher than magnetic abrasive finishing. The milling texture on part surface faded or disappeared after ultrasonic magnetic abrasive finishing. The surface original micro-cracks have been completely removed. The surface stress state changed from the residual tensile stress 280 MPa before finishing to residual compressive stress 20 MPa after finishing. It verified that the ultrasonic magnetic abrasive finishing can efficiently promote the surface integrity of titanium parts and ultimately gain the best surface quality and performance.

Surface integrity of titanium part by ultrasonic magnetic abrasive finishing

Rotation spring: Rotation symmetric compression-torsion conversion structure with high space utilization

Fundamental design equations for space curve meshing skew gear mechanism

Computerized design, simulation of meshing and stress analysis of pure rolling cylindrical helical gear drives with variable helix angle

Study on spatial curve meshing and its application for logarithmic spiral bevel gears

This article derives the space curve meshing equations for arbitrary intersecting gear mechanism, which could achieve continuous and smooth transmission between arbitrary angle intersecting axes, and then establishes the central curves equations of the driving and driven tines on the basis of space curve meshing equations. According to the equations, a calculation example is given and material prototype samples are made to experimentally validate the kinematic performance. The result shows that if the central curve of the driving tine is a circular helix, the central curve of the driven tine is close to a conical helix. This article will supply a basic theory for the application of the arbitrary intersecting gear mechanism in various areas.

A generalized space curve meshing equation for arbitrary intersecting gear

\n The geometric design, meshing simulation, and stress analysis of pure rolling rack and pinion mechanisms are presented. Both the pinion and the rack are based on the active design of the meshing line to provide pure rolling for the whole cycle of meshing. The parametric equations of the contact curves on the rack and pinion tooth surfaces are determined by coordinate transformation of the meshing line equations. Three types of meshing are derived according to the motion of the generatrices along the calculated contact curves: convex-to-concave meshing, convex-to-plane meshing, and convex-to-convex meshing. Then, the basic design parameters are analyzed and formulas for calculation of the geometric size are given. Four different cases of design are considered to compare the meshing performance and mechanical behavior of the proposed gear mechanisms. The results include contact patterns, the unloaded function of transmission errors, and the evaluation of stresses along two cycles of meshing. The analysis of the results shows that the proposed method of design of pure rolling meshing reduces the relative sliding between tooth surfaces, whereas it decreases the contact strength of the tooth surfaces. However, if the design parameters are properly evaluated as a result of simulation and applied as proposed here, the mechanical behavior of the proposed rack and pinion mechanisms can be more favorable than that of the standard geometry of involute rack and pinion sets.

Zhen Chen

Papers

Fundamental design equations for space curve meshing skew gear mechanism

Computerized design, simulation of meshing and stress analysis of pure rolling cylindrical helical gear drives with variable helix angle

A generalized space curve meshing equation for arbitrary intersecting gear

Geometric Design, Meshing Simulation, and Stress Analysis of Pure Rolling Rack and Pinion Mechanisms

Effects of regular triangular prisms on thermal and hydraulic characteristics in a minichannel heat sink