Wang Jinge

The study and analysis of a new Anti-backlash worm gear

In this paper, a new kind of the anti-backlash double-roller enveloping hourglass worm (ADEHW) with line contact between intersecting axes has been studied by means of the theory of gearing and the space engagement theory for the first time. The engagement equation and tooth profile equation have been derived by applying the theory of gearing. Meanwhile the important factors that impact the performances of the worm were numerical calculated analysis. Based on the developed mathematical model of the Anti-backlash Double-roller Enveloping Hourglass worm, computer graph of the gear set has been designed by applying Pro/Engineering. The study results show that the new kind of Anti-backlash worm gearing has the advantage of big carrying capacity and high efficiency, The most important is that can solve the problem of Anti-backlash on the worm gear.

Robot Pose Estimation and Accuracy Analysis Based on Stereo Vision

In order to meet the stereo vision navigation of the autonomous robot, stereo vision initial pose estimation based on unit quaternion is put forward and pose estimation accuracy is predicted and analysed. The research provides basis for further improving the pose estimation accuracy of robot. Gauss-distributed error covariance matrix propagation model was adopted to deduce the error propagation formulas from 3D landmarks errors to final output pose errors of robot. The rotation covariance and the translation covariance are detached by the correlation analysis of rotation and translation of robot pose. Covariance estimation is realized effectively. Experiment shows realistic accuracy of pose estimation based on unit quaternion method and accuracy of error model deduction are the same basically. Accuracy analysis method of pose estimation in this paper is practicable.

A Novel Worm Drive for Rehabilitation Robot Joint

Aiming at the rehabilitation robot joint, a novel worm drive consisting of a planar internal gear and a crown worm is presented. Theoretical calculation confirms that small induced principal curvatures, big sliding angles and large meshing area exist on the conjugate surfaces, indicating that the new worm drive is of smaller contact stress and better lubrication. A new machining method for crown worm is proposed based on the principle of virtual center distance. The crown worm and planar internal gear are manufactured. This study is expected to give rise to a new insight on the design of the future rehabilitation robot joint.

Contact Finite Element Analysis of Anti-backlash Double-roller-Enveloping Hourglass Worm Gearing

The anti-backlash double-roller-enveloping hourglass worm gearing is multi-tooth meshing transmission and it has complex tooth profile. It is difficult to obtain the load distribution among the meshing tooth pairs and the stress distribution along contact line with analytical model. So, based on the geometrical model of the anti-backlash double-roller-enveloping hourglass worm gearing, the Finite Element Method is used to analyze its load capability. The contact finite element model of this kind of worm gearing is created with 10-node tetrahedral element Solide92 and face to face contact mode. Using the nonlinear contact module of ANSYS software, the contact finite element model is solved with the large displacement static deformation mode. The results show that the load distributions among the meshing tooth under the different conditions are uneven. And the stress distribution along every contact line takes on an obviously descent trend from the addendum to the dedendum of worm wheel.

Study on the tooth profile and meshing equation of the anti-backlash double-roller enveloping hourglass worm with errors

The mismatched errors of the anti-backlash double-roller enveloping hourglass worm (ADEHW) plays a very critical role on its performance, but the influence of errors on ADEHW are rarely reported in available literatures, and the most important thing that we concerned is how to acquire the meshing equation and generate the tooth profile of ADEHW involving errors. Therefore, the new anti-backlash double-roller enveloping hourglass worm tooth profile equation which involved the grinding wheel radius, angular position error of the worm wheel axis, the centre distance errors and the shaft angle was established for the first time in order to study the effects of worm parameters on the worm tooth profile by using the theories of differential geometry and gear meshing. A new method to acquire the contact line of worm was presented by using the corresponding computer program and dichotomy. The real tooth surface was acquired based on the Pro/E software using the contact helix line equation and the three-dimension (3D) geological modeling of the Anti-backlash double-roller enveloping hourglass worm was established. The results obtained show that the formula established of worm tooth profile is important to analysis the characters of gearing mesh and parameter.