Papers by Author: Qiang Li

Abstract: The contact characteristics of spherical gear and ring-rack are researched in this paper. First, the tooth profile surface equation of spherical gear is established on the basis of the transmission theory of spherical gears. After that, the profile surface equation of ring-rack is established. Then, kinematics of the transmission of spherical gear and ring-rack is researched, the appreciate coordinates are established, and the profile surfaces of spherical gear and ring-rack are described in the same coordinate. Then, the contact analysis is conducted between spherical gear and ring-rack, and the contact point and ellipse parameters are acquired, as well as the rules of their evolvements. The conclusions above are benefit to further research on the transmission of spherical gear and ring-rack.

Abstract: Motions of natural creatures appear flexible and rhythmical characteristics. The bionic undulating propeller imitates undulating motion of a fish’s flexible long fin, and its propelling efficiencies are affected by bionic units’ characteristics. In order to improve the flexibilities of both structure and bionic motion, the paper designed a bionic undulating propeller driven by hydraulic system, and then carried out some modeling work on the rotatable direction valve. At last, some experiments are brought forward on a prototype of bionic undulating propeller. In the experiments, rotatable-direction-valve could control fluid flowing through all the oil orifices periodically and in sequence, so as to drive the bionic units swinging rhythmically. Under the control of rotatable-direction-valve, the prototype gains flexible starting and stopping processes, as well as self-resume character of bionic undulating wave, which are coincident to nature fish. The results show that application of hydraulic system in bionic undulating propeller is feasible, and theoretic model of rotatable direction valve is correct.