Flexible Follower Response of a Translating Cam with Four Different Profiles for Rise-Dwell-Fall-Dwell motion
The flexible follower response of a translating cam with four different profiles for rise-dwell-fall-dwell (RDFD) motion is investigated. The cycloidal displacement motion, the modified sinusoidal acceleration motion, the modified trapezoidal acceleration motion, and the 3-4-5 polynomial motion are employed to describe the rise and the fall motions of the follower and the associated four kinds of cam profiles are studied. Since the follower flexibility is considered, the contact point of the roller and the cam is an unknown. Two geometric constraints formulated to restrain the unknown position are substituted into Hamilton’s principle with Lagrange multipliers. Applying the assumed mode method, one can obtain the governing equations of motion as non-linear differential-algebraic equations. The equations are solved using Runge-Kutta method. Then, the responses of the flexible follower undergoing the four different motions are investigated in time domain and in frequency domain. Keywords—translating cam, flexible follower, rise-dwell-falldwell, response
Steady-State Residual Vibrations in High-Speed, Dwell-Type, Rotating Disk Cam-Follower Systems
Followers driven by high-speed, dwell-type, rotating disk cams can exhibit undesirable residual vibrations during dwell. These vibrations have been studied with linear models mostly using results from transient vibration analysis, assuming quiescent initial conditions. Here, the residual vibrations are studied with closed-form solutions to the steady-state vibrations obtained with a circular convolution integral. The steady-state vibrations, which can extend over the entire cam cycle, are periodic and continuous. It is shown that significant differences exist between the residual vibration results obtained from steady-state analysis and those obtained from transient analysis. The undamped steady-state vibrations exhibit resonances. Away from the resonance conditions, the steady-state residual vibration amplitudes are consistently smaller than those predicted by transient analysis. The results from the two approaches agree quantitatively only for relatively stiff and damped follower systems.
Experimentelle untersuchungen an Koppelgetrieben mit Leistungsausgleich
Zusammenfassung Es wird ein Uberblick uber Methoden des Leistungsausgleiches von Gelenkgetrieben gegeben. An drei viergliedrigen Koppelgetrieben mit und ohne Leistungsausgleich werden der Ungleichformigkeitsgrad, Auflagerkraft und Leistungsbedarf experimentell ermittelt. Dabei zeigt sich, daБ Getriebe mit Leistungsausgleich einen groБeren Leistungsbedarf haben, obwohl das Motor-moment ausgeglichen ist. Der Einfluss der Reibung darf nicht vernachlassigt werden, der theoretische und tatsachliche Ungleichformigkeitsgrad konnen stark voneinander abweichen. Die drei Koppelgetriebe werden hinsichtlich einiger dynamischer GroБen miteinander verglichen.