...Ruey-Hor Yen; Chien-Yu Chen To improve the performance of a reversible rotation herringbone journal bearing (Rev-HGJB), this study uses reversible elliptical grooves on a journal bearing (Rev-EGJB) and numerically analyzes its characteristics, utilizing the spectral element method. Load capacity...

... bench and some preliminary experimental results. A rotor of 1 kg mass and 37 mm diameter is rotated up to 75,000 rpm by an air turbine machined on the rotor. Capacitance probes, placed in two radial planes, allow orbit scanning of both the rotor and the bushing at different rotating speeds and suitable...

... on both transverse and polar radii of gyration of the rotor. An application example illustrates a rational procedure to specify nominal bearing clearance and its allowable tolerance range. In Figs. 10a 10b are charts of M critical , cylindrical for static- and rotating-groove designs...

... rotation nonlinear dynamical systems vibrations viscoelasticity torque damping sliding friction Despite the many publications in technical journals treating the modeling of mechanical system vibrations with the presence of friction ( 1 2 3 4 5 6 7 8 9 10 11 ), only a handful attempt...

... lubrication rotation friction Theories for predicting the leakage and the rotordynamic coefficients of circumferentially grooved annular seals (CGAS) have been under development for the last two decades. The main difficulty is that due to the high leakage rate and the elevated rotation speeds...

... of the elements of the slipping clutch. The hydrodynamic and asperity contact pressures are then calculated and the interactions and mutual influences between these two kinds of pressures are shown. In addition, the influences of the rotation speed on the resistant torque are investigated both theoretically...

... to irrelevant power loss produced by the relative rotation between semi-rings. The semi-rings allow a better EHD contact profile in conditions of maintaining and improving the support ring stability. One curvature is changed from a negative value to a positive value and each ball is radial supported...

... with κ J = f J R J , κ B = f B R B , and the friction factors f J , B depend on the bearing and journal surface conditions and the flow Reynolds numbers relative to the rotating R J and stationary R B...

...G. H. Jang; J. W. Yoon This paper presents an analytical method to investigate the stability of a hydrodynamic journal bearing with rotating herringbone grooves. The dynamic coefficients of the hydrodynamic journal bearing are calculated using the FEM and the perturbation method. The linear...

... measurement surface topography rough surfaces elasticity rotation mechanical contact One of the greatest challenges in lubrication research is to understand and develop useful predictive models for the mixed lubrication regime, where the load on a contact is distributed between regions...

... received April 3, 2002. Associate Editor: J. A. Williams. 09 October 2001 03 April 2002 31 12 2002 rolling friction failure analysis mechanical contact interface phenomena deformation rotation Cross wedge rolling (CWR) is a metal forming technique that is used to mass...

...G. H. Jang; S. W. Jeong This research presents an analytical model to investigate the stability due to the ball bearing waviness in a rotating system supported by two ball bearings. The stiffness of a ball bearing changes periodically due to the waviness in the rolling elements as the rotor rotates...

...Chaw-Wu Tseng; Jr-Yi Shen; C.-P. R. Ku, R&D Director,; I. Y. Shen, Assoc. Prof., This paper studies how temperature variations affect natural frequencies of rocking vibration of a rotating disk and spindle system through mathematical modeling and experimental measurements. Existing literature has...

... of harmonics may be present at any rotational frequency (unrelated to rigid body modes/frequencies) because of misalignment and deflection that cause intermittent rub between rotor and stator (see also Vance, 1 p. 356). In the author’s experiment the speed is supercritical and the harmonics shown are integer...

...Hooshang Heshmat,, Ph.D. [S0742-4787(00)02802-2] machine bearings failure (mechanical) rotation harmonics heat tribology mechanical contact Dr. Green has inquired as to whether some theoretical explanation for the particular experimental observation that I have reported in my paper...

.... Associate Technical Editor: L. San Andres. 10 October 1999 18 February 1999 23 June 1999 vacuum pumps machine bearings electric motors optical scanners rotation slip flow design engineering The rotational speed of a laser scanner motor has been increased significantly...