Yorikazu Shimotsuma

8—A STUDY OF APRON-DRAFTING PART I: EXPERIMENTAL STUDIES

Experimental studies of the motion of floating fibres in apron-drafting are reported. The pressure distribution in the apron zone is discussed, and apparatus designed to enable this to be measured is described. The properties of the fibre flux are considered in relation to the frictional and withdrawal forces of single fibres. Methods of determining the distribution of fibre-acceleration points are described, and a mathematical treatment for calculating this distribution is presented. There is a brief discussion of the irregularity of the fibre flux.

Paper XVIII(ii) Study on fundamental characteristics of rotating lip-type oil seals

The purpose of this paper is to investigate the friction and lubrication conditions within the sealing zone of lip-type oil seals. The friction coefficient, oil film breakdown ratio, and dynamic lip motion are simultaneously measured from extreme low-speed of 0.003 m/s (1 rpm) to high-speed of 18 m/s (7000 rpm). Up to the present, it has been accepted that the lubrication conditions within the sealing zone are subject to fluid film lubrication. However, experimental results show that they vary from dry friction in the extreme low-speed region to fluid film lubrication in the high-speed region through boundary and elastohydrodynamic lubrication conditions.

Paper XXI(iii) Study on lubrication in a ball bearing

Seizure damage sometimes occurs suddenly in bearings being operated stably at high speeds even though they ostensivly demonstrate fluid lubrication characteristics. The purpose of this research is to obtain basic materials to study the cause of this. Hereupon, we first of all investigated the position of oil film breakdown on the rolling surface using ceramic balls; and secondly, we quantitatively measured the oil film breakdown phenomena at the micro asperities using a DC current circuit and a capacitor.