Tokio Sasaki

Bio: Tokio Sasaki is an academic researcher from Kyoto University. The author has contributed to research in topics: Lubrication & Lubrication theory. The author has an hindex of 5, co-authored 14 publications receiving 78 citations.

The Cutting Mechanism of Abrasive Grain : (1st Report, Experimental Observations of the Stock Removal and the Swell-up Phenomena)

Abstract: The investigations of the basic cutting mechanism in the finishing processes using grains for the cutting edge are the fundamental measures for improving the finishing efficiency and for elevating the smoothness of a finished surface. The model cutting tests of grains have been carried out under such conditions that the cutting edge angle and the cutting speed may reproduce the original form of the cutting states of the finishing operations such as grinding, superfinishing and single-point cutting. As the result of these tests, the relations between the stock removal or the swell-up and the cutting edge angle or the cutting speed are clarified, and the influence of cutting conditions on the ratio of the tangential and the normal cutting force is found. Moreover, the relation between the cutting mechanism and the cutting speed is obtained.

The Cutting Mechanism of Honing

Abstract: For the purpose of inquiring into the cutting mechanism of fine-grain abrasive stones in the honing, an experimental research has been carried out with an external honing apparatus. Concerning the cutting speed, the best cutting efficiency is obtained at a cutting speed of 40 m/min. The cutting direction angle of 40°∼50°is the most suitable, and the cutting direction angle is the most decisive factor in the cutting mechanism of honing. As to the bond hardness, it is suitable to use the harder stone. Comparing the honing with the superfinish, the most suitable values of cutting direction angle and cutting speed are same in both cases. But the cutting efficiency of superfinish is 5∼10 times that of honing, and the stone wear per unit amount of stock removal of honing is slightly smaller than that of superfinish.

Theory of Grease Lubrication of Cylindrical Rooler Bearing

Abstract: The lubrication theory on the substances of rheological behaviour as grease is a recent theme. In particular, as the grease is often used for the lubrication of rolling bearing, it is important to establish a theory of grease lubrication for rolling bearings. In this paper, considering the grease as a Bingham plastic, a theory of grease lubrication for cylindrical roller bearing has been deduced. That is, the special core formation in grease film, the frictional resistance of rolling bearing, the pressure distribution and the load capacity of grease film entrapped between roller and race of cylindrical roller bearing have been researched. In addition, the above grease lubrication theory is compared with the oil lubrication theory.

Prediction of Mechanical Efficiency of Parallel-Axis Gear Pairs

Abstract: A computational model is proposed for the prediction of friction-related mechanical efficiency losses of parallel-axis gear pairs. The model incorporates a gear load distribution model, a friction model, and a mechanical efficiency formulation to predict the instantaneous mechanical efficiency of a gear pair under typical operating, surface, and lubrication conditions. The friction model uses a new friction coefficient formula obtained by using a validated non-Newtonian thermal elastohydrodynamic lubrication (EHL) model in conjunction with a multiple linear regression analysis. The load and friction coefficient, distribution predictions are used to compute instantaneous torque/ power losses and the mechanical efficiency of a gear pair at any given rotational position. Efficiency measurements from gear pairs having various gear designs and surface treatments are compared to model predictions. Mechanical efficiency predictions are shown to be within 0.1% of the measured values, indicating that the proposed efficiency model is accurate. Results of a parametric study are presented at the end to highlight the influence of key basic gear geometric parameters, tooth modifications, operating conditions, surface finish, and lubricant properties on mechanical efficiency losses.

Abrasive fine-finishing technology

Abstract: Abrasive fine-finishing technology is often applied as a final finishing process, and the selection of the right technology is crucial to obtaining the desired performance of functions such as fatigue life. This paper begins with classifications of the technology along with fundamentals and brief histories of the individual methods. The material removal mechanisms, specific energies, and finishing characteristics of the various technologies are summarized giving assessments of the surfaces created by them. Guidelines developed for selecting the appropriate methods, and case studies illustrate the effectiveness of various methods. This paper ends with a discussion of the future prospects of the technology. (C) 2016

Magnetorheological polishing devices and methods

Abstract: A method of polishing an object is disclosed In one embodiment, as shown in the figure, the method comprises the steps of creating a polishing zone (10) within a magnetorheological fluid (2); determining the characteristics of the contact between the object and the polishing zone necessary to polish the object (4); controlling the consistency of the fluid (2) in the polishing zone (10); bringing the object (4) into contact with the polishing zone (10) of the fluid (2); and moving at least one of said object (4) and said fluid (2) with respect to the other Also disclosed is a polishing device (1) In one embodiment, the device comprises a magnetorheological fluid (2), a means (6) for inducing a magnetic field, and a means for displacing the object (4) to be polished or the means (6) for inducing a magnetic field relative to one another