In this paper, the load distributions in the linear motion ball bearings, varying the radial clearances for the shaft from positive to negative value, were measured by means of strain gages bonded on the elastic beam type detecting units which were machine-worked on the outer sleeves of bearings. Then, the measured values weres compared with the theoretical analyzed and calculated results, reported already in 1st and 2nd reports, and after some discussion following results were obtained.
(1) Fairly good agreement were obtained between measured and calculated values of the load distribution and the maximum distributed load in bearings.
(2) When some radial clearance exists in the bearing and the eccentricity rate of external force for bearing becomes greater than unit, the maximum distributed load increases extremely and the stiffness of bearing decreases considerably owing to most of force is supported by two balls situated respectively at up and down ball tracks of bearing both ends.
(3) Because the external force is supported by many balls in bearing provided the bearing is preloaded, then the maximum distributed load goes down considerably, moreover the stiffness of bearing is improved.

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The ultimate purpose of this study is to create a new lathe by which roundness≈0, cylindricity≈0 and and surface roughness≈0 can be obtained in turning of aluminium alloy, copper alloy, iron, steel, and so on. At first, in this report, it is analyzed theoretically roundness≈0 turning can be realized by combining the insensitive vibration cutting mechanism and the main spindle system with the hydro-static bearing. And this analytical result can be confirmed by the experiments using a newly developed vibration cutting lathe with the improved main spindle of the cylindrical grinding machine with the hydro-static bearing. The main cutting conditions are as follows: the vibration tool ; in the same direction as that of cutting, frequency ; 21. 52, 28. 72, 30. 15 kHz, amplitude ; 13, 18, 26 rim, cutting speed ; 12, 27 m/min, depth of cut ; 0. 03, 0. 05 mm, feed ; 0. 02, 0. 05, 0. 08 mm/rev, cutting tool material and profile ; carbide tool K 10, (0°, 0°, 8°, 5°, 6°, -4°, 0 mm), (0°, 0°, 10°, 10°, 50°, 40°, approximately 1 mm), etc. Aluminium H_B = 26, brass H_B= 124, carbon steel H_B = 155, stainless steel H_B=179 are used. The main results are as follows: 1) The roundness value is decreased to about 1/2-1/10 of that of the conventional cutting lathe by means of the ball or roller bearing. 2) Roundness of 0.4 μm is obtained in these materials. This value of 0.4 μm has made a new record in turning. 3) By this study, it is proved that this new lathe combining the vibration cutting and the hydro-static bearing has the possibility of roundness≈0 turning.

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The paper describes a method for predicting the orthogonal metal cutting quantities such as shear angle, cutting forces, distribution of cutting temperature, and those of stress and strain without any cutting experiment. The method proposed is the simulation analysis of cutting process with aid of digital computer. The equations of equilibrium, plastic flow rule, heat transfer together with the characteristics of material strength and friction on the tool face, obtained from independent material tests, are solved simultaneously in the form of the finite element method. The predicted quantities are verified to be in good agreement with experi-mental results.

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Conventional interferometric photoelasticity is a well established and elegant method: however, its use is laborious and requires very great skill in practical use. In this paper, a simple interferometric photoelasticity by using the moiré technique is discussed in detail. It is described theoretically and experimentally that the imperfection of the optical elements and the photoelastic model is eliminated by using the moiré technique. In this method, the true information about the stress state of the photoelastic model is obtained as the moiré pattern by superposing the interferograms of the unstressed and stressed states through the imperfect optical system and the non-parallel plate model. The described method is closely related to holographic photoelasticity, but it is usually simpler and applicable to practical use.

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A theoretical investigation on the wedge-indentation of the work-hardening material is discussed here. Its primary consideration consists of the following three phases: the true tensile stress and the true elongation of the work-hardening material have an exponential relation giving a work-hardening exponent of n; the application of both the representative strain derived from the value of a wedge angle and the representative yield stress; and the dualized stress field of both the slip-line field and the elastic stress field of a flat punch. Hence, the mean pressure, the ratio of the mean pressure to the representative yield stress, the specific value of the maximum depth of the plastically deformed zone, the distinction between the compression-type of indentation and the cutting type of indentation are decided only by the stress-strain index of the material, pre-strain rate and its semi-angle of the wedge. The observed results are good in agreement on the theoretical values within 15% as had to be expected in case of the wedge angles being 120°, 136° and 150°.

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In the transitional cutting process such as milling or grinding, there exist transient regions (elastic deformation region and plastic deformation region) in the initial part of contact between tool and workpiece. These regions are left in the finished surface and affect the surface generation mechanism. From the above point of view, a model experiment is conducted to account for the mutual interference state between tool and workpiece. Variations of cutting forces and various residual stocks in the elastic, plastic and cutting region in the initial part of contact are analyzed experimentally. Furthermore, the effects of different machining conditions on the sliding phenomenon of a cutting edge are investigated. The results show that the sliding length decreases with an increase of the interference angle, and that plastic deformation and cutting begin at respective constant depth. It is also found that the sliding length increases with an increase of the width of cut and the nose radius of a cutting edge, while the sliding length decreases with an increase of the system stiffness.

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The effect of dimensions of hydraulic copying control device using throttle valve on the copying accuracy is minutely investigated in the tapering and machining a square shoulder, from the points of the response velocity and the moving force a:ting on copying piston. The factors (dimensions of copying control device) which influence the accuracy of tapering or machining a square shoulder are clarified analytically. And using this result, the approximate equations are obtained to estimate the dynamic characteristics of the hydraulic copying control device using throttle valve. These equations are useful in the design of hydraulic copying control device.

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It is difficult to obtain a characteristic, periodical signal of gears, that is, the transmission error, as many irregular signals due to lubrication, frictional losses and so on are relatively larger and involved. This report tries to obtain the transmission error by processing method with average, using a new developed machine which can directly and rapidly show an error spectrum and phases of the static transmission error.
(1) The processing method with average is very useful to obtain the transmission error of gears during rotation.
(2) The limit of rotational speed to measure the static transmission error of the above mentioned machine is about 300 rpm, and agrees with the theoretical limit. Therefore the limit can be estimated theoretically in general case.
(3) The dynamic motion of gears, which have a known static transmission error, obtained by the experiment agrees with the theoretical motion. Therefore the measured values by the above mentioned machine are very useful to estimate any motion of gears.

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A new method for measuring accurately the wear depth of a single abrasive grain in the "fly-milling test" is introduced. The wear in the method was measured on the basis of the tip of a diamond tool which was mounted at a short distance away in the direction of the wheel axis. A change in shape of the cutting point was observed simultaneously with it. Cutting force pulses were furthermore measured with a piezo-electric dynamometer. The self-sharpenability of cutting points is discussed on a basis of these results. Some results obtained in this paper are summarized as follows:
(1) The wear curve of cutting point is generally similar in shape to a flight of stairs with a gentle slope.
(2) Wear rates of individual grains are highly variable.
(3) Rate of wear by fracture of cutting points increases with increasing radial depth of cut, but rate of attritious wear is independent of it.
(4) Self-sharpenability of cutting point is affected by a combination of grit and workpiece material.
(5) Self-sharpenability of white aluminum oxide grits is better than that of green silicon carbide grits.

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Many kinds of gear tooth profiles and teeth combined with different profile curves, have been proposed. Otherwise, how to manufacture their profiles has ever been reported little. Even if the dressing apparatus, belonging to the well-known involute gear grinding machine, which can grind the modified involute tooth profiles, is used, it is impossible to manufacture particular tooth profiles other than involute tooth one. Here, the compound cycloidal tooth profile which has never been reported to grind, is made trial of manufacturing by means of N/C gear grinding machine developed by authors. The specifications of ground cycloidal gear are shown as follows : number of teeth 48, pitch diameter 96 mm, radius of rolling circle 4.8 mm, and both addendum and deddendum are 2 mm. Inspection of ground gears is held by means of the single frank meshing tester, which is newly developed applying digital computer. Two cycloidal gears composed of the same dimension are ground and meshed. The results of inspection is 60 seconds while 10 teeth profiles are meshed.

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