Side Wear Research Articles

성인 남성용 런닝형 니퍼패턴 개발

This research aimed for 20 latter man whose body shape of torso alters remarkably to develop nipper pattern of running type considered characteristic of body shape of 20 latter man to keep rather balanced body shape against middle age when body shape changes extremely. 1. running type nipper pattern design. Pattern of running, lining and nipper were designed by flattening surface shell. A basis line of running pattern is completed by applying reduction ratio after 3 times of modification & complement based on surface shell. Nipper pattern is designed with design line set by a plaster cast based on running pattern line. Lining pattern is designed with lining design line set by a plaster cast based on running type outside material and nipper pattern. 2. Functional evaluation of research and commercial nipper. Functional inspection through dress test was applied 5point evaluation method and the result of functional inspection on the sight of a wearer is that research nipper(running reduction ratio 15%, nipper reduction ratio 18%) averaged more 4.8point but commercial nipper averaged less 1.8point in the aspect of 20 items such as wear sensibility, motional function and external appearance aesthetic. Research running type nipper scored high in order of motional function, looks of side, back, front and whole and wear sensibility. Functional inspection in the point of view of an observer is that research nipper(running reduction ratio 15%, nipper reduction ratio 18%) averaged over 4.8point and commercial nipper averaged under 1.9point in 17 items of external appearance beauty. Research running type nipper marked high in order of looks of back, whole, front and side.

Influence of gauge width on rail side wear on track curves

Abstract The main property of the railway system is infrastructure objects and rolling‐stock. Holding any kind of a property requires huge expenses and renovation investments. Intensive wearing of the rails on the track curves is observed. This problem is always topical in railways. In this article a possibility to decrease wear of rails on curves is analysed. The purpose of the authors’ research was to estimate the influence of rail wearing on the track widening and permissible deviations on curves when radius is less than 650 m. Also, to estimate the possibility to reduce railroad maintenance expenses associated with the change of the worn rails, when gauge on curves with radius less than 650 m is widened. For this reason in this article a mathematical model is presented. This model evaluates the influence of the gauge width on rail wearing on curves. An experiment was carried out on Lithuanian railway line curves. Results and analysis of the experimental research are presented in the article.

An experiment study of hard coating and cutting fluid effect in milling aluminum alloy

This paper investigates the cutting performance of a tungsten carbide end mill with hard coating and a sulfurous boric acid ester cutting fluid in milling A6061P-T651 aluminum alloy. The experiments were conducted to compare the milling force responses and flank wear under various cutting conditions. The results indicate that adding sulfurous boric acid ester cutting fluid decreases tool wear by 12.5% for hard coating tungsten carbide end mills and decreases the milling force by 10%. Besides, the average values of side and end flank wear of TiAlN-surface multilayer end mills can be decreased 38.7% and 68.7% respectively compared with uncoated and dry end mills.

A NUMERICAL MODEL FOR THE SIMULATION OF EXTERNAL GEAR PUMPS

External gear pumps are the most widely employed source of power in hydraulic applications, allowing good performance and low manufacturing costs. The present paper reports the description of a numerical model for the simulation of these kind of machines, developed by the authors. The model has been implemented using the software AMESim ® , introducing new in-house C++ models, with the main aim of an accurate prediction of the pressure ripple at the delivery port and the calculation the flow rate time course through the pump. In fact the reduction of flow pulsations is one of the crucial targets in the development of these machines. The fluid dynamic model of the pump is based on a finite volumes framework: each chamber presents uniform fluid proprieties and is connected with the adjoining ones by variable orifices. The pump is described by the interaction between a fluid dynamic model, that predicts the instantaneous pressures and the flow rates between the chambers, with a geometrical sub-model for the evaluation of the actual values of the variable volumes (defined by teeth, housing, and side wear plates) and the throat areas, as functions of the shaft angular position. This paper reports a deep description of the fluid dynamic model and a comparison between its numerical results and data available from experiments, showing how a correct evaluation of the flow when the chambers expand (and oil is pushed from the supply tank) or decrease (and oil is ejected into the outlet port) allows a good prediction of the pump characteristics. The results reported in the paper show how the model can be a powerful tool for design and development of external gear pumps, e.g. it easily allows the prediction of the maximum and minimum pressure reached inside the teeth space volumes, giving important information to prevent cavitation and damages as well as to reduce the pump noise. Moreover the simulation environment easily allows the evaluation of the pump behaviour when it works in a given hydraulic system.

Wear of advanced cemented carbides for metalforming tool materials

Wear behavior of some advanced cemented carbides (TiC-base cermets and some WC-hardmetals) in a series of functional wear experiments (including blanking of electrotechnical sheet steel in production conditions) was analyzed. Comparative laboratory trials of related materials in abrasive-erosion and adhesive-wear conditions were conducted, complemented by SEM. A good correlation between adhesive-wear resistance of the alloys investigated and their resistance to side wear (flank wear of blanking tool) as well as similarity in the morphology of surface failure in both cases was found. With regard to blanking performance, TiC-base cermet with a Ni–steel binder proved to have advantages over conventional WC-base hardmetals (used in metalforming).

The cavernous body of the human efferent tear ducts contributes to regulation of tear outflow.

To test the hypothesis that the surrounding vascular plexus of the lacrimal sac and the nasolacrimal duct contributes to the regulation of tear outflow. Experiments in 30 probands aged between 15 and 37 years were performed in both nasolacrimal systems of each subject by observing with an endoscope the transit time of an applied tear drop containing fluorescein dye until its entry into the inferior meatus of the nose. Four different experiments were performed to determine the median transit time under normal conditions and the influence on transit time of a decongestant drug, a foreign body on the ocular surface, and a decongestant drug applied together with a foreign body on the ocular surface. Comparisons were made between the right and left nasolacrimal system, in males and females, eyeglass wearers and non-eyeglass wearers, and the different experiments and the results statistically analyzed. The tear transit time was independent of side (right or left), gender, or eyeglass wear. It showed great individual variability. Application of a decongestant drug or placement of a foreign body on the ocular surface both prolonged the dye transit time significantly. Application of a decongestant drug simultaneously with placement of a foreign body shortened the dye transit time significantly compared with the effect of the decongestant drug alone but revealed no significant difference compared with application of a foreign body alone. The cavernous body of the lacrimal sac and nasolacrimal duct plays an important role in the physiology of tear outflow regulation. It is subject to autonomic control and is integrated into a complex neuronal reflex feedback mechanism starting with the dense innervation of the cornea. Moreover, its function can be pharmacologically influenced.

Nonmodular One-Unit Cementless Acetabular Compoment in Primary Total Hip Arthroplasty: With Alumina to Polyethylene Articulation

Purpose : Modular acetabular components have the potential of fretting and back side wear leading to osteolysis. The present study evaluated the outcomes of total hip arthroplasties (THAS) using a nonmodular cementless acetabular component with those of press-fit titanium mesh coatings fixed. Materials and Methods : Eighty-two primary THAS in 75 patients were performed consecutively between April 1995 and August 1998. Sixtytwo hips were eligible for follow up for an average 62 months. Mean patients age was 59 years. The clinical evaluation was performed using the modified Harris hip score (HHS), inguinal pain and limping. The radiologic evaluation included, component stability, polyethylene wear rate, pelvic osteolysis and the remodeling pattern around the acetabular component. Results : Mean HHS improved from 50.2 points preoperatively to 90.5 points at the most recent follow up. All components were stable radiologically. The linear polyethylene wear rate was 0.07 mm/year. No pelvic osteolysis was found. Polar gaps found in 25 hips (40%) in postoperative radiographs and disappeared during follow up in 22 hips (88%). One hip was revised due to chronic unreduced dislocation. Conclusion : Total hip arthroplasty with a nonmodular cementless acetabular component seems to enhance satisfactory early mid-term results in terms of stability and acetabular remodeling with minimal wear and pelvic osteolysis.

Predicted Effects of Cylinder Kit Wear on Blowby and Oil Consumption for Two Diesel Engines

Durability is very important for current diesel engines. Diesel engine manufacturers are trying to make the engines live as long as possible before overhaul. The time to overhaul for an engine is usually dictated by high oil consumption or blowby. Therefore, it is necessary to understand how wear affects the cylinder kit dynamics, oil consumption, and blowby in an engine. This paper explores the effect of power cylinder component (rings and cylinder bore) wear by using a cylinder kit dynamics model. The model predicts how wear will affect ring motion, inter-ring gas pressure, blowby, etc. The parameters studied were: liner wear, ring face wear, and ring side wear. Two different engines were modeled. The characteristics of these two engines are very different. As a result, the effects of wear are different and the corresponding durability will be different. This illustrates the need to model each individual type of engine separately. The modeling shows that top ring face wear is very significant for maintaining good oil and blowby control. Liner wear is important, but does not have as large an effect as ring wear. The effects of side wear are significant for these two cases. [S0742-4795(00)00203-9]

Effect of the geometry and the surface treatment of punching tools on the tool life and wear conditions in the piercing of thick steel plate

The process behavior in the punching of holes in a larger thickness circular steel plate using punches of different outer diameters, convex double-shear angles, convex lengths, and surface treatments was investigated. Experimental results showed that the appearance of the punched hole for a small clearance between the punch and the die displays a great number of slips to extend almost to the end of the hole through shear. When punches of convex double-shear angles of 20° with surface treatment are used, the straightness and surface finish of the punched hole show a better state. The worn conditions of the punch during shearing can be broadly classified into side wear, face wear, chipping, crack, and gross fracture. The failure mode of a punch with a convex double-shear angle of 12.5° during the piercing holes was mainly side wear. In addition, the worn mode for a punch of a convex double-shear angle of 20° shows dominantly side wear and gross fracture. The tool life for a punch having a convex double-shear angle of 20° is greater than that for a punch of 12.5° convex double-shear angle. The effect of the convex length of the punch on the tool life for a convex double-shear angle of 20° is significant. In addition, the tool life for a punch with a TiC coating or lapping treatment is greater than that of a punch without surface treatment by 25–60%.

Laboratory tests for seizure of rail and wheel steels

In the last decade side wear of rails and wheels was increasing in many countries. Topographic features of wearing surfaces of the rail gauge face and wheel flange lead to the assumption that seizure makes a heavy contribution to side wear especially at small radius curves. The exploration of seizure as a form (mode) of wear has been made. Two mechanisms of seizure designated as scoring and galling were observed in the laboratory tests. It is shown that the main peculiarity of scoring is local plastic deformation of both surfaces with formation of riders—hard movable centres consisting of two wedges with hardness ∼1.6 times greater than the basic metal. The main peculiarity of galling is plastic deformation of one surface only with formation of welding incrustation (protrusion) on the countersurface. An attempt was made to find the boundary of the scoring and galling area in the hardness–pressure–slippage–sliding velocity–environment space. Ways of counteracting side wear of rails and wheels following from the scoring mechanism of seizure are suggested.

Studies on the wear conditions and the sheared edges in punching

This paper presented the worn conditions of the punch cutting edges in punching holes on a larger thickness AISI 52100 steel plate using punches of different convex shear angles. The characteristic behaviors of the sheared edges and slugs were also investigated. Experimental results indicated that when using a punch of the convex double shear angle of 12.5°, the wear on punches is mainly side wear. It is a result of the combinations of the adhesive wear, fatigue wear and abrasive wear. The punch life is characteristically lower. The punch displays dominantly the face wear with a larger round cutting edge for a punch of the convex double shear angle of 20°. A relatively longer punch life is obtained. However, the plastic deformation and eccentricity of the punched hole and burr of the slugs are relatively higher. The maximum hardness of the hardening layer for the punch of shear angles of 12.5 and 20° is about twice the initial hardness of the workpiece, and the depth of its layer with increasing number of the punched holes is about 0.17–0.35 times the thickness of the workpiece. The punched slugs during shearing have two smooth sheared and two rough fractured appearances. With increasing number of the punched holes, the primary rough-fractured portion of the slug becomes larger while the secondary smooth-sheared portion of the slug would become shorter or, in an extreme case, vanish. Hence, the punch life can be indirectly estimated through the characteristic observations of slugs.

Effects of Properties of Base Oil for Cutting Oil on Wear of Hard Cutting Tool and Finished Surface Roughness Generated in Turning.

A series of cutting tests was perfomed to investigate the effects of the viscosity grade and the molecular weight distribution of base oil for cutting oil on wear of hard cutting tools (cemented carbide, cermet and ceramic) and finished surface roughness generated in turning. The results obtained are summarized as follows. With a cemented carbide tool, boundary wear on the side flank decreased with increase of the viscosity grade of base oil, while front flank boundary wear was negligibly affected by the viscosity grade. The side flank wear was little influenced by the application of base oils. With cermet and ceramic tools, adhesive matter appeared around the area where the side flank boundary wear occurs with the cemented carbide or high-speed steel tool, and this did not allow confirmation of the occurrence of side flank boundary wear. With both tools, front flank boundary wear showed a tendency to decrease with higher viscosity grades, while side flank wear was little affected by the application of base oils. The minimum finished surface roughness was obtained using a base oil of medium viscosity grade. Oils with a wide range molecular weight distribution were superior to those with narrow range distributions in reducing wear of the cemented carbide tool, especially side flank boundary wear, and also in improving the finished surface roughness.

Selection of Number of Flutes on Multi-Thread Hob for Mass-Production Gears.

This is to report the selection of number of flutes on multi-thread high speed steel hob for mass -production gears of automobiles etc., under the severe cutting conditions like more than 100 m/min cutting speed and 3-5 mm/rev. hob feed. The damage of hob is caused by many fields, like hob itself, gear blanks, hobbing machines, cutting conditons etc., And various type of damage can be found. The authors are hereupon to concentrate some typical damage (Corner wear, Extraordinary corner wear, Extraordinary side wear, Crater wear, Thermal crack, Chipping of cutting edge) that must be decreased in high speed hobbing with high efficiency.

Wear and lubrication characteristics of a methanol-fuelled compression ignition engine — A comparison with pure diesel and bifuel operation

Ring wear investigations were carried out in a glow-plug-assisted neat methanol-fuelled engine and compared with the engine operated on pure diesel fuel and methanol-diesel bifuel. The crankcase oils used comprised a diesel engine lubricant and two methanol-compatible formulations. The tests were conducted under high load and low jacket temperatures refflecting severe wear conditions. Piston ring face and side wear in a glowplug-assisted neat methanol compression ignition engine were found to be lower than in a diesel-fuelled engine. Methanol-diesel bifuel operation resulted in maximum piston ring face wear in comparison with pure diesel or neat methanol operation. This was attributed to higher combustion pressures in the case of the former.

Wear of standard and hard-metal-coated couplings with oilfield tubing

An experimental program was established to determine the wear of down-hole oil field sucker rod couplings and tubing. A special component testing apparatus was designed which enabled a close control of side loads, wear track and frictional forces. It was found that a standard coupling wore more than a hard-metal-coated coupling and that the tubing wore less with the hard-metal-coated coupling. This was explained on the basis that there was a transfer of metal particles from the hard-metal-coated coupling to the softer tubing thus enhancing the wear resistance of the tubing. The way in which the metal surfaces work hardened as the wear process progressed is also explained.

Wear on TiN-coated high speed steel hobs.

TiN-coating on the flank surface of HSS hobs by the PVD method can lessen the flank wear and lengthen the life of hobs. Therefore, recently, hobs for mass-production gears are almost all treated with TiN-coating. In this study, the authors examine what mechanisms decrease the wear of hobs after TiN-coating, in the case of typical flank wear (Corner wear, Extraordinary corner wear, Extraoridnary side wear). As a result, the authors report on how to design the roughness on the flank surface, the clearance angle, and the tooth profile with protuberance, to be suitable for TiN-coated high speed steel hobs.

Development of Protective Coatings Against Primary Coolant Corrosion, Friction, and Wear

Surface coatings are considered to be the best protective method against gas side corrosion, friction, and wear. As the basic requirements for coatings, i.e., good adhesion, chemical stability, and...

Chrome face vs. iron side wear — an analysis of some radioactive piston-ringwear studies : R. G. Abowd. ASLE transactions, v. 1, no. 1, 1958, p. 91. For abstracts see Wear, v. 1, 1957/58, p. 360

Chrome face vs. iron side wear — an analysis of some radioactive piston-ringwear studies : R. G. Abowd. ASLE transactions, v. 1, no. 1, 1958, p. 91. For abstracts see Wear, v. 1, 1957/58, p. 360

Chrome face versus iron side wear — an analysis of some radioactive piston-ring wear studies : R. G. Abowd Jr. (Ethyl Corporation, Detroit, Michigan) — Presented October 7th, 1957. at Toronto, Canada. Preprint No. 57LC-3, Am. Soc. Lubrication Engrs. (ASLE)

Chrome face versus iron side wear — an analysis of some radioactive piston-ring wear studies : R. G. Abowd Jr. (Ethyl Corporation, Detroit, Michigan) — Presented October 7th, 1957. at Toronto, Canada. Preprint No. 57LC-3, Am. Soc. Lubrication Engrs. (ASLE)