Lock Nuts Research Articles

Redesain Cold Heading Dies Melalui Pendekatan Metode FMEA dan DFM di PT. ZYX

PT. ZYX is a foreign company automotive component sector for four-wheeled vehicles. In their third year of mass production, the production capacity reached 116 million pcs, resulting in the high cost of Dies purchase for Cold Heading machines. This condition worsened because things such as Dies having a low lifetime and the lead time for Dies purchasement is in the range of 20-40 days or more, which has the potential to cause machine downtime. This study aims to redesign the Dies of Cold Heading machine used today. Completion of the design uses the Pareto diagram analysis, FMEA, and DFM. The analysis result using the FMEA method shows the highest RPN value of 336 with the potential for insert carbide failure that cracks during assembly. The recommended corrective action is to make assembly support components, namely pokayoke parts, and make work instructions for replacing carbide inserts on Dies. The analysis results using the DFM method shows a change in term of cost. The cost for 1 unit of Dies purchasement was initially Rp. 10,247,113.00, but it dwindles to Rp. 4,623,914.23. Using the redesign to make case dies, lock nuts, collets, and stoppers components, resulted in cost efficiency of 54.87%.

Couplings slip determination of the threadbar of strength class 500 N/mm2

The authors present the results of RD on the topic of coupling slip of threadbar of class Av500P. The aim of the work was to obtain experimental data to study the effect of the threadbar coupling on the slip (deformability) of the joint and taking into account the characteristics of the joint in the design of structures. The strength and deformability of coupling samples of threadbar with a diameter of 16, 25 and 40 mm with an innovative four-sided (four-row) thread profile of class Av500P have been studied in accordance with the methodology of international and Russian standards. The samples were made with different tightening torques of the lock nuts and anchor-adhesive compositions inside the coupling. Along with the results of the study, it can be concluded that these couplings of innovative four-row threadbar of class Av500P meet the requirements of international and Russian standards when applying a certain tightening torque to the tightened lock nuts, depending on the diameter of the fittings to be joined and the use of anchor-adhesive compositions on large and medium diameters of the threadbar to be joined. The diagrams of thread joints obtained during the experiment can be used in design practice when design reinforced concrete structures according to the deformation model. Together, this makes it possible to introduce thread joints into the Russian construction regulatory code.

Preload from Tightening and Removal Torque

This paper presents a novel approach to determine preload in a bolted joint at installation or point of use. This approach uses both tightening torque and removal torque measurements. This work reveals preload is proportional to tightening torque minus removal torque and that taking this torque difference subtracts out friction. Tests with bolts, nuts, lock nuts, inserts and locking inserts are provided to assess this approach, and the results show good agreement with measured preload. The tests reveal the uncertainty in preload determined from this torque difference is less than the uncertainty in preload from tightening torque alone. A useful application of this work is to obtain a desired preload with nothing more than fastener thread pitch and a torque wrench to measure tightening torque and removal torque. This application is illustrated with data. The significance of this application is that preload is determined without any previously acquired torque–tension data as needed with tightening torque alone to achieve preload. In addition, this paper presents analysis and test data for quantifying self-loosening and primary locking in threaded fasteners from tightening and removal torque measurements.

Improved experimental and diagnostic techniques for dynamic tensile stress–strain measurement with a Kolsky tension bar

Kolsky tension bar experiments were improved for dynamic tensile stress–strain measurements with higher fidelity and minimal uncertainties. The difficulties associated with specimen gripping, relatively short gage section, and geometric discontinuity at the bar ends all compromise the accuracy of the traditional strain measurement method in a Kolsky tension bar experiment. In this study, an improved three-channel splitting-beam laser extensometer technique was developed to directly and independently track the displacement of the incident and transmission bar interfaces. By adopting a dual-channel configuration on the incident bar side, the resolution and measurement range of this laser extensometer were coordinated between the two channels to provide highly precise measurement at both small and large strains under high strain-rate loading condition. On the transmission bar side an amplified channel, similar to that used on the incident bar side, was adopted to measure the transmission bar displacement with high resolution. With this novel design, a maximum resolution of approximately 500 nm can be obtained for the bar displacement measurement, which corresponds to a strain of 0.0079% for a specimen with 6.35 mm gage length. To further improve the accuracy, a pair of lock nuts were used to tighten the tensile specimen to the bars in an effort not only to prevent the specimen from potential pre-torsional deformation and damage during installation, but also to provide better thread engagement between the specimen and the bar ends. As a demonstration of this technique, dynamic tensile stress–strain response of a 304L stainless steel was characterized with high resolution in both elastic and plastic deformations.

Dynamic Tensile Characterization of Vascomax® Maraging C250 and C300 Alloys

Vascomax® maraging C250 and C300 alloys were dynamically characterized in tension with Kolsky tension bar techniques. Compared with conventional Kolsky tension bar experiments, a pair of lock nuts was used to minimize the pseudo stress peak and a laser system was applied to directly measure the specimen displacement. Dynamic engineering stress–strain curves of the C250 and C300 alloys were obtained in tension at 1000 and 3000 s−1. The dynamic yield strengths for both alloys were similar, but significantly higher than those obtained from quasi-static indentation tests. Both alloys exhibited insignificant strain-rate effect on dynamic yield strength. The C300 alloy showed approximately 10 % higher in yield strength than the C250 alloy at the same strain rates. Necking was observed in both alloys right after yield. The Bridgman correction was applied to calculate the true stress and strain at failure for both alloys. The true failure stress showed a modest strain rate effect for both alloys but no significant difference between the two alloys at the same strain rate. The C250 alloy was more ductile than the C300 alloy under dynamic loading.

HIGH SPEED ELECTROMECHANICAL ENERGY STORAGE

Kinematical, electromechanical energy accumulator is a facility that converts supplied electrical energy to the kinetic one, stored in the rotating inertial system. Electric driving motors can operate both as a propulsion units, providing torque to the rotor shaft, and as generators in the course of braking. The prototype is designed to operate in a vacuum; the energy accumulator is located in a sealed pressurized vessel connected to the apparatus, which can generate vacuum pressure down to 1 Pa. The accumulator is destined for storage energy of 7.2 MJ at a speed of up to 20,000 1 / min. The energy accumulator is equipped with inert weight in the form of metal disc, connected to a composite band. In the course of operation, the rotor assembly is suspended in noncontact manner in housing assembly while the main body is fastened to the inner ring of the pressure vessel. The rotor consists of a shaft on which are mounted: a metal disc together with a band made of carbon fibre, inset into inert weight using epoxy resin; four disc rotors of two electric motors; two disks which are magnetic armature for electromagnetic bearings operating along the shaft axis; bushings of both sleeve bearings; fixing sleeves, washers and lock nuts to fix particular elements on the shaft. During normal operation the rotor is positioned in the radial direction through two electromagnetic bearings, top and bottom, located at both ends of shaft and operating in the differential arrangement, and in the axial direction - by a system of two eight-pole electromagnetic bearings. In the idle state rotor is based on the spherical tip of the mobile support and on the raceway of slide bearing located in the top cover. The prototype facility is designed to carry out performance tests, both under normal conditions of pressure and temperature and in vacuum environment, of: electromagnetic bearings, start-up/emergency devices, functional integration of all components and air tightness of tubing inside the tank. Measurement of radial and axial clearances between the rotor elements and housing for full speed range will be completed also.

Characteristic Analysis and Experimental Evaluation of Fluidic Muscle Cylinder

The fluidic muscle cylinder consists of an air bellows tube, flanges and lock nuts. Its features are softness of material and motion, simplicity of structure, low production cost and high power efficiency. Recently, unlike the pneumatic cylinder, the fluidic muscle cylinder without air leakage, stick slip, friction or seals was developed as a new concept actuator. It has characteristics such as light weight, low price, high response, durable design, long life, high power and high contraction. In this study, we carried out finite element modeling and analysis on the main design variables such as contraction ratio and force, and diameter increment of the fluidic muscle cylinder. On the basis of finite element analysis, the prototype fluidic muscle cylinder was fabricated and tested. Finally, we compared the test results with the finite element analysis.

An Characteristics Analysis of the Fluidic Muscle Cylinder

The fluidic muscle cylinder consists of an air bellows tube, flanges and lock nuts. It's fbatures are softness of materialand motion, simplicity of structure, low production cost and high power efficiency. Recently, unlikely the pneumaticcylinder, the fluidic muscle cylinder without air leakage, stick slip, friction, and seal was developed as a new conceptactuator. In this study, we carried out the finite element modeling and analysis about the main design variables such ascontraction ration and force, diameter increment of fluidic muscle cylinder. On the basis of finite element analysis, theprototype of fluidic muscle cylinder was manufactured and tested. Finally, we compared the results between the test andthe finite element analysis.

Experience in operating hydraulic structures and quipment of hydroelectric stations

1. The “Guidelines on Starting, Adjusting, and Comprehensive Testing of Assembled Units” drawn up by the Union Institute for Planning and Organizing Power Construction (Orgenergostroi) in 1975 requires period updating onsideration of accumulated domestic and progressive foreign experience, comments, and suggestions of interested orgations and well as manufacturing plants. 2. The scheme of filling the water-delivery devices of the turbine should be specified by the design. 3. Accoording to the experience of starting and adjusting works, the best protection from unforeseen turnin otating parts of units is provided by pressing the braking jacks of the generator against the brake disk of the rotor by under a pressure of at least 50 kg/cm2 with fixing the brakes by lock nuts. The presence of anyone on rotating parts wit pressing the jacks by oil and locking the nuts should be categorically forbidden. Blowing out and converting the brake working from compressed air can be done immediately before starting the unit. 4. It is necessary to accumulate and systematize nonstandard situations when conducting starting and adjusting we including as an aid for training the appropriate personnel.

Protezlerin Astarlama İşlemlerinde Kullanılan Bir Yöntem (

SUMMARY Rehiring is the readaptation of a denture base to the residual alveolar ridge and is accomplished by adding more resin denture base material. When relining is to be done, an impression must be made using the denture as a tray. Approximately 1.0 mm of clearance over the ridge is created by grinding the tissue surface of the base with acrylic trimmers. After its base is trimmed, an autopolymerizing acrylic reline material is mixed. The sections of the jig are assembled and closed gradually and evenly by tightening the lock nuts. The relive jig is placed in a pressure pot.

The 10 Millisecond 150 Kiloampere Pulsed Power Supply for the Fermilab Neutrino Focussing Horn

During this past run for neutrinos to the 15' Bubble Chamber, approximately 750,000 pulses have been obtained from the power supply wihtout incident or failure of any tupe. To enhance reliability, the primary voltage was limited to 5.5 kv with an 80 kA secondary current. Initial problems during the test period were largely related to damage to the high current connections, i.e., pitting of the contact surfaces. This problem was resolved by copper plating the aluminum surfaces, followed by silver plating. Bolted connections with lock nuts were required in all cases to insure long term intimate contact. It is planned to raise the current to 120 kA for a substantial test period at the end of the present run to test the system under more stringent conditions. It is clear that for applications similar to this, a transformer is an excellent choice. The low primary current simplifies the ignitron circuit and the low voltage on the secondary simplifies the insulation requirements on the load circuit. These two factors substantially improve the total operational reliability and ease installation.

COPPER ALLOY No. 350

Abstract COPPER ALLOY No. 350 is a medium-leaded brass containing 0.8-1.4 lead. Its machinability is 70% of that of free-cutting brass. It is suitable for use in high-speed screw machine work and has many uses such as lock parts, templates, nuts and gears. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-277. Producer or source: Brass mills.

ベルト式無段変速機用特殊Vベルトについて (III)

This paper deals with no-load-fatigue test for belts conducted using several kinds of special V-belts for variable speed mechanisms. After the experiment, we decided what type of belt was the strongest, and improved the belt to make it stronger.After having designed a new belt, we performed the fatigue test on it by changing the tension in it, and found the limit of safety tensions of the new belt. Fig. 1 and 2 show the testing apparatus employed.In Fig. 1, (1) belt tested(2) sheaves(3) lock nuts(4) plate on which sheaves are set, sliding through guides (5)(5) guides of plate (4)(6) pulleys for hanging the weight(7) ropes(8) rope fastening(9) weight(10) motor (7, 2000r.p.m.)(11) transmission belts.We used four kinds of belts for the fatigue test. Fig. 3 shows the dimension of the belt tested. Fig. 4-7 show the section of these belts. We indicate the endurance of belt by the number of bending.If I put n, number of bending, D, diameter of belt, N, rpm, L, belt length, t, time of endurance, thenObserving the fatigue test, we found that the initial crack took place in the core of V belt, and that, after a while, at both sides of V belt, it started to break. Gradually the cracks became larger, and at last, the side cracks and the core crack jointed together and then the belt broke.While observing of the fatigue test, I designed new belts, which are shown in Fig. 9, 10. We call these belts device A, and device B. We made a running test, and measured the coefficient of friction and the amount of abrasion of belt, using these belts.

A Throw Net for Capturing Female Waterfowl on the Nest

The importance of renesting data in waterfowl research is becoming more and more evident. Research on renesting requires the capture of the hen on the nest. Several methods of doing this have been devised and they have been discussed by Sowls (Sowls, L. K. 1950. Techniques for waterfowl nesting studies. Trans. N. A. Wildlife Conf., 15: 478-487). During the summer of 1951, the author carried on waterfowl research in the Potholes Area south of Moses Lake, Grant County, Washington. In the course of the research, a throw net for the capture of females on the nest was developed. The net has a frame constructed of two pieces of one-half inch, thinwalled electric conduit, nine and ten feet long. Each of these pieces was bent into a semicircle. The ends of both pieces were flattened for a distance of six inches and two 5/16 inch holes were drilled three inches apart in each end. The short piece was placed with the flattened ends inside and adjacent to those of the long piece. Machine bolts 5/16 inches in diameter and one inch long were used to bolt the pieces together. The bolts marked x (Fig. 1) were provided with lock nuts. This formed a permanent hinge joint. The bolts marked y were provided with wing nuts to facilitate their removal. When properly assembled with all four bolts in place, the frame is elliptical in shape, six feet long and five feet wide. Removal of the y lock-joint bolts allows the short piece to fold inside the long piece, thus resulting in a fairly compact net which is easy to transport. To complete the net, this frame was covered with one and three-quarter inch mesh netting which was not removed for folding. The netting should not be stretched tight on the frame but . a