Curvic coupling, find complete details about curvic coupling,curvic coupling from other machine tools accessories supplier or manufacturerseoam machinery ind. The present study, as a further evolution, proposes an experimentally validated closed form. When using standard tooth proportions, the surface contact area of the curvic teeth will remain constant fig. Curvic couplings are extensively used in aerospace machinery, such as helicopter, aeroengine, or other aircrafts. A model accounting for stiffness weakening of curvic couplings. The inspection of curvic coupling geometry is usually done by using a mating master curvic to check the transfer of a very thm coating of engineering blue from the master to the curvic being inspected. This report covers some design considerations, analyses, and tiench tests of the positiveengagement clutch. Precision machine design alignment principles 23 figure 3. Buy best curvic coupling, hirth coupling with escrow buyer protection. Curvic gear couplings are available in three standard sizes for the majority of applications.
Nov 12, 2010 upon closer look the gap was just a slight chamfer on the back coupling. This is particularly important to companies that drive productivity and innovation, and maintain traceability to requirednational and international standards 2, 11, 12. The curvic coupling design includes a compound fillet radius, comprised of a large and a small. Threedimensional models were created in beasy and ansys, and are described in the following subsections. Design the coupling with following materials, material for shaft material for shaft as 40c8 syt 380 mpa, material for bolts is 30c8 400 mpa and flanges are madeup of cast iron fg 150 sut 150 mpa.
A hirth joint or hirth coupling is a type of mechanical connection named after its developer albert hirth. Cad model of curvic coupling the cad model of curvic coupling was saved in step format for importing it into ansys workbench for the structuralanalysis purpose. Sort by relevance 1 smart couplings remove guesswork from measurements in machinery applications. Table rotation is guided by high precision roller bearings with a mechanical clamping system. Contact pattern measurement using current method of ink transfer.
Grinding services including curvic coupling grinding services. Analysis of contact and bending stiffness for curvic. Stiffness analysis of curvic coupling in tightening by. The stiffness of the curvic couplings is of guiding significance to the engineering design of aeroengine rotors as it is significantly different from that of continuous structures. We provide prompt quotations, competitive pricing, and top quality gears. Both haves are bottomed so the valleys will need work also. Curvic coupling use for turret of cnc lathe machining center, robot, gas turbine, airplane, etc feature. The principle of the hirth coupling was picked up by an american manufacturer of gearboxes, it was improved and renamed curvic coupling. Hirth coupling mechanical engineering general discussion. Typical curvic coupling curvic couplings are produced by plunging a cup shaped grinding wheel towards the blank material, i. A study on the cadcam of curvic couplings turbo expo. Investigating curvic coupling behavior by utilizing two and.
Design and mathematical modeling of fluid coupling for. Investigating curvic coupling behavior by utilizing two. The materials used for the curvic coupling are structural steel and silicon carbide which are in isotropic behavior. Curvic couplings articles, news and companies related to. It is designed and manufactured by our skilled team of professionals in adherence with international quality standards using quality. March 2000 machine was sent to gleason for full mechanical and electrical overhaulupgrade. Hirth joints consist of radial teeth formed by grooves milled or ground into the end face of.
The stiffness and the accuracy of centering the coupling have become very important. In th is study, a numerical model was developed to investigate the stress dist ribution and the contact evolution at. Amongst many components in a jet engine, is curvic also referred to as curvic coupling. Strength formula for curvic coupling division accuracy.
Curvic couplings are frequently used in aeroengine rotors. Curvic gear couplings comprise two crowned and barreled steel hubs, coupled by a matching polyamide sleeve. Request pdf a study on the cadcam of curvic couplings the curvic coupling was first developed by gleason works about sixty years ago. Results are obtained by computing the centre line slope generated by an applied couple using a program for automatic finite element calculations pafec 75. The program reported herein was accomplished during the period from 10 april 1972 to 3 june 1973. The fixed curvic coupling is used extensively in the construction of builtup. Curvic coupling is used for turret of nc lathe machining center, robot, gas turbine,airplane,etc the index table does not need to be lifred.
The fixed curvic coupling is used extensively in the construction of builtup turbine and compressor rotors for airfig. Komet5 is used in bevel gear gearing and face type coupling production curvic couplings to calculate corrections for machine settings andor tool data in order to reduce variations between nominal and actual geometry. Hirth couplings, also regarded as curvic couplings, are widely used for torque transmission between mating discs in turbine machinery and are not covered by international standards for instance iso, din or agma. The three basic types of curvic couplings are the fixed curvic coupling, the semiuniversal coupling and the relating coupling. Design charts are presented whereby the practicing design engineer can determine the equivalent flexural stiffness of flanged or curvic toothed couplings. We specialize in the curvic grinding of engine, apu and transmission couplings and dynamic balancing of rotating engine components. Single reduction curvic coupling differential carriers.
Design and production of a curvic coupling for testing purposes. However the allowable load differs to the size of the curvic coupling in use. This paper develops a method for calculating the contact and bending stiffness of a curvic coupling, and investigates stiffness changes according to the coupling shape and surface roughness characteristics. As the old adage goes, there is more than one way to skin a cat. In addition to these services, anmark offers engineering support, turning, milling and precision grinding on customersupplied product as well as the complete manufacture of product according to design requirements. In this paper, definitions and relations of the structure parameters for a curvic coupling are firstly introduced. Other builders were using what they called face gears or face couplings, not possessing. A lower stress and higher service life curvic coupling design is disclosed for use on coupling mechanisms for assembly of components that comprise rotating elements, such as impellers, turbine wheels and couplings for gas turbine engines and other types of engines having highly stressed components. Our engineering staff can help with analysis of new designs as well as improvements on existing designs. The only cautionary aspect of curvic coupling application is that good guarding must be provided around the base of the turret, top of saddle, to prevent the entry of chips into the coupling. Twin shaft coupling a semifloating shaft coupling is combined with a floating shaft coupling to make the twin shaft coupling, which is.
Pdf digital inspection of fixed curvic coupling contact pattern. I dont know how they ended up with a half of a curvic coupling set. Curvic coupling design having chosen the ininal size of the curvic coupling, it is necessary to determine the number of teeth and the face width. It is designed and manufactured by our skilled team of professionals in adherence with international quality standards. Pdf curvic couplings are frequently used in aeroengine rotors. The general arrangement of a typical curvic coupling is shown in figure 1. A model accounting for stiffness weakening of curvic. Hirth couplings hirth serration rings and specialized serration services this formlocking, selfcentering and easily detachable connection component connects shafts, disks, rotors, wheels and cranks with remarkable precision and maximum torque capacity. Once program and dataspecific parameters have been configured, komet5 is a fully automatic, intuitive correction program. The curvic coupling portions of the test clutch were designed and manu factured with the cooperation of gleason works, rochester, new york.
It is preventable for chips to enter into the index table. Gears, splines, curvic couplings equitable engineering. Our design, through several revisions, was successful in this. Hirth couplings, also regarded as curvic couplings, are widely used for. Quite often, the collection of precise data in drive technology applications can be problematic. Pinion with curvic plate coupling for highprecision. This maintenance manual describes the correct service and. Design and analysis of geometrical parameters influencing on curvic coupling raviraj madhekar department of mechanical engineering, v. Design features of 612bolt coupling performance performance performance max. Test couplings were designed, manufactured, and inspected at california. To the best of our knowledge, the specifications contained herein are accurate but should be verified at time of inspection. The coupling provides a positive drive along with precision centering and high load carrying capacity. The mating master curvic is also used to measure dimensions such as swash, radial runout and overall stacking height. Then, it has been implemented through design and manufacture methods to be used for connecting shafts of gasturbine engine.
We have unique expertise and comprehensive resources allowing us to provide master, and curvic couplings everything from the initial special design to manufacture including precision grinding. Curvic is a ring type specialist hardened steel component comprising of a number of teeth on the upper face spline equally spaced around its circumference at constant depth 5. Digital inspection of fixed curvic coupling contact pattern. The curvic coupling was first developed by gleason works about sixty years ago. Us6672966b2 curvic coupling fatigue life enhancement. The basic procedure that gleason recommends for determining tooth contact pattern is as.
The bolt stress of the curvic coupling under the conditions of a blade release in the 3d finite element model was analyzed by richardson et al. Welcome to the premier industrial source for grinding. The fixed curvic coupling is also sometimes referred to as a permanent curvic coupling due to. Although the stage 2 aft curvic is modeled, similar techniques may be applied to other curvic locations. Customized manufacturing for specific purposr is available. Curvic coupling grinding series gleason corporation. Our mindset will be concentrated on satisfying the needs of our customers and working hard to become a futureoriented company.
It is used to connect two pieces of a shaft together and is characterized by tapered teeth that mesh together on the end faces of each half shaft. The curvature of the teeth give these couplings their very own and unique selfcentering feature. Fixed curvic couplings the fixed curvic coupling is a precision face spline for joining two members, such as two sections of a shaft, to form a single operating unit. In designing a fixed curvic coupling it is essential to con sider the method of. A protected type flanged coupling is required to transmit 60 kw power at 1440 rpm. Late in the day i did get a referall from the aerospace company to a smaller company. Curvic couplings were first massproduced in 1942 to meet the need for couplings that require extreme accuracy and maximum load capacity, along with a high production speed. An accurate curvic stress determination early in the design process is required. The curvic coupling design includes a compound fillet radius. Curvic coupling buy coupling,hirth coupling,index table. Hubs are fully machined and zinc plated for corrosion protection.
The surface of the onsite curvic coupling is chosen as reference for a most accurate simulation. The companies featured in the following listing offer a comprehensive range of grinding. Curvic coupling, curvic coupling manufacturer in india. The grinding wheel has a chamfer angle on its edge equivalent to the flank angle required on the curvic tooth, the chamfer being on. Curvic coupling curvic coupling is product description. Relying on our stateoftheart manufacturing set up, we are offering premium quality range of curvic coupling. Us20030017878a1 curvic coupling fatigue life enhancement.
In this case, the shaft of the coupling is supported with a single bearing, arranged as closely as possible to the outer sprocket or pulley. Institute of engineering and technology, solapur, india raviraj. The aim of this paper is to reveal new insights into the behavior of bolted joint with curvic couplings according to the bolt geometry and physical parameters by an analytical model. Equitable engineering uses cadcam engineering to manufacture a wide variety of precision gears, splines, and curvic couplings. Pressure angle and whole depth will be considered in later sections. In fact, this is usually disregarded in the standard procedure, but its. Dlc is a specialized manufacturer of curvic coupling such as curvic, index curvic coupling, turret curvic coupling, airplane curvic coupling, 2pieces curvic coupling, 3pieces curvic coupling. Provided coupling is known for its accurate alignment and precision centering capability whenever it is in mesh.
Curvicis used for connecting engine members to form a single assembled unit. Selfloosening behavior of bolt in curvic coupling due to. We will lead this market at the head of this field. Hirth couplings, also regarded as curvic couplings, are widely used for torque transmission. If you have any further questions please call me at 207 7841999. A study on the cadcam of curvic couplings request pdf. Inspection of curvic couplings using a cmm wit press. Experimental use of cmm for generating measurement data to be used for.
Privy to only bits and pieces of the design details it was never any consideration of using anything other than a curvic even though the hirth coupling was brought up several times. Based on the recommendations from the computational study a conventional fluid coupling with one driver shaft and one driven shaft was fabricated and tested. However, you would probably be better off with a hirth coupling these days and they are a lot simpler to design. Methods for modelling flanged and curvic couplings for. As the coupling obtains a significant level of clamp force and hardness, it is optimally used for index tables at machining centers for heavy cuttings and in torque transfers. Curvic coupling design novdec 1986 gear technology. View product details of curvic coupling, hirth coupling from dlc co. Gleason model 887 cnc curvic coupling grinder with fanuc 18mb control. Pdf a model accounting for stiffness weakening of curvic. A fullyautomatic grinding cycle enables the production of extremely accurate.
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