Handbook for chain engineering design and construction examples of calculation version 2010. Speedwiz features two separate camshaft calculations. Professional cam and perfect cam software to design the cams. The vibration in the camshaft reduces the efficiency of the engine and increase the friction between the rocker arms and the camshaft. Determine torque in shafts from gears, pulleys, sprockets, clutches, and couplings. Theoretical calculations carry out to design the cam profile using displacement drawing and cam profile drawing. Analysis was carry out to evaluate the design using traditional materials cast iron and forged steel. Cam design calculation of torque required by cam shaft. This is the angle between the inltake and exhaust camshaft lobe peaks described in camshaft degrees. Camshaft lobe design camshaft lobes are designed by starting with the lift curve, and working backwards to determine the lobe shape that will produce the lift curve.
Cam design please help im trying to find the torque to drive an existing cam the calculations were lost ages ago. What this means for the engine builder is a camshaft that requires less spring pressure to increase. Camshaft design torque mechanical engineering general. In fact the software allows, to design valve lift law, to calculate cam profile for the main type of valve train system, to verify the valve train system with the spring load calculus and also to analyze the geometry of. Ivan tighe engineering use wider lobe centrelines on speedway application, for this reason. Kg company headquarters, parent of the independent subsidiary companies.
Pdf camshaft design for an inletrestricted fsae engine. When shopping for camshafts from different manufacturers, enter each of their supplied cam card specs into mgis camshaft calculator. The translational or rotational displacement of the follower is a function of the rotary angle of the cam. Camshaft lobe design tilden technologies camshaft design. This helps to give the engine the correct balance inlet to exhaust.
Camshaft is along with the suction and exhaust systems it determines the useful rpm range of the engine. Flat tappet with design cam shown inside the old cam with larger basecircle. Design a was characterised, somewhat glibly, as one with a. The science behind camshaft design is as advanced as anything in a race car, so most of usincluding experienced engine buildersdepend on the manufacturer to help spec the right cam for a. However, the manufacturing of cams is expensive and the wear effect due to the contact stresses is a disadvantage. In this study, the effects of modifying the restrictor design, intake runner length, intake camshaft profile, exhaust geometry, and silencer design were measured using a transient dynamometer. Zoomed in on the top of the accelleration curve, shows the difference in 1 and 0. Design and analysis of cam shaft in automobiles using. Net valve lift is a function of camshaft lobe lift and rocker arm ratio.
If the engine has an overhead valve design, the camshaft is usually located in the block above the camshafts,valve trains,intake and exhaust systems 171 figure 92 in many engines,the camshaft drives the distributor and the oil pump through a shaft from the end of the distributor. Figure 93 the fuel pump plunger rides on the camshaft. Cam mechanisms are widely used because with them, different types of motion can be possible. For this reason, we need to learn a bit more about lift curves before we can discuss how lobes are designed. Handbook for chain engineering design and construction. Development of an interactive camshaft design tool diva. Constant velocity figure 23 the s v a j diagrams of a bad cam designpure constant velocity h 0 s v 0 0 90 180 270 360 a 0 j 0. Baez morandi approved 20611 examiner ulf sellgren supervisor ulf sellgren commissioner contact person abstract camshafts are crucial components in combustion engines. A similar design procedure for other follower mechanisms can be pursued. Though electronic motion controllers have replaced cams in my applications, cams may still be best in situations that require complex motions. Cam and follower design basics design of cam profiles and. We would normally recommend that you use specialist software for the design of engine camshaft because there are special requirements for valve timing cams.
This concept is important in cam profile design and is called the trace point of. The rocker arm transfers the motion of the valve lifter riding on the cam lobe to the valve and increases the lobe lift by the amount of the rocker ratio. These designs will be used here to numerically illustrate this article, so you can refer back 2 to find their characteristics of lift, duration, acceleration, velocity and jerk. While mechdesigner software is particularly suited to packaging machine design, it can also be used to design camshafts for engines. The challenge of designing a camshaft needs the designer to solve a large number.
However, the manufacturing of cams is expensive and the wear effect due to the. Basic radius r 0 disc and cylindrical cams motion length l c linear cams cam width b c roller radius r r roller width b r for follower shape cylinder eccentricity e disc cams for translating follower eccentricity angle. An interactive camshaft calculator where engine builders can see how valve overlap and boost efficiency is affected by a camshaft s physical design. The static analysis is done using ansys work bench 14. Generally speaking the majority of cams will fall between 98 and 120 degrees. This analysis is an important step for fixing an optimum. I think im going to recommend that we buy some software for it, because it seems like the calculation that zekeman did would have to be repeated many times around the surface of the cam. An interactive camshaft calculator where engine builders can see how valve overlap and boost efficiency is affected by a camshafts physical design. Development of an interactive camshaft design tool.
The first step when design cam is to define the mathematical functions to be used to define the motion of the follower. Understanding camshafts camshaft basics camshaft design. Camshaft math to design competitive performance engines. They differ only in the way in which the cams basic profile event positions are specified. A projection on a rotating part in machinery, designed to make sliding contact with another part while rotating and to impart reciprocal or variable motion to it. The goal of the project is to design cam shaft analytically, its modeling and analysis under fem. Another way to approach it is to calculate the work in moving the follower, first using torque, and then using force. Cam design equations replace graphics machine design.
Currently, highspeed motors are often used with camshaft with profiles that are designed according to the given motion rules of xupap. Cams can provide unusual and irregular motions that may be impossible with the other types of mechanisms. There is no such thing as cam design, there is only valve lift profile design which. If we were to ask for a show of hands, its a safe bet to.
The term dxdtheta is the velocity of the follower, relative to the cam rotation angle, and is easy to get. Whether were talking about axle ratios, compression, carburetor size, timing, or e. In this case, introduction of two mass, single degree of freedom and multiple degree of freedom dynamic models of cam follower systems are. Ability to show comparison cam shape lift, velocity, accelleration and jerk on the design page. Pdf design manufacturing and cost estimation of camshaft used. The motion requirements, listed below, are commonly used in cam profile design. A designer can define the function according to the specific requirements in the design. It is highly recommended that for the best results, the flow figures for the cylinder heads are used.
In addition camshaft can include a gear to drive the distributor and an eccentric to drive a fuel pump. Find bending moments from gears, pulleys, or sprockets that are transmitting loads to or from other devices. Shaft design objectives compute forces acting on shafts from gears, pulleys, and sprockets. Norton, design of machinery introduction to cam design. Mallikarjuna and others published design manufacturing and. Finite element analysis fea is performed on the crank shaft. Vibration analysis of the camshaft using finite element method. With the rotation of the cam, the follower the shaft with the roller at bottom in the above picture gets oscillated or translated according to the profile of the cam. Camshaft is along with the crankshaft it determines firing order. Mar 22, 2007 the science behind camshaft design is as advanced as anything in a race car, so most of usincluding experienced engine buildersdepend on the manufacturer to help spec the right cam for a. Fracture analysis of camshaft to design good mechanism linkages the dynamic behavior of the components must be considered, this includes the mathematical behavior of physical model. Its greek jargon, or street parlance to the rest of the world, but it often defines us.
Professional cam and perfect cam is the ideal and complete software for engineering, team, tuner, etc. Cam design and analysis programs for more than three decades, computerized cam program development at andrews products has been a continuous effort. Linear and cylindrical cams for translating follower pivot distance y disc and linear cams for swinging arm arm length l a disc and linear cams for. This video explains the aspects of camshaft lobe design. Oct 08, 2017 this video is 1 of 2 videos that explain camshaft design. Valve opening and closing points are used in the first calculation, while duration and lobe center angles are used in the second cam calculation. The closer the lobe centreline the harder the engine will come on the cam. Development of an interactive camshaft design tool federico e. Design calculation for crankshaft the configuration of the diesel engine for this crankshaft is tabulated in table i table i specifications of atul shakti engine capacity 395 cc number of cylinders 1 bore x stroke 86 x 68 mm compression ratio 18. Jan 24, 2015 net valve lift is a function of camshaft lobe lift and rocker arm ratio. Lobe lift sometimes called cam rise is the height of the eccentric portion of the cam lobe above the base circle. Camshaft basics from the february, 2009 issue of chevy high performance by bob mehlhoff.
Request pdf design and analysis of camshaft the objective of this paper is to modelling design and analysis of a cam and follower. Programs originally written for dos based computers have been converted to operate on windows pc operating systems including xp, vista, win 7 and more recently, windows 8. Differentiating equation 2 with respect to t, we have velocity of the. Research paper design and analysis of crankshaft for single. Draw two perpendicular axes locating the cam center at a. It is normally connected with a prime mover, which rotates it. The nose portion is the large central area with negative curvature. Material optimization was carry out to replace the traditional material with new composite alloys.
189 345 890 620 1092 180 542 507 530 932 314 1628 209 745 626 527 497 1047 529 445 64 669 506 317 351 149 869 758 863 479 584 643 1487 1378 492 56 10 807 1151