Proceedings of SerbiaTrib '13

mechanism these parameters are finally set: R b b=35mm and L=50 mm.The camprofile is shown in Figure 5. The 3Dmodel of the designed cam mechanism is illustratedin Figure 6.Figure 5. Cam profile.Figure6: 3D model of the cam mechanism.5. FORCEANALYSISS OF CAM MECHANISSMCONSIDERING FRICTION FORCESIn this section the dynamic forceanalysis off thedesigned mechanism considering the friction forcebetween follower and its guide and the frictionforce between cam and flat face followerr isinvestigated.The force transmission of a radial cam with areciprocating flat-faced follower is shown in figure7, where P is the external load on the follower, μ isthe coefficient of friction between the follower stemand its guide, μ o the coefficient of friction f betweenthe cam andthe flat facefollower and d is the guidediameter.13 th International Conference on Tribology – Serbiatrib’13Figure 7: Forcee transmissionn of cam mechanism withtranslating flat-face follower.From the equilibrium e equations of horizontalandvertical forces and moments about the point Adandassuming that t difference the between μ N12dandμ N2is negligible, the forces Fc, N 1 and N 22are determined [1]:withandΝ2N1FCbPΓ aμ0ξb PΓ 0 a μ b 1 ξ PΓΓ b2aμ μμ0b12ξP ms cskwhere m is thee follower mass, s, s an nd s are thedisplacement,velocity and acceleration of thefollower respectively, c is the dampingcoefficient,k isthe spring constant, c s 0 is the initial compressionof the spring and F b is the follower weight.Furthermore, the friction forces arewritten as:Qμ F(11)0 Q 1Q 2μ μNμ μNandthe cam shaft torque due to the frictionis given by:d dTf Q 0 Rb s Q1 Q2(14)2 20ss F012b(8)(9)(10)(12)(13)273