A disc cam rotating in a clockwise direction is used to move a reciprocating roller with simple harmonic motion in a radial path, as given below : (is) outstroke with maximum displacement of 25 mm during 120 of cam rotation, (ii) dwell for 60 of cam rotation, (iii) return stroke with maximum displacement of 25 mm during 90 of cam rotation, and (iv) dwell during remaining 90 of cam rotation. The line of reciprocation of follower passes through the camshaft axis. The maximum radius of cam is 20 mm. If the cam rotates at a uniform speed of 300 r.P.M. Find the maximum velocity and acceleration during outstroke and return stroke. The roller diameter is 8 mm.
Answers
Answer:
Step-by-step explanation:
Follower type = Knife edged, in-line; lift = 50mm; base circle radius = 50mm; out stroke with SHM, for 600 cam rotation; dwell for 450 cam rotation; return stroke with SHM, for 900 cam rotation; dwell for the remaining period. Determine max. velocity and acceleration during out stroke and return stroke if the cam rotates at 1000 rpm in clockwise direction.
Cam Solved Problems
Cam profile: Construct base circle. Mark points 1,2,3…..in direction opposite to the direction of cam rotation. Transfer points a,b,c…..l from displacement diagram to the cam profile and join them by a smooth free hand curve. This forms the required cam profile.
Calculations:
Angular velocity of cam = clip_image006=104.76 rad/sec
Max. velocity of follower during outstroke = vomax = clip_image008=
=7857mm/sec =7.857m/sec
Similarly Max. velocity of follower during return stroke = , vrmax = =
= = 5238mm/sec = 5.238m/sec
Max. acceleration during outstroke = aomax = rω2p (from d3) = clip_image016 =
2469297.96mm/sec2 = 2469.3m/sec2
Similarly, Max. acceleration during return stroke = armax = clip_image020 =
1097465.76mm/sec2 = 1097.5m/sec2
Answer:
Step-by-step explanation: