What is pressure angle with reference to cam & follower?
What is it’s impor- tance? (b) A cam having a lift of 10mm operates the suction valve of a four stroke SI engine. The least radius of the cam is 20mm and nose radius is 2.5mm. The crank angle for the engine when suction valve opens is 40 after TDC and it is 500 after BDC when the suction valve closes. The crank shaft speed is 2000 rpm. The cam is of circular type with circular nose and flanks. It is integral with cam shaft and operates a flat faced follower. Estimate i. the maximum velocity of the valve, ii. the maximum acceleration and retardation of the valve, and iii. the minimum force to the exerted by the spring to overcome inertia of the valve parts which weight 2 N. [4+12] 6. (a) State and explain ?law of gearing?. (b) An internal spur gear having 200 teeth meshes with a pinion having 40 teeth and a module of 2.5mm. Determine i. the velocity ratio if the pinion is the driver ii. the centre distance, and iii. if the centre distance is increased by 3mm, find the resulting pressure
