Which of the following statements is/are true for cam profile? Uniform velocity, Simple harmonic motion, Uniform acceleration and retardation, and . 7. A In case of roller follower, trace ... B Uniform acceleration and retardation of follower motion. with Uniform Acceleration and Retardation. 1500 00 to 1200 uniform acceleration and retardation rise of 36 mm, 1200 to 1800 uniform velocity rise of 12 mm, 1800 to 2400 dwell, 2400 to 3600 simple harmonic motion fall of 48 mm. D All of the above. 19. … Uniform Velocity Motion The displacement, velocity and acceleration diagrams when a knife-edged follower The cam profile will be discontinuous. the cam shaft and follower detail the complete displacement graph the complete cam profile. The … Construct radial plate cams of given uniform velocity, simple harmonic motion, uniform acceleration and retardation to in-line knife-edge followers. uniform acceleration & retardation Prob. A follower with Uniform Acceleration and Retardation (UAR) will accelerate and decellerate at the same rate. Follower**:** 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. Name four profiles normally used in cams. (ii) Follower to dwell for 60o of cam rotation. Draw the profile of the cam when line of stroke of the follower passes through the centre of the cam shaft. Introduction 20.1. Draw the cam profile for conditions same with follower off set to right of cam center by 5mm and cam rotating counter clockwise. C SHM follower motion. 8. The displacement, velocity and acceleration diagrams are plotted for one cycle of operation i.e., one rotation of the cam. Shown over is the outline of a cam with UAR rise and UAR fall. 13. The displacement, velocity and acceleration patterns are shown in fig.6.9. In a cam drive with uniform velocity follower, the sharp corners of the displacement diagram are rounded off at the beginning and at the end of each stroke. Types of motion of the follower • Uniform velocity • Uniform acceleration and retardation • Simple harmonic motion • Cycloidal motion 7 Uniform velocity Steps for graphical construction of displacement diagram of constant velocity Constant velocity of the follower implies that the displacement of the follower is proportional to the cam displacement and slope of the … Pitch point on … Draw the profile of the cam. (Q-6) [5] Q2) Draw the displacement, velocity and acceleration diagrams for a follower when it moves with uniform acceleration and retardation. stroke with Uniform acceleration and retardation,for 90° cam rotation; dwell for the remaining period. The cam profile will be tangential to these roller circles. (b) Follower to dwell for 50° of cam rotation. If the clutch is an old clutch, then uniform rate of wear assumption is more valid. follower displacement. (iii) Follower will return to its initial position during 120 of cam rotation with uniform acceleration and retardation. Derivatives of Follower motion: Velocity and acceleration of the followers for various types of motions. Determine the maximum velocity and acceleration during rise and return if the cam rotates anti-clockwise at 900 rpm. From the displacement diagram, velocity and acceleration of the follower can also be plotted for different angular displacements θ of the cam. 5 Which of the following statements is/are true for cam profile? 1. 1- Displacement, Velocity and Acceleration Diagrams when the Follower Moves with Uniform Velocity:- In order to have acceleration in beginning and retardation at the end of stroke within the finite limits. Cycloidal motion. 1: draw the profile of disc cam to given uniform velocity motion to the knife edged follower during outstroke of 60mm during 1st half revolution. Uniform Acceleration and Retardation … 20.6 Displacement, Velocity & Acceleration Diagrams when Follower Moves with Uniform Velocity 12/3/2013 1. Keywords: Main parameters, cam profile, acceleration jump, cam follower, valve spring * Corresponding author: Oguzhan Yildiz. Simple harmonic motion, iii. 3. Circular Arc Cam with Flat-faced Follower. In a cam drive with uniform velocity follower, ... Because of difficulty in manufacturing cam profile. through 40 mm in of revolution, keep it fully raised through 1/10 th 1 th 4 revolution and to lower it with uniform acceleration and retardation in 1/6 th revolution. Emphasise direction. B. Displacement, Velocity and Acceleration Diagrams when the Follower Moves with Cycloidal Motion. ... Follower Moves with Uniform Acceleration & Retardation 12/25/2015 11. Construct cam profiles and displacement diagrams. is required to move an offset roller follower with a uniform and equal acceleration and retardation on both the outward and return strokes. The motion curve and velocity and acceleration curves are as shown. The follower again turns to its original position with velocity during next half of three revolution . Cam Follower Design Terminologies. a. fig.6.9 (c) Follower motion with uniform acceleration and retardation (UARM): Here, the displacement of the follower varies parabolically with respect to angular displacement of cam. Design a cam for operating the exhaust valve of an oil engine. 11. Determine the maximum velocity and acceleration of the follower when the cam shaft rotates at 900 rpm. The displacement of the follower is to take place with uniform acceleration and uniform retardation. DisplacementDiagram: Cam profile: Cam profile with 5 … The angle of ascent, the angle of dwell (between ascent and descent) and the angle of descent is 120°, 60° and 90° respectively. Draw the profile of the cam. 4. Assuming that, there is no dwell between the ascent and descent, determine the lift of the valve, the flank radius and the acceleration and retardation of the follower at a point where circular nose D. Because the uniform velocity motion is a partial parabolic motion. Uniform acceleration and uniform retardation. The valve remains closed during the rest of the revolution. (iv) Follower will dwell for remaining 60o of cam rotation. View Answer ... 16 For S.H.M. Uniform acceleration and retardation 4. The motion may be uniform and/or simple harmonic and/or uniform acceleration and retardation. Return of cam also takes place with uniform motion during remaining half of cam revolution. the plate cam profiles for these different motions and different followers. Cams with Specified Contours. Uniform acceleration and retardation. It is normally connected with a prime mover, which rotates it. The minimum radius of the cam is 25 mm. Construct displacement diagrams for given cam profiles. Types of Cam Followers There are three types of cam followers, and since the type of follower influences the profile of the cam it is worthwhile considering the advantages and disadvantages of each type. the displacement of follower is to take place with uniform acceleration and uniform retardation. Assume minimum radius of cam as 25 mm. Draw the profile of disc cam to give uniform acceleration and retardation out stroke of 25 to a knife edge follower during first half of revolution. Uniform velocity, ii. Displacement diagrams are basic requirements for the construction of cam profiles. Simple harmonic motion, and 3. A cam and follower mechanism has the following motion: (i) the follower moves out by 35 mm for 120 0 of cam rotation with uniform acceleration and retardation. 12. Draw a cam profile to drive an oscillating roller follower to the specifications given below: a. Follower to move outwards through an angular displacement of 20° during first 120° rotation of cam b. Uniform acceleration and retardation and iv. Draw the profile of the cam (i) when the line of stroke of the follower passes through the centre of the cam shaft, and (ii) when the line of stroke of the follower is off-set by 15 mm. Cycloidal motion 12/3/2013 Dr. Mohammad Suliman Abuhiba, PE 20 . Note that the acceleration is zero for the entire motion (a=0) but is infinite at the ends. Construct standard cycloids. A cam rotating clockwise at a uniform speed of 200 r.p.m. It is required to give equal uniform acceleration and retardation during opening and closing of the valve each of which corresponds to 60^{\circ} of cam rotation. Draw the profile of cam, if the axis of follower passes through the axis of cam. infinite as in the uniform velocity type of motion. Uniform acceleration and retardation cams are used to controls the motion of linkages in complex machinery. Draw the profile of a cam to raise a valve with S.H.M. 21. The lift of the valve is 37.5 mm and the least radius of the cam is 40 mm. Uniform Acceleration and Retardation (Parabolic) In such a follower programme, there is acceleration in the first half of the follower motion whereas it … Cam**:** The cam is the driver. Displacement, Velocity and Acceleration Diagrams when the Follower Moves with Uniform Velocity We shall now discuss the displacement, velocity and acceleration diagrams for the cam when the follower moves with the above mentioned motions. Derive the expression for velocity and acceleration during outstroke 10. This must be done at a scale of 1:1 to use it to generate the cam profile. (M/J 2009) The four profiles normally used in cams are i. 1. SHM, Uniform velocity, Uniform acceleration and retardation and Cycloidal motions Knife-edge, Roller, Flat-faced and Mushroom followers. The cams are usually rotated at uniform speed by a shaft, ... in contact with the nose of cam. 9. Uniform velocity, 2. Construction of Cam Profiles. = 25 mm; Angle of action of cam = 150o and cam shaft speed = 600 rpm. The path of UAR is parabolic and can be drawn using the rectangle method. Understand the applications for all the curves constructed. The follower may be placed at any angle that reciprocates on a line which passes through the centre of the cam shaft. 1.1 Definitions Related to Cam: The following terminologies are used to draw cam profile. Cycloidal motion. Due to infinite accelerations, high inertia forces will be created at the start and at the end even at moderate speeds. Tangent Cam with Reciprocating Roller Follower. Draw the profile of a cam with oscillating roller follower for the following motion : (a) Follower to move outwards through an angular displacement of 20° during 120° of cam rota- tion. the cam profile are same whereas for a roller follower, they are separated by the radius of the roller. We shall now discuss the displacement, velocity and acceleration diagrams for the cam when the follower moves with the above mentioned motions. The valve must remain in the fully open position for 20^{\circ} of cam rotation.