2 Draw a smooth curve connecting the points, which will form the displacement curve. The lift of the follower is 40 mm. 120-210, follower rises 21 mm with uniform retardation. machinery, gear-cutting machines, and screw machines. Therefore, the coordinates Divide the cam into multiple sections using straight lines, and draw the modified constant velocity profile in the sections. Design the cam follower for the specific application, such as type of motion, load, speed and environment. To create a cycloidal motion in cam design 3 Plot the Y ordinates from the graph, radially from the base circle along each 30 interval line. Maximum velocity during rise and return stroke, cycloid motion Draw arrows in the direction of the motion at each interval. Since this thing is said to be a \high-speed" cam we need to keep the 2nd kinematic coe cient y00continuous between motion segments. 150 of 100 rpm is to be designed to give the motion for Constant acceleration motion is shown in Figure 6-11d, e, f. As indicated in e, the velocity Fig.4: Follower motion with uniform acceleration and retardation s = Stroke of the follower o and r = Angular displacement of the cam during outstroke and return stroke. Add details to the cam design such as slots, holes, and screws. Lift of the follower = S = length AB arc AB = = 53 mm. This line should be horizontal and represent the outer edge of the cam profile. Plate cam, rotating anticlockwise. It will yield a cam mechanism with the lowest vibration, stress, noise and shock characteristics. Next, draw a straight line along the plot showing the constant acceleration state. Position the gage so that it is directly above the reference points and make sure that the gage is touching the cam profile. The modification is to have the follower undergoing uniform accelera Determine the size and type of roller that you need for the cam. Draw arrows that point out the direction of motion at specific times. It is not possible for me to explain here. Analyze the graph to determine the characteristics of the cam, such as the velocity and acceleration of the follower. 3. pls solve the problems. 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 rotation. By this method, you ower (the driven element), and the frame (the su Draw vertical lines for the y-axis, representing the displacement or height of the plate follower. L interest. Draw two curved lines that follow the lines of the lapels. Connect the oval to the circle with a line. This should include the desired profile of the cam, showing the movement of the follower. E characteristics of the cam profile. On the vertical speed axis, label the zero mark at the bottom as 0 FPS and the top as the maximum speed that the elevator can reach. Connect the points to create a graph of the motion of the follower. B Falling Phase: As the cam continues to rotate, the follower descends back to its initial position. Draw a line perpendicular to the base line. Mark points 1,2,3..in direction opposite to the direction of cam rotation, on prime circle. machinery this is particularly important because of the forces that First, draw a curved line that follows the profile of the cam. (iii) To lower during Establish reference points at the beginning and end points of the angles. circle and the cam profile. Draw additional curved lines to indicate the feathers of the wings. Use a 3D printer or CNC machine to fabricate the cam profile from your CAD model. The cam milling machine is used to cut the cam profile into the work piece. 165K views 6 years ago How to draw cam profile & Other important videos on Theory of machines This video explains how to draw displacement diagram in case of follower motion with S.H.M. E c In radial cams, the follower reciprocates or oscillates F by modifying the motion. This is the line of displacement. Similarly Max. Mark the edges of the cam at the appropriate angles to designate each division. BASE CIRCLE r=50 mm. Make sure the teeth are evenly spaced and line up with the hole in the cylinder. machinery in which automatic control and accurate timing are 0 1 2 3 4 5 6 0 1 2 3 4 5 6 Least distance from follower to cam centre, 30 mm. By imagining This will be the center of the cam. Although the axis of the follower and the face are at 90 in this example, other angles are in common use. having a curved outline or a curved groove, The follower typically follows a circular or an elliptical track and is rotated by a crank or an eccentric wheel. Please contact the submission author. This is the basic idea of a cam. a Positive mechanical constraint To dwell for next 80 3. Choose the appropriate bearing: Select an appropriate bearing that best suits the application. Draw small lines along the grooves to increase the depth of the grooves. At this moment, the angle 0 1 2 3 4 5 6 Measure the displacement at each point on the diagram. Make the Sir I need tangent cam and circular arm notes Plz help me sir, This is very helpful information you provided. Determine the cam displacement needed by looking at the specifications of the cam profile plate. In the illustration given, point P appears to be the greatest distance, and hence the follower will require to be at least R in radius to keep in contact with the cam profile at this point. s radial followers. Add any additional details to the performance curve, such as a representation of the lift profile throughout the range of motion. M So can be calculated from equation. The fundamental principle in designing the cam profiles is still inversion, similar to that that for ing the cam to be stationary and allowing t Add any other desired features to the graph such as grid lines or a trend line. Draw a line from the base circle to the edge of the cam and make sure it follows the modified constant velocity profile. A No acceleration discontinuities, therefore it time or degrees) and draw a horizontal line to correspond with each vertical line. Develop process drawings, assembly drawings, and detail drawings. Show the locations, sizes, and shapes of these details with additional lines and circles. 4. CNC (Computer Numerical Control) milling. Draw the profile of the cam when the axis of passes through the axis of cam shaft. Draw a curved line that comes up from the corners of the pocket and meets the top of the pocket. If they match, the cam profile has been successfully measured. C acceleration during outstroke = aomax = r2p (from d3) = =, Similarly, Max. Start by drawing a straight line on a piece of paper representing the center line of the cam profile. Manufacture the cam follower body and bearing shaft, and fit them together. 20 mm diameter roller follower. Connect the cam follower to the lobe with a curved line. This line marks the center of the cam profile. Use a protractor to mark the angle between the center line and the outer circular edges. except at the end of the stroke would be zero, as shown in c. The 1 2 3 4 5 6 01 2 3 45 6 RISE DWELL RETURN DWELL coordinates of the knife edge of the follower should be (So + S, 2 Cut the cam profile onto the work piece. Draw two circles representing the rollers path of motion around the cam. 30 60 90 120 150 180 Angular displacement of cam. Measure the displacement of the cam profile at each point along the curve and label them on the curve. m rotation. 30 Calculate the acceleration of the follower, with respect to the cam profile, and plot it on the angular displacement diagram. These forces are 20 mm diameter roller follower set 20 mm to the right of the centre line for the camshaft. velocity and acceleration during out stroke and return stroke if the cam rotates at 1200 rpm in clockwise direction. Calculate the time required by the follower to reach its final position, with respect to the cam profile, and plot it on the angular displacement diagram. ANGLE OF ROTATION as a guide). Label the axis accordingly and add a title to the graph. Draw a line representing the follower displacement, starting at the origin (x=0, y=0). Sketch the desired profile on graph paper with the desired start and end points. The minimum radius of the cam is 50 mm and the diameter e can shaft is 35 mm. B These circles will be the profiles of the cam. The follower then dwells for next 90 cam rotation. important in cam profile design and is called the. This can be done by drawing a thin, straight line in the center of the cam. Draw a long, curved line from the follower's head down to its feet. This could include circles or other shapes. velocity and acceleration during out stroke and return stroke if the cam rotates at 1000 rpm in clockwise direction. Using the cam graph as the centre line for each position of the roller, draw 14 mm diameter circles as shown. Cylindrical cam, rotating anticlockwise, operating a roller follower 14 mm diameter. OFFSET CIRCLE r=20 mm 6 Draw two curved lines coming down from the collar. Draw the line of the cam followers movement. Load the SimDesign file simdesign/cam.translating.sim. 23287/Cams-0001.png cannot be found in /users/23287/Cams-0001.png. G Flat-Faced Cam This type of cam has a flat face with a groove or slot for the follower. The follower dwells for the D Finalize the cam profile: Carefully review the final cam profile and make any necessary changes to ensure that it provides the optimal performance and efficiency. Since acceleration is 3/5 times retardation during return stroke. velocity of follower during outstroke = = 4240.2 mm/sec, vrmax = Max. A follower displacement diagram is a cam center. Draw the profile of the cam. Draw a graph of the profile you have created. velocity of follower during return stroke = , vrmax = =, Max. I want to design a cylindrical cam and follower mechanism.Can you help me with the force calculations.?? A of the cam shaft. uniform acceleration and retardation and simple harmonic motion outputs; output characteristics of eccentric circular cams, circular arc cams and cams with circular arc and . This includes machining, grinding, and heat treating. segment will result in 3 This will be the cuff edges. This line should be the center of your cam profile. (a) Follower to move outwards through an angular displacement of Include the shaft size, length, and diameter. Cam cylinder, 60 mm diameter. nstant as shown in fig cam profile. G H L Draw a small circle in the center of the pocket. S = 2 r A At each of these points a,b,c draw perpendicular lines to the radials, representing flat faced followers. This line will represent the modified constant velocity motion of the cam. The weight of the follower system is sufficient to maintain contact. L Transfer points a,b,c..l from displacement diagram. 0 Divide the line into equal sections and label the sections on either side. the problem is based on design of cams and cam followers. is the motion of the follower toward the cam center. For video: https://www.youtube.com/watch?v=86PV-37Frfg, Hareesha N Gowda, Dayananda Sagar College of Engg, Bangalore, Gear measurements:- MECHANICAL MEASUREMENTS AND METROLOGY, 5.5 gyroscope effect in 4 wheeler vehicle, Unit 2 Design Of Shafts Keys and Couplings, ME6503 - DESIGN OF MACHINE ELEMENTS UNIT - V NOTES, KOM - Unit 3 -kinematics of cam mechanisms, linear transformation and rank nullity theorem, Application of interpolation and finite difference, Numbering Metals and Alloy (UNS)ASTM E 527 - 83. The basic principle of designing a cam profile with the inversion method is still used. The displacement, velocity and acceleration patterns are shown in fig.6.9. Begin by drawing the general shape of the cam follower, which is typically a curved or oval-shaped object. I (Chen 82). Some of the most common forms will be considered in this Plot the depth of the track in the front elevation from the end elevation, as shown. 30 If necessary, adjust the curve to match any additional data from the manufacturer. Cam & Profile Manthan Chavda 24.1K views74 slides Module 1 introduction to kinematics of machinery taruian 14.8K views63 slides Module 4 gears taruian 5.6K views39 slides More Related Content Slideshows for you (20) Unit 3 Kinematics of cam mechanisms Parrthipan B K 2K views CAM AND FOLLOWER Kunj Thummar 3.5K views large forces that will The drawing shows the completed cam together with a section through the vertical centre line. J The stroke of the follower is 40 mm and the minimum radius of the cam is 50 mm. KINEMATICS OF CAM AND This marks the beginning of the cam profile. (7) Draw the cam profile for following conditions: Follower type = oscillating follower with roller as shown in fig. An upward shadow on the front of the cam follower and a downward shadow on the back of the cam follower will give it the appearance of falling. Plate cam, rotating anticlockwise. Draw four symmetrical arcs extending from the base circle to the profile circle. am or the ratio of the angular displacemen To give the cam a realistic, textured appearance, draw small, curved lines in the shaded area. We can also classify cams by the different types of motion profile of the cam. This parallel line should also be horizontal and will represent the inner edge of the cam profile. rotating in clockwise direction with a uniform M 4 Follower 5 6 L Vector Art, Images, and Graphics Download. Finally, draw a dotted line to represent the uniform acceleration of the cam follower. Camshaft diameter, 20 mm. . Draw four lines connecting the profile circles. This line will represent the modified constant velocity motion of the cam. Use arrows to indicate the direction of the cam's falling motion. These are the points around which the profile will be measured. Part of a uniform-velocity cam graph is shown in Fig. compact mechanical The This line should start at one end of the rotation and end at the other. contour of the cam. The minimum radius of the cam is 25 mm. If necessary, adjust it to improve the engine performance. Draw two vertical lines coming down from the edges of the collar. In one minute, the cam rotates for 60/5.5 times. Once you have achieved the desired motion, secure all hardware and test one final time. Assume the cam turns clockwise. relative motion, let the cam remain fixed and the follower performs motions. These will be the pockets. in a direction perpendicular to the cam axis. Label the maximum displacement, the minimum displacement, and the equilibrium point of the curve. 150 ; Label the x-axis for the angular displacement of the follower in degrees and the y-axis for the corresponding displacement of the follower. To lower the valve during next 66 by uniform acceleration and retardation. thanks guys. (iv) Dwell for the remaining fig. Cut the cam profile. Thank you.Can we have it in the form of aPdf as well. 0-180, follower moves 70 mm to the right with simple harmonic motion. Erase any unnecessary lines and your cam shaft and performance curve are complete! Start by using a piece of wood and cut it into a cylinder shape, making sure that the sides are all the same thickness. This would include specifying the starting and ending points, the total travel, and the desired speed of travel. 7(a), (b) and (c) respectively. he cam. Abrupt changes in velocity with high-speed cams result in large accelerations and cause the followers to jerk or chatter. This forms the required cam profile. This will create a guide for the follower as it travels along the cam profile. 210 P 60 Start by sketching out a basic outline of the camshaft. 270-360, follower falls 30 mm with uniform retardation. Connect each line with a smooth curve to create the cam profile. We have inverted the mechanism. 9. follower in seconds, in relation to time or the rotary angle of the requirements, listed below, are commonly used in cam profile design. The acceleration/retardation of the follower becomes constant accordingly. returns. D acceleration during return stroke =. ion of cam with SHM. 5 Draw the best curve through the points to give the required cam profile. Above figures are examples of t Rise Least distance from the roller centre to the camshaft centre line, 50 mm. Determine the maximum velocity and . These are the raised portions that make contact with the tappets. 4 Draw a curved line that connects the top and bottom of the cam profile. 60 30 60 If the motion of the follower were a straight line, Figure 6-11a,b,c, it would have equal displacements 4 Plot the Y ordinates from the cam graph along each of the radial lines in turn, measuring from the base circle. 24.3 by adding radii to remove the sharp corners. This will be the pocket button. Leonardo found cam to define a knife-edge follower and a translating follower cam mechanism. The flat follower requires that everywhere the surface of the cam is convex. 4 The line of motion of the follower has an offset 10 mm to the right angle of cam shaft axis. freedom (DOF) of the mechanism, you must imagine that the roller devices are versatile, and almost any arbitrarily-specified motion can Draw a horizontal line along the paper as your baseline. will be. of the follower whose motion is the combination of the relative The translational or rotational displacement of the follower is a function 9. Using a caliper, measure the necessary angles between the flanks and the base circle, in order to make the desired motion profile. Place the compass on the line and draw a circle. In Figure 6-15, only part of the cam profile BK is shown. Select the minimum cam radius i.e. Draw a third curved line connecting the two lines in the middle. motion. Place the gage to measure the cam profile. e with simple harmonic motion. J Drill a hole into the center of the cylinder. Therefore, time for one rotation = Angle of out stroke = Angle of first dwell = Angle of return stroke = Angle of second dwell = Since acceleration is 3/5 times retardation during return stroke, (from acceleration diagram) But Displacement diagram is constructed by selecting ta and tr accordingly. velocity and acceleration during outstroke and return stroke, if the cam rotates at 600 rpm. Cam profile: Construct base circle and prime circle (25mm radius). 24.2. 0 Note also that a flat follower can be used only where the cam profile is always convex. Start with the base circle, and plot the intersecting circles at various points around the circumference, with each point corresponding to the angle calculated in step Connect the points with a smooth profile. Return Phase: At 360 degrees of cam rotation angle, the follower returns to its initial position. 5 The follower dwells for the next 90 of ca Different types of cams are presented, how to draw profile that is also discussed. (c) Follower to return to its initial position in 90 of cam rotation with uniform acceleration and . This line represents the constant speed of the elevator. Divide these into same number of divisions as in the displacement diagram. periphery of the The stroke of the follower is 2.5cm; the diameter of roller is 4cm; the minimum radius of the cam is 5cm; the line of stroke of the follower is radial and the outward and return stroke takes place with uniform equal acceleration and retardation. Adjust the gages scale to match the scale on the cam profile. Draw a vertical line from the center of the base circle to the center of the lift angle. The Utilize freehand sketching and orthographic projections. N, curve is the path traced by a p Shade the areas of the cam that represent the modified constant velocity motion. Mark points 1,2,3..in direction opposite to the direction of cam rotation. Draw an arrow indicating the direction of the motion. The angle of action for the outstroke and the return stroke is 600 each, interposed by a dwell period of 600. Angular velocity () is the speed of the c Since the cam usually rotates at constant Plot the radius at each angle on the cam profile in order to transfer the points from the displacement diagram. A cam with a minimum radius of 25 mm, The acceleration, 2 Draw a base circle 32 mm radius, and divide into 30 intervals. Without changing this feature of their The minimum radius of the cam is 25 mm. The axis of the roller and the cam fall on the same vertical line. To make the grooves more visible, add more details. Please contact the submission author. TRACE POINT, curve : The path The acceleration being 2/3 of retardation for 150 of cam roatation with UARM. (Dec 2016) Refer: "Theory of Machines and Mechanisms" by Uicker, J.J., Pennock G.R andShigley, J.E., Page No:251 - 252. paramount, the cam is an indispensable part of mechanism. Draw a line perpendicular to the first line at the point of intersection. +0. Vincis sketches in his J The follower dwells for the next 90 of ca m rotation. Please contact the submission author. Finally, draw a line from the base circle to the edge of the cam that represents the reference line. Test the performance of the cam profile, making adjustments to the profile as needed. The displacement, velocity and acceleration patterns are shown in fig. Finally erase the unnecessary lines that were drawn earlier. The construction involves drawing a semi-circle and dividing it into the same number of parts as the cam-displacement angle. ines the shape of the cam. while the cam turns 120, hold it at rest for 60, allow it to return to its original position with harmonic motion while the cam turns 120 and hold it at rest for the remainder of the cycle. Then the principle of kinematic . 1. Angle of dwell F 4. When the angular displacement of the cam is , the oscillating displacement The X axis has been drawn to scale, where 12 mm represents 30 of shaft rotation. 4 Measure the base circle of the cam, and plot the base circle on the graph paper. Draw two lines from the end of the offset line to the sides of the circle to create the path of the roller follower. School of Technology Create a digital version of the profile using a CAD program such as AutoCAD or SolidWorks. Calculate the angular velocity of the follower, with respect to the cam profile, and plot it on the angular displacement diagram. tion at the end of the constant velocity interval, so that the velocity c Transfer points a,b,c..l from displacement diagram. 6 Question: Example Problem 3 (Uniform Acceleration and Retardation Follower) A cam, with a minimum radius of 50 mm, rotating clockwise at a uniform speed, is required to give a knife edge follower the motion as described below: 1. elements, the cam and the follower, mounted on a fixed frame. 4 Least radius of cam, 30 mm. he follower to rotate opposite to the directi Cam speed = 240rpm. the two ends of the This is done to ensure that the profile is functioning correctly and moving the follower as intended. Draw the roller bearing axles and their bearings, making sure that they are rotatable. 30 Now I see how the whole thing really is. This forms the cams shape. 1 This should be aligned with the lines drawn in Steps 1-6. Finally, draw a diagonal line from the end of the time axis to the end of the speed axis. and uniform retardation for 1 in.) Draw a second curved line starting at the left mark and ending at the right mark, this line should be offset from the first line by 20 mm. b The same descends with SHM. Calculate the jerk of the follower, with respect to the cam profile, and plot it on the angular displacement diagram. Plan your cam profile. Allocate the memory region using mmap, specifying the size and protection of the region. Modified Uniform Velocity, the cam profile, we employ problem of calculating the tangent points of a sequence of rollers in Repeat the process at regular intervals along the line until the desired distance is reached. This will ensure that the profile you measure accurately reflects the profile youve programmed. Constraints on the Follower This will be the pocket flaps. Measure the cam surface to determine the profile and calculate the contact pressure. Manufacture the cam follower: Manufacture the cam follower using the appropriate materials and tools. BASIC PRINCIPLE, to give the following motion to a knife-edged follower : Draw a curved line connecting the cam to the follower, indicating the increasing speed of the cam follower. It is given that Least radius of the cam is 60 mm, Lift of the follower is 45 mm, Angle of ascent is 60 degrees, Angle of dwell between ascent and descent is 40 degrees, and Angle of descent is 75 4 Check the point of contact between the curve and each tangent and its distance from the radial line. on to the follower are called eccentric cam decreases at a uniform rate during the second half of the motion. draws the profile of the cam. 2345 effects inherent from the uniform velocity can be reduces in this way, we have actually inverted the mechanism. The coordinates of the knife edge at this moment into any other motions is often conveniently accomplished by means of Angular velocity of cam = =104.76 rad/sec, Max. translating follower. This type of motion is not desirable for high speeds. 210-270, follower falls 20 mm with uniform acceleration. the configuration and arrangement of the follower, and the shape of 90-150, follower rises 30 mm with simple harmonic motion. L Moving to the right of the first line, draw another line from the baseline going up the same displacement as before. asses through the pitch point is called Pitch circle the cam ; K cam. 40mm K 1 0 Please contact the submission author. It is usually consists of a cam (the driver), the foll Someone will definitely do. Starting from the first point of contact between roller and base circle, draw a smooth free hand curve, tangential to all successive roller positions.
