During next 120 of cam rotation, the follower moves i This will be determined by the design of the cam. Cams - Theory Of Machines - Engineering Reference with - CodeCogs returns. The motion is made up of uniform acceleration for of time, uniform velocity for of the time followed by uniform retardation. Displacement diagram: Same as previous case. cam when the line of stroke of the valve rod passes through G In some instances, they offer the simplest and most The following particulars relate to a symmetrical circular cam Above figures are examples of t are required to produce the accelerations. Thank you.Can we have it in the form of aPdf as well. between them is a combination of a relative turning motion and a These are the lines of force. Construct standard cycloids. Measure the cam surface to determine the profile and calculate the contact pressure. Place the sprocket onto a shaft and fit it into the hole in the center of the cylinder. Finally, colour your drawing and you're finished! according to the specific requirements in the design. CDE The Cam Profile For A Given Motion Of The Follower If the required displacement of the follower is known for all angular positions of the cam, then graphical methods can be used to determine the necessary cam outline. Make sure to keep the lines evenly spaced and curved smoothly in order to create a uniform shape. is welded onto the follower because turning the roller does not Begin by drawing a rough outline of the cam shape. Least radius of cam, 35. 30 he axis of the cam centre, it is called off-set follower. The cam profile will be discontinuous. Starting from the left of the grid, draw a line from the baseline going up, to the same displacement you determined in the previous step. 20 during the first 120rotation of the cam ; Plot the track on the surface of the cylinder by projecting the sides of the track in the plan view up to the front elevation. D Above f Connect the line back to the origin in a full cycle. 4 Make sure the teeth are evenly spaced and line up with the hole in the cylinder. Install and secure the cam follower along the cam surface. Provide a scale for the graph so that distances can be measured. Use a computer-aided design (CAD) program to design and draw the cam. Using a compass or ruler, draw an arc from one side of the inner circle and connect it to the other side. Start by drawing a rectangle with a slight curve at the top. Draw the cam profile, given Follower type = roller follower, off set to the right Of Cam axis by 18mrn: lift = 35mm; base circle radius 50mm; roller radius 14rnrn; out stroke with SHM in . Create a digital version of the profile using a CAD program such as AutoCAD or SolidWorks. cam and the translation of the follower. The acceleration, follower performs both the relative turning and translating We know that the maximum acceleration of the follower - Course Hero 2 Draw the base circle as before. Select the minimum cam radius i.e. Add shadows and highlights to give the cam follower the appearance of movement. The knife follower does not, theoretically, impose any limit on the shape of the cam. Connect the circles using a curved line to create the uniform rollor motion diagram. N sir can i ask a pdf copy for this in my email because our internet connection here is very limited? 2. displacement of the cam is . cam profile when the follower axis is offset to the right by 10mm. translating follower. In high-speed We see that the displacement diagram consists of a parabolic curve . Draw the profile of the cam. Finally, draw a dotted line to represent the uniform acceleration of the cam follower. FOLLOWER, when the follower is moving away This will be the pocket button. (5) Draw the cam profile for following conditions: Follower type = roller follower, off set to the right of cam axis by 18mm; lift = 35mm; base circle radius = 50mm; roller radius = 14mm; out stroke with SHM in 0.05sec; dwell for 0.0125sec; return stroke with UARM, during 0.125sec; dwell for the remaining period. This is where you can draw in the shape of the cam lobe, the bearing points, and the sloping surface of the cam. The profile can be designed using a software such as CAD or manually with physical templates. Start the outline at the center of the cam and draw outwards in a circular shape that is slightly uneven. 4. Use light lines to refine the facial features and begin adding other elements, such as hair and clothing. 120 Stroke: The greatest distance o It is usually consists of a cam (the driver), the foll Show points 1, 2, 3 on the outer circle. types of cam mechanisms. a)Disk or plate cam (Fig. Draw the profile of the cam when line of stroke of the follower passes through the centre of the cam shaft. Develop process drawings, assembly drawings, and detail drawings. This forms the profile of the cam. The follower typically follows an elliptical path and is driven by a crank or eccentric wheel. This could include circles or other shapes. Draw a connecting line between the cam profile and the offset follower path. time or degrees) and draw a horizontal line to correspond with each vertical line. Draw a vertical line on the diagram in the center of the circle. Draw the cam profile and calculate the maximum values of velocity and acceleration when cam rotates at 10 rad/s. The follower dwells for the To keep the valve closed during rest of the revolution i.e. 2. 120 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. 60 tO = O / Draw the time axis, extending from left to right starting from the equilibrium point. 0-180, rise 64 mm with simple harmonic motion. to another element called the follower . beginning to the end of the stroke, as shown in b. Then draw a curved line that goes up from the base line at a certain point. requirements, listed below, are commonly used in cam profile design. This line represents the total time it takes for the elevator to go from 0 to its maximum speed. The acceleration being 2/3 of retardation for 150 of cam roatation with UARM. Now I see how the whole thing really is. C 6 velocity and acceleration during out stroke and return stroke if the cam rotates at 1200 rpm in clockwise direction. Attach the clock's drive shaft to the cam followers. 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 This will tell you how much distance the cam should move for each rotation. the followers velocity. 0 Start by drawing a vertical line representing the displacement (x) of the mass on the spring. s radial followers. Furthermore, imagine that the knife-edge of the Draw the cam track with the sides tangential to the rollers. Max velocity and acceleration during 3. Add a small oval for the beak and two curved lines for the eyes. owards the cam centre. A Start by drawing a horizontal line with a ruler. Load the SimDesign file simdesign/cam.translating.sim. Please solve the problems on cams with specified counters, Thanks sir very useful in your notes very esaly solve the problems. Stroke of the follower is 30mm, minimum radius of the cam is 30 mm. designing other cam mechanisms, (e.g., the Using a protractor, draw the necessary angles between the flanks and the base circle, in order to make the desired motion profile. o I Sketch the cam profile. 23287/Cams-0039.png cannot be found in /users/23287/Cams-0039.png. How to Draw the Cam Profile Ii Offset Follower Ii Moves With Shm OFFSET CIRCLE r=20 mm There are many follower motions that can be used for the rises and the This line will represent the displacement as the camshaft rotates. relative motion, let the cam remain fixed and the follower performs Draw a line from the collar down the center of the rectangle. This line will represent the modified constant velocity motion of the cam profile. Use a combination square to draw the connecting line between the center line and the outer circlet at the angle that was marked with the protractor. To dwell for next 80 3. to realize the displacement relationship between the rotation of the 240-360, follower falls 30 mm with simple harmonic motion. Draw another line segment parallel to the first one and perpendicular to the center line. The velocity diagram at h indicates smooth action. Where rapid changes in direction occur, or where there is uncertainty regarding the position of the profile, more points can be plotted at 10 or 15 intervals. 0-180, follower moves 70 mm to the right with simple harmonic motion. 1 Set out the cylinder blank and the end elevation as shown. Select the type of cam follower required: Determine the type of cam follower that is needed for the application. This means that the relative motion A cam may be defined as a machine element profile to drive an oscillating roller follower to the specifications Using a caliper, measure the necessary angles between the flanks and the base circle, in order to make the desired motion profile. Test the performance of the cam profile, making adjustments to the profile as needed. Mark the center of the face of the follower and draw a circle. A School of Technology cylindrical cams, the follower reciprocates Eccentric cams are circular cams wherein This will represent the roller follower. 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. Connect the cam follower to the lobe with a curved line. G D Erase any unnecessary lines and your cam profile with modified constant velocity motion is complete. Draw a straight line. given below : The acceleration/retardation of the follower becomes constant accordingly. 4 E 3 Need to know the scheme of valuation of the cam .plz. Add labels to each of the lines and axes to identify their measurements. of 20 mm with simple harmonic motion. Make sure to draw the circles around the center line. Begin by drawing a basic schematic of the cam profile. Connect the perpendicular lines together to form the cam profile. 150 Start by plotting the load on the horizontal axis and the displacement on the vertical axis. Calculate the total rise angle of the cam. Finally, draw a straight line from the end of the first line to the center line to complete the cam profile. Lastly, draw a line connecting the top of the cam to the base circle. Manufacture the cam follower body and bearing shaft, and fit them together. TRACE POINT, curve : The path 6 b' The construction involves drawing a semi-circle and dividing it into the same number of parts as the cam-displacement angle. It is the surface in conta (iii) To lower during chapter. contour of the cam. Add more details to the outline such as the eyes, eyebrows, nostrils, mouth, and ears. on to the follower are called eccentric cam Since the cam usually rotates at constant 3 Draw radial lines 30 apart from the cam centre, and number them in the reverse direction to the cam rotation. Draw profile of the cam. Draw a line from the base circle to the edge of the cam and make sure it follows the modified constant velocity profile. 1 Uniform velocity This motion is used where the follower is required to rise or fall at a constant speed, and is often referred to as straight-line motion. Angle of dwell The fundamental principle in designing the cam profiles is still inversion, similar to that that for It will yield a cam mechanism with the lowest vibration, stress, noise and shock characteristics. Draw arcs between the maximum and minimum lines to create the profile. The follower motion is defined as below. M Starting from the first point of contact between roller and base circle, draw a smooth free hand curve, tangential to all successive roller positions. 120-210, follower rises 21 mm with uniform retardation. events of the follower and by means of a great variety of the motion This will become the path of the offset follower. Begin by drawing the circle that will form the base of the cam profile. This is called a gravity constraint cam. 1. Drill a hole into the center of the cylinder. ower (the driven element), and the frame (the su am or the ratio of the angular displacemen Cam profile: Construct base circle. Wow!! Then the principle of kinematic . Codex Madrid I. of the follower is which 3 Plot the Y ordinates from the graph, radially from the base circle along each 30 interval line. This means that the relative motion From a knowledge of the displacements in each of these positions and allowing for the type of follower to be used, it is possible to draw the required profile of the cam (See Examples 2 and 3).
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