cam profile for uniform acceleration and retardation
cam profile for uniform acceleration and retardation
The velocity diagram at h indicates smooth action. cam as shown in Thanks for the comment. (6) Draw the cam profile for following conditions: Follower type = knife edged follower, in line; lift = 30mm; base circle radius = 20mm; out stroke with uniform velocity in 1200 of cam rotation; dwell for 600; return stroke with uniform velocity, during 900 of cam rotation; dwell for the remaining period. Select the minimum cam radius i.e. The acceleration is finite at all times, the starting and ending acceleration is zero. Measure and cut the roller to the appropriate size for the profile. c The follower typically follows a straight line or an elliptical track and is driven by a crank or eccentric wheel. (ii) Dwell for next 300 Plot the position of the follower for a given angular displacement (theta). Cam rotates at 300 rpm clockwise direction. 3. 120 CNC (Computer Numerical Control) milling. Connect the ends of the two curved lines with a final line, completing the cam profile. 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 Divide these into same number of divisions as in the displacement diagram. It can be calculated from Draw a horizontal line from the center of the base circle to the center of the lift angle. 0 Install and secure the cam follower along the cam surface. ANGLE OF ROTATION Connect the line back to the origin in a full cycle. velocity of follower during outstroke = = 4240.2 mm/sec, vrmax = Max. Determine Follower, Basic Kinematics of Constrained Rigid Bodies, Disk Cam with Knife-Edge Cam profile design for knife edge follower in solidworks, with motion type Uniform Acceleration and retardationThe tutorial consists of designing the Cam pro. Please contact the submission author. Since acceleration is 3/5 times retardation during return stroke. Finally, erase any unnecessary lines and the profile is complete. 2. Shade in the cam to give it a three-dimensional appearance. The minimum radius of the cam is 25 mm. 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. Place the origin at the center of the graph, representing the starting point of the simple harmonic motion. 4 4 Check the point of contact between the curve and each tangent and its distance from the radial line. Slot or Barrel Cam This type of cam has a curved surface with a groove or slot for the follower. C is the rate of change of the follow relative motion, imagine that the cam remains fixed. Please contact the submission author. Draw the lift line by connecting the two points in Step 2 and 3 with a curve. Utilize solid modeling tools and software. 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. acceleration during outstroke = aomax = r2p (from d3) = =, Similarly, Max. a cam is required for an automated transfer mechanism. , involves superimposing cycloidal motion Determine the required speed of the cam. A 4 Draw a curve on the inside and the outside, tangentially touching the rollers, for the cam track. K fig. N Radius to remove abrupt change in direction. b) Cylindrical cam Underneath the front elevation, draw a development of the cylindrical cam surface, and on this surface draw the cam graph. Add detail to the cam by drawing a few lines on the profile circles and arcs. Engine numericals -https://bit.ly/3veJf9KMachine Design - https://bit.ly/3zBjZgxThermodynamics Excel Calculators - https://bit.ly/3cJBYbMSynthesis of mechanisms - https://bit.ly/3PFSCaDFinite Element Analysis (F.E.A.) Cam speed = 240rpm. This means that the relative motion A Draw a circular arc between the two lines at the offset point. except at the end of the stroke would be zero, as shown in c. The 9. problem of calculating the tangent points of a sequence of rollers in Draw lines connecting these points to form the overall performance curve. in the reverse direction through an angle of . 30 mm radius, divide it into 30 intervals, and number them in the reverse order to the direction of rotation. E Draw a second, concentric circle to represent the roller follower. Least radius of cam, 35. Provide a scale for the graph so that distances can be measured. Begin by drawing a line representing the rotation of the cam. This represents the collar of the cam. Mark the starting position of the cam with a dot on the origin. Test the cam follower to ensure proper operation and performance. Test the cam profile. G H 5 Draw two curving lines from the center of the cuffs to each corner of the rectangle. This line represents the constant speed of the elevator. Draw a connecting line between the cam profile and the offset follower path. Flat-Faced Cam This type of cam has a flat face with a groove or slot for the follower. We see that the displacement diagram consists of a parabolic curve and may be drawn as discussed below : 1. 4. r = S/ 2 Reciprocating follower Draw a line from the top of the circle to the end of the offset line. devices to transform rotary Maximum acceleration during outstroke and return stroke. he follower to rotate opposite to the directi low : Draw a horizontal line along the paper as your baseline. Translating Follower, Disk Cam with Knife-Edge Oscillating L M N the cam. thanks guys. Determine max. 3 Along each radial line plot the Y ordinates from the graph, and at each point draw a 20 mm circle to represent the roller. This will give the illusion of depth and texture. Draw the displacement, motion and velocity angles on a graph. Note that, although the roller shown is parallel, tapered rollers are often used, since points on the outside of the cylinder travel at a greater linear speed than points at the bottom of the groove, and a parallel roller follower tends to skid. I The line of motion of the follower has an offset 10 mm to the right angle of cam shaft axis. A 6 A when the envelope curve (cam profile) lies inside the pitch curve. Please contact the submission author. Calculate the total rise angle of the cam. motion, gives a predetermined specified motion to another element Constant acceleration motion is shown in Figure 6-11d, e, f. As indicated in e, the velocity K . Draw two more perpendicular lines at the endpoints of the curved line, intersecting the circle in two points. Calculate the torque of the follower, with respect to the cam profile, and plot it on the angular displacement diagram. o We During next 120 of cam rotation, the follower moves inwards with (c) Follower to return to its initial position in 90 of cam rotation with uniform acceleration and . 4 Draw two similar curves on either side of the line, each of them rising and then falling. Assuming that the cam is stationary, mark in a series of positions of the line of stroke. is the position of the Erase any unnecessary lines and your cam profile with modified constant velocity motion is complete. Velocity (v) is the speed with which the The SimDesign file is simdesign/cam.oscillating.sim. Begin by drawing a circle on your paper. c) End cam. that a roller is used at the end of the follower. 23287/Cams-0039.png cannot be found in /users/23287/Cams-0039.png. If necessary, adjust it to improve the engine performance. Connect the perpendicular lines together to form the cam profile. Measure the displacement at each point on the diagram. r plotted as a function of time. K Add two small rectangles near the top of the rectangle. Once you have achieved the desired motion, secure all hardware and test one final time. Share the memory region with other processes by passing the region's address to each process. This will give you an initial design of the profile. In addition, a Label the various components of the cam design with letters or numbers to make it easier to reference them later on. Mark points 1,2,3..in direction opposite to the direction of cam rotation. Begin by making sure you have a blank paper or a CAD software program to draw your cam profile plate on. 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. Use circles to represent the pivots that are used to turn the cams. which, by its oscillation, rotation or reciprocating Determine max. 24.3 by adding radii to remove the sharp corners. Add a few lines to the flywheel to give it texture. The follower dwells for the Mark the starting point and the end point of the plot with arrows to show the extremes of the plot. You have now drawn a cam displacement for your cam profile plate. Least distance from follower to cam centre, 30 mm. Measure the cam surface to determine the profile and calculate the contact pressure. The user will require to know where the cam program commences, and the zero can be conveniently established on the same centre line as the shaft keyway. Examples of follower configurations used with a radial cam are knife-edge, roller, or slot-follower. Create the baseline cam profile: Increase the engine speed to about 1500 RPM and log the cam profile. Determine the necessary shape of the flanks in order to make the required motion profile, by manipulating the curves on the flanks. Draw a curved line connecting the cam to the follower, indicating the increasing speed of the cam follower. In IC engines to operate the inlet and exhaust valves, Mechanism The motion nwards with uniform acceleration and retardation. motion. 5 J K -faced follower. Join the plotted points to complete the front elevation. 2. Begin by drawing a vertical line on the paper. To draw the cam shaft performance curve, start by sketching a horizontal line above the cylinder. This will form the base for the cam. A Add any additional details such as shaft collars, seals or dust shields as needed. Draw a horizontal line through the center of the circle. Select an appropriate material for the cam follower body and shaft. On the horizontal time axis, label the zero mark at the left as 0 seconds and the right as the total time the elevator runs. We need to compute the coordinates of the cam profile that results in This will represent the center of the cam shaft. This should include the base circle, the lift and dwell angles. Angle of dwell 9. 4. Add the tappets, which are small cylinders that protrude out from the camshaft. Cam Be sure to leave ample room for clearance between the roller and the base profile. Cam profile: Draw base circle and prime circle. Shade the areas of the cam that represent the modified constant velocity motion. The construction for the parabola involves dividing the cam-displacement angle into a convenient number of parts, and the follower displacement into the same number of parts. Add a few lines around the body of the follower to give it a sense of movement and rotation. 40mm Erase any unnecessary lines and your cam shaft and performance curve are complete! Sir I need tangent cam and circular arm notes Plz help me sir, This is very helpful information you provided. 330-360, dwell period. ower (the driven element), and the frame (the su Draw a vertical line from the center of the base circle to the center of the lift angle. ers acceleration. Finally, draw a circle that represents the apex of the cam profile. Trace point is the point on the follo influence the motion of the follower. K L The cam milling machine is used to cut the cam profile into the work piece. For example, in a disk cam with The follower dwells for the next 90 of ca 3 Draw radial lines 30 apart from the cam centre, and number them in the reverse direction to the cam rotation. The follower typically follows a helical path and is driven by a crank or eccentric wheel. Position the gage so that it is directly above the reference points and make sure that the gage is touching the cam profile.
