A shaft has a constant diameter between bearing 800 mm. Located between the bearing are 2 pulleys which are keyed to shaft. One pulley has a diameter of 200 mm and weighs 80 N is located 200 mm to the right of the left bearing. The other pulley which has a diameter of 400 mm and weighs 240 N is located 550 mm to the right of the left bearing. Shaft rotates at 900rpm. Tight and slack sides of tge belts are horizontal and parallel, 18KW is supplied to the 200 mm pulley. Power is transmitted from the 400 mm pulley to another pulley located so as to give a smaller bending moment in the shaft, with belt strands horizontal as already stated. The belt stress is limited to a maximum of 2MN/m^2. Ratio of diameter of pulley to belt thickness is limited to a max of 30 . A belt thickness of 6 mm will be used. Coefficient of friction from belt and pulley is 0.3 . Shaft is made from hot rolled steel for which ultimate strength is 50MN/m^2 and yield point is 340MN/m^2. Conditions of loading are steady with no shock. Determine the necessary diameter of shaft based on strength and critical speed. Neglect the weight of the shaft and pulley for the strength calculations How do I evaluate this? Will I consider the belt tensions as load in calculating critical speed, or will the horizontal load be resolved with the vertical loads before calculating based on critical speed.
When calculating the critical speed of a system involving belts and pulleys, it is important to consider the belt tensions as part of the load. The belt tensions play a significant role in determining the critical speed and should be included in the analysis. In this context, the combined effect (resultant or equivalent load) of both horizontal and vertical loads, including the belt tensions, should be taken into account when evaluating the critical speed.
What kind of formula am i using if i have 2 plummer block bearings on both ends, a motor drive on drive end and nde (free end). I need your help on this sir.
In most of the cases we will consider the bearing as a simple support unless its a long bearing... So you can consider the shaft as a simply supported beam at both ends and consider the loads in between.... If you need the exact formula i need information regarding the nature of load... For further queries contact me @ dmecengr@gmail.com
@@themechanicalengineer thank you very much. I have a problem solving the critical speed of a centrifugal fan impeller. It is a simply supported beam with a bearing center to center distance of 3654mm, bearing portion diameter is 160mm, weight of impeller at the center is approximately 3 tons.
A shaft has a constant diameter between bearing 800 mm. Located between the bearing are 2 pulleys which are keyed to shaft. One pulley has a diameter of 200 mm and weighs 80 N is located 200 mm to the right of the left bearing. The other pulley which has a diameter of 400 mm and weighs 240 N is located 550 mm to the right of the left bearing. Shaft rotates at 900rpm. Tight and slack sides of tge belts are horizontal and parallel, 18KW is supplied to the 200 mm pulley. Power is transmitted from the 400 mm pulley to another pulley located so as to give a smaller bending moment in the shaft, with belt strands horizontal as already stated. The belt stress is limited to a maximum of 2MN/m^2. Ratio of diameter of pulley to belt thickness is limited to a max of 30 . A belt thickness of 6 mm will be used. Coefficient of friction from belt and pulley is 0.3 . Shaft is made from hot rolled steel for which ultimate strength is 50MN/m^2 and yield point is 340MN/m^2. Conditions of loading are steady with no shock. Determine the necessary diameter of shaft based on strength and critical speed. Neglect the weight of the shaft and pulley for the strength calculations
How do I evaluate this?
Will I consider the belt tensions as load in calculating critical speed, or will the horizontal load be resolved with the vertical loads before calculating based on critical speed.
When calculating the critical speed of a system involving belts and pulleys, it is important to consider the belt tensions as part of the load. The belt tensions play a significant role in determining the critical speed and should be included in the analysis.
In this context, the combined effect (resultant or equivalent load) of both horizontal and vertical loads, including the belt tensions, should be taken into account when evaluating the critical speed.
There is an error in problem 2 in calculating the uniformly distributed load
Hello sir...2nd numerical mein E= mm square hai aur baaki ka value m mein hai toh kya ...m ko phir mm mein change karn hoga
What kind of formula am i using if i have 2 plummer block bearings on both ends, a motor drive on drive end and nde (free end). I need your help on this sir.
In most of the cases we will consider the bearing as a simple support unless its a long bearing... So you can consider the shaft as a simply supported beam at both ends and consider the loads in between.... If you need the exact formula i need information regarding the nature of load... For further queries contact me @ dmecengr@gmail.com
@@themechanicalengineer thank you very much. I have a problem solving the critical speed of a centrifugal fan impeller. It is a simply supported beam with a bearing center to center distance of 3654mm, bearing portion diameter is 160mm, weight of impeller at the center is approximately 3 tons.
Would you kindly share the title of the text book you use for these notes
Theory of machines by J.K.Gupta
@@themechanicalengineer thank you
Sir e ka value is not given in tutorial 4
E = 200GN/m^2