A Double-threaded Acme Screw Of Known Major Diameter Is Used In A Jack Having A Plain Thrust Collar Of Known Mean Diameter. Coefficients Of Running Friction Are Estimated As 0.09 For The Collar And 0.12 For The Screw. Assume That The Starting Friction Is About 1/3 Higher Than Running Friction (a)Determine The Pitch, Lead, Thread Depth, Mean Pitch Diameter, And Helix Angle Of The Screw (b)Estimate The Starting Torque For Raising And For Lowering A 4000 N Load (c) Lf The Screw Is Lifting A 4000 N Load, Determine The Efficiency Of The Jack Double-threaded

Question-Answer › Category: Machine Design › A double-threaded Acme screw of known major diameter is used in a jack having a plain thrust collar of known mean diameter. Coefficients of running friction are estimated as 0.09 for the collar and 0.12 for the screw. Assume that the starting friction is about 1/3 higher than running friction (a)Determine the pitch, lead, thread depth, mean pitch diameter, and helix angle of the screw (b)Estimate the starting torque for raising and for lowering a 4000 N load (c) lf the screw is lifting a 4000 N load, determine the efficiency of the jack Double-threaded

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Mazurek Gravity Staff asked 2 months ago

A double-threaded Acme screw of known major diameter is used in a jack having a plain thrust collar of known mean diameter. Coefficients of running friction are estimated as 0.09 for the collar and 0.12 for the screw. Assume that the starting friction is about 1/3 higher than running friction (a)Determine the pitch, lead, thread depth, mean pitch diameter, and helix angle of the screw (b)Estimate the starting torque for raising and for lowering a 4000 N load (c) lf the screw is lifting a 4000 N load, determine the efficiency of the jack Double-threaded