1. For the design result you found in solving a. Find the friction drag torque. b. Find the power dissipated as a result of friction drag. 2. A hydrodynamically lubricated plain bearing is to be designed for a machine tool application in which a rotating steel spindle must be at least 1.00 inch nominal diameter,…

1.A hydrodynamically lubricated plain bearing is to be designed for a conveyor-roller support application in which the rotating cold-rolled steel shaft must be at least 100 mm nominal diameter and the bushing is to be made of poured babbitt, reamed to size. The radial bearing load is to be 18.7 kN. The desired ratio of…

1. A helical idler gear (see Chapter 15) is to be supported at the center of a short hollow circular shaft using a single-row radial ball bearing. The inner race is presses on the fixed nonrotating shaft, and the rotating gear is attached to the outer race of the bearing. The gear is to rotate…

1. Repeat problem 12-7 if everything remains the same except that the power screw has double square threads. 2.A 40-mm rotating power screw with triple square threads has a pitch of . The screw is to be used to lift a 22 kN load at a speed of 4 m/min. Friction coefficients for both the…

1. A 20-mm power screw for a hand-cranked arbor press is to have a single-start square thread with a pitch of 4 mm. The screw is to be subjected to an axial load of 5 kN. The coefficient of friction for both threads and collar is estimated to be about 0.09. The mean friction diameter…

1.You have been assigned the task of examining a number of large flood gates installed in 1931 for irrigation control at a remote site on the Indus River in Pakistan. Several large steel bolts appear to have developed cracks, and you have decided that they should be replaced to avert a potentially serious failure of…

1.A high-speed “closing machine” is used in a tomato canning factory to install lids and seal the cans. It is in the middle of the “pack” season and a special bracket has separated from the main frame of the closing machine because the -24 UNF-2A hex-head cap screws used to hold the bracket in place…

1.A standard coarse-thread metric cap screw made of steel has a major diameter of 10.0 mm. If a torque wrench is used to tighten the cap screw to a torque of 35 N-m, estimate the axial preload force induced in the cap screw. It may be assumed that the coefficient of friction is about 0.15…

1.A -20 UNF-2A SAE Grade 2 steel cap screw is being considered for use in attaching a cylinder head to an engine block made of 356.0 cast aluminum . It is being proposed to engage the cap screw into an internally threaded hole tapped directly into the aluminum block. Estimate the required length of thread…

1. You are asked, as a consultant, to determine a procedure for finding a “best estimate” for the design stress to be used in designing the helical-coil springs for a new off-the-road vehicle. The only known information is: ( 1. ) The spring material is a ductile high-strength ferrous alloy with known ultimate strength, ,…