## Design a helical extension spring to handle a dynamic load that varies from 60 lb to 75 lb over 0.5-in working deflection.

1.       Design a helical extension spring to handle a dynamic load that varies from 60 lb to 75 lb over 0.5-in working deflection. Use music wire and standard hooks. The forcing frequency is 1 200 rpm. Infinite life is desired. Minimize the package size.

2.       Choose appropriate safety factors against fatigue, yielding, and surging. Design a straight-ended helical torsion spring for a static load of 50 N-m at a deflection of 60° with a safety factor of 2. Specify all parameters necessary to manufacture the spring. State all assumptions.

### design suitable bearings to support the load for at least 5E8 cycles at 1 200 rpm using deepgroove ball bearings.

The shaft shown in Figure P11-4 was designed in Problem 10-19. For the data in row (a) of Table P11-1, and the corresponding diameter of shaft found in Problem 10-19,….

### Find the minimum film thickness for a long bearing with the following data: 30-mm dia, 130 mm long, 0.0015 clearance ratio, 1 500 rpm, ISO VG 100 oil at 200°F, and supporting a load of 7 kN.

1.       A paper machine processes rolls of paper having a density of 984 kg/m3. The paper roll is 1.50-m OD X 22-cm ID X 3.23-m long and is on a simply supported, 22-cm OD, steel….

### Find the minimum film thickness for a bearing with these data: 30-mm dia, 25 mm long, 0.0015 clearance ratio, 1 500 rpm, ON = 30, ISO VG 220 oil at 200°F.

1.       Problem 7-12 estimated the volume of adhesive wear to expect from a steel shaft of 40 mm dia rotating at 250 rpm for 10 years in a plain bronze….