## What will the pressure angle be if the center distance of the spur gearset in Problem 12-39 is increased by 6%?

1.       Figure P12-2 shows an involute of a circle that starts at point (0, rb) and continues to point P (x, y). The angle θ is known as the roll angle and φ is the involute pressure angle. Derive expressions for the and coordinates of in terms of the base circle radius rb and the involute pressure angle only. Plot vs. over the range 0° < φ=””>< 40°=”” for=””>rb = 2 in.

2.       A 39-tooth spur gear is in mesh with an 18-tooth pinion. The pd = 8 and φ = 25°. Find the contact ratio

3.       A 79-tooth spur gear is in mesh with a 20-tooth pinion. The pd = 8 and φ = 20°. Find the contact ratio.

4.       What will the pressure angle be if the center distance of the spur gearset in Problem 12-39 is increased by 6%?

### 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….