# Power Transmitted by a Shaft

## 314 Maximum Shear and Relative Gear Rotation of a Compound Steel Shaft

## 309 Finding the Diameter of a Propeller Shaft Transmitting a Power

**Problem 309**

A steel propeller shaft is to transmit 4.5 MW at 3 Hz without exceeding a shearing stress of 50 MPa or twisting through more than 1° in a length of 26 diameters. Compute the proper diameter if G = 83 GPa.

## 308 Maximum Horsepower That Can be Transmitted by Steel Shaft

**Problem 308**

A 2-in-diameter steel shaft rotates at 240 rpm. If the shearing stress is limited to 12 ksi, determine the maximum horsepower that can be transmitted.

## 307 Power Transmitted by Solid Steel Shaft of Unknown Diameter

**Problem 307**

A solid steel shaft 5 m long is stressed at 80 MPa when twisted through 4°. Using G = 83 GPa, compute the shaft diameter. What power can be transmitted by the shaft at 20 Hz?

## 306 Maximum Shearing Stress of Marine Propeller Shaft

**Problem 306**

A steel marine propeller shaft 14 in. in diameter and 18 ft long is used to transmit 5000 hp at 189 rpm. If G = 12 × 10^{6} psi, determine the maximum shearing stress.

## Torsion

**TORSION**

Consider a bar to be rigidly attached at one end and twisted at the other end by a torque or twisting moment T equivalent to F × d, which is applied perpendicular to the axis of the bar, as shown in the figure. Such a bar is said to be in torsion.