Ok, maybe not this kind of key: The function of the key, used in torque transmission

We see many different mechanical parts daily, but we dismiss the functionality of them. Let discuss the functionality of such components, in particular the shaft and other mechanical parts associated with the key.

 Have you ever wondered why this key is used? 

The key is the machine element used to connect the shaft with other machine elements such as gears, pulleys, couplings, sprockets or flywheels. The key prevents relative rotation between the two components and can initiate torque transmission.

Both the key shaft and the machine element need to be connected. This is called a keyway. These joints are subject to temporary fastening elements and are subject to crushing and shearing stress.

Different types of keys are used in power transmission, square key, flat key, dowel key and so on.

Why key used?

Suppose we have a situation where the key is not used in the power transmission as shown in the picture below. When there is a sudden increase in torque, there is a possibility of slipping between parts.

This ensures that the connection does not interfere with load, power and rotation and delivers the required design accuracy. Jointless part slip and the capacity decreases.

The key is responsible for preventing rotation between the shaft and the bore and contains a portion of the torque load for the key. Torque transmission through keys is the most common and widely used method of power transmission. Unfortunately, mechanical failures can occur due to incorrect keys and keys. Therefore, to ensure optimal alignment, the standard key and dimensions of the keyway width and height should follow the recommended tolerances. There are major sizing industry standards in various burrows for English and metric systems.

Therefore, the keys and hinges on the power transmission shaft have two essential functions:

  • Prevent the shaft from turning in the bore
  • Turn on the power transmission by torque

The key prevents relative rotation between the two components and can initiate torque transmission. For a key to work, the shaft and rotating machine element must have a key and key, which must fit the slot and pocket key.