The crank rocker linkage is one type of which linkage?

The crank rocker linkage is classified as a four-bar linkage. A four-bar linkage consists of four links connected in a closed loop with four joints. Each link can rotate about its joint, allowing for a complex range of motion. In the case of the crank rocker linkage, it specifically includes a driving crank, a rocker arm, and two fixed frames.

The configuration allows for rotary motion to be transformed into oscillatory motion, making it suitable for applications such as in mechanical presses or in the design of certain types of engines where converting rotary input into linear motion is required. This makes it a versatile mechanism in mechanical engineering, helping to demonstrate relationships between input and output in motion.

In understanding why the other choices are not applicable, it's clear that a single bar linkage would not provide the necessary complexity for defining a crank rocker, and a three-bar linkage does not encapsulate all the required components to meet the definition of a crank rocker system. Additionally, while a double rocker linkage consists of two rockers moving without a crank, the crank rocker specifically includes a crank as one of its components, solidifying its classification as a four-bar linkage.