Which type of friction bearing can be installed at any position on a shaft?

The correct choice of a split journal bearing is significant due to its design and functionality. A split journal bearing consists of two separate halves that can be easily installed around a shaft, which allows for flexibility in positioning along the length of the shaft. This capability is particularly advantageous in applications where access is difficult or when maintenance is required, as it can be installed without needing to remove the entire shaft from the assembly.

In contrast, thrust bearings are designed to specifically handle axial loads and wouldn’t typically be positioned anywhere on the shaft as they're more suited for applications requiring control of thrust. Moreover, plain bearings, while versatile, generally require more precise alignment and are more challenging to install once in position. Roller bearings, designed to support both radial and axial loads, are also less adaptable than split journal bearings regarding positioning during installation or maintenance.

Thus, the split journal bearing stands out due to its adaptability in being installed at any location along the shaft, effectively addressing various mechanical needs in rotating machinery.