A mechanical joint constrained to move in a straight line along guides, isolating the piston rod from the angular thrust of the connecting rod. It is essential in large, slow-speed engines and compressors to prevent the piston from wearing unevenly against the cylinder wall.
Heard on the job
The crosshead guides are scored and need to be re-machined before we reinstall the piston.
Do not mix it up with
- Trunk piston: A trunk piston connects directly to the connecting rod and absorbs side loads itself, whereas a crosshead setup uses a separate sliding block to take the side loads.