Cam followers of the KR design are fitted with needle rollers and have a thick outer ring making them suitable for shock loads.
Concentric cam follower
The outer ring is guided via the integral flange at the head of the stud and the pressed on side washer
SKF Cam followers on the PPA design have axial slide rings of polyamide 66
These slide rings reduce the friction and give relatively cool operation that is advantageous for the grease service life
In the radial direction the slide ring forms a narrow gap to the outer ring that protects against course contaminations
Operating temperature range is -30 to +100°C
The PPA design has an improved profile of the runner surface which gives a better stress distribution, also under misaligned conditions
The PPA design has a crowned running surface
Supplied with grease nipples
Lubrication can be done at the Head or thread end, except KR 16 & 19 which can only be lubricated at the head