InsaneHydraulics - Sergiy Sydorenko © 2009-2012 All Ridghts Reserved
What is the first thing that comes to your mind when you hear the word
"flathead"? I bet you are thinking about either a screwdriver, or an
engine configuration, or a fish... or maybe that neighbor of yours with
his "funny" hairdo...
Well, after looking at these pictures there will be one
more "flathead related" entry in your associative vocabulary.
Check out this rotary group from a Rexroth A4V closed loop pump. The piston heads got worn out completely flat (hence - "flathead"), and also the swashplate got this peculiar radial crack pattern - something I've never seen before and still not sure what exactly caused the appearance of the cracks.
In any case they look cool.
Add-on from 16 May, 2012:
I received several emails concerning this breakdown, and all say the same thing -
this pattern is no news, and the radial cracks are the result of local overheating of the swashplate surface, caused by insufficient lubrication between the piston shoes and the swashplate,
caused by the excessive oil temperature.
Many thanks to Davis (Canada), Kevin (USA) and Doug (Canada) for their professional opinion and valuable contribution to this post.