The endplates are bolted onto the side of the tilt pad bearing shell. They contain the oil and prevent axial movement of the pads. Check out page 5 of this link for a picture.
http://magnetic.waukbearing.com/__data/page/550/DHB10.pdf
I am trying to determine what the diametrical clearance for the endplates of a 5.25" ID tilt pad journal bearing should be. The assembled bearing clearance is .008" so the endplate clearance must obviously be something larger than this. I've found lots of literature on titl pad bearing design...