Hi Guys
The next part in line is the yoke that connects the displacer piston to the connecting rod. This is basically a sheet metal part but the size does make it kind of fussy.
Here is a 3d screen shot of part in question.
I cut out the blanks on the laser at work, notice that I put the two small holes in the flat. While I thought this was a good idea it ended up being a problem, so a second set was cut without the holes. The small holes at each end need to be very close in alignment with each other and it was difficult to put 4 bends in the part and have them come out that way. So these ended up being test parts.
Here are a couple of the parts after bending. I used the press brake at work to do the bends which made this job quite easy.
Here is a shot showing how tiny these are.
A 1 to 1 print out is helpful for checking angles and dimensions when setting up the brake.
The sides of the yoke where the bearing sleeves mount need to be parallel with each other so a light skim was taken off the outside of each one to just clean them up.
Then the yoke was mounted to a fixture block the 2-56 holes drilled and tapped. Only one hole was done at a time then the part was flipped over and the other one done. Each time before the part was removed the block was transferred to the UPT and the hole tapped.
Next the hole for the displacer piston is drilled.
This is a pretty crappy picture but what I’m doing here is taking a skim across the surface where the piston rod seats. The yoke was indicated level using the bearing sleeves to insure when mounted to the piston the bearing sleeves will be parallel to the axis of the crankshaft.
Here is one completed set, the sleeves are made from tool steel and are hardened and polished. Like in many other places on these engines the screws also had to be made.
And finally here is a photo of the yoke and bearings installed on one of the connecting rods.
Thanks for stopping by, more to follow.
Dave
