Old sliding door roller assembly
Thanks for posting. Looking at your patio roller, it seems it might be just the inside portion of a complete assembly. The outer housing might still be lodged in the door. Now, without seeing the entire roller I can't be certain, but please take a look at the 81-019. This was used in Lumidor patio doors. Also see the 81-020; this was used in WT patio doors. The 81-020 roller was originally made with aluminum like yours, but later was changed to steel. If these won't fit or work for you look at the 81-272 roller and axle kit. This might be a way to also repair you rollers. Take a look at all the rollers suggested from the web site along with the related information and videos.
Glad to hear! Let us know if you need anything else, and thanks again for reaching out.