Hi @Robertk and welcome, I reckon you’d best post a photo of the broken gear and surrounding area, it may help some one to identify the gear and solve this issue for you much quicker..
I reckon every printer is worth saving if you like to work with it, you could try removing some parts to gain more access to the gear, then try repairing the gear with some Araldite adhesive and leave overnight to dry before testing it out..