This a gyratory crusher for limestone, 1200 tph. The problem is that the upper mantle is turning around the main shaft. I guess the backing material is gone, but I was wandering if the mantle locking mechanism is also gone. My guess is that the locking device is damaged and that's why the mantle is turning. What types of locking mechanism exist? the manual of the crusher does not mention anything about it.
Aren’t thr jaws bedded in an epoxy material ? If that epoxy starts to crumble it isn’t long before it is gone. I think the jaws have a keyed profile so that the epoxy is under compression also . Maybe whoever last replaced the jaws was short on the epoxy and thought “that’s good enough”. Unless the jaw or mantle (?) is cracked or broken that’s all I can help you with. I only helped a few times on the crusher and didn’t get taught much— only told “do this; don’t do that”