US Patent 10088034 Double-nut cooling ball screw

A double-nut cooling ball screw includes two nuts threadedly engaging with a threaded shaft and having connecting end portions facing toward each other and cooling channel assemblies in fluid communication through coupling holes in the connecting end portions, and a spacer interposed between the connecting end portions and having notched recesses for accommodating guiding assemblies. Each guiding assembly is rotatable relative to the nuts between a non-stored position for facilitating fastening thereof, and a stored position to be concealed between the nuts.