I am very fluent with SketchUp for my mechanical engineering needs. What I need is to make the parts move as in this Tiktok videos:
Would be grateful for an advice!
Blender 3D is a free and open source animation software that despite not being specifically targeted at CAD work, Solid modelling or mechanical rigging, is great at animation rendering and presentation, and should be able to do what you require.
It can import various mesh file formats or you can model them directly inside Blender.
An alternative is FreeCAD which is a proper solid based parametric CAD in the same vein of SolidWorks. Presentation is not its focus, so while not aimed at animation and rendering it can make gears and animate them.
You can also combine both softwares into your workflow, by taking advantage of solid based tools of FreeCAD for modeling, then export it as STL file format, import it into Blender, and take make use of tools for the animation and aesthetic side of the job.