Rotary vane vacuum pump 3D model is available on CGTrader for $9. Original author: Dufe. Specs: 5668 polys, 2810 verts.
STL (Stereolithography, filesize: 277 KB), OBJ (OBJ, filesize: 805 KB), IGE (IGES, filesize: 2.3 MB), DWG (AutoCAD, filesize: 492 KB), FBX (Autodesk FBX, filesize: 158 KB), MAX (Autodesk 3ds Max, filesize: 868 KB), STP (STEP, filesize: 1.1 MB)