Three-planet 4:1 gearbox open assembly
3D model · STEP · 6.1 MB
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Source: Innerscene - original model
Description
Three-planet 4:1 gearbox open assembly, modeled from published dimensions. Overall 108 x 108 x 31.5 mm. Key dimensions: module 1.5 mm; pressure angle deg 20; sun teeth 18; planet teeth 18; ring teeth 54; planet count 3; planet center radius 27 mm; ratio ring fixed 4; gear face width 12 mm; sun bore 8 mm; planet bore 6 mm; case mount PCD 100 mm; case mount holes 5.2 mm. Original three-planet arrangement: 18-tooth sun, three 18-tooth planets, internal 54-tooth ring. Ring fixed gives 4:1 sun-to-carrier reduction. Three equally spaced planets satisfy (18+54)/3 = 24 for assembly phasing. Spline-fitted 20-degree involutes and selected backlash. Case, carrier, pins, washers and gears are separate solids; the lower housing clears the rotating carrier. Bearing races, seals, fasteners and lubrication are omitted. No load rating or manufacturing gear class is claimed. Exact solid STEP geometry in millimeters, opens in any CAD system. Export to STL, OBJ, GLB and other formats from the viewer. Nominal dimensions for layout, fit checks and visualization; they do not establish a manufacturing tolerance class, load rating or standards certification. Original Innerscene model, released CC0.
File: planetary-open.step · added 2026-10-05 · available until 2030-10-05. Added from Innerscene - original model under its CC0 dedication; see the library terms. Think this part infringes someone’s rights? Use Report on the viewer page or see our copyright policy.