This simulator models an ideal open flat-belt transmission at pitch radii between two coplanar pulleys — driver and driven — including wrap angle, tight/slack-span tension, imposed slip and a capstan-relation traction audit. Adjust pulley diameters, center distance, driver speed, tension demand and friction coefficient, and watch speed ratio, torque, power and traction feasibility develop.
• A real-time 3D cutaway workbench of the machined driving pulley and input shaft, driven pulley and output hub, an open flat belt with moving surface markers across exact tangent spans and wrap arcs, tight/slack-span tension indicators, a center-distance adjustment slide, and two shaft-support bearing blocks with a removable transparent guard, with home view, focus-selected-part, full-enclosure/cutaway toggle, exploded view, auto-rotate, expand and show/hide labels controls. • An Equipment laboratory tab with a labeled parts index (driver, driven, belt, tension, slide, supports, audit) and click-to-inspect component callouts, plus a live driver/driven speed-comparison chart. • Fixture controls: driver speed (0–1800 rpm), driver pitch diameter (60–180 mm), driven pitch diameter (80–300 mm), shaft center distance (350–800 mm), imposed driven-side speed slip (0–20%), tight-span tension (100–500 N), slack-span tension (20–90 N) and flat-belt friction coefficient (0.1–0.6). • Playback controls: pause/resume, 0.1 s and 1 s step, five speeds (100× and 10× slow motion, real time, 10× faster, 1 minute per second), plus start/stop, reset-imposed-slip and reduce-tension-demand quick actions. • A Curves & measurements tab with two live charts (driven speed; input/delivered power and slip loss) plus the underlying model equations (wrap angle, exact open-belt pitch length, no-slip and slip-adjusted speed, torque from tension difference, capstan traction limit) and snapshot readouts for fifteen metrics including required tension ratio and traction-limit pass/fail. • An Experiments tab with four guided fixtures (nominal 2:1 reduction, equal pitch diameters, imposed slip, insufficient traction) and a Model verification bench that runs independent deterministic checks against a fresh model without disturbing your live trial, plus a timestamped event log and a copyable trial report. • A Learn & assess tab with guided lessons, a knowledge-check quiz with reset, and a written model-scope statement with a referenced technical background link.
With no slip, belt speed at the pitch line is conserved between pulleys: π·D1·n1 = π·D2·n2, so the no-slip driven/driver speed ratio depends only on the two pitch diameters — changing center distance changes wrap angle and required belt length, but leaves that ratio unchanged. An open belt (as opposed to a crossed belt) also preserves rotational direction between the two shafts.
Driver torque comes from the tension difference across the two spans acting at the pitch radius: Torque = (Ttight − Tslack)·r. The same tension difference acts at the driven pulley's larger or smaller pitch radius, which is why changing the driven diameter changes delivered torque for the same tension difference even though speed ratio depends on the diameter ratio alone.
The capstan relation sets an ideal friction limit on how large a tension ratio the smaller wrap angle can sustain without slipping: Ttight/Tslack ≤ exp(μ × min(θ1, θ2)). The simulator's traction audit compares your specified tension demand against this limit and flags an infeasible operating point rather than predicting an actual slip percentage — imposed slip is a separate, independently specified teaching input, not something the model derives from friction physics.
This is an ideal open flat-belt model at pitch radii with coplanar shafts and prescribed steady speed and tensions. It excludes V-groove wedging, tooth engagement, centrifugal tension, belt elasticity, creep and vibration; slip occurs only at the driven side by prescription while driver-side belt speed is retained, and friction coefficients are teaching parameters rather than material certification values.
No. The no-slip speed ratio is set entirely by the two pulleys' pitch diameters (π·D1·n1 = π·D2·n2). Center distance changes wrap angle and the required belt length, but not that diameter-based ratio.
No. The capstan relation only checks whether your specified tension demand is feasible given the friction coefficient and wrap angle — it flags an infeasible operating point rather than predicting a real slip rate. This simulator lets you impose slip independently so you can compare the two effects.
Torque at each pulley equals the tight/slack tension difference times that pulley's own pitch radius. A larger driven pulley multiplies the same tension difference into more torque, even though the no-slip speed ratio depends only on the diameter ratio, not on either radius alone.
No. It models an ideal open flat belt at pitch radii only. V-groove wedging, tooth engagement, centrifugal tension, belt elasticity, creep, vibration and wear are all outside this teaching model's scope.