This simulator drives a motor, a three-to-one gear reducer and a dynamometer load, and keeps a power ledger for every stage. The power that does not become useful output is collected as heat in a single cooled thermal mass whose temperature you can watch rise toward its steady value.
• A 3D motor with cooling fins, reduction gear cutaway, dynamometer load, heat collection and a power-flow ledger. • Six sliders: electrical input (200-2000 W), motor efficiency (0.6-0.98), gear efficiency (0.6-0.98), useful-load efficiency (0.6-0.98), motor speed (300-1800 rpm) and thermal resistance (0.02-0.15 K/W). • Six live readouts: useful output, total dissipated power, overall efficiency, lumped temperature, gear-output torque and power-balance error. • Two presets: Three 80% stages (512 W useful output, 51.2% overall) and Less cooling (larger steady temperature rise and a longer thermal time constant).
Power passes through each stage: P1 = eta_m P_in, P2 = eta_g P1 and P_useful = eta_L P2, so the overall efficiency is the product eta_m eta_g eta_L and the total loss is P_loss = P_in - P_useful. Gear-output torque is P2 divided by the output speed, where output speed is the motor speed divided by 3. The lost power heats a lumped mass according to C dT/dt = P_loss - (T - 25) / R with C = 1000 J/K, so a larger R raises the steady temperature and lengthens the time constant.
Stage efficiencies are constant operating values and the shaft speed is imposed. The single thermal node is a teaching approximation, not a motor winding temperature or an equipment thermal rating. The animation is slowed independently of the shaft rpm. Lower any one stage and watch the overall efficiency fall by the same factor, then raise the thermal resistance to see temperature respond.
Efficiencies in series multiply: 0.8 x 0.8 x 0.8 = 0.512. Every stage loses a share of what reaches it, so the losses compound.
Into the thermal node. The ledger balances useful output plus dissipated heat against the input, and the dissipated power warms the lumped mass toward equilibrium.
The total loss power and the thermal resistance: the temperature settles at 25 degrees C plus the loss power times R. C sets only how fast it gets there.
It uses constant efficiencies and an imposed shaft speed. The single thermal node is not a winding temperature or a rating, and no saturation or speed-dependent losses are included.