80:1 Right Angle Worm Gearbox
For engineers and OEM buyers: estimate output speed, torque and heat loss using your efficiency assumption.
What the estimate lets you decide
Use the output to frame a supplier discussion. The ratio fixes speed reduction; the remaining selection depends on the actual gearbox and load. By AMR Gearbox. Published , reviewed .
Calculation method and what remains unknown
For steady forward operation: n₂ = n₁ / 80; P₂ = P₁ × η; T₂ = P₂ × 60,000 / (2π × n₂); heat loss = P₁ × (1 − η). Power is in kW, speed in RPM and torque in Nm. Daily heat energy is heat loss × running hours.
The equations follow rotational power balance. They assume the entered mechanical input power throughout the running period and use unrounded intermediate values. Display values use four significant figures. Motor losses, starting torque, regeneration and transient temperatures are outside the model.
| Item | Basis | Needed before selection |
|---|---|---|
| Output speed | Input RPM divided by fixed 80:1 | Actual loaded motor speed and exact catalog ratio |
| Running torque / heat | Entered shaft power and assumed efficiency | Model-specific efficiency and rated output torque |
| Continuous temperature | Unknown; no heat-transfer model | Ambient, airflow, housing, oil and mounting position |
| Peak torque / service factor | Unknown; shock adds guidance only | Inertia, starts/hour and torque-versus-time cycle |
| Self-locking / braking | Unknown; not calculated | Reverse-load evaluation and independent brake specification |
Efficiency sensitivity, not a catalog curve
These three hypothetical efficiencies show why supplier data matters. They are not a measured range, guarantee or comparison of brands. All rows use 0.18 kW, 1,500 RPM, 80:1 and 8 hours/day.
| Assumed efficiency | Running torque (Nm) | Heat loss (kW) | Heat energy (kWh/day) |
|---|---|---|---|
| 35% | 32.09 | 0.117 | 0.936 |
| 45% | 41.25 | 0.099 | 0.792 |
| 65% | 59.59 | 0.063 | 0.504 |
View benchmark calculation breakdown
Benchmark baseline: 0.18 kW motor, 1,500 RPM input, 45% assumed efficiency, 8 hours/day operation under smooth load. Reproducible calculation for thermal budgeting.
Three operating scenarios to take to a supplier
| Scenario and inputs | Calculated result | Decision / next action |
|---|---|---|
| Intermittent fixture: 0.18 kW, 1,500 RPM, 2 h/day, smooth | 18.75 RPM; 41.25 Nm; 0.099 kW heat; 0.198 kWh/day | Check starting torque, holding load and on/off intervals. Low daily energy does not prove a safe peak temperature. |
| Continuous conveyor: 0.18 kW, 1,500 RPM, 24 h/day, smooth | 18.75 RPM; 41.25 Nm; 0.099 kW heat; 2.376 kWh/day | Same instantaneous torque and heat, greater daily energy. Obtain a continuous thermal rating. |
| Indexing load: 0.75 kW, 1,200 RPM, 8 h/day, heavy shock | 15 RPM; 214.9 Nm; 0.4125 kW heat; 3.3 kWh/day | Running torque excludes acceleration peaks. Send inertia, peak torque and starts/hour for service-factor review. |
Thermal review: power loss does not predict temperature
A 0.099 kW heat estimate means 99 W must leave the unit at steady state. It does not say how hot the oil will become. Request a thermal rating for the chosen size, mounting position, input speed, ambient conditions and ventilation. SEW lists these application inputs; its guidance is not a transferable rating for another product.
Do not use a universal 93–107°C limit or an arbitrary motor-power cutoff. The applicable oil, seals and gearbox manual set the operating limits. If the rated duty cannot be met, compare a larger housing, supplier-approved cooling or another gear arrangement.
Holding loads and lubricant changes require separate decisions
Compare alternatives at the same required output
Request quotes for the same speed, running/peak torque and duty. SEW explains the efficiency benefit of a helical pre-stage for its worm combinations; actual performance and cost still need a model-specific comparison.
| Arrangement | What to investigate | Tradeoff / purchase question |
|---|---|---|
| Single-stage worm | Right-angle packaging and available 80:1 sizes | Can the mechanical and thermal ratings meet this duty? Include brake and cooling costs. |
| Helical-worm | How ratio is split and efficiency at the operating point | Does reduced worm-stage loss justify the extra stage, size and quotation cost? |
| Bevel-helical | Available total ratio, running losses and mounting fit | Does energy use over the required service life justify the installed cost? Confirm holding requirements separately. |
Selection risks and practical mitigations
| Risk | What can go wrong | Smallest useful next step |
|---|---|---|
| Misuse: treating estimates as ratings | Overload, overheating or unexpected reverse motion | Obtain written torque, thermal and holding limits for a named model. |
| Cost: comparing only purchase price | Cooling, brake, maintenance or energy costs change the choice | Request installed cost and annual energy at equal useful output and duty. |
| Scenario mismatch: intermittent versus continuous | Average hours hide long loaded runs or frequent starts | Provide torque-versus-time cycles and ambient temperature, not only hours/day. |
| Installation mismatch | Shaft loads, orientation or oil fill fall outside the catalog | Send a mounting drawing, overhung/axial loads and lubrication requirements. |
Questions before choosing an 80:1 worm gearbox
Calculation
What output speed does 80:1 give at 1,500 RPM?
18.75 RPM: divide actual gearbox input speed by 80. Use the motor’s loaded shaft speed, not an assumed synchronous speed.
Does 80:1 multiply torque by 80?
Only in an ideal lossless model. Running torque equals input torque × 80 × running efficiency. It still must remain within the chosen gearbox’s torque rating.
Why is the default efficiency 45%?
It is an illustrative assumption for sensitivity analysis, not a catalog rating or a conservative guarantee. Obtain running efficiency for your model, input speed, load and lubricant.
Should I enter motor nameplate power or electrical input?
Enter mechanical power delivered to the gearbox input at the operating point. Nameplate shaft power gives a full-load scenario; electrical input also contains motor and drive losses.
Why does running time change daily heat but not torque?
The tool assumes constant power while running. Hours multiply heat-loss power to give daily energy; they do not model cooldown or change instantaneous torque.
Selection and safety
Is an 80:1 worm gearbox guaranteed to self-lock?
No. Ratio alone cannot establish self-locking. Geometry, friction, lubrication and operating conditions matter. Use an independently specified brake or holding device where reverse motion could be hazardous; confirm the complete design with the manufacturer.
Can I run an 80:1 gearbox 24/7?
Only if the selected model meets continuous mechanical and thermal ratings under the actual installation conditions. Daily hours alone cannot establish this; obtain a thermal review and compare alternatives.
Can the tool predict starting torque or oil temperature?
No. It models steady forward power flow. Starting friction, acceleration, housing heat transfer and ambient conditions require additional manufacturer data.
How should I handle heavy shock loads?
Supply peak torque, inertia, starts/hour and load cycles. Ask for the manufacturer’s service factor and permissible peak loads; the tool does not multiply its result into an allowable rating.
Installation and purchasing
What type of oil is best for an 80:1 ratio?
Use the exact lubricant and viscosity approved for the selected gearbox and mounting position. Check oil, seal and coating compatibility before a change. Mobil Glygoyle has specific mixing restrictions; PAG is not a universal substitution.
Is a helical-worm or bevel-helical alternative always better?
No. Compare verified efficiency at the same required output torque and speed, envelope, duty, brake needs and total cost. Generic ratio alone does not establish a price or performance ranking.
What should I send with an engineering inquiry?
Download the estimate and add the candidate model, required running and peak torque, load cycles, ambient temperature, mounting position, shaft dimensions and loads, and independent brake requirements.
Sources, date and evidence limits
Sources reviewed October 1, 2026. Manufacturer guidance below supports the stated principles; none supplies a certified efficiency or thermal rating for an unspecified 80:1 gearbox. The 45% default and all scenarios are explicitly hypothetical.
- KHK — Worm gear technical information
Worm-pair efficiency depends on operating conditions; reverse prevention may require an additional brake. Pair data is not a complete gearbox rating.
- SEW-EURODRIVE — S and W gear unit efficiency
Sliding losses and efficiency factors for SEW gear units; no universal 80:1 efficiency is given.
- SEW-EURODRIVE — Self-locking
Helical-worm guidance, edition 02/2025. Self-locking must not be the only hoist safety function.
- SEW-EURODRIVE — Thermal-rating data for DRU gearmotors
Project-planning guidance, edition 03/2024, lists ratio, speed, effective torque, input power, mounting position, ambient temperature and installation conditions for thermal review. SEW product-family guidance, not a rating for an unspecified gearbox.
- Mobil — Glygoyle 11, 22 and 30 application notes
Product-specific lubricant, seal and coating compatibility. Do not generalize one PAG formulation to every lubricant.
Turn the estimate into a reviewable specification
Download your estimate, then add a candidate model, required running and peak torque, starts/hour, duty cycle, ambient temperature, mounting drawing, shaft loads and brake requirements. Ask for confirmed mechanical and thermal ratings plus approved lubrication before ordering.