20:1 Right Angle Speed Reducer
Calculate nominal speed and torque, compare right-angle options, and verify model-specific ratings. Results are screening estimates, not a model rating.
20:1 Performance Calculator
Quick estimate only. Enter the model’s efficiency when known; verify exact ratings with the manufacturer.
Key Engineering Conclusions
- 1Ratio determines nominal speed, not model capacity. At 20:1, output speed is input speed divided by 20. The torque estimate also depends on the efficiency assumption entered in the calculator.
- 2Efficiency and heat are model-specific. Manufacturer catalog data varies with reducer design, input speed, and running-in. For continuous duty, check the selected unit’s thermal rating under the actual operating conditions.
- 3Hypoid is an option to verify, not a confirmed 20:1 rating. Sumitomo lists a 5:1–1440:1 family range, but its current catalog’s up-to-93% efficiency statement begins at 30:1. Confirm exact 20:1 model availability and catalog data.
- 4A multi-stage ratio is the product of its stages. A 4:1 right-angle stage and 5:1 planetary stage multiply to 20:1 as an arithmetic example. Product availability, total efficiency, and backlash must be checked with a supplier.
Critical Application Risks
Do not treat self-locking as a safety brake
Ratio alone does not establish a worm reducer’s self-locking behavior. For its helical-worm units, SEW-EURODRIVE says the static criterion depends on forward efficiency and warns that self-locking must not be the sole safety function for hoists. Use a separately rated holding brake where the application requires one.
Check thermal capacity for the real duty
Continuous operation can be limited by heat balance. Compare the selected reducer’s thermal rating with the actual operating conditions; a different topology is an option to evaluate, not an automatic fix.
Specify how backlash is measured
A catalog value is meaningful only with its definition and test condition. State whether the requirement is lost motion or backlash, the measurement load, and the new or end-of-life limit; request the same basis from every supplier.
Published October 12, 2026 · editorial and source review October 12, 2026
- Bonfiglioli VF/W catalog, efficiency section says worm-unit efficiency depends on tooth helix angle, driving speed, and running-in. Use the selected model’s published data rather than a universal efficiency value.
- Bonfiglioli VF/W selection procedure includes load type, starts per hour, and operating hours per day in its service-factor selection. Include those values in the model inquiry; this calculator does not apply a product-specific service factor.
- Sumitomo HYPONIC product information describes lower friction for hypoid versus worm gearing and lists an overall product-family ratio range of 5:1–1440:1; range alone does not confirm an exact 20:1 model. ItsHYPONIC 2026 catalog states up to 93% efficiency for ratios from 30:1 to 1440:1. That headline figure does not cover a 20:1 ratio; verify the exact model’s efficiency and ratings before comparing it.
- SEW-EURODRIVE self-locking guidance ties static self-locking to forward efficiency and says it is not permitted as the sole safety function for hoists.
- AGMA standards listing includes AGMA 947-B26, “Gear Reducers—Thermal Capacity.” The applicable thermal rating must be checked for the actual product and operating conditions.
Public sources support these directional comparisons, but do not establish one cross-brand efficiency, backlash, cost, or life value for each topology. The calculator therefore requires an explicit efficiency assumption and labels its outputs as screening estimates.
Architecture Trade-offs at 20:1
A nominal ratio does not determine a reducer’s efficiency, backlash, capacity, or safety behavior. Compare exact model data on a common measurement basis before selecting a topology.
| Topology | Published evidence | Verify before selection |
|---|---|---|
| Worm gear | Bonfiglioli states worm efficiency depends on tooth helix angle, speed, and running-in; do not use a generic percentage as a model rating. | Confirm rated torque, thermal capacity, starts per hour, permitted duty, backlash, and whether an independent brake is needed. |
| Hypoid gear | Sumitomo lists a 5:1–1440:1 HYPONIC family range, but its 2026 catalog’s up-to-93% efficiency statement begins at 30:1. Do not carry that figure into a 20:1 comparison. | Verify the exact 20:1 model’s available frame, efficiency, rated torque, backlash, thermal rating, and mounting limits. |
| Spiral bevel + planetary | Stage ratios multiply: 4:1 × 5:1 is a conceptual 20:1 combination, not evidence that a specific supplier offers that pairing. | Request stage-wise ratio, efficiency, backlash, torque, thermal, and torsional-stiffness ratings for the assembled unit. |
Need to compare a catalog rating with your application’s duty, backlash target, or mounting limits?
Request an exact 20:1 model checkFrequently Asked Questions
Why choose a 20:1 right angle speed reducer?
A nominal 20:1 reducer divides input speed by about 20 and increases output torque subject to efficiency losses. Whether it fits depends on the load, duty, package, backlash, and safety requirements.
Is a worm gear the only option for a 20:1 right angle reducer?
No. Worm, hypoid, and multi-stage right-angle arrangements are possible paths. Check a specific product catalog for the exact ratio, rated torque, efficiency, backlash, and thermal rating.
What is the efficiency of a 20:1 worm gear reducer?
There is no single efficiency value for every 20:1 worm reducer. Use the selected model’s catalog data at the relevant speed, load, lubricant, and running-in condition.
How does the calculator estimate output torque?
It calculates motor torque from power and speed, then multiplies by 20 and the efficiency percentage you enter. It does not include the reducer’s rated capacity, service factor, or transient loads.
Does the result confirm that a reducer is correctly sized?
No. Compare the calculated demand with the exact model’s catalog rating and verify thermal capacity, duty, backlash, mounting, and any radial or axial output loads.
Can a worm reducer hold a suspended load by itself?
Do not assume it can from the ratio. Self-locking depends on the reducer and operating conditions, and it must not serve as the sole safety function for a hoist. Verify the application’s independent brake requirements.
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