The Effect of Hub Moment on Main Rotor Shaft Drive Gears
Bibliographic record
Abstract
A common helicopter drive system configuration has a planetary final stage with the carrier driving the main rotor shaft. If the carrier is hard-mounted to the main rotor shaft, it is deflected by any main rotor hub moment or transverse load which bends the main rotor shaft. The deflection of the carrier is resisted at the sun and ring gear meshes. Thus, the planetary stage acts as a support that reacts to main rotor hub moments and transverse loads. The loads carried by the planetary stage of a S-92® helicopter in different flight conditions are quantified using Romax® software. To validate the approach, the results are correlated to in flight measured strains on a gearbox housing. As another validation point, a separate Romax model is correlated to quasi-static strain measurements on a UH-60 planetary carrier plate with the transmission subjected to torque and hub moments in a lab. This work enables greater fidelity in the design and analysis of helicopter transmissions. It may help to improve reliability and reduce weight in current and future designs. The work also presents an application of system-level modelling and analysis. Instead of considering the various components in isolation with simplified boundary conditions, the analysis considers the full system and how the components interact across connection points such as splines, bearings, and gear meshes.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".