Bevel-gear documentation: A proper working drawing for a bevel gear includes both the gear blank dimensions (outside diameter, face width, bore/keys, mounting) and the cutting/tooth data needed for manufacture. Decide whether this statement is correct.
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ACorrect
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BIncorrect
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COnly the blank is shown; tooth data stays secret
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DOnly tooth data is shown; the blank is vendor-defined
Answer
Correct Answer: Correct
Explanation
Introduction / Context: Manufacturing a bevel gear requires both a machinable blank and precise tooth specifications. Drawings that omit either aspect force guesswork or extra RFIs. This question checks understanding of what belongs on a complete working drawing.
Given Data / Assumptions:
- Blank definition: OD, hub/boss, face width, bore, keyways, material, heat treat.
- Tooth data: module/DP, pressure angle, numbers of teeth, pitch angles, hand/spiral data (if spiral), mounting distance.
- Notes: inspection, surface finish, balance, and runout tolerances.
Concept / Approach: The shop must be able to make and inspect the part. Blank data enables turning/milling prior to tooth cutting; tooth data directs the gear cutting/grinding operation. Both must be present for a standalone, unambiguous part definition suitable for procurement and QA.
Step-by-Step Solution:1) Specify blank geometry and tolerances.2) Provide full gear data for cutting/grinding.3) Add mounting distance and datum scheme for inspection.4) Include notes on heat treatment and finishing.
Verification / Alternative check: Vendor checklists for gear drawings require both blank and tooth data; coordinate measuring machine (CMM) programs depend on these specs.
Why Other Options Are Wrong:Withholding tooth data prevents manufacturing to spec; leaving out blank data blocks pre-cut preparation.Claiming the vendor defines the blank contradicts controlled part-number practice.
Common Pitfalls: Missing keyway tolerances; inconsistent face width vs mounting distance; omitting crown/relief notes.
Final Answer: Correct