ASME ASME Mechanical Power Transmission 1 — Questions and Answers
Question 1: Which ASME standard covers the design of spur and helical gears for general industrial use?
- ASME B6.1 (Correct answer)
- ASME B18.1
- ASME B29.1
- ASME B16.5
Correct answer: ASME B6.1
ASME B6.1 covers the specification of spur and helical gear tooth form, proportions, and accuracy for industrial applications.
Question 2: In mechanical power transmission, what is the 'pitch circle' of a gear?
- The outer circle defined by the tooth tips
- The circle passing through the teeth contact point during meshing (Correct answer)
- The root circle at the base of the gear teeth
- The addendum circle minus the clearance
Correct answer: The circle passing through the teeth contact point during meshing
The pitch circle is the imaginary circle that passes through the point of contact between meshing gear teeth, used as the reference for gear calculations.
Question 3: What is the 'diametral pitch' of a gear?
- The center-to-center distance between meshing gears
- The number of teeth per inch of pitch diameter (Correct answer)
- The distance between adjacent tooth flanks
- The ratio of pitch circle to outside circle diameter
Correct answer: The number of teeth per inch of pitch diameter
Diametral pitch (DP) is the number of teeth per inch of pitch diameter, the fundamental sizing parameter for US customary gears.
Question 4: For two gears to mesh correctly, which parameter must be equal for both gears?
- Number of teeth
- Face width
- Pressure angle and diametral pitch (or module) (Correct answer)
- Addendum and root circle diameters
Correct answer: Pressure angle and diametral pitch (or module)
Meshing gears must have equal pressure angles and equal diametral pitch (or module in metric) to ensure correct tooth contact geometry.
Question 5: In AGMA/ASME gear design, what does the 'service factor' (KS or Ko) account for?
- The material hardness of the gear material
- Overloads and shock loads beyond the nominal transmitted power (Correct answer)
- The duty cycle percentage over 24 hours
- The gear mesh efficiency losses
Correct answer: Overloads and shock loads beyond the nominal transmitted power
The service (overload) factor accounts for shock and overload above the nominal design power, multiplying the required load capacity accordingly.
Question 6: Which type of gear arrangement can transmit power between non-parallel, non-intersecting shafts?
- Spur gears
- Bevel gears
- Helical gears
- Worm gears (Correct answer)
Correct answer: Worm gears
Worm gear sets transmit power between non-parallel, non-intersecting (skew) shafts, typically at 90 degrees, with high reduction ratios.
ASME ASME Mechanical Power Transmission 1
Which ASME standard covers the design of spur and helical gears for general industrial use?