Gears and Belt Drives Flashcards
7 cards from real Bennett Mechanical Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Gears and Belt Drives flashcards as text
Three gears mesh in a line: 20, 40, and 20 teeth. The overall ratio from first to last gear is:
Answer: 1:1
The middle gear acts as an idler, so the first and last 20-tooth gears give a 1:1 ratio.
Increasing the number of teeth on the driven gear while keeping the driver fixed will:
Answer: Lower output speed
More driven teeth means a larger ratio and slower output.
Compared to a chain drive, a belt drive is generally:
Answer: Quieter but more prone to slipping
Belts run quietly but can slip, while chains grip teeth without slipping.
A motor spins at 1200 RPM driving a gear ratio of 4:1 reduction. The output speed is:
Answer: 300 RPM
A 4:1 reduction divides input speed by four, giving 300 RPM.
What does a tensioner or jockey pulley do in a belt system?
Answer: Maintains proper belt tension
A tensioner keeps the belt tight to prevent slipping.
If two gears must turn in the SAME direction without changing the ratio, you should add:
Answer: One idler gear
A single idler gear reverses direction so the output matches the driver's direction.
A larger pulley diameter on the driven side of a belt produces:
Answer: More torque, less speed
A larger driven pulley turns slower but with greater torque.