Gear Drives 1

What characteristic(s) can a gear change in a gear drive?

• Direction and speed of the rotary motion

• Speed of the rotary motion only

• Direction of the rotary motion only

• Power transmitted

What is an idler gear used for?

• Obtain a specific speed ratio in a gear train

• Maintain the same direction of rotation between a driving and a driven gear

• Prevent gear motion in one direction

• Allow the meshing of teeth cut at different pressure angles

What is backlash in a gear drive?

• The energy used to force the gear teeth to mesh

• A hub on the back side of the gear teeth

• The play between two meshed gear teeth

• The parallel misalignment between two adjacent gears

Which of the following characteristics must be the same on two gears for their teeth to mesh correctly?

• Diametral pitch and teeth width

• Pressure angle and circular pitch

• Pitch diameter and pressure angle

• Diametral pitch and pressure angle

Which of the following ratios are equivalent?

• Teeth and outside diameter ratios

• Pitch diameter and outside diameter ratios

• Pitch diameter and teeth ratios

• Backlash and circular pitch ratios

Which gears produce a thrust load?

• Spur gears

• Bevel gears and helical gears

• Helical gears only

• None

As opposed to sprockets and sheaves, adjacent gears

• turn in the same direction

• turn in the opposite direction

• cannot turn

• always turn at the same speed

If the driving gear of a two gear drive has 40 teeth and the driven gear has 10 teeth, the driven gear rotates

• four times faster than the driving gear and in the same direction

• four times faster than the driving gear and in the opposite direction

• four times slower than than the driving gear and in the same direction

• four times slower than the driving gear and in the opposite direction

Power is transferred between an electric motor and a pump with a two gear drive. Calculate the required number of teeth on a driven gear if the driven shaft must rotate at 1765 r/min. The driving gear is installed directly on the motor shaft and has 30 teeth. The motor plate indicates a nominal speed of 1000 r/min.

• 30 teeth

• 15 teeth

• 17 teeth

• 54 teeth

Which instrument is used to measure the amount of backlash between two meshed gears?

• Tape rule

• Feeler gauge

• Dial indicator

• Straight edge