Gears—General

Which type of gear has teeth inclined to the axis of rotation and can be used to transmit motion between both parallel and nonparallel shafts?

What is the term for the ratio of the number of teeth on a gear to its pitch diameter, typically expressed in teeth per inch?

A gearset consists of a 20-tooth pinion driving a 50-tooth gear. If the diametral pitch is 2.5, what is the center distance between the gears?

What is the primary advantage of using involute profiles for gear teeth?

What is the smallest number of teeth a full-depth spur pinion can have to run with itself (a one-to-one gear ratio) without interference, if the pressure angle is 20 degrees?

A helical gear has a transverse diametral pitch (Pt) of 8 teeth/in and a helix angle (psi) of 30 degrees. What is its normal diametral pitch (Pn)?

In a worm gearset with a 90 degree shaft angle, what is the relationship between the axial pitch (px) of the worm and the transverse circular pitch (pt) of the gear?

A simple gear train consists of a 20-tooth driving gear, a 50-tooth idler gear, and a 100-tooth driven gear. If the driving gear rotates at 1000 rev/min, what is the speed of the final driven gear?

What is the term for the contact of portions of gear tooth profiles that are not conjugate, often occurring when the pinion has too few teeth?

A pinion with a pitch diameter of 50 mm runs at 1750 rev/min and transmits 2.5 kW of power. What is the transmitted load (Wt)?

A two-stage compound gear train is needed for a 40:1 speed reduction. To minimize package size, what is the ideal gear ratio for each stage?

In a compound reverted gear train, what geometric condition must be satisfied in addition to the ratio requirements, assuming a constant diametral pitch?

What is the formula for the train value 'e' of a planetary gear train?

In the force analysis of a straight-tooth bevel gear, a resultant force W has three components. What are these three components?

What is Tredgold's approximation used for in the context of bevel gears?

A helical gear has a normal pressure angle (phi_n) of 20 degrees and a helix angle (psi) of 30 degrees. What is its transverse pressure angle (phi_t)?

For a helical gear with N actual teeth and a helix angle psi, what is the formula for its virtual number of teeth N'?

What is the recommended minimum contact ratio for gears to avoid impact between teeth and reduce noise?

What is the relationship between circular pitch (p) and diametral pitch (P)?

A worm has a lead (L) of 1.0472 inches and a pitch diameter (dW) of 2 inches. What is its lead angle (lambda)?

What type of gear is used to transmit motion between intersecting shafts, with teeth formed on conical surfaces?

What is the term for the radial distance from the top land of a gear tooth to the pitch circle?

A gearset is designed with a 15-tooth pinion and a 60-tooth gear. Both have a 20-degree pressure angle. According to Equation (13-11), what is the smallest number of teeth the pinion could have to avoid interference?

What type of gear resembles a screw and is typically used when the speed ratios of the two shafts are quite high, such as 3 or more?

A gear has a pitch diameter of 3 inches and rotates at 1800 rev/min. What is its pitch-line velocity (V) in ft/min?

In a planetary gear train, the sun gear (first gear) rotates at -100 rev/min (clockwise), the arm rotates at -20 rev/min (clockwise), and the train value is -0.25. What is the speed of the ring gear (last gear)?

What is a double helical gear, also known as a herringbone gear, equivalent to?

In the context of gear nomenclature, what is the 'pinion'?

What is the relationship between the base pitch (pb) and circular pitch (pc) of a spur gear with pressure angle (phi)?

A straight-tooth bevel pinion has 15 teeth and drives a 45-tooth gear. What is the pitch angle (gamma) of the pinion?

In a helical gear system, a transmitted load (Wt) of 50 lbf is applied. The transverse pressure angle (phi_t) is 22.8 degrees and the helix angle (psi) is 30 degrees. What is the axial thrust load (Wa)?

What is the primary reason for using a larger pressure angle, like 25 degrees instead of 20 degrees, in gear design?

Which gear manufacturing process involves cutting teeth with a tool shaped like a worm?

For a standard 20 degree straight bevel gear, what is the minimum number of teeth recommended for a pinion that mates with a 30-tooth gear?

What happens to the pressure angle and the length of the line of action when the center distance of a pair of involute gears is increased?

In a simple gear train, the train value 'e' is positive if the last gear rotates in the same sense as the first. This occurs when the number of meshes is what?

Which type of gear is patented, has curved teeth, but a zero spiral angle?

What is the primary characteristic of hypoid gears that distinguishes them from spiral bevel gears?

What is the module (m) of a gear with 50 teeth and a pitch diameter of 125 mm?

A gearset transmits 5 hp at a pitch-line velocity of 406 ft/min. What is the transmitted load (Wt) in lbf?

What is the general term for tooth profiles designed to produce a constant angular-velocity ratio during meshing?

A gear with a module of 3 mm has 60 teeth. What is its pitch diameter?

In a planetary gear system shown in Figure 13-26, the sun gear has 20 teeth and the ring gear has 80 teeth. What is the train value 'e' assuming a fixed arm?

For an internal gear meshing with a pinion, where is the addendum circle of the internal gear located?

In a worm gearset, the efficiency (eta) is given by the formula (cos(phi_n) - f * tan(lambda)) / (cos(phi_n) + f * cot(lambda)). What happens to the efficiency as the lead angle (lambda) increases, assuming f and phi_n are constant?

What is the primary purpose of the finishing processes of shaving, burnishing, grinding, or lapping gear teeth?

A gearset is being designed with an incorrectly large center distance. What is the effect on the base circles of the two gears?

What is the formula for calculating the sliding velocity (VS) in a worm gearset, given the worm pitch-line velocity (VW) and the lead angle (lambda)?

A two-stage compound reverted gear train is being designed for an exact 30:1 ratio with a 20 degree pressure angle. The first stage ratio is 6:1. If the smallest pinion (N3) must have at least 16 teeth, what is the smallest integer value for N3 that will result in an integer number of teeth for all gears?

What is the primary distinguishing feature of a gear rack profile when generated from an involute system?