Gear Ratio

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gear ratio

[′gir ‚rā·shō]
(mechanical engineering)
The ratio of the angular speed of the driving member of a gear train or similar mechanism to that of the driven member; specifically, the number of revolutions made by the engine per revolution of the rear wheels of an automobile.

Gear Ratio


(1) In a gear drive, the ratio of the number of teeth of a pinion to the number of teeth of a gear, u = z2/z1.

(2) In a worm gear, the ratio of the number of teeth of a worm wheel to the number of threads of a worm.

(3) In a chain drive, the ratio of the number of teeth of the larger sprocket to the number of teeth of the smaller one.

(4) In a belt drive or nonregulated friction drive, the ratio of the diameter of the larger pulley or roller to the diameter of the smaller.

The gear ratio is also used in the design of multiple reduction gears. In contrast to the transmission ratio, the gear ration is always greater than or equal to 1.

References in periodicals archive ?
Both vehicles benefit from nearly imperceptible gear changes due in part to very evenly spaced gear steps between each gear ratio.
Fourth fixed gear ratio with electric boost/braking.
The VGRS system enables easier handling during low-speed driving and provides better stability during high-speed driving than conventional steering by changing the gear ratio.
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0 overall gear ratio spread provides a numerically higher 4.
The transmission offers a number of benefits over a conventional automatic gearbox including a lower first gear ratio that improves acceleration from 0-60mph in 8.
The transmission has a lower first gear ratio that improves acceleration from 0-60mph in 8.
The VGRS system selects the steering gear ratio according to vehicle speed, enhancing responsiveness and driver control.
In addition to being one of several sponsors of the AJR team, Xybernaut wearable computer technologies and solution services are also being used in the pits during practices and in the garage/paddock areas throughout race weekends to gather, manage, analyze and communicate various types of information, such as timing and scoring, vehicle configuration and performance analysis, inspections/maintenance, gear ratio analysis, asset management/tracking and parts/tools/material inventories.
0 overall gear ratio spread is wider than GM s six-speed automatic transmissions, providing a numerically higher first gear ratio to help drivers start off more confidently with a heavy load or when trailering.
33:1 gear ratio and 27-amp alternator to feed all the electrical toys common on pontoon boats.
Along with a team of engineers, Baltali developed the following hypothesis: By slightly over-spec'ing engines in order to run more consistently in the "sweet spot," choosing a gear ratio low enough to suit a fleet's application and location, and enabling the correct fuel-efficient, engine-specific parameters, fuel economy will improve by 0.