# Advice 1: How to calculate gear ratio

As you know, gear in the car transfer torque from the engine to the drive of the other node. One of their main characteristics is the transfer number. Gear ratio is the ratio of the number of driven gear teeth to the number of teeth leading. Using gears with different numbers of teeth, it is possible to adjust the torque.
Instruction
1
Calculate the gear ratio using its definition, according to the formula: K = K1/K2 where K1 is the number of driven gear teeth, and K2 is the number of drive gear teeth. For example, to calculate gear ratios torque from the transmission to the wheels you need to calculate the ratio of the spur gear differential and output shaft gear in the transmission, or as it is called by drivers to find the gear ratio for the main couple.
2
Count the number of teeth of the gear transmission output shaft, for example there are 15 teeth. Count the number of them on the driven gear, which is attached to the differential, let it be 51 barb. Substitute numbers in the above formula: 51 / 15 = 3,4. The resulting number will be the gear ratio for the main couples this gear. Consequently, the driven gear of the differential will revolve 3.4 times slower than the pinion shaft of a gear box as it rotates.
3
Calculate gear ratios transmission for each transmission by the above formula. The closer will be the gear ratio, the more smooth and rapid acceleration of the car with sequential gear shift. Count, how many times will reduce engine speed when you change the transmission, dividing the gear ratio is low transmission gear ratio higher.
4
Draw conclusions based on the presented estimations. Need to know: the higher the gear ratio, the vehicle speed will gain faster, but the transmission will need to switch often. Setting a pair with a lower gear ratio, you can increase the maximum speed of the car, however the car will accelerate worse. Calculate if necessary by the above formula, the gear ratio of gear of any parts in your car.
Note
In the transition from the four-speed transmission five speed you will have less to shift gears, and you can increase the maximum speed in each gear.

# Advice 2 : How to determine gear ratio

One of the devices most commonly used today in a variety of mechanisms, is the gearbox. It is a development of the idea of the lever and serves to transmit torque between the rotating pulleys. The main parameter characterizing a specific gear, is the gear number. It can be defined by performing calculations based on information about the type and parameters of the speed reducer.
You will need
• - knowledge of the parameters of the gear reducer.
Instruction
1
Determine gear ratio, consisting of a single gear. In devices of this type the torque is transmitted from the drive shaft driven by engagement of teeth of the gear installed on them. Gear can be both cylindrical and conical - in this case, it doesn't matter. First determine the number of teeth of the gear drive shaft by a simple calculation. Then perform the same operation for the driven gear shaft. Divide the second value to the first. This will be the desired gear reduction ratio.
2
When calculating gear ratios, made on the basis of chain transmission, operate similarly to the first step. Count the number of teeth of the driving and driven sprockets, and then divide the second value to the first.
3
To estimate the gear ratios on a belt it is necessary to know the radii (or diameters) of its driving and driven pulleys. Please note that this must be the radii of the circles, through which passes the inner part of the belt during its contact with the pulleys. Therefore, if the pulley is made in the form of a roller with a groove to hold a belt, it is necessary to measure the radius or the diameter of its inner part. In this case, to calculate gear ratio by dividing the radius of the driven pulley on the radius host.
4
In gearboxes is based on worm gear leading pulley is always the one on which is located the worm, and the slave - where is the worm wheel. In one revolution of the worm wheel (gear) turns on the number of teeth equal to the number of threads of worm (in the simplest case is a unit). Therefore, the gear ratio of such a gear is calculated by simple division of the number of teeth of the worm wheel by the number of visits worm.
5
The gear ratio of the reducer is composed of gear, determine by successively multiplying the ratios of its individual steps.
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