What is the gear ratio?
The gear ratio of any gearbox is one of its most important characteristics. It can be determined by the ratio of the number of teeth of the driving and driven gears.
Gear ratio is very importantan indicator, for example, two absolutely identical gearboxes (one firm and model) can have different gear ratios, which makes them completely non-interchangeable. Therefore, experienced motorists advise: before buying or replacing a faulty gearbox, especially on a car with a drive on both axles, you must first determine the gear ratio of the gearbox.
Naturally, if buying a new or formerin the use of the gearbox the former owner / seller can not name the gear ratio, it is better not to buy it. After all, it would be very foolish to fill, for example, a car from a column where the fuel mark is not specified. And the consequences of this error will be more significant than low-quality gasoline.
All the arguments that the sold reducer from a car with a similar engine are completely inconclusive, because:
- The semantic load of this argument is analogous to the one that would have been if you were told that the KAMAZ reducer being sold has the same color as your car.
- This is not a guarantee of truth, but it can be a deception or a mistake, while the seller pursues one goal - to sell the product sooner.
There are several ways to determine the gear ratio. But to begin with, it is better to consider the types of gearboxes that are generally installed and installed on different machines and mechanisms.
1. Cylindrical reducers. They are used most often in the mechanisms of load-lifting machines, as well as in other areas of production, where the load regime is repeatedly short-lived. They have high efficiency and great durability.
2. Bevel gears. Possess a more complex device than cylindrical ones. They have the most favorable ratio of performance and compactness. They are used in crane constructions.
3. Worm gearboxes. Designed to rotate between crossed shafts, i.e. by means of a worm and a conjugate worm wheel. Applied in lifting and transporting machines, machine tools (mainly metal cutting), as well as in trolleybuses. Pros - smooth operation and noiselessness. Cons - low efficiency and increased wear. And the gear ratio does not exactly meet the requirements.
4. Planetary gearboxes. They have the smallest specific metal consumption, but a greater load capacity.
5. Wave reduction gears. They are mainly used in the rocket and space or defense industries.
6. Combined reduction gears. This is the use of several types of gear in one enclosure.
The gear ratio of the car gearbox can be determined in the following ways:
1. Catalog method. This is the easiest way (it can be used without leaving home), but not the most reliable one. Determine by VIN car. To do this, write down the number from the certificate of registration of the car. Then in one of the online catalogs of auto parts stores enter the number in the search box and find detailed information about your car. After that, select the transmission and look for the gear ratio of the car.
2. "By name plate". This is the simplest and most reliable way. On the gearbox body, there may be either an engraving or a label (label) containing all the information about the gearbox.
3. Count. The most reliable way, but not suitable for cars. Of course, if you are not going to dismantle the bridge.