In the previous entry under the label of transmission, I had explained about the manual transmission. The manual transmission system is quite easily to understand but how about the automatic transmission system. It is so tough that I think better I give the overview of the article and if you are interested to learn more, just click on my source.

The automatic transmission consist some components that I think most of you did not even hear the name before unless you are the mechanic that usually repair the car. The automatic transmission consists of the ingenious planetary gearset, set of bands to lock part of gearset, three wet-plate clutches to lock other part of the gearset, hydraulic system that control the clutches and bands, and large gear pump to move transmission fluid.

The heart of the automatic transmission is the planetary gearset. The planetary gearset consists of sun gear, planet gears (with carrier) and ring gear.

Left to right: ring gear, planet carrier and two sun gears

The bands are steel bands that that wrap around sections of the gear train and connect to the housing. They are actuated by hydraulic cylinders inside the case of the transmission.

The bands

The clutches in the transmission are a little more complex. In this transmission there are four clutches. Each clutch is actuated by pressurized hydraulic fluid that enters a piston inside the clutch. Springs make sure that the clutch releases when the pressure is reduced. Take a look of the clutch below.

The clutch

Don’t feel enough information with this article. Check my source for more information.
Source:
1. http://auto.howstuffworks.com/automatic-transmission.htm

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Hello there. For this entry I want to bring all the readers the wonderful of transmission system in your car. Do you get an idea what is the transmission for the car? If you don’t, I want to ask you a question. Do you know what is gear 1, gear 2 and so on? If you drive a car, you must know all this terms. That is the basic idea of transmission. So, let’s explore what is exactly the system that can connect your wheel to the engine to move at your required speed. This time, we will explore about the manual transmission first.

Every gasoline engines has their own redline. Redline is a maximum RPM value above which the engine cannot go without exploding. The transmission allows the gear ratio between the engine and the drive wheels to change as the car speeds up and slow down. The reason for shifting the gears is for the engine can stay below the redline and near the RPM of its best performance.

Firstly, we try to get an idea of the transmission system. Pictures below show the two-speed transmission in neutral position.

Green shaft and gear comes from the engine through the clutch. I will reveal about the clutch in upcoming entry. The red shaft and gear or the layshaft directly connected with the green shaft through the meshed gear. The yellow shaft is a splined shaft that connect directly to the drive shaft through the differential to the driven wheels. The blue gears ride on bearing, so the motion of the yellow shaft without using the engine did not bring the blue gears to spin also. The collar is connected directly to the yellow shaft and can slide along the yellow shaft. The purpose of the collar is to connect either of the blue gear to the yellow shaft. The dog teeth on the collar fit into holes on the sides of the blue gears to engage them.

Then, let’s explore the transmission in first gear. First, see the pictures below.

The green shaft that received the power from the engine will turn the layshaft. The layshaft will turn the blue gears. Because of the collar. only the blue gears on the right will transmit the energy to the yellow shaft. The blue gears on the left will also spin but it will have no effect in turning the yellow shaft.

Do you get the basic idea on how the transmission work from the two-speed manual transmission? If so, then let’s look at the real transmission as using in many cars in the world, the five-speed manual transmission. Below are the layout of the five-speed manual transmission.

The picture below will explain about why the H-pattern related to the shifting gears.

The forward gears quite easy to understand but how about the reverse gear? The principle is the same as the forward gear but in addition of the idler gear between the red gear and the blue gear. See the pictures below.

So, that’s all for the basic principle of the manual transmission. If you want to learn more detail about the manual transmission system, you can check my source.

Source:
1. http://auto.howstuffworks.com/transmission.htm

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