Detailed description of the scooter shifting system CVT: Don't change the drive again

The invention of the CVT continuously variable transmission system makes cycling a lot easier. The CVT system consists of several organizations plays an important role in the power transmission of the scooter. At the same time, there are many car owners who are keen to modify. The ground is looking for the best transmission configuration, and as a user of the CVT system, have you really understood the CVT system under the seat cushion? Today, for scooters, take you to know the CVT system.


Do you know every part of the CVT?

What are the functions of the CVT system for scooter models?

Infinitely variable speed, automatic clutch, transmission power.

First of all, to introduce the most admirable stepless speed change mechanism, with the design of the Puli disk and the belt, according to the increase and decrease of the engine speed, automatically change various speed reduction ratios, and through the adjustment of the transmission configuration, it can also be more Meets the acceleration required by the Cavaliers. Incorporating the automatic clutch design, when the vehicle stops waiting for the red light, there is no need to operate the clutch, and there is no need to worry about the engine being turned off. In addition, it also has the function of transmitting power, and is responsible for transmitting the power output from the engine crankshaft to the rear wheel. .

What are the advantages and disadvantages of the CVT system in terms of scooter models?

Advantages: simple, comfortable, easy to use, disadvantages: low transmission efficiency.

Under normal use, the general gear should operate at least the throttle, clutch and gear lever. The CVT system used on the scooter saves the knight from shifting. It only needs to operate the throttle to drive the vehicle easily. In addition to being simple and easy to use, the combination of the belt and the Ply plate produces a relatively low vibration and maintains excellent comfort.

But the only thing that is criticized is that because the CVT structure on the scooter is simple, the transmission efficiency is relatively low, especially when the shifting is performed, the belt and the disc surface rub against each other, which will affect the efficiency of power transmission.

CVT Bridge: V-Belt

In the CVT system, it acts as a medium for shifting and transmitting power.

A fixed-length V-belt, one end is fixed between the Ply plate (the front group of the transmission), and one end is fixed between the opening and closing plate (the group after the transmission), and the shifting action is performed by the continuous change of the belt, and the belt is removed. In addition to the mechanism of shifting, it is also an important medium for transmitting power, transmitting the power generated by the engine to the rear wheel and rotating it.

The front and rear transmissions can be connected via a V-belt.

Compared with the chain drive used in the gear, the belt drive is simpler in cleaning and maintenance, and the shock-absorbing effect of the transmission is better. Therefore, the vehicle equipped with the belt drive will be more comfortable in riding.

In terms of appearance, it can be divided into two types: single-toothed belts and double-toothed belts. As the name suggests, single-toothed belts have only one side toothed, simple manufacturing process and relatively low cost, so they are common on small scooters. The double-toothed belt is designed with teeth on both sides of the belt to effectively improve transmission efficiency and belt life. It is commonly found on large scooters or American cruising vehicles.

The single tooth is the type of belt most commonly used by scooters.

The PGO TIGRA 150 features a double-toothed belt for improved transfer efficiency and durability.

The key to starting the CVT: Puli and Puli

The Ply disk mounted on the crankshaft end is responsible for receiving power from the engine, and is commonly referred to as the “pre-drive group” with the Pulizhu group. When the engine speed starts to increase, the Pulizhu will pull out due to the centrifugal force, and at the same time push the Puli plate to shorten the distance between the two plates, causing the V-belt in the two plates to be extruded outward, simulating the front teeth of the gear. The state of the increase; conversely, when the engine speed begins to decrease, the Puli bead that loses the centrifugal force will gradually move closer to the crankshaft. At this time, the position of the V-belt will also be close to the crankshaft to simulate the state in which the rear teeth of the gear is enlarged.

The lighter the Priscilla, the faster it starts?

This statement is not completely correct. Pulizhu affects the speed of engine speed rise. When the Pulizhu is lighter, the engine speed rises faster, and vice versa. The faster the speed rises, the lighter the riding experience, but it does not mean that the faster the vehicle starts, so the lighter the philips, the faster the start is not absolute, it must be determined by the transmission configuration.

The weight of the Pulizhu affects how fast the speed rises, not the starting speed. The secret of CVT shifting: the opening and closing disc and the large spring in the CVT system are interlocking shifting characters.

The front group of the transmission has a Pulizhu and a Puli plate, while the rear group of the transmission is composed of three mechanisms: an opening and closing plate, a large spring and a clutch. When the front group of the drive starts to move, the V-belt will start to operate, and the V-belt clamped between the opening and closing discs will start to control the spacing between the opening and closing discs. Beginning to play the role of shifting, its softness affects the speed ratio of the vehicle, and the ratio of speed can be compared to the speed and slowness of the gear shifting action.

Drive rear group.

The V-belt is clamped between the opening and closing discs.

CVT does not turn off the secret: clutch

The function of the clutch is to stop the vehicle from stopping when the vehicle is stopped. For a general-purpose car, the clutch must be manually operated, and on the scooter, there is no need to manually control the clutch. This is because the CVT system is designed with the vehicle speed as the setting and the automatic clutch is designed.

The design of the automatic clutch allows the CVT to be powered without pulling the clutch. The clutch used in the CVT system is called a centrifugal clutch. It is divided into a clutch cover (commonly known as a bowl), a clutch plate and a drive plate according to the mechanical structure. The clutch plate and the drive plate are connected to the opening and closing disk group, and the clutch is external. The cover is connected to the rear wheel through the rear axle of the transmission. In addition to maintaining the engine operation, it is also responsible for rotating the rear wheel.

The clutch is connected to the opening and closing disk.

The bowl connected to the rear wheel will also follow the rear wheel when turning. When the number of revolutions of the engine is increased, the belt starts to drive and then the opening and closing disc rotates. At this time, the driving plate connected with the opening and closing disk will rotate accordingly, and the clutch plate will be opened outward due to the centrifugal force, and the combination will drive the bowl. Since the bowl and the rear wheel are connected, the rear wheel will also rotate, which will drive the vehicle forward. Conversely, when the throttle is released, the clutch plate will be separated from the bowl and the rear wheel will be powered off, but the engine will not be turned off. Stop running.

The secret of CVT re-acceleration: Torque cam

Based on the above principle, the shifting mechanism of the scooter CVT system is mainly controlled by the engine speed, and cannot be changed according to the needs of the knight or the condition of the road. If the CVT is facing the situation of “re-acceleration”, how should it be dealt with? ? Therefore, engineers have added the design of the torsion cam when developing the CVT system for the scooter.

Torque cam is similar to the function of gear shifting. When the vehicle encounters an uphill or overtaking, the knight will increase the throttle. By the action of the mechanical principle, the torque cam will sense the instantaneous torque output and push the opening and closing disc. The spacing is again shortened, so that the overall transmission system's reduction ratio will increase, similar to the effect of downshifting.

The grooves and beads are torque cams.

Whether you are a knight who prefers the CVT system alone or a car enthusiast who is keen on modifying the transmission, through this elementary school, you will definitely have a better understanding of the CVT system on the car, and then you will be able to accurately grasp the love of the car. The situation is over.