CVT device on a scooter

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

CVT is a modern transmission device, and its use in various techniques is gaining popularity every day. The mechanism of the CVT on scooters is very simple: its developers relied on the action of centrifugal force, which made the design light.

Components of the variator

The scooter has a small weight and dimensions (compared to motorcycles and cars), respectively, and the gearbox should be small.

From automotive, scooter variator inherited:

• two pulleys - driving and driven (although here they are wedge-shaped, and each consists of two halves);
• belt (its shape is trapezoidal, unlike the car).

That's the legacy.

The position of the wedge-shaped halves (cheeks) of the drive pulley is adjusted by the rollers. The opening and closing of the cheeks of the driven pulley is handled by the central spring connected to the clutch.

More about how it works

So… The scooter is running and idling. What happens in the variator? The drive pulley rotates at minimum speed. The belt is slightly higher from the center of cheek contact. Follower's cheeks are compressedcentral spring. The belt on them moves along the maximum radius.

The scooter started moving. It's worth mentioning the videos here. They are located behind the inner cheek of the drive pulley. When the speed of rotation of this pulley increases, the centrifugal force pushes the rollers towards the outer radius, thereby compressing the drive pulley halves together. The belt between these halves moves outward - the radius of its turn on the leading cheeks increases.

The driven pulley does exactly the opposite. During the acceleration, centrifugal force acts on it, just like on the rollers, with the help of which the cheeks move apart, compressing the central spring and passing the belt between them. This is how overclocking happens.

Due to this synchronous operation of the pulleys, the speed increase occurs at constant speed and maximum engine power.

Setting up a variator on a scooter

Adjusting the variator achieves the desired dynamics of the scooter. You can improve it by replacing both the factory rollers and the spring.

The operation of the rollers on the scooter variator depends on their weight. The manufacturer selects the optimal one when assembling the box. But lovers of fast driving change them to heavier ones. With weighted rollers, a scooter with a CVT accelerates more slowly at the start, but after reaching maximum speed, the engine gives out a speed of 10-15 km / h more than with factory rollers.

Using lighter weight rollers leads to the opposite principle: the scooter starts abruptly, butit's hard for him to reach top speed.

Changing the spring rate also affects the speed. Stretched and weak, it will not be able to tightly press the cheeks of the driven pulley. This will cause the belt to run constantly at a smaller radius than necessary. A too stiff spring, on the contrary, will not allow to reduce this radius (respectively, increase the speed of the driven pulley) and develop the maximum speed of the scooter.

Repair of the variator on a scooter. Replacing items

Change in the acceleration rate and the appearance of extraneous noise in the variator indicate that some part (or parts) is worn out and needs to be replaced.

To find out the cause of the malfunction, the variator should be disassembled:

1. Remove the cover. We do this carefully so as not to damage it. As a rule, the variator cover on scooters has a sealing gasket. It is necessary to assess its condition and, if necessary, change it.
2. To remove the belt from the variator, you need to remove the drive pulley. And you can get to it only by removing the retaining ring, clutch and gear.
3. When the belt and pulley halves are ready, remove the rollers.
4. All items must be carefully inspected and tested. Serviceable cheeks have a flat surface without chips and scuffs. The belt must not contain any lubricants. If it looks shabby, then it's time to change it.
5. After identifying faults, we assemble the variator in reverse order.

There are two main features that determine the quality of the variator: belt movement and engine speed. ATin a working variator, the belt does not slip in the pulleys. But, if the motor roars, but the scooter does not move, this is the first signal that it is time to look inside the device and examine the condition of the belt and spring.

The engine's operating speed must correspond to its maximum power. If this does not happen, it's time to start setting up the variator.