Dry type transformer on load switch

At present, this kind of switch is mainly used in oil immersed transformer, and the switch also takes transformer oil as insulation medium. Some switches for dry-type transformers are also derived from oil immersed switches. The structural form has not changed much, but the structural size has been increased. Most of these switches are cylindrical in shape, and the switching switch part uses a rotating cam to open or connect the on-off contacts. The cam surface is affected by rolling and sliding friction forces. The stress conditions are bad, the vibration is strong, the noise is large, and the service life is short. In the tap selector, the Geneva mechanism is used for transmission. The moving contact is a wide clamping plate, which can bridge two contacts. It is a live moving contact with uneven speed and unstable movement, which is easy to cause contact burning. The fixed contact arrangement is mainly cylindrical, while the tap contact of dry-type transformer is a plane type, so the leads are staggered, which is easy to cause the phenomenon of short circuit between lines or wrong connection of line ends. Due to the above problems, this kind of switch can not meet the needs of dry-type transformer.
 

　　the upper box body is set on the lower box body. When the eccentric wheel rotates to drive the upper box body to move, for example, the upper box body moves to the right, the lower box body is still under the action of the limiter, and the spring is compressed, that is, the upper box The left inner wall of the body is pressed on the upper half of the left end of the spring, and the lower half of the right end of the spring is pressed on the inner wall of the right end of the lower box. When the eccentric wheel continues to rotate and the upper box is about to reach the right dead center of the upper box body, the eccentric wheel or the convex point of the upper box body presses the control end of the limiter to release the stopper, and the lower box body moves rapidly to the right under the action of the spring force In the same way, when the eccentric wheel drives the upper box to move to the left, the lower box moves quickly to the left. A cam is arranged on the curved plate of the lower box body. The cam is connected with the moving contact of the on-off contact through the insulator. When the curved plate moves left or right quickly with the lower box, the cam drives the moving contact of the on-off contact up or down, so as to open or close the on-off contact, and the static contact of the on-off contact head is fixed on a fixed plate. The tap selector is under the change-over switch and is composed of intermittent gear pair, singular contact lead screw, singular contact moving plate, odd fixed contact lead screw, even contact moving plate and even fixed contact. Intermittent gear pair is composed of intermittent gear and gears on both sides, and one gear is fixed at odd number On the upper end of the contact lead screw, another gear is fixed on the upper end of the even number contact lead screw, the singular contact screw is connected with the moving plate of the singul