JPH0147885B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a contact device for a load tap selector for a tap-changing transformer as defined in the preamble of claim 1. Such a contact device is known from German patent DE-PS859650.

This contact device has the disadvantage that the contact roller rolls over the edge of the fixed tap contact during the rolling process from the fixed tap contact. This edge wears out strongly and irregularly, especially due to arc erosion, which makes it even more difficult to keep the point and position of contact separation constant over a long period of time. This irregular erosion of the edges and contact rollers furthermore results in difficulties due to rolling contact or rolling separation of the contact rollers from the fixed tap contacts. For example, displacements occur in the contact roller, resulting in problems in maintaining the track of the contact roller.

It is an object of the present invention to provide for the above-mentioned known contact device a contact separation that is as precisely limited as possible over a long period of time and to ensure that the trajectory of the contact roller is maintained, thereby making optimum use of the erosion amount. It is. This object is achieved by the measures of the invention according to the features of patent claim 1.

A feature provided by the present invention is that there is no contact separation or multiple occurrences on fixed tap contact edges. The condition of contact separation occurs only at the contact surfaces of the tap contacts, which allows the use of large amounts of erosion. Furthermore, a safe and reliable movement of the contact rollers takes place.

Other embodiments of the invention which provide features that allow the creepage distance between the individual tap contacts to be increased are as set forth in claim 2.

Embodiments of the invention are described in detail below in conjunction with the accompanying drawings.

As is clear from the accompanying drawings, a large number of fixed tap contacts 1, 2, 3, 4 are seated on the wall of the cylinder 5 and have a connecting part 14 on the outside, arranged in a circle.
and three contact rollers 6, 7, 8 carried on an insulating carrier 9 fixed on a rotatable insulating tube 10 (FIG. 3). Each contact roller 6 , 7 , 8 is supported by a respective shaft 13 which is supported on a contact carrier 9 . The contact rollers 6, 7, 8 are moved from the fixed tap contact 1 to the adjacent tap contact 3 by means of the insulator tube 10 and the contact carrier 9.
Then, it can be rotated stepwise on a circle from tap contact 1 to tap contact 2 or vice versa. Insulator rollers 61, 62, 7 are provided on both sides of the contact rollers on the shaft 13 alongside each contact roller.
1, 72, 81, and 82 are arranged. In each switching step, these insulator rollers are connected to control cams 11, 12 and 21, 2 arranged above and below each tap contact 1, 2, 3, 4.
2, 31, 32, etc. These control cams 11, 12, 21, 22, 31, 32,
41, 42 are insulator rollers 71, 72 in which the central contact roller 6 is located approximately in the center of the contact 1 of the tap contact in the disclosed operating state, and the other two contact rollers 7, 8 are juxtaposed, respectively. Alternatively, the control cams 81, 82 and the control cams 11, 12 are formed so as not to come into contact with the tap contact 1. This arrangement forms the contact roller 6 as the main switching contact in the usual manner, and the two other contact rollers 7, 8 also act as resistive switching contacts.

For example, the switching operation from tap contact 1 to adjacent tap contact 3 is performed as follows. By rotating the insulator tube 10, the contact carrier 9 is moved in the direction of the arrow in the required switching step. At this time, the contact roller 6 rotates along the contact surface of the tap contact 1 to the adjacent one,
The rear roller 7 is thereby released from the control cams 11 and 12 and at the same time the tap contact 1
rolling on the contact surface of the The upper insulator roller 81 rolls past the upper control cam 11 and the lower insulator roller 82 then moves from the lower control cam 12 to the lower control cam 32 of the tap contact 3. When the two insulator rollers 61, 62 of the contact roller 6 roll onto the control cams 11 and 12, the contact roller 6 is moved away from the contact surface of the tap contact 1, ie reaches the edge of the tap contact. If only the rear contact roller 7 is now on the tap contact 1, a resistor is connected in a known manner. Further, when the rear contact roller 7 rolls along the contact surface of the tap contact 1, the insulator rollers 81, 82 of the front contact roller 8 are lowered over the control cams 31, 32, so that the contact roller 8 is turned Contact is made with the contact surface of the contact 3. At this time, the upper contact roller 61 is connected to the control cam 1.
1 further passes over the central contact roller 6
is guided onto the lower control cam 32 of the tap contact 3 by the lower insulator roller 62. Further, the control cams 11, 1 of the tap contacts 1
2, the two insulating rollers 71, 72 of the rear contact roller 7 reach and at the same time separate this contact roller 7 from the tap contact 1, ie a separation at the edge of the tap contact is avoided. The central contact roller 6 is
During its descent over the control cams 31, 32 of the tap contact 3, its insulator rollers 61, 62 contact the tap contact 3, and the insulator rollers 81, 82 of the front contact roller 8 furthermore contact the tap contact. 3 on the control cams 31, 32, so that the contact roller 8 does not make contact with the tap contact and the central contact roller 6 reaches the central part of the tap contact 3. The rear contact roller 7 has its insulator rollers 71, 72 and tap contacts 3
The contact state with the tap contact is terminated by the control cams 31 and 32. This completes the switching operation.

In particular, the control cams 11, 12, 21, 22, 31,
In the particular arrangement of 32, each upper control cam is disposed downwardly and oppositely. This serves to increase the creepage distance between the fixed tap contacts. For example, the control cams 31, 32 of the tap contact 3 are required for reliable switching to the control cams 41, 42 of the adjacent tap contact 4, so that an insulator roller is placed between the control cam and the adjacent tap contact. It should be noted that it is possible to avoid stagnation. On the other hand, control cams that extend to other tap contacts essentially reduce the creepage distance between the tap contacts. Due to the staggered arrangement of the control cams 31 and 32 or 41 and 42, the guidance of the insulator rollers can take place during the switching step, one above and the other below, so that no penetrating control cams are required. This makes it possible to increase the above-mentioned creepage distance between the respective tap contacts.

[Brief explanation of drawings]

FIG. 1 is a simplified top plan view of the device of the present invention. FIG. 2 is a side view from inside the circle.
FIG. 3 is a perspective explanatory view. The correspondence of the main reference numbers in the attached figures is as follows. 1, 2, 3, 4: fixed tap contact, 5: cylinder, 11, 12, 21, 22, 31,
32, 41, 42: Control cam, 6, 7, 8: Contact roller, 61, 62, 71, 72, 8
1,82: Insulator roller.

Claims (1)

[Scope of Claims] 1. It has a plurality of fixed tap contacts disposed on the circumference and a movable switching contact that can rotate in steps on the circumference, and the movable switching contact is connected to a contact roller. and with each switching step rolls away from one stationary tap contact and rolls into contact with an adjacent stationary tap contact, in which case the contact roller is driven by a shaft guided in the contact carrier. In a contact device for a load tap selector for a tap-changing transformer, which is configured to be mounted, each shaft 13 is provided with at least one insulating roller 61, 6 other than the contact rollers 6, 7, 8.
2, 71, 72, 81, 82 are arranged;
In addition to fixed tap contacts 1, 2, 3, 4, control cams 11, 12, 21, 22, 31, 32, 4 made of insulators are provided on the track of the insulator roller.
1, 42 are arranged, said insulator roller rolling on a control cam before the contact roller rolls away from the fixed tap contact during the switching process, thereby causing separation of the contact roller from the fixed tap contact. A contact device characterized in that: 2. In the contact device for a load tap selector for a tap-changing transformer according to claim 1, insulator rollers 61, 62 or 71, 72 or 81, 82 are provided on both sides of the contact rollers 6, 7, 8. A control cam 11, 12 or 21, 22, etc. is arranged in the corresponding upper and lower parts of the fixed tap contacts 1, 2, 3, 4, in which case the tap contacts e.g. 3 upper control cams e.g. 3
1 extends in the direction of an adjacent tap contact, e.g. 4, and a control cam, e.g.
In this case, the control cams of adjacent tap contacts are
The extension of the control cam, e.g. 31, arranged on the upper side and the extension of the control cam, e.g. 41, arranged on the lower side of the adjacent tap contact, e.g. contact device installed in