RU2734038C1 - Butt pad for running rails with improved conductivity - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to transport machine building. Standard butt pad is equipped with a copper insert as an electric connector, which is placed in the bosom between the rail neck and the strap neck. Configuration of insert, area of adjacency and section are selected so that during joint assembly sufficient conductivity for currents of subway traction system is provided, and insert sustained long-term permissible currents on running rails of subway. Design makes it possible to do without welded electric connectors on running rails of subways and electrified railways.

EFFECT: providing passage of maximum allowable current of traction network of underground.

1 cl, 1 dwg

Description

Usage: when assembling the joints of the running rails of the subway.

State of the art. Until now, on all domestic metros, to compensate for additional resistance at prefabricated electrically conductive joints, butt electrical connectors made of copper flexible wire with a cross-sectional area of 95 sq. mm, which are welded to the side non-working edges of the rail heads, see the photo in the appendix.

On electrified railways, where an alternating current of 300 A and a voltage of 25 kV, the maximum permissible current for an electrical connector - 368 A, significantly exceeds the average in the contact network - 300 A (for each running rail there is 150 A), the situation is quite satisfactory.

On the subway, at a voltage of 825 V, the starting currents of only one train reach 8000 A, and the continuous permissible current on the contact rail is 5000 A. On each running rail, a continuous permissible current of 2500 A must be provided, on each plate at least 1250 A. Standard plates are used: 1P65 Double-headed rail pad for wide gauge railways. GOST 33184-2014. 4 electrical connectors on each rail (just such a mistake is replicated on the contact rail!) - unacceptable, besides, it is difficult to achieve a high-quality welded joint.

The cardinal solution to the problem - to make a copper plate - is unacceptable in terms of cost and entails unnecessary bureaucratic obstacles in the form of product strength tests, etc.

However, it is possible to place the electrical connector in the groove that forms in the space between the rail neck and the pad. Now the electrical connector will be a copper insert 286 mm long, with a cross-sectional area of 1580 square meters. mm and a configuration inscribed on one side in the journal of the running rail, on the other in the journal of the standard lining, see Fig. 1.

Legend in Fig. 1 - The device of the insert-electrical connector in the bushing of the running rail:

1 - running rail

2 - butt plate

3 - insert-electrical connector

4 - zone of contact of the liner to the rail neck

5 - milling area on the pad

6 - place of sinus protection with graphite grease

7 - hole for the tightening bolt.

From the inside, the strip [2] is milled to a depth of 3 mm, where the insert-electrical connector [3] is pressed in. The recess [5] prevents the longitudinal displacement of the insert [3] relative to the lining [2] in the event of a temperature shift of the rail itself [1]. Thus, we supply the standard pad with an insert with which the pad is a single whole; this is the invention.

The thickness of the liner is deliberately made larger by 2 mm relative to the width of the bosom and on the entire surface of the liner [4], adjacent to the rail neck, before assembling the joint, a 1 mm layer of Superkont grease is applied. When tightening the lining bolts with a force of 80 daN * m per bolt, excess lubricant is squeezed out, and copper particles in the lubricant are compressed, ensuring reliable contact of the liner with the rails. The area of the contact surface of the liner and the neck of the rail is at least 6850 sq. mm to each of the two ends of the rail. To prevent corrosion of the liner from moisture in the sinus, at both ends of the liner [6] and the gap between the ends of the rails are coated with graphite grease.

The lining with a copper insert can withstand a long-term maximum permissible current of more than 2950 A, and with an aluminum insert - more than 2300 A, which significantly exceeds the required maximum continuous current according to the properties of the subway traction network with a voltage of 825 V.

The essence of the invention consists in the transfer of a butt electrical rail connector in the form of a copper or aluminum insert into the bosom between the rail strip and the rail neck. This makes it possible to multiply the cross-section of the electrical connector to ensure the passage of the maximum permissible currents of the subway traction network and to abandon the welded electrical connectors on the running rails of the subway (the welded joint is unreliable, poorly controlled, and the place of welding of the connectors leads to defective rails). The latter can be applied to running rails of electrified railways.

Claims (1)

Butt strip for running rails with improved conductivity with a copper insert as an electrical connector that fits in the bore between the rail and the strip and withstands continuous currents on underground running rails.

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