RU204267U1 - Brake resistor - Google Patents

Abstract

The utility model relates to electrical engineering, namely to electrical devices designed to operate on the rolling stock of rail transport, and can be used in systems for electrodynamic cooling of electric trains and cooled by an incoming air flow by convective heat removal. The braking resistor is a rectangular case made of stainless steel, inside which a resistive unit is installed. The body consists of two end walls, two side walls and four top covers, fastened together and fixed to the supports, which are made in the form of three support beams installed on the roof of the device at an equidistant distance from each other. The casing is closed at the bottom with two lower covers; perforation is made in the lower covers and in the two upper walls of the casing to ensure cooling of the resistive unit. The other two walls and top covers are covered with thermal shields that protect the car from the thermal effect of the resistive unit. A box is fixed on the front end wall of the case, which serves to protect the connection of external power cables to the output busbars of the device, a cutout is made in the wall of the box to provide access to the output busbars, the cutout is closed with a removable cover that is bolted to the box. On the end walls of the device body there are grounding bolts, and also four brackets with bushings are fixed, designed to limit the movement of the safety cables. The resistive unit consists of six resistive units, having a row arrangement, made of rectangular plates with ends bent in opposite directions. The resistive units are fixed to the end walls of the housing through support insulators and are interconnected by copper buses in accordance with the electrical schematic diagram. To connect to the electric circuit of the electric train, two buses are brought into the box, fixed on ceramic support insulators, on the top wall of the box there is an opening for entering external power cables. For fastening external power cables, M10 screws with washers and nuts are installed on the busbars, external cables are led into the box through the cable entry located on the box. The resistive unit is a tape installed through insulators and on two pins, the tape with insulators is fixed on the bracket pins. Support insulators are fixed on the brackets, which serve to fix the resistive unit in the housing. The tape consists of individual elements, with stamped stiffeners, and output plates, spot-welded into a single structure. The technical result consists in increasing the reliability of the braking resistor design, maximum dissipated power with a minimum weight, effective natural cooling and protection of the equipment of metro cars from thermal effects, since there is a minimum effect of temperature on other equipment of metro cars during rheostat braking. 7 ill.

Description

The utility model relates to electrical engineering, namely to electrical devices designed to operate on the rolling stock of rail transport, and can be used in systems for electrodynamic cooling of electric trains and cooled by an incoming air flow by convective heat removal.

The braking resistor is a component part of an electric train, which is used in subway cars and belongs to traction electric devices.

From the prior art, a braking resistor module of an electric locomotive is known, which includes a module body and blocks of braking resistors with air-permeable resistive elements in heat and electrical insulating enclosing structures with inlet and outlet windows and electrical connections, as well as devices for air intake and exhaust, a fan motor and a discharge channel, which, together with the enclosing structures of the braking resistor units, form a ventilation air path. At the same time, the module body is made with a system of vertical paired guides with stops fixed by means of support and fastening fittings, and the brake resistor unit is a set of separate resistive elements made with sidewalls with shoulders and their own heat and electrical insulating enclosing structures with input and output windows, forming an integral block with a row arrangement when they are inserted into the corresponding vertical paired guides with their shoulders hanging on the stops of the vertical guides of the module body and fixing them with threaded connections on the stops of the vertical guides with the possibility of individual vertical mounting and dismantling of each resistive element and forming their own fencing structures, a single cooling channel in the ventilation air path between the discharge channel and the device for air exhaust with direct abutment to them. Moreover, the module case is made with removable roof sheets (RU181839, IPC B06L7 / 00, publ. 07/26/2018).

The disadvantage of the known module of braking resistors of an electric locomotive is the presence of forced air cooling. In the event of a fan motor malfunction, the only way to cool the braking resistor module, since there are no additional ventilation holes in the enclosing structures, ventilation of the entire braking resistor block above stops, as a result of which the braking resistor module loses its functionality.

A known module of braking resistors of an electric locomotive, including an axial motor-fan, a diffuser, a block of braking resistors, electrical connections of current leads of resistive elements among themselves, a node of electrical connections to the power electrical circuits of an electric locomotive and a supporting frame body with devices for air intake and exhaust and service hatches, a housing made in the form of a rectangular parallelepiped with an external frame with connecting flanges. On the side walls inside the body, a system of paired guides open from above, located in a vertical plane opposite each other, is made with the help of support and fastening fittings, in which, with the help of their sidewalls, air-permeable resistive elements are installed in rows along the longitudinal axis of the body and screwed down with threaded connections to form a block of braking resistors with the possibility of individual removal of each resistive element from the housing. The electrical connections of the current leads of the resistive elements to each other are made on top of the braking resistor block by rigid removable electric buses using threaded connections, and the unit of electrical connections to the power electrical circuits is in the form of a box on the outside of one of the side walls with a cable connection. The casing also has a transverse wall with a hole in the middle for installation on the outside of the motor-fan, which forms an open-top compartment of the motor-fan, reinforced from the end part by horizontal cross beams, and from the inside - a single-channel diffuser, in which the larger section is rectangular and adjacent to the braking resistor unit. The case is closed from above with removable service covers. Housings with through air channels, the outer openings of which are covered with protective nets, are attached to the ends of the body with threaded connections. One of the shrouds closest to the fan motor serves as an air intake device, the other as an air exhaust device and is equipped with a sill, while a rectangular duct is installed between the casing, which acts as an air exhaust device, and the braking resistor unit, and the bottom of the housings and the housings are equipped with drain holes (RU181840, IPC B60L 7/00, B60T 8/00, publ. 07/26/2018).

Among the disadvantages of the known solution can be noted the presence of forced air cooling, which increases the weight and dimensions of the resistor and, as a consequence, complicates the design. Also, the disadvantage of this resistor is the power consumption of the fan motor.

A block of self-ventilated resistors for electric public transport is known, which has resistive elements installed in rows in the supporting and fastening fittings and current leads connected to the electrical connection unit. The resistive elements are electrically and mechanically interconnected. Each of the rows of resistive elements is composed of vertically oriented air-transparent spirals wound from a round refractory shaped metal wire with a diameter of 1.5-5 mm, with a spiral pitch of at least 1.5 wire diameters and a winding diameter of no more than 12 wire diameters. The spirals are installed between the upper and lower current-carrying holders and are fixed to them through their extreme turns (RU 2570923, IPC B60L 7/02, H01C 3/00, H01C 1/014, publ. 20.12.2015).

The design of this solution is aimed at reducing the operating temperature of the resistor block while reducing its size and weight. The disadvantage is the complexity and low-tech design due to the presence of nested elements in the body, such as the outer and inner frames and the fastening of the inner frame in the casing, the complexity of assembly in a confined space. Also, the design drawback is the absence of additional ventilation holes in the enclosing parts, which leads to poor cooling when the vehicle stops, and the presence of welded structures causes increased thermal stresses and deformations in them, which can cause structural destruction, that is, this reduces the reliability of the structure.

The closest in technical essence to the claimed utility model is a powerful air-cooled resistor containing a housing made in the form of a casing on a mounting frame with an in-line arrangement of air-permeable resistive elements, supports, inlet and outlet vents, resistive elements have a two-row arrangement with a horizontal orientation of the resistive elements, the casing is made of frameless composite, including the enclosing structures that form a prismatic space for the placement of resistive elements, the enclosing structures themselves are interconnected and fixed with naramebolt joints and consist mainly of flat sheet parts, except for the roof, made with pyramidal protrusions with a bulge upward with tops above the most heated points of resistive elements, and side walls made in their upper parts with bent sides directed towards the longitudinal axis of the casing, while in the lower parts of the end and side walls There are arrays of ventilation openings in the sides and in the bent sides, continuous arrays of ventilation openings are made in the roof parts, continuous arrays of stamped ventilation louvers are made in the bottom parts, the supports are made in the form of four dampers installed at the ends of the installation frame. At the same time, a partition was introduced into the composition of the enclosing structures, dividing the prismatic space formed by the enclosing structures into two sections, each row of resistive elements consists of two resistive elements, the roof parts are made identical in an amount equal to the number of sections of the prismatic space formed by the enclosing structures, the casing is additionally fixed to the frame with struts, and the ventilation holes are rectangular (RU168740, IPC H01C 3/10, publ. 17.02.2017).

The disadvantages of the prototype are that it has a large overall dimensions, the absence of heat shields using heat-insulating material that protect the vehicle from the thermal effects of resistive elements and the installation of a resistor only on the roof of the vehicle. Since the roof sheets have ventilation openings and are not protected from the ingress of foreign particles, for example, graphite particles from the pan of the pantograph, etc., if foreign particles get inside, the insulation of the resistive elements may deteriorate and subsequently deteriorate the operability of the resistor as a whole.

The technical result achieved when using the claimed utility model consists in increasing the reliability of the braking resistor design, maximum dissipated power with minimum weight, effective natural cooling and protection of metro car equipment from thermal effects, since there is a minimum effect of temperature on other metro car equipment during rheostat braking.

The technical result is achieved by the fact that the braking resistor is a rectangular case made of stainless steel, inside which a resistive unit is installed. The body consists of two end walls, two side walls and four top covers, fastened together and fixed to the supports, which are made in the form of three support beams installed on the roof of the device at an equidistant distance from each other. The casing is closed at the bottom with two lower covers; perforation is made in the lower covers and two upper walls of the casing to ensure cooling of the resistive unit. The other two walls and top covers are covered with thermal shields that protect the car from the thermal effect of the resistive unit. A box is fixed on the front end wall of the case, which serves to protect the connection of external power cables to the output busbars of the device, a cutout is made in the wall of the box to provide access to the output busbars, the cutout is closed with a removable cover that is bolted to the box. On the end walls of the device body there are grounding bolts, and also four brackets with bushings are fixed, designed to restrict the movement of the safety cables. The resistive unit consists of six resistive units, having a row arrangement, made of rectangular plates with ends bent in opposite directions. The resistive units are fixed to the end walls of the housing through support insulators and are interconnected by copper buses in accordance with the electrical schematic diagram. To connect to the electric circuit of the electric train, two buses are brought into the box, fixed on ceramic support insulators; on the top wall of the box there is an opening for entering external power cables. For fastening external power cables, M10 screws with washers and nuts are installed on the busbars, external cables are led into the box through the cable entry located on the box. The resistive unit is a tape installed through insulators and on two pins, the tape with insulators is fixed on the bracket pins. Support insulators are fixed on the brackets, which serve to fix the resistive unit in the housing. The tape consists of separate elements, with stamped stiffeners, and lead plates, spot welded into a single structure.

FIG. 1 shows a front view of a braking resistor, FIG. 2 shows view A in FIG. 1 braking resistor, Fig. 3 shows a left side view of a braking resistor, FIG. 4 shows a top view of the braking resistor, FIG. 5 shows a front view of the elements of the braking resistor, FIG. 6 shows a left view of the elements of the braking resistor, FIG. 7 shows a resistive node, FIG. 8 shows an electrical schematic diagram of a braking resistor with the designation of the elements of the resistor (designations of the elements of the resistor are indicated conditionally).

The design of the claimed device consists of functional elements: 1 - end walls, 2 - side walls, 3 - top covers, 4 - support beams, 5 - bottom covers, 6 - thermal shields, 7 - box, 8 - cutout in the box, 9 - removable cover, 10 - grounding bolts, 11 - brackets, 12 - resistive units, 13 - support insulators, 14 - tape, 15, 16 - insulators, 17 - bracket, 18 - copper busbars, 19 - lead busbars, 20 - ceramic support insulators ...

The braking resistor is a rectangular case made of stainless steel, inside which a resistive unit is installed.

The casing consists of two end walls 1, two side walls 2 and four top covers 3, fastened together and fixed to three support beams 4. The casing is closed from below by two bottom covers 5. To ensure cooling of the resistive block in the bottom covers 5 and one of the end 1 and side walls 2 of the body are perforated. Two other end 1, side 2 walls and top covers 3 are closed with thermal shields 6, which protect the car from the thermal effects of the resistive unit. On the front end wall 1 of the housing, a box 7 is fixed, which serves to protect the connection of external power cables to the output busbars 20 of the resistor. A cutout 8 is made in the wall of the box 7 to provide access to the lead-out rails 19. The cutout 8 is closed by a removable cover 9. The cover is attached to the box 7 with bolts. On the end walls 1 of the resistor housing there are grounding bolts 10. On the end walls 1 there are four brackets 11 with bushings. The brackets 11 are designed to restrict the movement of the safety cables (not shown in the drawing).

The resistive unit consists of six resistive nodes 12, fixed to the end walls 1 of the resistor body through support insulators 13.

The resistor unit 12 is a tape 14 installed through the insulators 15, 16 on two pins. The tape 14 with insulators 15, 16 is fixed on the studs of the bracket 17. On the brackets 17, support insulators 13 are fixed, which serve to fasten the resistive unit 12 in the housing. The tape 14 consists of separate elements, with stamped stiffeners, and lead plates, spot welded into a single structure.

Resistive nodes 12 are interconnected by copper buses 18 in accordance with the electrical circuit diagram. To connect to the electrical circuit of the electric train, the resistor box 7 is supplied with two output buses 19, fixed on ceramic support insulators 20. On the top wall of the box 7 there is an opening for entering external power cables. M10 screws with washers and nuts are installed to fix external power cables on output rails 19. External cables are led into the box 7 through the cable entry located on the box 7.

In the design of the braking resistor, a resistive unit is used, disclosed in patent RU168031, IPC B60L 7/02, H01C 3/10, H01C 1/016, publ. 17.01.2017.

The brake resistor works as follows. Install the resistor under the bottom of the car on three support beams 4 (Fig. 4) so that the resistor is located across the width of the car, that is, across. With rheostat braking of metro cars, the resistor is cooled by sucking in outside air through the bottom covers 5 (Fig. 1). The flow of cooling air passes through the resistive unit (Fig. 5), after which the heated air comes out in a certain direction through the perforated holes in the end 1 and side 2 (Fig. 1 and Fig. 3) walls. The body, which includes end walls 1 and side walls 2, provides effective cooling due to the fact that the flow of hot air (heat) comes out only in a certain direction, thereby protecting other parts of metro cars from overheating, as well as thermal shields 6, which provide protection of metro car equipment from thermal effects. The horizontal arrangement of resistive units 12 (Fig. 5) allows to obtain a compact design of the resistor in height, providing good composability under the car bottom. When servicing the resistive nodes 12, one of the lower covers 5 (Fig. 1) can be removed, which ensures the simplicity of the work carried out. In addition, a safety cable (not shown in the drawing) is provided in the resistor. The essence of this device is as follows. A safety cable is pushed through the hole in the bracket 11 located on the front end wall 1, then it passes along the bottom perpendicular to the resistor and pushes through the hole of another bracket 11 installed on the opposite end wall 1 and then is attached to the bottom of the car. Thus, the safety wire protects the resistor from falling.

In comparison with the known technical solution, the claimed utility model increases the reliability of the braking resistor design, maximum power dissipation with minimum weight, effective natural cooling and protection of the metro car equipment from thermal effects, since there is a minimum temperature effect on other metro car equipment during rheostat braking. In addition, the braking resistor has low noise, compact housing, low inductance, since there is no ventilation unit. The design of the braking resistor housing is arranged in such a way that the flow of hot air (heat) comes out only in a certain direction, thereby protecting other parts of metro cars from overheating. The walls and top covers of the braking resistor are covered with thermal shields, which can significantly reduce the thermal effect of the resistive unit on equipment installed in the immediate vicinity, cable lines, etc.

Claims (1)

A braking resistor containing a housing with resistive elements installed in it, supports, ventilation holes, characterized in that a rectangular housing made of stainless steel, inside which a resistive unit is installed, the housing consists of two end walls, two side walls and four top covers , fastened to each other and fixed to the supports, which are made in the form of three support beams installed on the roof of the device at an equidistant distance from each other, from the bottom the body is closed by two lower covers, to ensure cooling of the resistive block in the lower covers and two upper walls of the body, perforation is made , two other walls and top covers are closed with thermal shields that protect the car from the thermal effect of the resistive unit, a box is fixed on the front end wall of the body, which serves to protect the connection of external power cables to the output buses of the device, a cutout is made in the wall of the box to provide access to the output buses, the cutout is closed with a removable cover, which is bolted to the box, there are grounding bolts on the end walls of the device case, and four brackets with bushings are fixed, designed to restrict the movement of the safety cables, and the resistive unit consists of six resistive nodes, having a row arrangement, made of composite of rectangular plates with ends bent in opposite directions, resistive nodes are fixed to the end walls of the body through support insulators and are interconnected by copper buses in accordance with the electrical schematic diagram, for connection to the electric circuit of the electric train, two buses are brought into the box, fixed on ceramic support insulators , on the top wall of the box there is a hole for entering external power cables, for fastening external power cables on the buses, M10 screws with washers and nuts are installed, external cables are brought into the box through a cable entry located on the box, and the resistive unit is It is a tape installed through insulators and on two pins, the tape with insulators is fixed on the studs of the bracket, on which the support insulators are fixed, which serve to fasten the resistive unit in the case, the tape consists of individual elements with stamped stiffeners and lead plates, welded by spot welding into a single design.

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