RU2155427C1 - Voltage converter case - Google Patents

Abstract

FIELD: electrical engineering for rail transport and other industries. SUBSTANCE: proposed case has walls with longitudinal and transverse groups of parallel ribs on their surfaces. Novelty is that mentioned groups of ribs are arranged on different sides of walls and are made of L-shaped strips. Longitudinal groups of parallel ribs are arranged on inner or outer sides of wall and transverse groups, on outer or inner sides. EFFECT: improved heat transfer; reduced mass and increased mechanical strength of case. 3 dwg

Description

 The invention relates to the field of electrical engineering, in particular to the construction of electric machines, and can be used in the design of buildings of powerful voltage converters used to power rail vehicles.

 A well-known case of an electric machine containing walls, one of which has parallel blinds of a certain configuration (see the Handbook of converting technology, under the editorship of IM Chizhenko. Kiev: Technique, 1978, p. 288).

 However, the known housing design cannot be effectively used for large-sized powerful voltage converters, as this will require the use of thick sheet metal or the use of complex devices to strengthen the housing if thin sheet material is used.

 A known housing of a voltage converter (bed of an electric machine) containing walls on the surface of at least one of which are longitudinal and transverse groups of parallel ribs (see AS USSR N 1403240, class H 02 K 5/04 from 24.07 .86).

 Despite the originality of this design, there are drawbacks, especially in the insufficiently efficient heat transfer, since the cast surface gives off heat worse than the rolled surface.

 The technical result is an increase in heat transfer while providing lightness and strength of the structure.

 To do this, in the housing of the voltage transducer containing the walls, on the surface of at least one of the longitudinal and transverse groups of parallel ribs are located, the above groups of ribs are located on different sides of the wall and are formed from plates of the L-shaped profile, and the longitudinal group of ribs is located on the inner side of the wall, and the transverse group of ribs is located on the outer side of the wall or the longitudinal group of ribs is located on the outer side of the wall, and the transverse group of ribs is located on the inner s side wall.

According to the invention in the housing
0.2 <h1 / L1≤0.6, where h1 is the step between the ribs located on the outside of the wall,
L1 is the height of the above ribs;
0.5 <h2 / L2≤1.5, where h2 is the pitch between the ribs located on the inner side of the wall,
L2 is the height of the above ribs;
0.05 <S / L1≤0.13, where S is the thickness of the rib located on the outside of the wall,
L1 is the height of the rib located on the outside of the wall;
L-shaped plates are strengthened by contact spot welding, moreover
1,5 <h3 / d≤3, where h3 is the step between the welding points,
d is the diameter of the welding point.

 The essence of the invention lies in the fact that the location of the longitudinal and transverse groups of parallel ribs on different sides of the wall made it possible to increase the structural strength of the housing.

 The implementation of the wall of the rolled material and the ribs of the plates of the L-shaped profile made it possible to increase the efficiency of heat transfer.

 Comparison of the invention with the prototype allows us to claim compliance with the criterion of "novelty", and the absence of distinctive features in the analogues indicates compliance with the criterion of "inventive step".

 Preliminary tests confirm that the criterion is “industrial applicability”.

 In FIG. 1 is a front view of the device of FIG. 2 is a side view, and in FIG. 3 - section along aa.

 The housing contains walls 1, on the surface of at least one of which are longitudinal and transverse groups of parallel ribs 2 and 3, located on different sides of the wall and formed from plates of an L-shaped profile.

 The longitudinal group of ribs 2 can be located on the inner (or outer) side of the wall 1, and the transverse group of ribs 3 can be located on the outer (or inner) side, respectively.

 The plates of the L-shaped profile are made of rolled material and strengthened by contact spot welding with a certain diameter of the welding point 4.

In this case, the following relation should be satisfied
0.2 <h1 / L1≤0.6, where h1 [mm] is the pitch between the ribs located on the outside of the wall,
L1 [mm] is the height of the outer rib 2.

 This ratio ensures that, when the flow around the ribs 2 of the outer side of the wall 1 flows in such a viscosity in the region immediately adjacent to the surface of the ribs 2 and forms the aerodynamic boundary layer of the inhibited flow, at which the boundary layer does not close and the finning coefficient takes an optimal value.

For the ribs 3 of the inner side of the wall 1, the relation
0.5 <h2 / L2≤1.5, where h2 [mm] is the step between the ribs located on the inner side of the wall,
L2 [mm] - rib height 3.

 This ratio ensures that when the ribs 3 of the inner side of the wall 1 are surrounded by the flow of the surrounding medium, such a viscosity in the region directly adjacent to the surface of the ribs 3 and forming the hydrodynamic boundary layer of the inhibited flow, at which the boundary layer does not close, and the finning coefficient takes an optimal value.

In addition, the following relation should be satisfied
0.5 <S / L1≤0.13, where S [mm] is the thickness of the rib 2,
L1 [mm] - rib height 2.

This ratio is selected taking into account the minimization of the material consumption of the casing while optimizing the thermal conductivity of the rib. The following relation should also be satisfied
1,5 <h3 / d≤3, where h3 [mm] is the step between the welding points,
d [mm] is the diameter of the welding spot.

 This ratio is obtained through a thorough experimental study of thermal processes under the condition of ensuring a minimum thermal transition resistance between the base of the body and the ribs and the technological capabilities of resistance welding.

 All of the above relations were found by solving the equations of heat conduction and using empirical dependences obtained on the basis of the similarity theory, under the condition of ensuring maximum heat removal with minimal heat pressure, reducing material consumption and technological production capabilities.

 With these ratios, the thermophysical design of the transducer casing is effective, which ensures optimal thermal resistance while minimizing mass, dimensions and aerodynamic drag.

 Thus, the use of contact spot welding allows to strengthen the L-shaped plates on a large surface of thin-walled metal, obtaining an increased heat transfer area, since direct thermal contact between the L-shaped plates and the body wall is carried out only in places of spot welding.

 The location of the longitudinal and transverse groups of L-shaped plates perpendicular to each other can significantly strengthen the wall of the housing without increasing its thickness.

Claims (1)

 The housing of the voltage transducer containing walls, at least one of which is provided with longitudinal and transverse groups of parallel ribs, characterized in that the above groups of parallel ribs are formed from a plate of a L-shaped profile, while the longitudinal groups of parallel ribs are located on the inner or outer sides of the wall and the transverse groups of parallel ribs are located on the outer or inner sides of the wall.

Images