FR2655472A1 - MAGNETIC CIRCUIT WITH PHASE BAND FOR ALTERNATING CURRENT ELECTRICAL EQUIPMENT. - Google Patents

Abstract

A magnetic circuit 10 comprises a stack of thick sheets 12, 14, 16, and a phase shift ring 18 partially surrounding the pole surface 30, being slightly recessed with passage in a groove 28 made between two contiguous sheets. The groove 28 is produced by stamping in the lateral face of at least one branch 24, 26 of each sheet. Applications:. Alternating current electrical equipment, in particular electromagnets, contactors, remote control switches and MX and MN tripping auxiliaries.

Description

The invention relates to a magnetic circuit for switchgear

  ac electric generator, comprising a stack of U-shaped elementary laminations and, in ferromagnetic material, and a phase shift ring partially surrounding a polar surface of the magnetic circuit to create an asymmetry in the magnetic flux distribution,

  said ring being formed by a conducting coil in short

  circuit having a substantially square or rectangular section. The presence of the phase shift ring avoids the magnetic circuit vibrations due to AC excitation of the control coil It is conventional to insert the phase shift ring in a notch formed in the polar surface of the magnetic circuit The ring surrounds approximately two-thirds of the polar surface to create asymmetry in the flow distribution The notch is generally obtained by a cutting operation, and is at least as wide as the thickness of each tale Such a technology is suitable for sheets thin

less than 1 mm thick.

  For a magnetic circuit with thick plates, including a thickness close to 2 mm per sheet, the implementation of the phase shift ring is difficult to achieve by a cutting operation which requires a notch width greater than the thickness of Of course, there is still the possibility of milling a narrower notch, but this method of

manufacturing is expensive.

  The object of the invention is to improve the implementation of a phase shift ring for a magnetic circuit with thick plates. the magnetic circuit according to the invention is characterized in that the ring extends parallel slightly slightly with respect to the polar surface, with passage in a groove formed between two contiguous sheets, said groove being made by stamping. the groove is formed in the lateral face of at least one branch of each sheet, the depth of the groove being less than the thickness of a sheet, and substantially equal to

  that of the recessed side of the ring.

  The sheets are made by a cutting tool after stamping the grooves The sheet bundle is then riveted after stacking the elementary plates The phase shift ring is embedded in the magnetic circuit, without any discontinuity

  in the corresponding front polar surface.

  Two opposite parallel sides of the phase-shift ring protrude from the outer edge and the inner edge of two plates

  consecutive consoles of the magnetic circuit.

  Other benefits and features will come out more

  clearly from the following description of a mode of

  embodiment of the invention given by way of non-limiting example, and shown in the accompanying drawings, in which: Figure 1 is a perspective view of a grooved sheet; Figures 2 to 4 show the different stages of mounting the sheet package; FIG. 5 represents a perspective view of the circuit

magnetic assembled.

  With reference to FIGS. 1 to 5, a U-shaped magnetic circuit 10 comprises a stack of three thick elementary metal sheets 12, 14, 16 of ferromagnetic material, and at least one ring 18 of

phase shift in conductive material.

  The phase-shift ring 18 is formed by a short turn

  circuit obtained by cutting or cutting a tube of

square or rectangular section.

  The sheets 12, 14, 16 have an identical U-shaped structure, each having an individual thickness of around 2 mm. Each sheet is made by cutting, and comprises two front surfaces, 22 (FIG. 1) arranged at the ends of the two branches 24, 26. of equal lengths A rectangular groove 28 is formed in one of the lateral faces of each branch 24, 26, the depth of the groove 28 being smaller than the thickness of each sheet 12, 14, 16, and allowing the insertion of one side of the phase shift ring 18. The grooves 28 are made by stamping before the operation

cutting sheets.

  The assembly of the magnetic circuit 10 is represented in FIGS.

2 to 4:

  In FIG. 2, the phase-shift ring 18 is first inserted into the groove 28 of the first sheet 12 extending perpendicular to the branch 26. The second sheet 14 is then pressed against the first sheet 12 after passing (see arrow). F1, FIG. 3) through the window of the ring 18 In FIG. 4, the third sheet 16 is applied in the direction of the arrow F 2 against the second sheet 14, so as to trap the phase-shift ring 18 in the package, which can then be riveted for the final assembly of the plates 1 2,14,16 of the magnetic circuit

(Figure 5).

  Note in Figure 5 that two opposite parallel sides of the ring 18 project from the outer edge and the inner edge of the branch 26 of the first and second sheets 12,14, while the other two opposite sides of the ring 18 are inserted totally in the corresponding groove 28 of the first and third

12,16.

  The phase-shift ring 18 is slightly set back with respect to the polar face 30 constituted by the shoulder of the three flat polar surfaces 22. The other polar face 32 of the

  magnetic circuit 10 is devoid of phase shift ring.

  Such an arrangement of the ring 18 facilitates manufacture and avoids any discontinuity in the polar face 30 of the circuit

magnetic 10.

  The magnetic circuit 10 can be used in AC electrical equipment, including electromagnets, contactors, remote switches and auxiliary trip devices.

  current transmission MX or lack of voltage MN.

  Depending on the type of moving pallet, a second phase shift ring can be incorporated in the grooves 28 of the branches

  24, set back from the polar face 32.

Claims (4)

  A magnetic circuit for AC electrical equipment, comprising a stack of U-shaped elementary laminations (12, 14, 16) and of ferromagnetic material, and a phase-shift ring (18) partially surrounding a polar surface (30) of the circuit magnetic device (10) for creating an asymmetry in the distribution of the magnetic flux, said ring being formed by a short-circuit conducting coil having a substantially square or rectangular section, characterized in that the ring (18) extends parallel in a light direction withdrawal relative to the polar surface 30, with passage in a groove (28) formed between two sheets (14,16) contiguous,   said groove being made by stamping.   Magnetic circuit according to Claim 1, characterized in that the groove (28) is formed in the lateral face of at least one branch (24, 26) of each sheet (12, 14, 16), the depth of the groove (28) being smaller than the thickness of a sheet, and substantially equal to that of the recessed side of the ring (18).   3 magnetic circuit according to claim 2, characterized in that two opposite parallel sides of the ring (18) phase shift protrude from the outer edge and the inner edge of two consecutive plates (12,14) contiguous magnetic circuit (10).   Magnetic circuit according to one of Claims 1 to 3,   characterized in that the magnetic circuit (10) comprises three identical sheets (12, 14, 16), the thickness of each sheet being close to 2 mm.