Eddy current apparatus

Abstract

The invention relates to an eddy current device comprising a stator assembly (6) and a rotor assembly adapted to pivot relative to the stator assembly about an axis of rotation (X), the stator assembly (6) having an annular support (14) and at least one pole block (22) fixed to the annular support; one of the annular support and the at least one pole block having a groove (26) and the other having a tab (18) fitted into the groove. Figure to be published with the abbreviation: Figure 2

Description

Title of the invention: Eddy current apparatus Technical field of the invention

[0001] The invention relates to an eddy current device and, in particular, an electromagnetic idle speed control device. Such an electromagnetic idle speed control device can be used to supplement the braking systems of vehicles of all categories, and in particular motor vehicles such as trains, trucks, or commercial vehicles, for which it is particularly advantageous. Prior art

[0002] Eddy current devices comprise a stator assembly and a rotor assembly designed to pivot relative to the stator assembly around an axis of rotation. To reduce production costs, it is desirable to manufacture part of the stator assembly from laminated sheet metal or sintered material. However, laminated sheet metal and sintered materials do not withstand the high temperatures induced by rotor radiation well. Indeed, under the effect of heat, the sheets of the lamination detach from one another. Furthermore, it is not possible to drill a hole in a sintered material in a direction perpendicular to the laminated sheets. Presentation of the invention

[0003] It is desirable to allow the manufacture of an annular support in laminated sheet metal or sintered material which resists the radiation induced by the rotor and which resists over time. Summary of the invention

[0004] The present invention relates to an eddy current apparatus comprising a stator assembly and a rotor assembly adapted to pivot relative to the stator assembly around an axis of rotation, the stator assembly comprising an annular support and at least one pole block fixed to the annular support; one among the annular support and the at least one pole block comprising a groove and the other comprising a tab arranged fitted in the groove.

[0005] The features described in the following paragraphs may optionally be implemented. They may be implemented independently of each other or in combination with each other: - the annular support comprises at least one polar core, and in which at least one polar block comprises a solid steel polar flare; one of the groove and tongue being formed on the polar flare, and the other of the groove and tongue being formed on at least one polar core. - at least one polar block comprises a polar core and a polar expansion manufactured from a single piece of solid steel, and in which one of the groove and tongue is formed on the polar core; the other of the groove and tongue is formed on the annular support. - the annular support is made of laminated sheet metal, the annular support is made of sintered material. - the groove is open at each of its ends, the tongue being designed to slide in the groove. According to a less advantageous variant, the groove is closed at each of its ends and the tongue forms a tenon fitted into the groove. - The groove and the tongue extend parallel to the axis of rotation. According to a less advantageous variant, the tongue and the groove extend perpendicular to the axis of rotation. - one of the groove and the tongue has a containing dovetail shape and the other has a contained dovetail shape. Brief description of the figures

[0006] [Fig-1] is a perspective view of an eddy current device according to the present invention;

[0007] [Fig.2] is a perspective view of part of a stator assembly according to a first embodiment of the invention;

[0008] [Fig.3] is a perspective view of part of a stator assembly according to a second embodiment of the invention;

[0009] [Fig.4] is a perspective view of part of a stator assembly according to a third embodiment of the invention. Detailed description of the invention

[0010] The eddy current device 2 according to the invention is described below in its preferred, but not limiting, application to an eddy current retarder.

[0011] The eddy current device 2 can also be implemented in an electromagnetic retarder and generator assembly.

[0012] The eddy current device 2 comprises a rotor assembly 4 and a stator assembly 6. The rotor assembly is fixed by means of an intermediate piece to a transmission shaft of a vehicle equipped with a retarder. The rotor assembly 4 comprises an armature sleeve 8, a hub 10, and angled arms 12 that connect the armature sleeve to the hub. The hub is adapted to pivot about an axis of rotation XX.

[0013] The stator assembly 6 according to the first embodiment comprises an annular support 14 fixed by suitable means to the vehicle chassis or to the vehicle's gearbox housing. The axis of the annular support 14 is coaxial with the axis of rotation XX. In the first embodiment illustrated in [Fig.2], the annular support 14 is provided with peripheral polar cores 16.

[0014] The polar cores 16 are distributed at regular intervals along a circle centered on a center O of the axis of rotation X. The polar cores have respective axes Y perpendicular to the axis of rotation XX.

[0015] In this first embodiment, the annular support 14 and the polar cores 16 are made of laminated sheet metal or sintered material.

[0016] The free end of the polar cores 16 has a tab 18. The tab, the polar cores and the annular support are made in one piece of laminated sheet or sintered material.

[0017] Preferably, the tab 18 extends parallel to the axis of rotation XX. In the embodiment shown and in no way limiting, the tab extends from one end of the polar core to the opposite end.

[0018] Preferably, the tongue has a depth of between 1 and 20 millimeters. Preferably, the tongue has a width of between 1 and 20 millimeters.

[0019] The stator assembly 6 comprises inductor coils 20 shown in [Fig. 1]. The inductor coils are arranged around pole cores 16. Each inductor coil 20 comprises a conducting wire wound around a pole core. The winding directions of the conducting wire alternate from one inductor coil to the next, so as to alternate the polarities of the inductors. Each inductor coil 20 is traversed by a pole core with axis Y. With reference to [Fig.2], the stator assembly 6 further comprises pole blocks 22 fixed to the annular support 14. The pole blocks are made of solid steel. In the first embodiment of the invention, the polar blocks 22 include polar flares 24.

[0020] The polar flares 24 serve to immobilize the inductor coils 20 with respect to the polar cores 16. The polar flares also ensure a good distribution of the magnetic flux in the induced sleeve 8 and therefore an efficient generation of eddy currents.

[0021] In the first embodiment of the invention, the polar flares 24 are therefore made of solid steel.

[0022] Advantageously, since the polar flares are made of solid steel, they protect the annular support 14 made of laminated sheet or sintered material from the radiation of the induced sleeve 8.

[0023] In this first embodiment illustrated in [Fig.2], the blooms Each of the polar cores 24 has a groove 26. The grooves 26 are adapted to cooperate with the tabs 18 of the polar cores. In particular, the grooves 26 have a shape and dimensions corresponding to the shape and dimensions of the tabs 18.

[0024] The tabs 18 are arranged in a fitted manner in the grooves 26 so that the polar flares 24 are fixed to the polar cores.

[0025] Here, the grooves 26 extend parallel to the axis of rotation XX. According to a less advantageous variant, the tongues and grooves extend perpendicularly to the axis of rotation XX.

[0026] In the illustrated embodiment, the grooves 26 are open at each of their ends. The tabs 18 are adapted to slide in the grooves. According to a less advantageous variant, the grooves 26 are closed at least at one of their ends and the tongues form tenons fitted into the grooves.

[0027] According to an unrepresented variant, the grooves 26 have a containing dovetail shape and the tongues 18 have a containing dovetail shape.

[0028] The [Fig.3] represents part of a stator assembly 28 according to a second embodiment.

[0029] The stator assembly 28 according to the second embodiment is similar to the stator assembly 6 according to the first embodiment, except that the annular support 30 has pole cores 32, each provided with a groove 34, and that the pole blocks 36 include pole flares 38, each provided with a tab 40. The tabs 40 are arranged in a fitted manner in the grooves 34 so as to fix the pole flares 38 to the pole cores of the annular support.

[0030] The elements of the stator assembly 28 according to the second embodiment, which are identical to the elements of the stator assembly 6 according to the first embodiment, will not be described a second time. In particular, the annular support 30 is made of laminated sheet metal or sintered material, and the pole pieces 38 are made of solid steel. Similarly, the variants of the stator assembly 6 according to the first embodiment are also feasible for the stator assembly 28 according to the second embodiment.

[0031] The [Fig.4] represents part of a stator assembly 42 according to a third embodiment.

[0032] The stator assembly 42 according to the third embodiment is similar to the stator assembly 6 according to the first embodiment, except that the annular support 44 of this assembly does not have pole cores and the pole blocks 46 of this assembly include pole cores 48 and thick- polar thrusts 50.

[0033] The annular support 44 is made of laminated sheet metal or sintered material. The annular support 44 has grooves 54 distributed at regular intervals along a circle centered on a center O of the axis of rotation XX.

[0034] The polar cores 48 each include a tab 52. The polar blocks 46 are fixed to the annular support 44. For this purpose, the tabs 52 are arranged in a fitted manner in the grooves 54. In the embodiment shown and in no way limiting, the grooves 54 have a dovetail containing shape and the tongues 52 have a dovetail containing shape.

[0035] Alternatively, the grooves 54 have a dovetail shape and the tongues 52 have a dovetail shape. According to another embodiment, the tongues 52 and the grooves 54 have a shape similar to that illustrated in Figures 2 and 3.

[0036] In this third embodiment, the polar cores 48, the polar flares 50 and the tabs 52 are formed in one piece of solid steel.

[0037] The other elements of the stator assembly 42 according to the third embodiment are identical to the elements of the stator assembly 6 according to the first embodiment and will not be described a second time. The variants of the stator assembly 6 according to the first embodiment are also feasible for the stator assembly 42 according to the third embodiment.

Claims

Claims

1. An eddy current apparatus (2) comprising a stator assembly (6, 28, 42) and a rotor assembly (4) adapted to pivot relative to the stator assembly about an axis of rotation (X), the stator assembly (6, 28, 42) comprising an annular support (14, 30, 44) and at least one pole block (22, 36, 46) fixed to the annular support; one of the annular support (14, 30, 44) and the at least one pole block (22, 36, 46) comprising a groove (26, 34, 54) and the other comprising a tongue (18, 40, 52) arranged fitted in the groove.

2. The eddy current apparatus (2) of claim 1, wherein the annular support (14, 30) comprises at least one pole core (16, 32), and wherein at least one pole block (22, 36) comprises a pole shoe (24, 38) of solid steel; one of the groove (26, 34) and the tongue (18, 40) being formed on the pole shoe (24, 38), and the other of the groove (26, 34) and the tongue (18, 40) being formed on at least one pole core (16, 32).

3. The eddy current apparatus (2) of claim 2, wherein at least one pole block (46) comprises a pole core (48) and a pole shoe (24, 38, 50) integrally fabricated from solid steel, and wherein one of the groove (54) and the tongue (52) is formed on the pole core (48); the other of the groove (54) and the tongue (52) is formed on the annular support (44).

4. Eddy current apparatus (2) according to any one of claims 1 to 3, wherein the annular support is made of laminated sheet metal.

5. An eddy current apparatus (2) according to any one of claims 1 to 3, wherein the annular support is made of sintered material.

6. Eddy current apparatus (2) according to any one of claims 1 to 6, wherein the groove (26, 34, 54) is open at each of its ends, the tongue (18, 40, 52) being adapted to slide in the groove.

7. An eddy current apparatus (2) according to any one of claims 1 to 6, wherein the groove (26, 34, 54) and the tongue (18, 40, 52) extend parallel to the axis of rotation (XX).

8. An eddy current apparatus (2) according to any one of claims 1 to 7, wherein one of the groove (26, 34, 54) and the tab (18, 40, 52) has a containing dovetail shape and the other has a contained dovetail shape.

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