Eddy current apparatus

Abstract

The invention relates to an eddy current device comprising a stator assembly (56, 76) and a rotor assembly adapted to pivot relative to the stator assembly about an axis of rotation (XX), the stator assembly (56) having an annular support (58) comprising at least one pole core (60) and at least one pole flare (62); and wherein the stator assembly (56) has a protective cover (64) made of solid steel fixed to said at least one pole flare (62). 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, to an electromagnetic retarder. Such an electromagnetic retarder makes it possible to supplement the braking systems of vehicles of any category, and in particular land motor vehicles such as trains, heavy goods vehicles or even utility vehicles, for which they are particularly advantageous. State of the prior art

[0002] Eddy current devices comprise a stator assembly and a rotor assembly capable of pivoting relative to the stator assembly about an axis of rotation. To reduce production costs, it is desirable to manufacture a portion of the stator assembly from laminated sheet or sintered material. However, laminated sheet and sintered materials have poor resistance to the high temperatures induced by radiation from the rotor. Indeed, under the effect of heat, the sheets of the sheet detach from each other. Furthermore, it is not possible to drill a hole in a sintered material and in a direction perpendicular to the laminated sheets. Presentation of the invention

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

[0004] More generally, it is desirable to protect the windings regardless of the material of the annular support or the pole extensions. Summary of the invention

[0005] The present invention relates to an eddy current apparatus comprising a stator assembly and a rotor assembly capable of pivoting relative to the stator assembly about an axis of rotation, the stator assembly comprising an annular support comprising at least one polar core and at least one polar expansion; and in which the stator assembly comprises a solid steel protective cover fixed to said at least one polar expansion.

[0006] The features set out in the following paragraphs may optionally be implemented. They may be implemented independently of one another or in combination with one another: - said protective cover comprises a bottom wall and at least two side walls parallel to each other, said at least one polar expansion comprising at least two opposite side faces, and in which the two walls side panels of the protective cover are slidably mounted against the two opposite side faces of at least one polar expansion. - at least one side wall of the protective cover and at least one side face of the at least one pole flare comprises at least one tapped hole and in which the stator assembly comprises at least one fixing screw fixed in the at least one side wall of the protective cover and in the at least one side face of the at least one pole flare. - the side faces of the at least one polar expansion comprise a projection and the side walls of the protective cover comprise a groove cooperating with the projection of the polar expansion. - the side walls of the protective cover comprise a projection and the side faces of the at least one polar expansion comprise a groove cooperating with the projection of the protective cover. - the annular support is made of laminated sheet metal. - the annular support is made of sintered material. Brief description of the figures

[0007] [Fig-1] is a perspective view of an eddy current apparatus according to the present invention;

[0008] [Fig.2] is a perspective view of a part of a stator assembly according to a first embodiment of the invention;

[0009] [Fig.3] is a perspective view of a part of a stator assembly according to a second embodiment of the invention. Detailed description of the invention

[0010] The eddy current apparatus 2 according to the invention is described below in its preferred, but non-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 apparatus 2 comprises a rotor assembly 4 and a stator assembly 56. The rotor assembly is fixed by means of an intermediate piece on a transmission shaft of a vehicle equipped with the retarder. The rotor assembly 4 comprises an armature sleeve 8, a hub 10 and bent arms 12 which connect the armature sleeve to the hub. The hub is capable of pivoting about an axis of rotation XX.

[0013] The stator assembly 56 according to the first embodiment comprises an annular support 58 fixed with appropriate means to the chassis of the vehicle or to the gearbox casing of the vehicle. The axis of the annular support 58 is coaxial with the axis of rotation XX. Referring to [Fig.2], the annular support 58 comprises peripheral polar cores 60. The polar cores 60 are distributed at regular intervals along a circle centered on a center O of the rotation axis X. The polar cores have respective axes Y perpendicular to the rotation axis XX.

[0014] The annular support 58 is made of laminated sheet metal or sintered material.

[0015] The stator assembly 56 further comprises inductor coils 20 shown in [Fig.l]. The inductor coils are arranged around the pole cores 60. The inductor coils 20 each comprise a conductive wire wound around a pole core. The winding directions of the conductive 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 of axis Y. With reference to [Fig.2], the stator assembly 56 further comprises pole shoes 62.

[0016] The polar expansions 62 serve to immobilize the inductor coils 20 relative to the polar cores 60. The polar expansions also ensure good distribution of the magnetic flux in the induced sleeve 8 and therefore efficient generation of eddy currents.

[0017] The polar expansions 62 are also made of laminated sheet metal or sintered material. The polar expansions 62 have an upper face 63 and four side faces 65.

[0018] The stator assembly 56 further comprises protective covers 64 fixed to the pole shoes. In the embodiment shown in [Fig. 2], the protective covers 64 each comprise a bottom wall 66 and two side walls 68 parallel to each other. The two side walls 68 of the protective covers are slidably mounted against and on the two opposite side faces 65 of the pole shoes. In particular, the two side walls 68 of the protective covers enclose the two opposite side faces 65 of the pole shoes.

[0019] In the embodiment illustrated in [Fig.2], the protective cover 64 is mounted to slide in a direction perpendicular to the axis of rotation XX. Alternatively, the protective cover 64 is mounted to slide along the other two lateral faces 65, the protective cover 64 is then mounted to slide in the direction of the axis of rotation XX.

[0020] Advantageously, the protective cover 64 is made of solid steel, also called solid steel, so that it is not affected by the radiation of the rotor.

[0021] Advantageously, the protective cover 64 protects the annular support 58 from the radiation of the rotor.

[0022] Advantageously, the protective cover 64 can be fixed in a fitted manner without making a hole in the annular support.

[0023] The side walls 68 of the protective cover may comprise two smooth holes 70 and the side faces 65 of the pole shoe comprise two tapped holes 72. The stator assembly 56 comprises fixing screws 74 fixed in the side walls of the protective covers and in the side faces of the pole shoe.

[0024] This additional fixing with fixing screws can be carried out in an annular support made of laminated sheet metal because the protective cover 64 is fixed without making holes in a direction perpendicular to the laminated sheets.

[0025] [Fig.3] represents a part of a stator assembly 76 according to a second embodiment.

[0026] The stator assembly 76 comprises an annular support 78. The annular support 78 comprises polar cores 80 and polar expansions 82 made of laminated sheet metal or sintered material.

[0027] In this embodiment, the polar expansions 82 comprise an upper face 83 and lateral faces 84. Two opposite lateral faces 84 of the polar expansions comprise a projection 86.

[0028] In the illustrated and in no way limiting embodiment, the projections 86 form rims which extend in the extension of the upper face 83 of the polar expansions.

[0029] The stator assembly 76 further comprises protective covers 88 fixed to the pole shoes 82. The protective covers 88 have a bottom wall 90 and side walls 92. The side walls 92 each comprise a groove 94 adapted to cooperate with a projection 86 of the side faces of the pole shoes.

[0030] The protective covers 88 are slidably mounted and clamped against the lateral faces 84 of the polar cores so that they do not move during operation of the eddy current apparatus.

[0031] In the embodiment illustrated in [Fig. 3], the protective covers 88 are mounted to slide in a direction parallel to the axis of rotation XX. The projections 86 are formed on the lateral faces of the polar expansions arranged opposite another polar expansion.

[0032] According to a variant not shown, the protective covers 88 are mounted to slide in a direction perpendicular to the axis of rotation XX. The projections 86 are formed on the lateral faces of the polar expansions which are perpendicular to the axis of rotation XX.

[0033] According to another variant not shown, the side walls of the protective cover 88 comprise a projection and the side faces of the polar expansions comprise a groove cooperating with the projection of the protective cover.

[0034] Alternatively, the pole shoes are made of solid steel.

[0035] Alternatively, the annular support and its polar cores are made of solid steel.

Claims

Claims

1. Eddy current apparatus (2) comprising a stator assembly (56, 76) and a rotor assembly (4) capable of pivoting relative to the stator assembly about an axis of rotation (XX), the stator assembly (56, 76) comprising an annular support (58, 78) comprising at least one pole core (60, 80) and at least one pole shoe (62, 82); and wherein the stator assembly (56, 76) comprises a protective cover (64, 88) made of solid steel fixed to said at least one pole shoe (62, 82).

2. Eddy current apparatus (2) according to claim 1, wherein said protective cover (64, 88) comprises a bottom wall (66, 90) and at least two side walls (68, 92) parallel to each other, said at least one pole shoe (62, 82) comprising at least two opposite side faces (65, 84), and wherein the two side walls (68, 92) of the protective cover are slidably mounted against the two opposite side faces (65, 84) of the at least one pole shoe.

3. An eddy current apparatus (2) according to claim 2, wherein at least one side wall (68) of the protective cover and at least one side face (65) of the at least one pole shoe comprises at least one tapped hole (70, 72) and wherein the stator assembly (56) comprises at least one fixing screw (74) fixed in the at least one side wall (68) of the protective cover and in the at least one side face (65) of the at least one pole shoe.

4. Eddy current apparatus (2) according to claim 2, wherein the side faces (84) of the at least one pole shoe (82) comprise a projection (86) and the side walls (92) of the protective cover (88) comprise a groove (94) cooperating with the projection of the pole shoe.

5. An eddy current apparatus (2) according to claim 2, wherein the side walls of the protective cover comprise a projection and the side faces of the at least one pole shoe comprise a groove cooperating with the projection of the protective cover.

6. Eddy current apparatus (2) according to any one of claims 1 to 5, wherein the annular support (58, 78) is made of laminated sheet metal.

7. An eddy current apparatus (2) according to any one of the claims- indications 1 to 5, in which the annular support (58, 78) is made of sintered material.

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