Busbar for distributing power between wound rotor and non-contact excitation system

Abstract

The invention relates to a bus bar (4) for an electric motor of a motor vehicle, intended to be interposed between a ball bearing (6) and a mechanical shaft (5) of the electric motor. The bus bar comprises: a distal end (9) equipped with means for connecting the bus bar to a contactless excitation system (3) for contactless excitation of a wound rotor (2) of an electric motor; a proximal end (10) equipped with means for connecting the bus bar to the wound rotor (2) of the electric motor; one or more branches (11, 12); and electrical leads (13) which are inserted into axial channels formed in the branches (11, 12) such that electrical contact can be made between the contactless excitation system (3) and the wound rotor (2).

Description

Technical Field

[0001] This invention relates to supplying power to the wound rotor of an electric motor in a motor vehicle, and more particularly to the interconnection of the wound rotor of the electric motor with an excitation system. More specifically, this invention relates to the electrical connection between the wound rotor and a non-contact excitation system.

[0002] A non-contact excitation system for energizing a wound rotor performs the same function as an excitation system for energizing an electric motor including a rotating brush commutator. Specifically, their function is to supply power to the wound rotor. However, in a rotating commutator, the brushes continuously rub against the rings, resulting in wear of both the brushes and the rings. Therefore, the non-contact excitation system prevents friction and thus avoids the risk of wear between the brushes and the rotating commutator rings of the electric motor.

[0003] In the field of motor vehicles, applications of wound rotor motors are rare, and the use of non-contact excitation systems to excite wound rotors is extremely rare or non-existent. While this is an advantageous way to limit the risk of wear, such systems require connection to the wound rotor to supply power to it. Summary of the Invention

[0004] One subject of the present invention is a busbar for an electric motor in a motor vehicle, the busbar being designed to be inserted between the ball bearings and the mechanical shaft of the electric motor. The busbar includes: a distal end equipped with means for connecting the busbar to a non-contact excitation system for exciting a wound rotor of the electric motor; a proximal end equipped with means for connecting the busbar to the wound rotor of the electric motor; one or more branches; and electrical leads inserted into axial channels formed in the branches, thereby allowing electrical contact between the non-contact excitation system and the wound rotor.

[0005] The busbar is configured to be radially inserted between a ball bearing and a slotted mechanical shaft to fix the busbar in a rotatable position.

[0006] Alternatively, the busbar is produced by overmolding and comprises thermoplastic material.

[0007] Advantageously, the electrical leads protrude from each end and form a connecting hook.

[0008] According to one embodiment, the first connecting hook contacts the cable of the non-contact excitation system, and this contact is made by welding, crimping, or using a connecting piece.

[0009] According to one embodiment, the second connecting hook contacts the cable of the wound rotor, and this contact is made by welding, crimping, or using a connecting piece.

[0010] Advantageously, the manifold includes a guiding surface that can collect and guide a portion of the lubricating fluid to the non-contact excitation system by centrifugation, particularly for cooling the non-contact excitation system.

[0011] Optionally, the guide surface has a truncated conical shape.

[0012] Another subject of the present invention is an electric motor that includes a busbar as defined above.

[0013] Another subject of the present invention is a motor vehicle that includes a busbar as defined above. Attached Figure Description

[0014] Further objects, features, and advantages of the invention will become clear from the following description, given only by way of non-limiting example and with reference to the accompanying drawings, in which:

[0015] - [ Figure 1 [Image] is a partial schematic diagram of an electric motor in a motor vehicle, which is equipped with a busbar connected to a non-contact excitation system and a wound rotor;

[0016] - [ Figure 2 [This is a partial cross-sectional view of an electric motor in a motor vehicle, equipped with a busbar positioned on a mechanical shaft; and]

[0017] - [ Figure 3 [Image] is a partial schematic diagram of an electric motor in a motor vehicle, which is equipped with a busbar positioned on a mechanical shaft. Detailed Implementation

[0018] [ Figure 1 The figure shows a portion of an electric motor in a front-wheel-drive motor vehicle that is at least partially electric, indicated by general reference numeral 1.

[0019] The motor includes a wound rotor 2, a non-contact excitation system 3 for energizing the wound rotor 2, and a busbar 4 for supplying power from the excitation system to the rotor 2.

[0020] The wound rotor 2 is supported by a mechanical shaft 5, which abuts against a bearing (such as a ball bearing 6) lubricated by a lubrication circuit.

[0021] The excitation system 3 is designed to supply power to the wound rotor 2. The excitation system specifically includes an excitation component 7 and a rectifier circuit 8, which is fastened to the housing of the electric motor and designed to collect current, and the rectifier circuit is designed to transmit current to the wound rotor 2 via busbar 4.

[0022] The busbar 4 is configured to radially surround the shaft 5, or more precisely, is inserted between the shaft 5 and the bearing 6.

[0023] Busbar 4 includes: a distal end 9 equipped with means for connecting busbar 4 to the non-contact system 3 of the wound rotor 2; a proximal end 10 equipped with means for connecting busbar 4 to the wound rotor 2; and one or more branches 11, 12 forming an axial channel. Busbar 4 also includes electrical leads 13 inserted into the axial channels of branches 11, 12, thereby allowing electrical contact between the wound rotor 2 and the non-contact system 3. Branches 11, 12 thus allow power to be delivered from the distal end 9 to the proximal end 10 via electrical leads 13.

[0024] [ Figure 2 The image illustrates how the busbar 4 is mounted on the shaft 5. The shaft includes grooves 14 that receive branches 11 and 12 of the busbar 4 to secure the busbar in rotation. Therefore, branches 11 and 12 also serve to secure the busbar 4.

[0025] According to one embodiment, the busbar 4 includes a radial support at the proximal end 10, thereby allowing the branches 11, 12 to be held in place.

[0026] Electrical leads 13 protrude from each end 9, 10 and form connecting hooks 9a, 9b, 10a, 10b.

[0027] like[ Figure 1 As shown, on the distal end 9 side, the electrical lead 13 forms one or more first connecting hooks 9a, 9b, and on the proximal end 10 side, the electrical lead 13 forms one or more second connecting hooks 10a, 10b.

[0028] According to one embodiment, hooks 9a, 9b, 10a, and 10b are made of metal (e.g., copper-plated) and are current conductors.

[0029] Therefore, the means for connecting the busbar 4 to the non-contact system 3 of the wound rotor 2 includes first hooks 9a, 9b that contact the cables Xa, Xb at the output end of the rectifier 8. According to various embodiments, the contact between the hooks 9a, 9b and the cables of the rectifier 8 is achieved by welding, crimping, or by using connecting tabs.

[0030] The device for connecting the busbar 4 to the wound rotor 2 includes second hooks 10a and 10b that contact the cables Ya and Yb of the coil of the wound rotor 2, as shown in […]. Figure 2 As shown in the figure. The contact between hooks 10a, 10b and the cable of the wound rotor 2 is made, for example, by welding, crimping or by using a connecting piece.

[0031] In other words, cables Xa, Xb, Ya, and Yb are, for example, wound around hooks 9a, 9b, 10a, and 10b respectively, or welded or crimped to hooks 9a, 9b, 10a, and 10b respectively.

[0032] Therefore, these contacts allow the wound rotor 2 to be electrically connected to the excitation system 3.

[0033] Advantageously, the busbar 4 is overmolded and comprises thermoplastic.

[0034] Busbar 4 also includes [ Figure 3 The radial guide surface 15 is shown. This guide surface 15 collects lubricating fluid downstream of the bearing 6 and is configured to guide the lubricating fluid to the excitation system 3. Therefore, the guide surface 15 allows for faster cooling of a larger area of ​​the rapidly heating non-contact excitation system 3.

[0035] In various embodiments, the guide surface 15 can have various shapes, as long as its shape allows the lubricating fluid to be centrifuged into the excitation system 3. For example, the guide surface 15 has a truncated conical shape.

[0036] When the wound rotor 2 is supplied with power, the assembly including the wound rotor, shaft 5, and busbar 4 is driven to rotate together with the rectifier circuit 8 of the excitation system 3. As these components rotate, the excitation component 7 of the non-contact excitation system 3 remains stationary and secured to the housing of the electric motor.

Claims

1. A busbar (4) for an electric motor in a motor vehicle, the busbar being designed to be inserted between a ball bearing (6) and a mechanical shaft (5) of the electric motor, characterized in that, The busbar includes: a distal end (9) equipped with means for connecting the busbar to a non-contact excitation system (3) for exciting a wound rotor (2) of an electric motor; a proximal end (10) equipped with means for connecting the busbar to the wound rotor (2) of the electric motor; one or more branches (11, 12); and an electrical lead (13) inserted into an axial channel formed in the branches (11, 12) to allow electrical contact between the non-contact excitation system (3) and the wound rotor (2).

2. The busbar (4) as claimed in claim 1, wherein the busbar is configured to be radially inserted between the ball bearing (6) and the mechanical shaft (5), the mechanical shaft (5) being slotted to fix the busbar (4) in rotation.

3. The busbar (4) as claimed in any one of claims 1 and 2, wherein the busbar is produced by overmolding and comprises thermoplastic.

4. The busbar (4) as described in any one of claims 1 to 4, wherein, The electrical leads (13) protrude from each end (9, 10) and form connecting hooks (9a, 9b, 10a, 10b).

5. The busbar (4) as claimed in any one of claims 1 to 5, wherein the busbar is configured such that the first connecting hook (9a, 9b) contacts the cable (Xa, Xb) of the non-contact excitation system (3), the contact being made by welding, crimping or using a connecting piece.

6. The busbar (4) as claimed in any one of claims 1 to 6, wherein the busbar is configured such that the second connecting hook (10a, 10b) contacts the cable (Ya, Yb) of the wound rotor (2), the contact being made by welding, crimping or using a connecting piece.

7. The busbar (4) according to any one of claims 1 to 7, the busbar comprising a guide surface (15) capable of collecting and guiding a portion of the lubricating fluid to the non-contact excitation system (3) by centrifugation, particularly for cooling the non-contact excitation system.

8. The busbar (4) as described in claim 8, wherein, The guide surface (15) has a truncated conical shape.

9. An electric motor comprising a busbar (4) as claimed in any one of claims 1 to 9.

10. A motor vehicle comprising a busbar (4) as claimed in any one of claims 1 to 9.

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