Patent ID: 12244180

The elements which are identical, similar or analogous retain the same reference from one figure to another. The ordinal numbers are used to differentiate features. They do not define a position of a feature. As a consequence, for example, a third feature of a product does not mean that the product has a first and/or a second feature. The words “axial”, “axially” relates to the direction of the axis of rotation A of the rotary electric machine.

FIG.1shows a section of a schematically depicted rotary electrical machine1. The rotary electrical machine1comprises a shaft4with a rotor3sitting thereon. The shaft4is for example mounted by means of a first bearing11and second bearing12so as to be rotatable about an axis of rotation A relative to a stator2. The stator2comprises a stator core9and a stator winding8. For example, the stator core9is a laminated stator core9comprising several stator plates. The stator core9comprises radially oriented stator teeth. Slots are formed between the teeth. The stator winding8comprises conductors. The conductors are arranged in the slots. Stator winding ends10are electrically connecting the conductors to form the stator winding8. For instance, the stator winding8is a U-Pin type stator winding or a multi-lobed stator winding. For example, the stator winding is three-phase alternating current stator winding or a double three-phase alternating current stator winding.

For example, the first bearing11sits in a first bracket5, and the second bearing12sits in a second bracket6. The first bearing11and the second bearing12are for instance ball bearings, roller bearings or plain bearings. In the embodiment ofFIG.1, the rotary electric machine includes a housing32. The housing32comprises the first bracket5, the second bracket6and a housing part7. The housing part7connects the first bracket5and the second bracket6. For example, the stator core9is press fitted in the housing part7in particular, the housing part7comprises a cylindrical inner surface in which an outer cylindrical surface of the stator core9in press fitted. In another embodiment not shown, the first bracket or the second bracket comprises a first tubular portion in which the stator core is press fitted. The other bracket can comprise a second tubular portion. A cooling chamber can be formed between the first tubular portion and the second tubular portion. In another embodiment not shown, a cooling chamber is formed in the housing part.

The shaft4can be rotationally linked to a driving member13such as a pulley or a gear wheel.

The rotor3is rotationally connected to the shaft4.

FIG.2shows a schematic partial section view perpendicular to the axis of rotation A of a rotor3according to a first embodiment of the invention. The rotor3is, in particular, a separately excited rotor, also commonly referred as a wound rotor or a slip ring rotor. In this type of rotor, the rotor comprises coils16connected to an external power supply through slip rings (not shown). The slip rings correspond to electro-mechanical devices configured to allow the exchange of electric power between a rotating element and a fixed element, here respectively the windings16and the external power supply.

The rotor3comprises a plurality of electromagnetic poles17. Each electromagnetic pole comprises a tooth18and one coil16. The tooth18comprises a tooth body19comprising a magnetic material. The tooth body is for example a laminated tooth body comprising a plurality of steel plate stacked in the direction of the axis of rotation A. The tooth18is radially oriented. It comprises a recess21as shown inFIG.3. The coil16is arranged in the recess21. The coil16comprises a plurality of wire turns20wound around the tooth18between a first radial end28and a second radial end29. The turns20which are the most distant from the tooth body19between the first radial end28and the second radial end29form outer wire layer22.

The coil16comprises a bracing wire14. The bracing wire14is wound on the outer wire layer22from the first radial end28to the second radial end29in less than one turn around the tooth18so as to hold in position the outer wire layer22. For example, the outer wire layer22comprises at least seven turns.

In the embodiments shown in the figures, the coils16of adjacent electromagnetic poles17are wound in opposite directions.

In another embodiment not shown the coils of adjacent electromagnetic poles are wound in the same direction.

For example, the coil16comprises a first coil part33starting at the second radial end29and ending at a third radial end30. The third radial end30is between the second radial end29and the first radial end28. The size of the turns of the outer wire layer22is increasing from the second radial end29to the third radial end30. The first coil part33has for example a trapezoidal shape.

The coil16comprises for example a second coil part35starting at the first radial end28and ending at a fourth radial end31. The fourth radial end31is between the first radial end28and the third radial end30. The size of the turns of the outer wire layer22increases from the first radial end28to the fourth radial end31. The second coil part35has for example a trapezoidal shape.

The coil16comprise for example a third coil part24starting at the third radial end30and ending at the fourth radial end31. For example, the size of the turns between the third radial end30and the fourth radial end31are equal.

The tooth body19comprises for example a first axial end39and a second axial end40. The coil16especially forms coil ends36projecting axially from respectively the first axial end39and the second axial end40. The tooth18comprises for example a first tooth end plate38bearing against the first axial end39. The tooth18comprises for example a second tooth end plate37bearing against the second axial end40.

The first tooth end plate38and the second tooth end plate37are especially located between the tooth body19and the coil ends36.

For instance, the bracing wire14is wound on the outer wire layer22from the first radial end28to the second radial end29at a location axially offset from the first axial end39on the side of the first tooth end plate38.

The rotor3comprises a rotor body15. The rotor body15comprises a rotor core27and the plurality of the tooth bodies19of the electromagnetic poles. For example the tooth bodies19are projecting radially.

For example the rotor core is a laminated rotor core comprising a plurality of steel plates stacked in the direction of the axis of rotation A.

In the embodiments shown in the figures, the tooth body19of each electromagnetic pole17is integral with the rotor core27. The rotor body15is for example a stack of laminations configured to be mounted coaxially on the shaft4. For example, the rotor body15is press-fitted on the shaft4. The press-fitting of the rotor body15on the shaft4relies on having an outer circumference of the shaft4slightly higher than an inner circumference of the rotor body15, before proceeding with the press-fitting.

In another embodiment not shown, the rotor core and the tooth bodies are distinct. For example the tooth bodies are secured on the rotor core thanks to a dovetail joint.

For example, the rotor4comprises a first end plate23. For instance, the first end plate23comprises the first tooth end plates38. In the embodiments shown in the figures, the first tooth end plates38are molded in one single part forming the first end plate23. In another example not shown, the first tooth end plates are distinct and are assembled together.

For example, the rotor4comprises a second end plate24. For instance, the second end plate24comprises the second tooth end plates37. For example, the second tooth end plates37are molded in one single part forming the second end plate24. In another example not shown, the second tooth end plates are distinct and are assembled together.

The first end plate23and the second end plate24provide for example a mechanical holding of the stack of laminations of the rotor body15.

FIG.4shows a second embodiment of the invention. In the second embodiment, the coil16comprises for example a tying portion41extending from the bracing wire14beyond the second radial end29. In the embodiments shown in the figures, the stator2is radially outside the rotor3and the tying portion41is radially inside the second radial end29.

In another embodiment not shown the rotor is radially outside the stator and the tying portion is radially outside the second radial end.

The first tooth end plate38comprises a first fastening pin42.

For example the first fastening pin42extends in the axial direction.

For example the first tooth end plate is a plastic part and the fastening pin is a globally cylindrical protrusion formed in the first end plate. The tying portion41is for example at least partially wound around the first fastening pin42. The tying portion41is for example in contact with one eighth to a half of an angular circumference of the first fastening pin42.

FIG.5shows a third embodiment of the invention. The third embodiment is similar with the second embodiment but the tying portion41makes a loop around the first fastening pin42.

FIG.6shows a fourth embodiment of the invention wherein the first tooth end plate38comprises a second fastening pin43in addition to the first fastening pin42. The second fastening pin43extends for example in the axial direction. The tying portion41is at least partially wound around the second fastening pin43.

For example, the tying portion41has a S-shaped path between the first fastening pin42and the second fastening pin43.

The bracing wire14is for example wound on the outer layer22of the coil end36of the coil16. In the embodiments shown in the figures, the bracing wire14is only wound on the outer layer22of the coil end36of the coil16. In another embodiment not shown the bracing wire extends on the outer layer exclusively or partially out of the coil end.

The embodiments of electromagnetic poles17shown in the figures relates to a rotor of a rotary electric machine wherein the stator2is radially outside the rotor3. In another embodiment not shown the electromagnetic pole is an electromagnetic pole of a rotor of a rotary electric machine wherein the stator is radially inside the rotor.

PART LIST

1rotary electrical machine2stator3rotor4shaft5first bracket6second bracket7housing part8stator winding9stator core10stator winding end11first bearing12second bearing13driving member14bracing wire15rotor body16coil17electromagnetic pole18tooth19tooth body20turn21recess22outer wire layer23first end plate24second end plate28first radial end29second radial end30third radial end31fourth radial end32housing33first coil part34third coil part35second coil part36coil end37second tooth end plate38first tooth end plate39first axial end40second axial end41tying portion42first fastening pin43second fastening pin