Patent Application
20250219483
The invention concerns a rotating machine rotor and in particular an electromagnetic retarder rotor for vehicles. The invention also concerns an electromagnetic retarder and generator assembly.
The rotor of electromagnetic retarder and generator assemblies generally includes an interior ring intended to be mounted on a rotary shaft, a lateral flange and a cylindrical body coaxial with the interior ring. The flange consists of a plate of annular shape that connects the interior ring to the cylindrical body. The cylindrical body constitutes the armature of the retarder.
Such a rotor is described in the patent application FR 18 55 848 filed in the name of the applicant. That rotor is entirely satisfactory. It would nevertheless be desirable to propose a more robust rotor.
A first aim of the present invention is to propose a more robust rotor. A second aim is to strengthen the ventilation of the windings of the retarder and the generator.
The present invention has for object a rotating electrical machine rotor, the rotor being able to turn about a rotation axis in a rotation direction relative to the stator, the rotation axis extending in an axial direction, the rotor including:
The fixing arms advantageously make it possible to increase the cooling of the cylindrical body by ventilation and account for a mechanical strength enabling severe deformation of the cylindrical body to be prevented.
The features disclosed in the following paragraphs may optionally be employed. They may be employed independently of one another or in combination with one another:
The distal end of the fixing arm advantageously forms a fin that directs air toward the cooling channels of the cylindrical body.
The invention also has for object an electromagnetic retarder and generator assembly, the assembly including a stator and a rotor, the stator comprising an external face and an internal face, the external face carrying a retarder field winding arranged facing an interior surface of the cylindrical body, the internal face carrying a generator armature, the rotor having any of the features mentioned hereinabove, the cylindrical body forming a retarder armature, the interior fixing ring comprising a generator field winding disposed facing the internal face of the stator.
Referring to
The rotor 2 is able to turn about a rotation axis X-X extending in an axial direction A. For the purposes of the present description there is defined a transverse plane PR perpendicular to the rotation axis X-X.
The rotor 2 includes an interior fixing ring 4 intended to be fixed to a rotary shaft, not represented, a cylindrical body 6 and fixing arms 8 connected to the interior fixing ring and to the cylindrical body.
The interior fixing ring 4 and the cylindrical body 6 are coaxial.
Referring to
The connecting lateral face 28 is the face to which the fixing arms 8 are connected. The fixing arms 8 are connected to the connecting lateral face 28 of the cylindrical body 6 in connection zones 27. The transverse plane PR passes through the connection zones 27 of the cylindrical body 6.
For each fixing arm 8 there is defined a plane PT1, PT2 tangential to the peripheral surface 30 at a point in the connection zone 27, as can be seen in
The peripheral surface 30 comprises a first edge 34 adjacent to the connecting lateral face and a second edge 36 opposite the first edge. The first edge 34 of the peripheral surface 30 is delimited in an axial direction by an end 42. The peripheral surface 30 is a radially external surface.
In the example depicted by way of non-limiting example the rotor includes ten fixing arms. The fixing arms are regularly distributed around the interior ring.
Each fixing arm comprises a proximal end 10 connected to the fixing interior ring and distal end 12 connected to cylindrical body.
As seen in the transverse plane PR the distal end 12 of the fixing arms is angularly offset in the upstream direction (rearwardly) relative to the proximal end 10 in the rotation direction R of the rotor relative to a stator. This offset α is between 50 degrees and 60 degrees inclusive.
The fixing arms 8 have a blade or band shape. They have a first main face 16, a second main face 14 parallel to and opposite the first main face, a first lateral face 18 intended to face a stator and a second lateral face 20 opposite the first lateral face. The first main face 16 is situated on the upstream (rear) side of the rotor in the rotation direction R of the rotor relative to a stator. In other words a vector normal to the first main face 16 is directed in an opposite direction to the rotation direction R. The second main face 14 is situated on the downstream (front) side of the rotor in the rotation direction R of the rotor relative to a stator. In other words a vector normal to the second main face 16 is directed in the rotation direction R. A first edge 15 is arranged between the second main face 14 and the second lateral face 20. A second edge 17 is arranged between the first main face 16 and the second lateral face 20. The first edge 15 at the proximal end 10 of the fixing arms is at an angle β1 between 25 degrees and 35 degrees inclusive to the transverse plane PR. The angle β1 is preferably equal to 30 degrees.
For each fixing arm the first edge 15 of the distal end 12 of the fixing arm is at an inclination angle β2 between 40 degrees and 60 degrees inclusive to the straight line segment D1, the straight line segment D1 being contained within the transverse plane PR and the tangential plane PT1 in the connection zone 27 of that fixing arm 8. The inclination angle β2 is preferably equal to 45 degrees.
The fixing arms 8 include a distal portion 21 connected to the cylindrical body 6. The distal portion 21 is inclined relative to an inclination axis Y-Y. The inclination axis Y-Y extends in a longitudinal direction of the distal portion of the fixing arms. The inclination axis Y-Y is preferably situated at the centre of the second lateral face 20, as depicted in
Referring to
In the first embodiment depicted in the figures the inclined distal portion 21 of the fixing arms corresponds to the third section. In other words the fixing arms begin to be inclined starting from the junction between the curved second section and the rectilinear third section. The fixing arms are progressively inclined more and more throughout the length of the third section.
In accordance with a second embodiment the inclined distal portion 21 of the fixing arms corresponds to the second section and to the third section. In this embodiment the inclination of the fixing arms begins from the point of inflection between the first section and the second section. The fixing arms are progressively inclined more and more over the second section and over the third section.
The first section 22 is curved in an opposite direction to the rotation direction R of the rotor relative to the stator. In other words a vector normal to its concave surface is directed in a direction opposite to the rotation direction R of the rotor.
The second section 24 is curved in an opposite direction to the first section 22. The first section 22 and the second section 24 form an S. The arms include a point of inflection between the first section 22 and the second section 24.
The first section 22 has a first radius of curvature R1. The second section 24 has a second radius of curvature R2. The first and second radii of curvature are shown and measured along the same main face 16. The ratio between the first radius of curvature R1 and the second radius of curvature R2 is between 1.5 and 2.5 inclusive.
This shape makes it possible to reduce the plastic deformation of the fixing arms at the same time as providing ventilation of the cylindrical body and the windings of the stator. The blade shape of the fixing arms as well as their inclination and their direction make it possible to ventilate the cylindrical body and the windings of the stator. This shape of the fixing arms also makes it possible to reduce aerodynamic losses and consequently enhances the electrical cost-effectiveness of the rotating electrical machine including such a rotor.
The cylindrical body 6 comprises cooling fins 38 fixed to the peripheral surface 30 of the cylindrical body. The cooling fins 38 are the shape of a curved blade.
The cooling fins 38 are disposed parallel to one another in at least two rows.
The cooling fins 38 of a first row are aligned along the first edge 34.
A vector normal to the concave face of the cooling fins 38 of the first row is directed in the rotation direction R of the rotor relative to the stator. The cooling fins are therefore able to direct a greater quantity of air toward the peripheral surface 30 of the cylindrical body.
Cooling fins 38 are disposed parallel to one another in a second row aligned along the second edge 36.
A vector normal to the concave face of the cooling fins 38 of the second row is directed in an opposite direction to the rotation direction R of the rotor. The evacuation of air is therefore accelerated.
The median plane PM of the cooling fins 38 of the first and second rows is oriented at an angle θ between 40 degrees and 60 degrees inclusive to the transverse plane PR. The angle θ is preferably substantially equal to 45 degrees.
The rotor 2 preferably further includes other cooling fins disposed parallel to one another in one of more other rows arranged between the cooling fins of the first row and the cooling fins of the second row.
The distal end 12 of the fixing arms preferably projects perpendicularly to a peripheral surface 30 of the cylindrical body so as to form a cooling fin able to direct air toward the peripheral surface of the cylindrical body.
The rotor 2 preferably further includes a ring 40 coaxial with the cylindrical body. The ring 40 forms with the cooling fins cooling channels 41.
In the preferred embodiment depicted in the figures the ring 40 caps only the cooling fins disposed on a central part of the peripheral surface 30.
The cooling fins 38 arranged on the first edge 34 and on the second edge 36 of the peripheral surface are open to the outside. In other words a part of the cooling fins 38 arranged on the first edge 34 and the second edge 36 of the peripheral surface is not covered by the ring 40.
The ring 40 is delimited by a lateral edge 44 adjacent to the end 42 of the peripheral surface. The lateral edge 44 of the ring is preferably at a distance D between 15 millimetres and 30 millimetres inclusive from the end 42 of the peripheral surface, this distance D being measured only in the axial direction A.
The distal end 12 of the fixing arms is preferably also connected to a lateral face 46 of the ring. As can be seen in
Referring to
The stator 50 comprises an external face 52 and an internal face 54. The external face 52 carries a retarder field winding 56 arranged facing an interior surface 32 of the cylindrical body. The internal face 54 carries a generator armature 58. The cylindrical body 6 of the rotor 2 forms a retarder armature. The interior fixing ring 4 comprises a generator field winding 60 disposed facing the internal face 54 of the stator.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2315347 | Dec 2023 | FR | national |
