ENCLOSED-VENTILATED, ELECTRICALLY EXCITED SYNCHRONOUS MACHINE

Abstract

An enclosed-ventilated electrically excited synchronous machine includes a shaft and a rotor which is non-rotatably positioned on the shaft. The rotor includes a plurality of pole bodies which project radially outwards. The pole bodies have each an exciter coil and form in their entirety a rotor winding, with each pole body having an end face formed with a coil winding head. A protective element is provided on the coil winding head to protect the coil winding head against abrasion.

Claims

1.-8. (canceled)

9. An enclosed-ventilated electrically excited synchronous machine, comprising: a shaft; a rotor non-rotatably positioned on the shaft, said rotor including a plurality of pole bodies projecting radially outwards, said pole bodies having each an exciter coil and forming in their entirety a rotor winding, each said pole body having an end face formed with a coil winding head; and a protective element provided on the coil winding head to protect the coil winding head against abrasion.

10. The enclosed-ventilated electrically excited synchronous machine of claim 9, further comprising a ring connected non-rotatably to the shaft, said protective element being arranged on the ring.

11. The enclosed-ventilated electrically excited synchronous machine of claim 9, wherein the protective element is positioned on the pole body such as to establish a predetermined air gap between the protective element and the coil winding head.

12. The enclosed-ventilated electrically excited synchronous machine of claim 9, wherein the protective element has a shell-shaped configuration.

13. The enclosed-ventilated electrically excited synchronous machine of claim 9, wherein the protective element is configured for attachment of a balancing weight and/or fan blade.

14. The enclosed-ventilated electrically excited synchronous machine of claim 9, further comprising a stator having a winding head, said protective element having a curved radial outer edge to divert a radial flow of air in an essentially axial direction away from an end face of the rotor to avoid abrasion at the winding head of the stator.

15. The enclosed-ventilated electrically excited synchronous machine of claim 9, constructed to only rotate in one direction of rotation under normal operating condition.

16. A drive or an electric generator of a ship, a locomotive a mining truck or another electrically-driven vehicle, comprising an enclosed-ventilated electrically excited synchronous machine including a shaft, a rotor non-rotatably positioned on the shaft, said rotor including a plurality of pole bodies projecting radially outwards, said pole bodies having each an exciter coil and forming in their entirety a rotor winding, each said pole body having an end face formed with a coil winding head, and a protective element provided on the coil winding head to protect the coil winding head against abrasion.

17. The drive or electric generator of claim 16, wherein synchronous machine includes a ring connected non-rotatably to the shaft, said protective element being arranged on the ring.

18. The drive or electric generator of claim 16, wherein the protective element is positioned on the pole body such as to establish a predetermined air gap between the protective element and the coil winding head.

19. The drive or electric generator of claim 16, wherein the protective elements has a shell-shaped configuration.

20. The drive or electric generator of claim 16, wherein the protective element is configured for attachment of a balancing weight and/or fan blade.

21. The drive or electric generator of claim 16, wherein the synchronous machine includes a stator having a winding head, said protective element having a curved radial outer edge to divert a radial flow of air in an essentially axial direction away from an end face of the rotor to avoid abrasion at the winding head of the stator.

22. The drive or electric generator of claim 16, wherein the synchronous machine is constructed to only rotate in one direction of rotation under normal operating condition.

Description

[0023] The invention, as well as further advantageous embodiments of the invention, is to be taken from the exemplary embodiments shown below. In the figures:

[0024] FIG. 1 shows a longitudinal section of a permanently excited synchronous motor with enclosed ventilation,

[0025] FIG. 2 shows a side view of an armature,

[0026] FIG. 3 shows a perspective diagram of the abrasion protection.

[0027] FIG. 1 shows an enclosed-ventilated, electrically excited synchronous motor 1 in a longitudinal section with a stator 2 and a rotor 3. A stator winding head 4 is present on the end faces of the stator 2. The rotor 3 has pole bodies 13 projecting radially outwards, each of which is provided with an exciter coil 15 and which in their entirety form a rotor winding 5. The exciter coils 15 are supplied with electrical power via a slip ring arrangement or a brushless exciter device not shown in any greater detail.

[0028] In this figure coil winding heads 16 of these exciter coils 15 can be seen on the end faces of the rotor 3. The rotor 3 is positioned non-rotatably on a shaft 7, which rotates around an axis 12. Through electromagnetic interaction of the winding systems of stator 2 and rotor 3 across the air gap 14, the dynamo-electric machine will be operated as a motor or as a generator.

[0029] The ambient air will be used for cooling this electrical synchronous machine 1, so that for example cooling air will be carried via a connector 8 into the interior of the synchronous machine 1. These flows of cooling air 19 will be distributed within the machine and flow inter alia via cooling channels in the stator 2, the rotor 3, the pole gaps 28 of the rotor 3 and the air gap 14.

[0030] Because of the speed of the flow of air, the particles carried inwards with said flow from the outside and the simultaneous comparatively high relative speed of the rotor 3 and thus of the rotor winding 5 in relation thereto, abrasion of the insulation of the coil winding head 16 of the exciter coils 15 and thus of the rotor winding 5 occurs at unfavorable sections of the coil winding head 16. In order to avoid this, protective elements 11 are provided in accordance with the invention as abrasion protection 6.

[0031] This can also be seen in FIG. 2 for example, where the protective elements 11 are arranged on a ring 10 and thus form a protection facility 21. The protective elements 11 are arranged on arms 20 of this ring 10 extending radially. The protective elements 11, viewed in cross section, are embodied in the shape of a shell and thus, viewed from the air gap 14, form an angle α of 90°. The angle α of a protective element 11 can however, depending on application, be embodied between 60 and 150°. In the direction of movement 17 of the armature or rotor 3 almost no air particles can strike the insulation of the coil winding head 16 and damage the insulation. The insulation is accordingly protected, which lengthens the service life and the maintenance intervals of the enclosed-ventilated, electrically excited synchronous machine 1.

[0032] Of course the protective elements 11 are also able to be attached individually to the pole body 13, which likewise includes the advantages mentioned above in relation to protection of the insulation of the winding of the rotor 3 and of the coil winding head 16.

[0033] FIG. 2 additionally shows an eight-pole rotor 3 with its pole bodies 13, around which an exciter coil 15 is laid in each case. In the direction of movement 17 in this case the protective elements 11 are now arranged on a central ring 10. The protective elements 11 are provided with means 18 that allow fan blades and/or balancing weights to the fastened to them.

[0034] These means 18 will be embodied as well during manufacturing—i.e. a casting process—of the protective element 11 or the protection facility. If necessary post-processing of these means 18, or of other surfaces of the protective element 11 or of the protection device 21, such as milling or drilling, is necessary.

[0035] FIG. 3 also shows a recess 22 of the ring 10, via which an electrical connection is made between slip ring body or a brushless exciter facility and the exciter coils 15 of the rotor 3.

[0036] In accordance with FIG. 3 a curvature 23 is provided on the radial outer end of the protection elements 11, which essentially deflects an essentially radial flow of air axially and in this way guides it away from the end face of the rotor 3. This embodiment of the protective element 11 avoids a radial flow of air with the particles contained therein striking the stator winding head 4 and leading to abrasion problems there on the insulation located there.

[0037] Advantageously the section of the protective element 11 that screens off the coil winding head 16 of the rotor 3 with its arm 20 is essentially embodied as follows. Regardless of whether it is embodied as a part of a protection facility 21 with ring 10 or will be positioned individually on the pole body 13, the protective element has three sections 25, 26, 27. Section 25 essentially runs in parallel to the end face of the rotor 3 and has the means 18. Section 26 is characterized by a bend, which is adjoined above all in the radially-outer area of the protective element 11 by a section 27, which essentially extends in the direction of pole gap 28.

[0038] The angle α in this case is essentially created by the bend in section 26.

[0039] Such abrasion protection 6 of an enclosed-ventilated electrically excited synchronous machine with shell-shaped protective elements 1 is preferably suitable for one direction of rotation. This is in particular advantageous for generators that will be driven by diesel engines, such as e.g. on locomotives, multiple units, mining trucks or ships.

[0040] For enclosed-ventilated electrically excited synchronous machines 1 for both directions of rotation, two shells are to be provided per coil winding head 16 for example, each with approx. 90°, or one shell will be used as a protective element 11 with approx. 180°, which thus has more of a tray-shaped structure.