SE428076B - ROTOR FOR A TURBOG GENERATOR - Google Patents

Description

101 15 20 25 50 eiøemaoeß corresponding conductor portions of other known: rotors, - are connected to the rotor winding via »a 'flexiItaIedaIeI-element. This; is also stressed by movements of relatively small amplitude, but with high frequency, namely movements mainly caused by the aforesaid deflection of the first-shaft portion, i.e. in its shaft portion which is not connected to the driving turbine. It has been shown to be very difficult to achieve. , flexible. "connection between the rotor winding and its current supply system," oehuman has * often been able to prove that saturation failure has occurred here in the above-mentioned aflexible conductor elements after "some time: operation. In the event of a total interruption, an arc occurs, which. easily 'results in harmful' heating. of .wrap capsule which. in fsin give »a very serious accident.

There are also examples of attractive shaft loading channels in the rotor shaft - through attaching fracture indications: f -L has resulted in * shaft fracture.

By using enzrotor construction .according to invention inventions. one can. avoid: the above-mentioned 'inconveniences.

'Invention call; in ï the following 'is described under fl reference * to the accompanying schematic drawings, figfl,' 2, 3 and 4 Lm very simplified representation 'shows, quadruplicate; Tfade, rotor, without ... rotor winding and 'associated winding capsule. Fig. 6 shows the same axis rotor fl-. in faïndvy perpendicular to' planetYI-Yï-y Y g 'with' Fig. 1.

Figß shows' enxdetålj avïden on. Fig. 9 shows the partial motor axial section along VIII-VIII in Fig. 9 showing a partial section along "III-IX" in Fig. 8, a cylindrical sectional isomeric coaxial with the air gap surface being spread out in a plane; Figs. 10, 11 and 12 show the respective partial root section along If-Xf and XI-XI and 'XII-XII' in Fig. 18, respectively.

Figf5-12 refers to a first variant fl of it on. 'fíg 1ivisade rotorn.

Fig. 7b 'shows, among other things: variant ^ avadenna rotor-in section along VII-VII on. fig 1.

The drawings show four, 1 ', 1 "' and 1" 'four different embodiments of a rotor according to the invention. In all cases the rotor has a solid steel out-of-rotor body which contains a substantially circular cylindrical portion 2, which is provided having a full length along its entire 'longitudinally extending winding groove 5.' A first shaft portion- i respectively 4 ', 4 ", 4"': and a second shaft portion 5, which form integral parts of said rotor body, starting from each end of said cylindrical portion, said second shaft portion being provided with a flange 7 for connection to a turbine, the ends of the rotor (not shown) being enclosed at each rotation by a winding capsule 6, which is crimped on said cylindrical portion.

In the text below, the rotor shown in Figs. 1, 5, 6, 7, 8, 9, 10, 11 and 12 will first be described in more detail. The rotor 1 receives mago etising current from a feed unit (not shown) mechanically connected to the shaft portion 4, or arranged via slip rings. this shoulder portion. The excitation current is supplied to the rotor winding via two supply lines 8 and 9, which run through the entire shaft portion 4 and the entire shaft. the cylindrical. the rotor portion 2, and which are electrically connected to the end faces of the rotor winding at the shaft portion 5. The supply lines 8 and 9 are arranged in each conduit channel 10 and 11, respectively, drilled in the rotor body. These are drilled on. each side of a central bore 26, which contains an inlet line and a return line for cooling water flowing through the conductor of the rotor winding (not shown). The two conduit channels diverge from each other in the direction of the shaft portion 5. The projections of the channels in an axis plane intersect at an angle of. at least 7 °, preferably at least 100, when imagining the axial plane arranged to give the maximum cutting angle. The part of the cylindrical portion 2 of the rotor body provided with winding grooves, which is traversed by the conduit channels 10 and 11, has an axial extent which preferably constitutes 20-70% of the groove length.

The rotor 1 is provided with twelve winding grooves 13 and with six equalizing grooves 14, which on. known methods are arranged in order to reduce the difference between different moments of inertia of the rotor cross-section and thereby avoid dangerous resonant frequencies of the rotor. The grooves 13 and 14 are made with one and the same groove width and are each provided with a groove wedge which consists of a plurality of sub-wedges 15 arranged axially one after the other.

The drilled conductor shafts 10 and 11 terminate in each of two diametrically or almost diametrically relative compensating grooves 14, the supply conductor axes 8 and 9 continuing in their respective compensating grooves ^ 5. The part of a supply line present in a leveling groove is then formed along a predominant part of its length in the same way as the line portion present in the drilled channel, ie with a circular cross-section with two cylindrical water pipes 16 clamped between two conductor halves, and with a enclosing insulating layer 17. The circular conduit portion is clamped in the groove 14 between an inner filling body 18 and an outer filling body 19 '10 15 20 25: B 119 Üliütílï-Å aided »by a pressure device known per se, which consists of a flattened metal tube _20 filled with gepoxy resin, which has been allowed to solidify under pressure. at least -100 bar. The 'two' filler bodies 18 and 19 are made of solid iron, 8 (favnagzxetic and 19 of non-greasy iron. Four of the six leveling grooves '14 'are, in a conventional manner, made with unchanged groove depth along the entire length and length of the groove). filled with filler bodies of iron. .The other two,: each: its supply line ».containing the leveling grooves are made with: reduced groove depth along .a smaller .part 'of' track length namely on. both sides of 'denjumkt the: drilled pipe channel mouths out in the track.

At the turn of it. tracked the rotor portion 2, from which the shaft portion S originates, the filling bodies 18 'and 1-9 to: for the most part replaced with a filling in fame of avu; iameilpaiev 21 -bestaenae of etzïfienai in giaa fi bulaminate m- .fö. ~ da, electrically insulating .1ame1ler, Isamt med ettekrxippe 22 of short copper rails avisaunnadimensionesom. like these. By means of a T-shaped connecting member 25 the lower section of the current supply line formed by the downwardly axial cross-section 8 * axially outside the grooved rotor portion hydraulically connected to the two rotor windings included, each with a cooling duct provided with conductors 24 * and 125. hinted. medfpi- .lar_på.fi_g 9. The dash-dotted line in P-P 'indicates the center of the pole. The conductor24 is never * current-carrying but has only a purely hydraulic function. The conductor 25 forms the opposite end of the coil group, in which all six rotor coils are connected in series with each other and connected to the current supply lines 8 and 9, the supply line being arranged in one of the equalizing grooves 14 and connected to the rotor winding on the similar set circumference.

Because the supply lines / B and 9 are pressed into winding grooves on. In the same way as the axially extending parts of the rotor winding, they will participate in rotor body oscillations in the same way as these, so that these oscillations do not cause significant deformations in the supply lines or in the connections arranged between these and the rotor winding.

The short-circuit rail 22 can be replaced by a full-hop of a different design, but the principle shown is considered to give better results, since by means of the bundle there are conditions which are very similar to those in force. , a winding track. It can be seen from Fig. 8 that the part of the supply line 8 formed with a rectangular cross-section and arranged in the lamella package 21 is formed with a double bend. It is also possible with good results to design the pipe section in the track completely straight.

If for some reason it is desired to design the rotor without axially extending equalization grooves, it is possible - as shown in Fig. 7A - instead of the conduits 10 and 11 drilled in the rotor body described above to use drilled conduits 10 'and 11', which are approximately as long as the channels 10 and 11 and open into respective winding grooves 15, the two winding grooves preferably being diametrically arranged relative to each other. In both the case shown in Fig. 7 and in Fig. 7A, the drilled conduits run in such a way that the distance between them has its minimum value in the part of the shaft portion 4 enclosed by a rotor bearing. This reduces the risk of magnetic fluxes generated. of the supply lines by induction must be able to give rise to appreciable electric currents in the storage.

In the rotor shown in Fig. 2, the supply lines 8 'and 9' are arranged in drilled conduits, which extend through the entire shaft portion 4 'and the entire grooved rotor portion 2'. This is a complication, insofar as the drilled holes thereby become very long. On the other hand, the precision requirements are lower than in the embodiment shown in Fig. 1, since the drilled conduit must not open into a groove.

The embodiment shown in Fig. 3 differs from that of. Fig. 1 shows that the projections of the drilled conduits in an axial plane do not intersect. In the same way, the embodiment shown in Fig. 4 differs from that shown in Fig. 2.

In addition to the embodiments shown in the drawings, the invention also comprises rotors, in which the conduits arranged in the channels 10 and 11, after opening in their respective axially extending grooves, extend in these in a direction which is opposite to that on. Fig. 8, the wires being connected to the winding approximately as shown in Fig. 8, but at the rotor end where the shaft portion 4 starts from the grooved portion of the rotor body.

In the event that the conduits are arranged to open into a winding groove, for example on. In the same way as the channels 10 'and 11' shown in Fig. 7A, the supply lines extending through the channels can be passed along the winding groove in one or the other direction and connected to the winding in the same way.

Claims (7)

B1ÜfíS1ÛÛ-I-r a similar way as the supply line 8 shown in Fig. 8, or the supply lines can be connected to the rotor winding in their respective winding grooves. The rotor described in connection with Figs. 1, 5, 6, 7, 8, 9, 10, 11 and 12 is intended to be cooled by means of direct water cooling. A rotor according to the invention can just as well be designed without cooling channels in the winding. A rotor according to the invention is usually made with at least twenty-four winding grooves. PATENT REQUIREMENTS Rotor for a turbo generator on. at least 20 MVA containing a rotor body formed of a magnetic material and one of these. supported rotor winding, while said rotor body contains a circular cylindrical portion (2; 2 '; 2 "; 2"' _) provided with a plurality of axially extending winding grooves (15), and that first (4; 4 '; 4 "; 4" ') in that second (5) from each end of said cylindrical portion extending shaft portion, wherein supply lines (8, 9; 58, 59; 8', 9 ') for the excitation current of the generator are arranged in two. in said rotor jumps (1; 1 '; 1 "; 1"') 'drilled conduits, which pass through a predominant part of said first shaft portion (4; 4'; 4 "; 4" '), .k n n e t e o k n a d thereof, to nërnde. conduit channels (10, 10f, E'1 ') pass through at least a portion of said cylindrical portion 2; 2 '; 2 "; 2 '"), while the channels - during the passage thereof as well as during the passage of said first shaft portion - diverge in the direction of said second shaft portion (5). HOW 'according to claim 1, 1: a: n n a t a a k n a d thereof, that namda fi ïlïföfseïlß fl ni fl- š fi r' (8, 9; 3-8, 59; BH 9 ') are connected. to approximate rate winding at the end at said second shaft portion (S) of the name "da. aylindrical portion (2; 2 '; 2"; em). 3. A rotor according to claim 1, characterized in that said conduit channels open into respective axially extending grooves (14ö 15) formed in said cylindrical portion, the two supply lanes (31 9š 551 39) ), in addition to being arranged in said conduit channels (10, 11; 10 ', 11'), is located in each such apar. 81061004 » 4. A rotor according to claim 3, characterized in that said supply lines are connected to said rotor winding at the end of said cylindrical portion (2) located at said first shaft portion (44 4 "). 5. A rotor according to claim 3, characterized in that the two grooves connected to their respective conduit (10 ', 11') are two. substantially diametrically in relation to each other arranged winding grooves (15). Rotor according to claim 5, k 'a'. n n e t e c k n a d of the fact that the rotor, in addition to the grooves (15) in which the winding is arranged, is provided with two i nuvudaal; dianatrally in relation to each other arranged nfjänningnapan (av) aan to da bada said, to each: Ladningakanal (10, 11) connected apåran consists of said additional tracks. 7. A rotor according to claim 5, characterized in that the part of said cylindrical portion (2) traversed by said rectilinear conduits (10, 11; 10 ', 11') corresponds to 20-60 few of its length.