MXPA96006093A

MXPA96006093A - Driver section for a stator structure of a dynamoelectric machine

Info

Publication number: MXPA96006093A
Application number: MXPA/A/1996/006093A
Authority: MX
Inventors: Couture Pierre; Francoeur Bruno; Langlois Andre; Leduc Jacques; Rieher Stephane; Svobada Jan
Original assignee: Hydroquebec
Priority date: 1994-06-23
Filing date: 1996-12-04
Publication date: 1998-02-01

Abstract

A conductor section for a stator core of a polyphase machine-electric. The stator core is provided with a series of parallel slots elongated to receive respective conductor sections. The conductor section includes two parallel sides (6, 8) which have a rectangular cross section and are designed to engage the corresponding parallel grooves in the stator core such that both sides define a plane. Said conductor section further includes at least one conductor head (10) having a rectangular cross section and connecting two adjacent ends of the two parallel sides. The head has a U-shaped body when viewed above perpendicular to the plane, and a sinuous body when viewed in the frontal view along said plane. The head has opposite surfaces, upper and lower. The upper surface faces one side of the plane while the lower surface faces the opposite side of the plane. The conductor section advantageously allows the efficiency of a motor to increase since the stator slot space factor is high, while at the same time allowing the sections to have small heads, thereby reducing the weight of the motor and the loss of lime

Description

DRIVER SECTION FOR A STATOR STRUCTURE OF A POLYPHASIC DYNAMOELECTRIC MACHINE BACKGROUND OF THE INVENTION The invention relates to a stator of a dynamo-electric machine and to a method for mounting at least one stator winding on a cylindrical stator structure. More specifically, the invention relates to a dynamoelectric machine which can be a motor or a generator. The machine can be provided with either an internal rotor or an external rotor. More specifically, the invention relates to stator windings having conductors of rectangular cross-section. Known in the art, is US Patent No. 3,453,468, granted the lo. from July 1979 to W.W. Lund. In this patent, a double-layer winding installation for a dynamo-electric machine stator core is described. This winding installation has a plurality of coils in which all the coils of a group of phases are connected in series and are formed from a single continuous conductor, each coil consisting of a single turn. The cross section of the conductor is rectangular so that the rectangular slots of the rectangular stator can be filled almost completely, which is not the case even if a conductor having a cylindrical cross-section is used. A disadvantage with the machine described by Lund is that the heads of each turn, which are part of the conductor and form a bridge from one slot to another, are quite large and long with respect to the stator core. This type of heads makes the machine heavier and causes significant losses of heat more particularly in the case of a machine having polar stages that are small with respect to the radius of the machine. French Patent No. 2,430,123 discloses a winding made of two or more of two layers formed of stranded conductive strands for electrical machines. A disadvantage with the winding described in this patent is that it is made of braided strands that do not provide a substantial fill factor for the stator slots. French Patent No. 2,244,284 discloses an armature winding for electric initiators. A disadvantage with the winding described in this patent is that each turn of the winding is circular in cross section. This does not provide a substantial fill factor for the stator slots. British Patent No. 11,896 describes asymmetric coils of an electrical machine but does not show the method for assembling these coils on the stator structure.

The following US patents are also known in the art: 693,578 3,675,058-3,914,860 SUMMARY OF THE INVENTION A disadvantage with all the aforementioned patents is that none of them provides a stator for a dynamoelectric machine with rectangular cross-section windings made of a plurality of turns connected in series where each turn has heads that are substantially small with respect to the stator core. An object of the present invention is to provide a stator for a dynamoelectric machine having windings of rectangular cross-section where the heads of the turns of the stator windings are smaller than those described in the prior art in order for the dynamo-electric machine to be lighter and generate less heat in operation. It is also an object of the present invention to provide a method for mounting at least one stator winding on a cylindrically shaped stator structure of a dynamo-electric machine. According to the present invention, a conductor section for a stator structure of a polyphase dynamoelectric machine is provided, said stator structure being provided with a series of parallel elongated slots for respectively receiving conductor sections, said conductor section comprising two parallel conductor sides of substantially rectangular cross section adapted to fit respectively in the corresponding parallel slots of said stator structuresaid two sides defining a plane, and at least one conductor head of substantially rectangular cross-section, connecting two adjacent ends of said parallel sides, the head having opposite lower and upper surfaces, the conductor section being characterized in that: said head shows a substantially U-shaped body when viewed from a top view perpendicular to said plane, and a wave-shaped body when viewed from a front view contained in said plane, with the top surface facing only one side of the plane and the lower surface facing only the opposite side of the plane. According to the present invention there is also provided a method for mounting conductive sections of a stator winding on a cylindrically shaped stator structure of a dynamo-electric machine, each of said conductor sections having two parallel conductor sides and at least one conductor head connecting two adjacent ends of said two parallel sides, said stator structure being provided with circumferentially distributed parallel grooves, the method comprising the steps of: a) circumferentially placing each of said conductor sections with respect to said stator structure in such a way that for each of said sections, a first conductor side immediately faces one of said slots, and a second conductor side is placed in a far position of said stator structure; b) after said step (a), inserting each of the first conductor sides in the corresponding slot; and c) inserting each of the second conductor sides in another of said slots, which has already received a first conductor side of another conductor section, until all said sides are mounted in said slots. According to the present invention, there is also provided a method for mounting conductor sections of a stator winding on a cylindrically shaped stator structure of a dynamoelectric machine, each of said conductor sections having two parallel conductor sides and less a conductor head connects two adjacent ends of said two parallel sides, said stator structure being provided with circumferentially distributed parallel grooves, the method comprising the steps of: a) inserting a first conductor side of each conductor section partially in a corresponding slot of said parallel grooves; b) placing a second conductor side of each conductor section one behind the other along said stator structure; c) after said steps (a) and (b), circumferentially displacing said second conductor sides with respect to said stator structure until said second conductor sides are respectively aligned with said first conductor sides to form pairs of aligned driver sides; and d) after said step (c), applying a force on said second conductor sides along a radial direction of said cylindrical stator structure to insert said pairs of conductor sides completely aligned in the corresponding grooves. The objects, advantages and other features of the present invention will become more apparent upon reading the following non-restrictive description of preferred embodiments thereof given solely for the purpose of exemplification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top-to-bottom view of a conductor section according to the present invention; Figure 2 is a perspective view of the conductor section shown in Figure 1; Figure 3 is a side view of the conductor section shown in Figure 1; Figure 4 is a top-to-bottom view of a conductor head of the conductor section shown in Figures 1, 2, and 3; Figure 5 is a front view of the driver head shown in Figure 4; Figure 6 is a side view of the driver head shown in Figures 4 and 5; Figure 7 is a partial perspective view of a plurality of conductor sections in combination with a stator structure according to the present invention; Figure 8 is a front view of the plurality of conductor sections in combination with a stator structure, shown in Figure 7; Figure 9 is a perspective view of another conductor section according to the present invention; Figure 10 is another perspective view of the conductor section shown in Figure 9; Figure 11 is a top-to-bottom view of a conductor head of the conductor section shown in Figures 9 and 10; Figure 12 is a front view of the driver head shown in Figure 11; Figure 13 is a partial front perspective view of a plurality of conductor sections in combination with a stator structure according to the present invention. Fig. 14 is a rear view of the plurality of conductor sections shown in Fig. 13; Figure 15 is a front view of the plurality of conductor sections shown in Figure 13; Figure 16 is an exploded perspective view of a two part mold with a conductor section according to the present invention; Figure 17 is an electrical circuit showing the connections of a plurality of conductor sections; Figures 18, 19, 20 and 21 are partial schematic side views of conductor sections with respect to a stator structure, showing different stages of a method for mounting the conductor sections on a cylindrically shaped stator structure; Figures 22, 23, 24 and 25 are partial schematic side views showing sections of conductor with respect to a stator structure, illustrating the steps of another method for mounting conductor sections on a cylindrically shaped stator structure; Figure 26 is a perspective view showing the end of a conductor section according to the present invention; Figure 27 is a partial top view of a stator structure provided with conductor sections; and Figure 28 is a partial perspective view of what is shown in Figure 27. DETAILED DESCRIPTION OF THE PREFERRED MODALITY In the following description, similar elements are identified by the same reference numbers in all the drawings. Referring now to FIGS. 1 to 8, a conductor section 2 for a stator structure 4 of a polyphase dynamoelectric machine is shown. The stator structure 4 is provided with a series of parallel elongated slots for respectively receiving conductor sections as is known in the art. The conductor section 2 comprises two parallel conductor sides 6 and 8 of substantially rectangular cross section adapted to fit respectively in two corresponding parallel grooves of the stator structure 4. The two sides 6 and 8 define a plane, which is the plane of the sheet on which figure 1 appears. The conductor section 2 also comprises at least one conductor head 10 of substantially rectangular cross-section, connecting two adjacent ends of the parallel sides 6 and 8. More specifically, the conductor section 2 shown in figures 1 to 8 has two conductor heads 10. Each of the heads 10 shows a substantially U-shaped body when viewed from a top view perpendicular to said plane, as shown in the figure 4, and a wave-shaped body when viewed from a front view contained in said plane, as shown in Figure 5. The head 10 has a upper surface 12 and a lower surface 14. Top surface 12 faces only one side of the plane while lower surface 14 faces only the opposite side of the plane.

In the prior art, the windings of a motor are normally made of cylindrical cross section conductors. With such circular cross section conductors, the filling of the slots in which the conductors are mounted determines a filling factor in the order of 50% to 55%. The efficiency of a machine depends directly on its filling factor. To improve the filling factor, a conductor of rectangular cross section is proposed. In the prior art, motor windings made of conductors of rectangular cross-section are known. However, the heads of these windings mounted in the grooves are relatively large as can be seen in Figure 1 of US Pat. No. 3,453,468. To overcome the aforementioned problem, a conductor section having at least one head as described above is proposed according to the present invention to obtain, at the same time, a conductor section having, on the one hand, a factor of filling of the order of 80% and, on the other hand, a driver's head that is smaller than the driver's head of the prior art. The use of smaller heads provides many advantages such as the reduction of the weight of the material used to make the windings, normally this copper material; the reduction of the heat loss produced by the current circulating in the conductors; and finally the development of a narrower engine. Preferably, the wave-shaped body of the head is asymmetric. Also preferably, the conductor section 2 is constituted by at least one turn to form a coil. The heads 10 of a conductor section 2 are constituted by two opposite heads located respectively at opposite ends of said two parallel sides 6 and 8. Preferably, each conductor section 2 comprises two connection ends 16 and 18 for connecting the conductor section 2 in series with other conductor sections 2. The two connection ends 16 and 18 are located on one of these heads. Preferably, each conductor section is made up of several turns. Referring now to Figures 13, 14 and 15, a plurality of conductor sections 2 is shown in combination with the stator structure 4. The stator structure 4 is a cylindrically shaped stator structure provided with circumferentially distributed parallel grooves. The structure 4 has a surface adjacent to a rotor 3 of the machine when the machine is assembled. The structure 4 is separated from the rotor by an air gap 5. Referring now more specifically to Figure 14, it is shown that the heads 10 of each conductor section 2 have a portion forming an external projection that is radial with respect to to the axis of rotation and within a cylindrical volume defined by the circumference of the air gap 5. In this way, the rotor 3 is axially slidable with respect to the stator structure 4 when the machine is assembled. Referring again to Figures 13, 14 and 15, conductor sections 2 are electrically connected in series to form at least two stator windings. In the current case, there are three stator windings. Each of the two sides of the conductor sections 2 is respectively engaged in two corresponding parallel grooves of the stator structure 4. Preferably, the grooves have substantially rectangular cross sections. Also preferably, the grooves are circumferentially distributed parallel external grooves, and consequently, the surface of the stator structure 4, adjacent the rotor 3, is an outer peripheral surface. In this way, the rotor 3 is placed around the stator structure 4 when the machine is assembled.

Referring now to Figures 7, 8 and 17, preferably, the stator windings comprise three stator windings so that the machine is a three phase machine. It can be seen that the conductor sections are electrically connected in series to obtain three stator windings. According to the foregoing, each of the heads has its two sides placed three slots of each other. Referring now more specifically to Figure 17, preferably, the stator structure 4 is provided with ninety-six slots. The three stator windings are supplied by three phase voltages A, B and C. Referring now to FIGS. 9 to 15, it is preferably shown that each conductor section 2 comprises two connection ends 16 and 18 to be connected in series with other conductor sections 2. The two connection ends 16 and 18 of each conductor section 2 are located respectively on the two opposite heads thereof. Referring now to Figure 16, a two-part mold 22 is shown to form a head 10 of the conductor section 2 so that each head 10 shows a substantially U-shaped body, as shown in Figures 4 and 11, and a wave-shaped body, as shown in Figs. 5 and 12. Referring now to Figs. 18 to 21, there is shown a method for mounting sections of stator winding conductor 2 onto a stator structure in the form of a stator winding. cylindrical 4 of a dynamoelectric machine. Each of the conductor sections 2 has two parallel conductor sides 6 and 8. Two opposing conductor heads respectively connect the two adjacent ends of the parallel sides 6 and 8. The stator structure 4 is provided with circumferentially distributed parallel grooves. The method comprises the steps of (a) circumferentially placing each of the conductor sections 2 with respect to the stator structure 4. For each of the sections 2, a first conductor side 8 immediately faces one of the grooves of the structure 4, and the second conductor side 6 is placed in a remote position of said stator structure 4; after step (a), (b) inserting each of the first conductor sides 8 into the corresponding slot, as shown in Fig. 19; and (c) inserting each of the second conductor sides 6 into another one of said slots, which have already received a first conductor side 8 of another conductor section 2, as shown in FIG. 20, until all said sides 6 and 8 are mounted in the slots of the structure 4, as shown in figure 21. Preferably, in step (a), conductor sections 2 are placed, one after another, starting from a point and moving from sequentially along the stator structure 4. Preferably, in step (b), the first sides 8 of conductor sections 2 are inserted, one after the other, starting from a point and moving sequentially along of the stator structure 4. Preferably, in step (c), each head has its two sides 6 and 8 placed in three slots of each other. Referring now to Figure 26, there is shown a conductor section 2 made up of several adjacent and parallel conductors 30 of rectangular cross-section. Referring now to FIGS. 22 to 25, another method for mounting conductor sections 2 of a stator winding on a stator structure 4 of a dynamo-electric machine is shown. Each conductor section 2 has two parallel conductor sides 6 and 8. Two opposing conductor heads respectively connect two adjacent ends of the parallel sides 6 and 8. The stator structure 4 has a cylindrical shape and is provided with circumferentially distributed parallel grooves. .

The method comprises the steps of (a) inserting a first conductor side 8 of each conductor section 2 at least partially into a corresponding slot of the structure 4, as shown in Fig. 22.; (b) placing the second conductor side 6 of each conductor section 2 one behind the other along said stator structure, as shown in Fig. 23; (c) after said steps (a) and (b), circumferentially displacing the second conductor sides 6 with respect to the stator structure 4, as shown in Fig. 24, until the second conductor sides are aligned respective way with the first conductor sides 8 to form pairs; and (d) after said step (c) applying a force 32 on the second conductor sides 6 along a radial direction of the stator structure 4 to insert the pairs of aligned conductor sides 6 and 8 completely into the corresponding slots. Steps (c) and (d) of the method are carried out by means of a crown-shaped device 34 having along its periphery a series of adjacent members 36 movable along a radial direction when applied a force by means of pistons 38. Referring now to Figures 27 and 28, a plurality of conductor sections 2 are shown in combination with the stator structure 4. The structure - 11 Stator 4 is a cylindrically shaped stator structure 4 provided with circumferentially distributed parallel grooves. The structure 4 has a surface adjacent to the rotor 3 of the machine when it is assembled. Structure 4 is separated from the rotor by an air gap. The plurality of conductor sections 2 is electrically connected in series to form at least two stator windings. The two sides of each conductor section 2 are respectively engaged in two corresponding parallel grooves of the stator structure 4. Each conductor section 2 is constituted by at least one turn to form a coil. Each conductor section 2 comprises two opposite heads 10 located respectively at opposite ends of the two parallel sides. Each conductor section 2 comprises two connection ends 16 and 18 connecting the conductor sections 2 in series through connection contacts 19. Each connection contact 19 is equidistant from the corresponding conductor sections 2. For each of the conductor sections, the two connection ends 16 and 18 are located on one of those heads. Although the present invention has been explained above by way of preferred embodiments thereof, it should be noted that any modification to those preferred embodiments, within the scope of the appended claims, is not believed to change or alter the nature and scope of the invention.

Claims

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the property described in the following claims is claimed as property. 1. A conductor section 2 for a stator structure 4 of a polyphase dynamoelectric machine, said stator structure 4 being provided with a series of parallel elongated slots for respectively receiving conductor sections, said conductor section 2 comprising two parallel sides of conductor 6 and 8 of substantially rectangular cross section adapted to fit respectively into the corresponding parallel grooves of said stator structure 4, said two sides 6 and 8 defining a plane, and at least one conductor head 10 of substantially rectangular cross-section , which connects two adjacent ends of said two parallel sides 6 and 8, the head having opposing upper and lower surfaces 12 and 14, the conductor section 2 being characterized in that: said head 10 shows a substantially U-shaped body when viewed from a top view perpendicular to that plane, and a body in shape of wave when viewed from a front view contained in said plane, facing the top surface 12 only one side of the plane and the bottom surface 14 facing only the opposite surface of the plane.
2. A conductor section according to claim 1, characterized in that said wave-shaped body is asymmetric.
A conductor section according to claim 1, characterized in that: said conductor section 2 is constituted by at least one turn to form a coil; and said at least one head 10 is constituted by two opposite heads 10 located respectively at opposite ends of said two parallel sides 6 and 8.
A conductor section according to claim 3, characterized in that it comprises two connection ends 16 and 18 for connecting said conductor section 2 in series with other conductor sections 2, said two connection ends 16 and 18 of said conductor section 2 being located in one of the heads thereof.
A conductor section according to claim 3, characterized in that it comprises two connection ends 16 and 18 for connecting said conductor section 2 in series with other conductor sections 2, said connecting ends 16 and 18 of said conductor section being located 2 respectively on two opposite heads of said conductor section 2.
6. A conductor section according to claim 3, characterized in that said at least one turn comprises several turns.
A conductor section according to claim 1, characterized in that said conductor section 2 is made of several parallel and parallel conductors 30 of the rectangular cross section.
A plurality of conductor sections according to claim 1 in combination with said stator structure 4, characterized in that: said stator structure 4 is a cylindrically shaped stator structure provided with circumferentially distributed parallel grooves, said structure 4 having a surface adjacent to a rotor 3 of said machine when said machine is assembled, the rotor 3 having an axis of rotation, said structure 4 being separated from said rotor 3 by an air gap 5, and having at least one of said heads 10 a portion that it forms an external projection that is radial with respect to the axis of rotation, within a cylindrical volume defined by the circumference of the air gap 5; said plurality of conductor sections 2 is connected in series to form at least two stator windings, the two sides 6 and 8 of each conductor section 2 respectively engaging in two corresponding parallel grooves of said stator structure 4.
9. A plurality of conductor sections in combination with said stator structure 4 according to claim 8, characterized in that said grooves have substantially rectangular cross sections.
10. A plurality of conductor sections in combination with said stator structure 4 according to claim 8, characterized in that said at least two stator windings comprise three stator windings.
11. A plurality of conductor sections in combination with said stator structure 4 according to claim 8, characterized in that said grooves are circumferentially distributed external parallel grooves, and said surface adjacent said rotor 3 is an outer peripheral surface.
12. A plurality of conductor sections according to claim 1, in combination with said stator structure 4, characterized in that: said stator structure 4 is a cylindrically shaped stator structure provided with circumferentially distributed parallel grooves, said structure having said structure 4 a surface adjacent to a rotor 3 of said machine when said machine is assembled, said structure 4 being separated from said rotor 3 by an air gap 5, the rotor 3 having an axis of rotation; said plurality of conductor sections 2 is connected in series to form at least two stator windings, the two sides 6 and 8 of each conductor section 2 respectively engaging in two corresponding parallel grooves of said stator structure 4; each of said conductor sections 2 is constituted by at least one turn to form a coil; said at least one head 10 of each of said conductor sections 2 is constituted by two opposite heads 10 located respectively at opposite ends of said two parallel sides 6 and 8; and each of said conductor sections 2 comprises two connection ends 16 and 18 connecting through connection contacts said conductor sections 2 in series, each of said connection contacts being equidistant from the two corresponding conductor sections. said two connecting ends 16 and 18 of each of said conductor sections 2 being located in only one of the corresponding heads thereof.
13. A method for mounting conductor sections 2 of a stator winding on a stator structure 4 of a dynamoelectric machine, each of said conductor sections 2 has two parallel conductor sides 6 and 8 and at least one conductor head 10 connecting two adjacent ends of said sides parallels 6 and 8, said stator structure 4 having circumferentially distributed parallel grooves, the method being characterized in that it comprises the steps of: (a) circumferentially placing said conductor sections 2 with respect to said stator structure 4 so that each of the conductor sections 2, a first conductor side 8 immediately faces one of said slots, and a second conductor side 6 is placed at a remote position of said stator structure 4; b) after said step (a), inserting each of the first conductor sides 8 into the corresponding slot; and c) inserting each of the second conductor sides 6 into another one of said grooves, which have already received a first conductor side 8 of another conductor section 2, until all said sides 6 and 8 are mounted in said grooves.
A method according to claim 13, characterized in that it further comprises, before said step (a), a step of forming said heads 10 of said conductor sections 2 so that each of said heads 10 shows a body substantially in U-shape when viewed from a top view perpendicular to a plane defined by the two corresponding conductor sides 6 and 8, and a wave-shaped body when viewed from a front view contained in said plane.
A method according to claim 13, characterized in that in said step (a) said conductor sections 2 are placed, one after the other, starting from a point and moving sequentially along said stator structure 4.
16. A method according to claim 13, characterized in that in said step (b) said first sides 8 of said conductor sections 2 are inserted, one after the other, starting from a point and moving sequentially along said stator structure 4 17.
A method according to claim 13, characterized in that in said step (c) the two conductor sides 6 and 8 of each conductor section 2 are placed with three grooves one from the other.
A method according to claim 13, characterized in that it further comprises a step (d) of electrically connecting at least some of said conductor sections 2 in series to obtain at least one stator winding.
19. A method according to claim 18, characterized in that said step (d) comprises a step of electrically connecting said conductor sections 2 in series to obtain three separate stator windings.
20. A method for mounting conductor sections 2 of a stator winding on a cylindrically shaped stator structure 4 of a dynamo-electric machine, each of said conductor sections 2 having two parallel conductor sides 6 and 8 and at least one conductor head 10 connecting two adjacent ends of said two parallel sides 6 and 8, said stator structure 4 having circumferentially distributed parallel grooves, the method being characterized in that it comprises the steps of: a) inserting a first conductor side 8 of each conductor section 2 at least partially in a corresponding slot of said parallel grooves; b) placing a second conductor side 6 of each conductor section 2 one behind the other along said stator structure 4; c) after said steps (a) and (b), circumferentially displacing said second conductor sides 6 with respect to said stator structure 4, until said second conductor sides 6 are respectively aligned with said first conductor sides. 8 to form pairs of aligned conductor sides 6 and 8; and d) after said step (c) applying a force on said second conductor sides 6 along a radial direction of said cylindrical stator structure 4 to insert said pairs of aligned conductor sides 6 and 8 completely into the corresponding slots .
21. A method according to claim 20, characterized in that it further comprises, before said step (a), a step to form said heads of said conductor sections 2 so that each of said heads 10 shows a substantially U-shaped body. when viewed from a top view perpendicular to a plane defined by the two corresponding conductor sides 6 and 8, and a body in waveform when viewed from a front view contained in said plane.
22. A method according to claim 20, characterized in that in said step (c), the two conductor sides 6 and 8 of each conductor section 2 are placed three slots one from the other.
23. A method according to claim 20, characterized in that it further comprises a step (e) for electrically connecting at least some of said conductor sections 2 in series to obtain at least one stator winding.